Keywords
coronary artery bypass graft surgery - CABG - aortic valve and root - mitral valve surgery - tricuspid valve
Introduction
“a man hears what he wants to hear and disregards the rest” (Simon and Garfunkel-The Boxer[6])
This manuscript summarizes publications selected through a systematic review process. Despite using a standardized methodology, the selection process is inherently influenced by (our) individual interpretation. To mitigate this, we prioritized a mechanistic perspective wherever possible and focused on information most relevant to a comprehensive data evaluation. We also tried to align randomized evidence with large registries or other observational studies for the purpose of external validation, an important aspect of clinical epidemiology. While readers may not agree with all aspects of our data interpretation, they can be confident that the presented data and associations are accurate and based on reliable sources.
As in previous years,[1]
[2]
[3]
[4]
[5] the systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines ([Supplementary Fig. S1], available in the online version). Publications were selected based on their relevance to indications, decision-making, surgical and patient information.
Summarizing and analyzing outcomes in the rapidly developing field of cardiovascular sciences may be challenging given the constantly growing number of scientific publications. It is therefore no surprise to find sometimes inconclusive or conflicting results. Interpreting those results in the setting of daily practice is not an easy task, especially if the above quote comes into play. That is why clinical epidemiology has developed tools supporting balanced evaluations. We have applied those tools (systematic literature searches, balancing all types of evidence, assessing biases and limitations, etc.) in our summary of 2024 publications.
Randomized controlled trials (RCTs) are considered the gold standard for evaluating the efficacy and safety of medical interventions and preferentially guide treatment recommendations.[7] However, the value of RCTs has received heavy criticism in 2024,[8]
[9]
[10]
[11]
[12] related to the presence of various biases,[13] conflicts of interests,[11] the assessment of treatment effects,[10] and the generalizability of data from very selected patient populations.[14]
[15] Registry data, derived from routine clinical practice may suffer from even more biases and are generally considered unfit for guiding treatment recommendations alone. However, they offer a valuable complement to RCTs by providing insights into broader, more diverse populations and long-term outcomes.[16] Importantly, external validation of randomized evidence through registry data is essential for assessing the applicability of trial findings to everyday clinical scenarios,[17]
[18] a feature that is a component of governmental regulations and the new medical device regulation.[19] Registries can uncover variations in treatment effectiveness across subgroups, geographic regions, and healthcare systems while identifying rare adverse events and real-world adherence patterns that RCTs may miss.[18]
[20] Thus, if RCTs and registry data support the same finding, a clear recommendation for clinical practice can be given. However, in cases where RCT and observational registry data point in different directions, the applicability of RCT findings to routine clinical practice must be questioned.
Publications in the year 2024 prototypically illustrate these points: in the field of coronary surgery, several observational registry publications confirmed the repeatedly documented survival advantage for CABG compared with PCI or medical therapy in previous RCTs,[21] specifically in high-risk subgroups such as patients with low left ventricular ejection fraction (LVEF), women, and patients with left main stenosis or even acute coronary syndromes.[2] In contrast, in the field of aortic valve surgery the published RCTs showing noninferiority of TAVI compared with SAVR have been questioned again in 2024, this time by long-term RCT data made public by the US Food and Drug Administration (FDA) and by consistent and completely opposing results in favor of SAVR from literally all registries worldwide. In the other areas, evidence is still developing.
Surgical Treatment of Coronary Artery Disease
Surgical Treatment of Coronary Artery Disease
Novell Perspectives for CABG
Two coronary studies published in 2024 have disruptive potential. The FASTTRACK CABG trial[22] evaluated the feasibility of using coronary computed tomography angiography (CCTA) to plan and conduct CABG without invasive coronary angiography (ICA).[22] At 30-day follow-up, CCTA in 102 patients (91.9%) showed an anastomosis patency rate of 92.6%, with major adverse cardiac and cerebrovascular events (MACCE) occurring in 7.2% and major bleeding in 2.7% of patients, thus demonstrating that CABG guided by CCTA is feasible and has an acceptable safety profile in a selected population of complex coronary artery disease (CAD).[22] While this study challenges the dominating role of ICA for decision-making, it is important to state, that the indication for surgery in this study was still based on ICA, and the isolated ability of CCTA for decision-making still remains to be demonstrated.[23] This discussion is mainly based on the tendency of CCTA to overestimate disease severity (in the FASTTRACK-CABG trial, the average SYNTAX score was 34 by ICA and 44 by CCTA). The newly funded IMPRO trial (G-BA:01NVF24302) will provide important information in this field.
The second trial—CAST-HF[24]—investigated the efficacy of a novel cardiac shockwave therapy (SWT) applied to the heart during CABG in patients with relevant CAD and LVEF ≤40%. This blinded, sham-controlled randomized study demonstrated that patients receiving SWT in addition to CABG experienced a significantly greater improvement in LVEF over 360 days compared with the sham group (mean increase of 11.3% vs. 6.3%, p = 0.015).[24] Additionally, SWT improved physical capacity (6-minute walk test) and caused better quality of life scores.[24] It is important to note that no other invasive therapy, thus far, has been able to improve ventricular function in trials of chronic CAD and heart failure.
In addition, a novel nomenclature has been suggested for patients with CAD, where acute myocardial ischemic syndromes (AMIS) are distinguished from nonacute myocardial ischemic syndromes (NAMIS).[25] This publication is worth reading in detail. It addresses epicardial and nonepicardial causes of ischemia and aligns with the mechanism-guided approach to invasive therapy of CAD described by us before.[26]
Finally, a nationwide readmissions analysis supported the safety of early discharge (≤4 days) after CABG in selected patients by showing less frequent readmissions than in matched routine-discharge patients (mainly from fewer infections).[27]
CABG versus PCI
In 2024, a meta-analysis including all RCTs evaluating the outcome of CABG and PCI with drug-eluting stents (DES) was published,[28] based on the rationale that advancements in stent technology may improve interventional outcomes. Contrary to the investigators' expectations, the randomized evidence confirmed a CABG survival advantage over PCI even with DES[28] ([Fig. 1]).
Fig. 1 Kaplan–Meier estimates with a 95% confidence interval of the probability of all-cause mortality. CABG, coronary artery bypass grafting; DES, drug-eluting stent; PCI, percutaneous coronary intervention. (Reproduced with permission from Urso et al.[28])
Registry data confirmed CABG superiority in general and in a wide range of patient subgroups. Omerovic et al[29] analyzed 57,097 patients with NSTEMI and multi-vessel disease in Sweden from 2005 to 2022 to compare long-term outcomes of PCI and CABG. CABG was associated with significantly lower risks of mortality, myocardial infarction (MI), repeat revascularization, and heart failure compared with PCI, especially in younger patients, those with left main disease, or left ventricular dysfunction.[29] In a meta-analysis, we demonstrated that CABG is superior to PCI in patients with chronic total occlusion(CTO)[30] and PCI is associated with higher mortality, MI, and repeat revascularization. Bloom et al published an analysis of Australian and New Zealand registries where they compared long-term outcomes of CABG and PCI in 2,042 patients with LVEF <35%, excluding those with STEMI or cardiogenic shock.[31] CABG was associated with significantly improved long-term survival compared with PCI (hazard ratio [HR]: 0.59), although it carried a higher risk of periprocedural stroke and a longer hospital stay.[31]
A pooled analysis of four RCTs comparing PCI with CABG in left main (LM) CAD, stratified by diabetes status, found no significant difference in 5-year all-cause mortality between the two treatments.[32] PCI was associated with a higher risk of spontaneous myocardial infarction and repeat revascularization, particularly in diabetic patients, but had a lower early stroke risk.[32] We showed that regional registry evidence supports the superior long-term outcomes (death, MI, MACE, and repeat revascularization) of CABG over PCI for LM stenosis,[33] aligning with updated guideline recommendations favoring CABG for distal LM disease and Heart Team discussions for shaft lesions, where PCI seems to offer the most benefit.[34] Interestingly, there was no difference in 30-day mortality after CABG or PCI in our registry analysis.[33]
Finally, Dimagli et al meta-analytically compared the short- and long-term quality of life (QoL) outcomes of CABG versus PCI using data from five RCTs.[35] Both procedures showed significant improvements in angina frequency. While PCI had better outcomes at 30 days,[35] CABG was superior in disease-specific QoL measures at 6, 12, and 36 to 60 months.[35] These findings highlight the differential temporal effects of CABG and PCI on QoL, supporting the notion that CABG offers greater long-term benefits.
Considering the many comparisons of CABG and PCI in 2024 and those before, the same pattern always emerges. All articles illustrating survival advantages or relevant clinical improvements with CABG always demonstrate reductions in MI by CABG (due to surgical collateralization[36]). This mechanistic correlation becomes also evident in an individual patient data meta-analysis of RCTs comparing CABG to medical therapy in chronic CAD patients.[37] While CABG carried higher periprocedural risk, it offered improved long-term survival benefits and lower risk of long-term MI,[37] an important finding that demonstrates the additive prognostic effect of CABG to medical therapy. Additionally, a meta-analysis focusing on elderly patients (over 70 years) revealed that those undergoing CABG had significantly better long-term survival compared with age-matched counterparts in the general population, highlighting the life-prolonging potential of CABG surgery.[38]
Trying to explore the known correlation between spontaneous MI and survival, the PREVENT trial[39] assessed the role of preventive PCI versus optimal medical therapy (OMT) alone for treating vulnerable atherosclerotic coronary plaques. Among 1,606 participants, the composite primary endpoint—cardiac death, target-vessel myocardial infarction, ischemia-driven revascularization, or hospitalization for unstable angina—was significantly lower in the PCI group (0.4%) vs. the OMT group (3.4%).[39] However, the observed benefit was driven alone by a reduction in ischemia-driven target-vessel revascularization and hospitalization for unstable or progressive angina, which prompted social media to critically comment “doing PCI to prevent future PCI?”
Finally, in 2024, the new ESC guidelines for the management of chronic coronary syndromes were published, offering updated recommendations for key scenarios encountered in the daily treatment of CAD patients.[40] The guidelines had to condense recommendations for the invasive treatment of chronic CAD with CABG or PCI into two comprehensive tables.[40] The guidelines emphasize the critical role of the Heart Teams, discouraging ad hoc interventions and specifically recommending heart team discussions if the level of recommendation for CABG and PCI is the same (which now includes patients with complex single LAD disease).[40] Patients with complex CAD are strongly recommended for CABG, while PCI is mainly recommended for symptom relief in patients with less complex CAD who remain symptomatic despite optimal guideline-directed medical therapy.[40] A 2024 editorial[41] provides a user-friendly summary of the key aspects from an invasive therapy perspective ([Figs. 2] and [3]).
Fig. 2 Role of the Heart Team and key considerations in decision-making between percutaneous coronary intervention and coronary artery bypass grafting in patients with stable multivessel and/or left main coronary artery disease. CABG: coronary artery bypass grafting; GDMT: guideline-directed medical therapy; LAD: left anterior descending artery; LMCAD: left main coronary artery disease; LVEF: left ventricular ejection fraction; MVD: multivessel disease; PCI: percutaneous coronary intervention; PROM: Society of Thoracic Surgeons predicted risk of mortality; STS-VD: vessel disease. (Reproduced with permission from Doenst et al.[41])
Fig. 3 Algorithm to assist in selecting the appropriate revascularization procedure for patients with multivessel or left main coronary artery disease. The class of recommendations and level of evidence (as indicated on the right side of the PCI and CABG diagram, as recommended) are based on the 2024 ESC Guidelines for the management of chronic coronary syndromes developed in collaboration with EACTS. CABG: coronary artery bypass grafting; CAD: coronary artery disease; LAD: left anterior descending artery; LMCAD: left main coronary artery disease; MVD: multivessel disease; PCI: percutaneous coronary intervention. (Reproduced with permission from Doenst et al.[41])
Technical Aspects of CABG
Technical advancements and clinical insights into CABG have been the focus of numerous studies in 2024, emphasizing the optimization of patient outcomes. For instance, Off-pump CABG is associated with reduced mortality risk in patients with elevated MELD-XI scores, underscoring its value in high-risk populations.[42] Multi-arterial CABG was consistently associated with improved long-term outcomes, including superior long-term survival and a significant reduction in major adverse cardiovascular events, as demonstrated in a 10-year follow-up of over one million patients[43] and a focused analysis of 23,798 cases.[44] Another study on 54,275 patients showed that compared with single arterial grafting, multiple arterial CABG is associated with improved long-term survival for both men and women.[45] The study highlighted potential gender disparities in treatment outcomes,[45] which prompted us to suggest a challenge-skill balance as a possible explanation, as women, being smaller and more fragile, pose a greater surgical challenge requiring higher skill to achieve comparable results.[46] Shimamura et al demonstrated in a meta-analysis that a hybrid approach may offer a similar long-term survival to conventional CABG but is associated with a higher incidence of MACCE and repeat revascularization.[47] Finally, an ESC and EACTS consensus statement offered comprehensive recommendations for intraoperative and postoperative conduit handling, aiming to improve graft patency and long-term outcomes.[48]
Minimally-Invasive CABG
Minimally invasive CABG has received significant attention in recent years. A study of 566 patients demonstrated that minimally invasive CABG provides excellent long-term survival, favorable cardiovascular outcomes, and good functional recovery, with results comparable to traditional CABG methods.[49] The authors reported a 12 year-survival for the entire cohort of 82.2%.[49] The safety and feasibility of totally endoscopic CABG were confirmed in an impressive cohort of 1,500 patients.[50] The reported 30-day mortality was 1.73%, 1-year survival was 94.7% and 1-year MACCE-free survival was 91.7%.[50] Additionally, a decade-long follow-up of robotic beating-heart totally endoscopic coronary artery bypass (TECAB) in 874 patients at a single institution showed excellent outcomes (96.9% freedom of cardiac mortality at 10 years).[51]
A new approach to the combined mitral valve and coronary surgery via left anterior mini-thoracotomy was reported by Babliak et al.[52] In a second publication Babliak et al reported another novel approach for simultaneous performance of aortic valve replacement and multivessel CABG through a single left anterior thoracotomy, showing its technical feasibility. These two surgical approaches published in 2024 offer sternotomy-sparing alternatives to traditional methods for combined valve and CABG procedures.[53]
Medical Treatment of CABG Patients
In 2024, two investigations evaluated therapeutic ways to reduce the incidence of postoperative atrial fibrillation (POAF). A meta-analysis, assessing perioperative high-intensity statin therapy in patients undergoing CABG, found a significant 57% reduction in postoperative atrial fibrillation incidence compared with controls.[54] This effect was notable with atorvastatin but not with rosuvastatin, and no significant impact on operative mortality or perioperative MI was observed.[54] In another meta-analysis of RCTs, we reported that perioperative colchicine administration in patients undergoing CABG was associated with a significant reduction in POAF rates compared with standard care (RR 0.54; 95% CI, 0.40–0.73; p < 0.01).[55] In 2024, Yu et al published the effect of colchicine on coronary plaque stability from a prospective, randomized, double-blind trial involving 128 patients with acute coronary syndrome and lipid-rich plaques.[56] Over 12 months, colchicine significantly increased minimal fibrous cap thickness and reduced lipid arc, macrophage extension, and inflammatory markers compared with placebo, thus suggesting that it may promote coronary plaque stabilization.[56]
The DACAB trial's 5-year follow-up demonstrated that 1 year of dual antiplatelet therapy with ticagrelor and aspirin postCABG significantly reduced MACE compared with aspirin monotherapy and ticagrelor monotherapy, but showed no difference in all-cause mortality.[57] The rate of major bleeding was 1.8% in the dual antiplatelet therapy group and 1.2% in the ticagrelor monotherapy group; no major bleeding event was reported in the aspirin monotherapy group.[57] Additionally, an analysis of the STS-Database examined the impact of preoperative clopidogrel administration on outcomes in patients undergoing isolated CABG.[58] The study found that CABG performed within 5 days of clopidogrel exposure was associated with a modest increase in operative mortality and re-exploration for bleeding, as well as a substantial increase in blood product use.[58] Notably, risks decreased with increasing time from discontinuation, plateauing after 3 days, suggesting that delaying surgery for at least 3 days postclopidogrel discontinuation may mitigate these risks.[58]
In conclusion, the evidence published in 2024 supports the following conclusions:
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CABG guided by CCTA is feasible and has an acceptable safety profile in selected patients with complex CAD.
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Combining direct cardiac shockwave therapy with CABG significantly improves LVEF and physical capacity in patients with ischemic heart failure.
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CABG provides superior long-term survival and reduces MI compared with PCI, especially in patients with complex CAD, diabetes, and CTO—both in RCTs and observational data.
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Minimally-invasive CABG techniques show excellent long-term survival and low postoperative mortality in selected centers and populations.
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The ESC guidelines emphasize the critical role of the Heart Team in decision-making for CABG and PCI. When CABG and PCI hold equal recommendations, a heart team discussion is strongly recommended.
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The ESC guidelines generally advocate for CABG in complex CAD and for PCI in symptomatic patients with less complex CAD.
Surgical Treatment of Valve Disease
Surgical Treatment of Valve Disease
Aortic Valve
Aortic Valve Replacement (SAVR) versus Transcatheter Aortic Valve Implantation (TAVI)
The management of severe aortic stenosis (AS) has disruptively changed since the advent of transcatheter aortic valve replacement (TAVI) as an alternative to surgical aortic valve replacement (SAVR). Similar to the coronary field, but timewise much more condensed, a series of randomized trials were conducted at various levels of patient risk, providing insights into the treatment effects of the two approaches. However, unlike in the coronary field, there appears to be a significant but consistent difference in outcomes between randomized and observational studies.[2] Randomized evidence suggests short-term superiority and long-term equality of TAVI (up to 5 years, thus far), but risk-adjusted registry data find no short-term difference in mortality or stroke and significantly better survival for SAVR at 5 years and beyond. This pattern can specifically be found in the 2024 publications, where several RCTs reported short-term outcomes in favor of TAVI in comparison to SAVR (DEDICATE, NOTION, TCW, NOTION 3). It is expected that these RCT results will induce a further shift in guideline recommendations toward TAVI, which may not be unproblematic from a patient perspective.
The German DEDICATE trial, conducted during the COVID-19 pandemic[59] published its safety endpoint at 1 year, while the primary endpoint is due after 5 years. The trial compared TAVI and SAVR in low- and intermediate-risk patients. Noninferiority for TAVI was reached at 1 year, but the numbers were even in favor of TAVI (death or disabling stroke: 5.4% vs. 10.0%; HR 0.53; p < 0.001). Mortality at 1-year (2.6% vs. 6.2%; HR 0.43) also favored TAVI.[59] The trial had a high crossover rate, with 70 Patients (9.8%) in the SAVR group undergoing TAVI.[59] While the quality of surgery was criticized[60] (which the authors explain with the possible impact of the COVID-19 pandemic on surgical outcomes[59]
[60]), 30-day mortality was still below STS-score expectations and consistent with German registry data.[61] Interestingly, interventional outcomes were excellent, but they differed substantially from German registry data.[61] Similarly, the NOTION trial[62] (performed in 2 centers in Denmark and Sweden), followed patients for 10 years, reporting comparable all-cause mortality for TAVI and SAVR (62.7% vs. 64%). This trial is the only RCT with below-average surgical results[63] and the TAVI outcomes also differ from a Danish national registry, in which SAVR again showed better long-term results than TAVI.[64] After the 5-year results of the PARTNER 3 trial were published in 2023,[65] the FDA provided the 6-year results in 2024.[66] The trial had randomized 1,000 low-risk patients with severe, symptomatic AS.[65] In this trial, survival curves crossed early, and at 6 years all-cause mortality was 14.6% for TAVI and 11.9% (SAVR). The survival curves seem to further diverge in favor of SAVR over time (Δ 1.8% at 5 and Δ 2.7% at 6 years).[66] Two RCTs evaluated outcomes in patients with aortic stenosis and CAD. The NOTION-3 trial[67] demonstrated that PCI reduced major adverse cardiac events compared with conservative treatment in TAVI patients, but increased bleeding risk.[67] The TCW trial also compared TAVI with FFR-guided PCI to SAVR with CABG and showed that the TAVI-PCI strategy was not only noninferior but also superior to SAVR with a surprisingly low incidence of the composite endpoint of mortality and complications at 1 year (4% vs. 23%; p < 0.001).[68] Finally, an RCT of 151 patients with small annulus found no significant differences between TAVI and SAVR in valve hemodynamics, mortality, stroke, or hospitalizations over 2 years.[69]
While these results give rise to the expectation of a further shift of guideline recommendations toward TAVI, there is a worrisome but consistent difference between RCT and registry data. Twelve national registries have reported risk-adjusted comparisons, thus far, with a universal result of superior survival for SAVR at 5 years and beyond.[70] As in the years before, registry data analyses in 2024 also demonstrate a clear SAVR advantage long-term. Not a single risk-adjusted registry study, thus far, demonstrated an advantage for TAVI. The survival difference in the above-mentioned risk-adjusted Danish registry is remarkable (all-cause mortality was 29.8% in the TAVI group and 16.9% in the SAVR group, p = 0.019[64]). In addition, the Austrian AUTHEARTVISIT registry[71] reported in 2024 higher median survival with SAVR vs. TAVI (8.8 years vs. 5 years; p < 0.001). In patients with bicuspid aortic valves, SAVR was also superior, as shown in an analysis of the US Medicare and Medicaid data, where TAVI was associated with higher rates of death, stroke, and pacemaker implantation compared with SAVR.[72] A meta-analysis of observational data showed that for patients with concomitant CAD, TAVI-PCI may have short-term benefits, but it is associated with worse long-term outcomes, including lower survival and higher MACCE rates at 5 years compared with SAVR-CABG,[73] standing completely against the TCW trial findings (see above).[68] Finally, the prospective OBSERVANT study from Italy showed that 10-year survival of low-risk patients who underwent TAVR was lower than SAVR,[74] again contradicting NOTION results.
While registry data have been heavily criticized (mainly for the inherent selection bias) and even excluded from generating guideline recommendations (if randomized evidence is available, such as in the TAVI-SAVR comparisons), in 2024, heavy criticism on RCT data for their representative value has been voiced.[75] Since RCTs usually suffer from severe selectivity due to often long lists of in- and exclusion criteria, the generalizability of RCT data to all comers has been questioned.[76] An additional, new critical aspect appears, if one relates outcomes to predicted risks. Except for the NOTION trials, all 30-day outcomes in trials showed observed to expected (O/E) ratios for mortality below 1, suggesting that trial outcomes are selected not only from a patient perspective but also from a technician perspective because the vast majority of “technicians” in the trials performed above average. If we then consider that surgical outcomes from RCTs are much closer to the available results from the various registries (SAVR mortality: GARY[77]/DEDICATE at 1 year 8.8% vs. 6.2%, STS low-risk data[78]/PARTNER 3 7.1% vs 8.2%), than the TAVI outcomes (low-risk TAVI 1-year mortality: GARY/DEDICATE 10% vs 2.6%[77]) a new “technician-bias” emerges that appears to primarily affect the TAVI arms. The ever-improving outcomes in the interventional arms of RCTs also stand in stark contrast to the 2024 published observation in the US (786 hospitals), where mortality increased in TAVI patients over the years, although predicted risks of TAVI patients has come down in the same time period.[79] Thus, the generalizability of RCT results experiences another level of concern, the “technician bias,” which appears specifically relevant in TAVI-SAVR comparisons.
Apart from the TAVI-SAVR comparisons, several other trials have evaluated TAVI therapy in different subgroups. The EARLY TAVR trial[80] randomly evaluated TAVI in asymptomatic patients with severe AS deemed unsuitable for SAVR. At 2 years, the composite endpoint (death, stroke, or unplanned hospitalization) was 15.2% in TAVI and 25.6% in controls, mainly due to fewer hospitalizations, as mortality and stroke rates were similar.[80] However, the prominence of unplanned hospitalizations in the combined endpoint raised concerns about the clinical relevance of the results. In addition, the lack of a surgical arm (the reasons for surgical unsuitability are difficult to identify in the publication) for comparison to the current gold standard in these patients makes data interpretation difficult, especially given the discussion on long-term outcomes (see above), which is key in asymptomatic patients with often long residual life expectancies. In this line of argumentation, Javadikasgari et al published long-term outcomes of SAVR in asymptomatic patients with severe aortic stenosis and normal LVEF and showed life expectancies comparable to the general population, with postoperative survival of 100%, 94%, 84%, and 76% at 1, 5, 10, and 15 years, respectively.[81]
The ALIGN-AR study[82] evaluated the Trilogy transcatheter heart valve in high-risk patients with symptomatic moderate-to-severe or severe native aortic regurgitation (AR). Technical success was 95% and 1-year all-cause mortality was 7.8%, meeting the predefined noninferiority goal.[82] New pacemaker implantation was required in 24% of patients.[82] In the absence of a surgical comparator group and the excellent outcomes often seen in surgical AR patients, the high pacemaker rates and the still missing long-term data currently qualify Trilogy as a valuable alternative for high-risk cases unsuited for surgery. For severe aortic stenosis with a small annulus, TAVI with a self-expanding supra-annular valve outperformed balloon-expandable valves, showing lower rates of valve dysfunction, prosthesis-patient mismatch, and mean gradients, while maintaining similar safety profiles.[83] These findings were confirmed by the OPERA-TAVI registry.[84]
Re-do SAVR versus Valve-in Valve TAVI
With the valve-in-valve (ViV) TAVI option as a much less complex alternative to redo SAVR for failed bioprosthetic valves, the number of patients receiving this treatment has increased tremendously in recent years,[85] although long-term data are limited and randomized trials are missing. In a retrospective cohort of 1,771 patients appearing from three US databases in 2024, ViV-TAVI was associated with lower periprocedural complications, including major bleeding, acute kidney failure, and pacemaker implantation, compared with redo SAVR,[86] but SAVR was associated with better long-term results. The 5-year all-cause mortality rate was 23.4% (95% CI, 15.7–34.1) in the ViV-TAVI group and 13.3% (95% CI, 9.2–18.9) in the redo SAVR group.[86] In a meta-analysis of 16 nonrandomized studies involving 4,373 patients Sá et al confirmed these findings.[87] They showed that ViV-TAVI was associated with a lower mortality risk within the first 6 months (HR 0.58; 95% CI 0.46–0.73, p < 0.001), but this advantage reversed after 6 months, favoring redo-SAVR for long-term survival (HR 1.92; 95% CI 1.58–2.33, p < 0.001)[87] ([Fig. 4]). The REPEAT trial (DFG 498525463) will generate the first randomized evidence on this topic.
Fig. 4 Kaplan–Meier incidence function of all-cause mortality in ViV-TAVI and redo-SAVR. (Reproduced with permission from Sa et al.[87])
Conventional Aortic Valve Surgery and Medical Therapy
Despite the increasing focus on interventional options, classic surgery possesses various treatment options to improve outcomes not achievable through transcatheter technologies.
Yang et al published in 2024 their early outcomes of the Y-incision technique to enlarge the aortic annulus. After enlargement, they reported a median prosthesis size of 27 with 54% of patients having a size 29 (i.e., the largest valve size available). The median annulus enlargement was 3 valve sizes, resulting in a postoperative mean gradient of 7 mm Hg.[88] The ARISE trial demonstrated that decellularized aortic homografts provided excellent 5-year outcomes in young patients, including low mortality (3.47%), minimal regurgitation, and low rates of reoperation, endocarditis, bleeding, and thromboembolism.[89] A meta-analysis of 15 studies (3,044 patients) reported superior overall survival and lower reintervention rates with valve-sparing aortic root replacement using the reimplantation technique (David procedure) compared with remodeling (Yacoub procedure), with early survival benefits favoring reimplantation but no differences beyond 4 years.[90] The potential of improving outcomes with mechanical prostheses was also demonstrated in 2024. A prospective registry of patients with On-X mechanical valves found that low-dose warfarin (INR 1.8; range: 1.5–2.0) plus aspirin reduced thromboembolism, valve thrombosis, and major bleeding by 57%, with an 85% reduction in major bleeding and no valve thrombosis, supporting the safety and efficacy of this low-INR strategy.[91]
Mitral Valve
The field of mitral valve surgery continues to evolve, driven by advancements in surgical techniques, transcatheter interventions, and comparative clinical studies.
The RESHAPE-HF2 trial showed that in patients with heart failure with moderate to severe functional mitral regurgitation (MR) who received medical therapy, the addition of transcatheter edge-to-edge repair (TEER) led to a lower rate of first or recurrent hospitalization for heart failure or cardiovascular death and a lower rate of first or recurrent hospitalization for heart failure at 24 months, demonstrating the effectiveness of mitral valve intervention in this group.[92] The comparison of TEER and classic surgery in patients with secondary MR and heart failure came from the German MATTERHORN Trial,[93] of which randomized 208 patients. After 1 year of follow-up, TEER was noninferior to surgery for the composite endpoint of death, re-hospitalization for heart failure, stroke, re-intervention, or implantation of a circulatory support device.[93] The trial results were evaluated in favor of TEER because secondary endpoints such as transfusion rates were lower in the TEER arm. The trial recruited patients over almost a decade but it is uncertain whether long-term results can be reported, due to the current lack of funding commitment from the original industry partner. We could show that long-term survival correlates with regurgitation degree before and after invasive mitral valve treatment.[94] From that perspective, it may be worrisome that at the 1-year mark in MATTERHORN, freedom from MR≥1 was achieved in 87.3% of the surgical group and only 73.1% of the intervention group ([Fig. 5]).[93] The percentage of patients with a fully competent valve was 53.5% for surgery versus 15.9% with TEER.[93] In addition to MATTERHORN, randomized comparison of TEER and surgery for structural MR (PRIMARY trial, NCT05051033) is ongoing, however, with a primary endpoint of 3 years and secondary endpoints of up to 10 years. While PRIMARY will deliver randomized evidence after more than a decade, risk-adjusted registry data (53,117 Medicare and Medicaid patients from 2012–2019) already suggest significant survival advantages, fewer heart failure re-admissions and fewer mitral re-interventions for surgery compared with TEER in the primary MR patient population ([Fig. 6]).[95]
Fig. 5 Relative frequency of mitral regurgitation (MR) severity grades in patients undergoing TEER and surgery at baseline and at 1 year after the procedure. Grade 0 indicates no mitral regurgitation, grade 1+ mild mitral regurgitation, grade 2+ moderate mitral regurgitation, grade 3+ moderate-to-severe mitral regurgitation, and grade 4+ severe mitral regurgitation. (Reproduced with permission from Baldus et al.[93])
Fig. 6 Survival after TEER versus surgical repair in matched patients with degenerative MR (Reproduced with permission from Chikwe et al.[95])
In 2024, two meta-analyses comparing surgical approaches for reconstructive correction of structural MR,[96] including reoperations,[97] were published. After the mini-mitral trial had not shown any large differences between sternotomy and mini-thoracotomy after 3 months,[98] both summaries of registry studies demonstrated advantages of minimally invasive surgery versus sternotomy in terms of postoperative complications and length of hospital stay. In the case of re-operations (such patients were excluded in the Mini-Mitral trial), a difference in mortality was also observed, favoring minimally invasive approaches.[97]
In addition, important updates regarding postoperative management for patients undergoing mitral valve repair were published in the 2024 EACTS Guidelines on perioperative medication in adult cardiac surgery.[99] The guidelines recommend low-dose ASA over vitamin K antagonists during the first 3 months postmitral valve repair surgery for patients without other indications for oral anticoagulation.[99]
Tricuspid Valve
In 2024, several publications addressed new and classic methods of tricuspid valve treatment. In the TRISCEND II Trial, transcatheter tricuspid-valve replacement with the EVOQUE system showed superiority over medical therapy alone, with a win ratio of 2.02 (95% CI, 1.56–2.62; p < 0.001), driven by improvements in quality of life (KCCQ score), functional class, and exercise capacity.[100] However, the procedure was associated with higher rates of severe bleeding (15.4% vs. 5.3%) and pacemaker implantation (17.4% vs. 2.3%).[101] The 3-year outcomes from the single-arm TRILUMINATE Study, evaluating tricuspid TEER for severe TR were also published. Results showed overall mortality of 27%, sustained TR reduction (moderate or less in 79% of patients), improved NYHA functional class and quality of life, and a significant decrease in heart failure hospitalizations.[102] Analyzing surgical results in the field, the TRIGISTRY cohort suggested that surgery (both repair or replacement) improved survival compared with conservative management in patients with a low TRI-SCORE (72% vs. 44% at 10 years), tricuspid repair showed benefit in the intermediate TRI-SCORE category but not in those with high scores.[103] Dreyfus et al illustrated also that surgical risk at low TRI-SCORE was equal to interventional risk but the 2-year outcome was better with surgery.[104]
The main findings in 2024 for classic valve surgery are:
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While TAVI continues to take over the majority of aortic stenosis treatments across all risk spectra, a worrisome difference between excellent RCT outcomes and long-term inferior registry outcomes emerges for TAVI compared with classic surgery. There is currently no external validation of RCT results from registries, a thus far, unparalleled condition. Questions regarding long-term outcomes, including mortality, durability, and applicability in lower-risk cohorts and other subgroups (lower age, concomitant CAD, bicuspid valve, etc.) remain to be addressed.
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Re-do SAVR seems to deliver superior long-term results compared with valve-in-valve TAVI for failed bioprostheses, challenging current concepts of lifetime management.
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New surgical techniques, such as the Y-incision technique to enlarge the aortic annulus have great potential to dramatically improve hemodynamic outcomes.
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TEER is noninferior to surgery for treatment of secondary MR at 1 year, with potential early safety advantages. However, long-term data are missing and registry analyses suggest that surgery is superior to TEER for treatment of primary MR and long-term.
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For all valves, risk-benefit assessment becomes more and more important, as surgery appears to provide the best long-term outcomes at potentially higher short-term risk.
Surgery for Terminal Heart Failure/Transplant Surgery
Surgery for Terminal Heart Failure/Transplant Surgery
For the surgical treatment of heart failure, important publications in 2024 assessed anticoagulation regimens and infection risks after LVAD and techniques to optimize heart transplant outcomes.
The DOAC LVAD trial investigated the safety and feasibility of using Apixaban in patients with fully magnetically levitated left ventricular assist devices (LVADs).[105] Thirty LVAD recipients were randomized to either Apixaban or warfarin therapy, with a 24-week follow-up.[105] The results showed no major hemocompatibility-related adverse events in the Apixaban group, while 14% of warfarin patients experienced major bleeding.[105] Lauenroth et al compared a prospective clinical trial intracorporeal loop positioning with no loop positioning for preventing driveline infections (DLI) in 80 LVAD patients and found no significant difference in DLI rates between the two groups after 1 year of follow-up.[106] In the field of transplantation, a multinational RCT compared static cold storage with hypothermic oxygenated machine perfusion (HOPE) for preserving donor hearts, finding a 44% risk reduction in the composite primary outcome with HOPE, although not statistically significant (p = 0.059). HOPE significantly reduced primary graft dysfunction (11% vs. 28%, RR 0·39; 95% CI 0·20–0·73) and major adverse cardiac transplant events (18% vs. 32%, RR 0·56; 95% CI 0·34–0·92).).[107] Another RCT evaluated intraoperative hemoadsorption in heart transplant recipients, comparing it to standard care.[108] Hemoadsorption improved hemodynamic stability, reduced rates of vasoplegic syndrome, acute kidney injury, and renal replacement therapy, shortened mechanical ventilation and ICU stays,[108] without affecting mycophenolic acid levels or increasing allograft rejection or mortality rates.[108] Finally, the first fully robotic heart transplant was performed in 2024, but beyond press releases, there was no scientific publication in 2024. The first-in-man robotic-assisted lung transplant was also published in 2024. The authors used a robotic telemanipulator system to implant a right lung in a 69-year-old recipient.[109]
Surgery of the Aorta
The new EACTS Guidelines Diagnosing and Treating Acute and Chronic Syndromes of the Aortic Organ were published in 2024, providing updated recommendations on the management of aortic diseases, including specific thresholds for surgical intervention in patients with bicuspid aortic valve-related aortopathy and a comprehensive approach to chronic aortic dissections.[110]
Further studies in 2024 have addressed the management of acute type A aortic dissection, focusing on surgical approaches and outcomes. A comparison of total arch replacement (TAR) and hemiarch replacement (HAR) for acute type A aortic dissection, analyzing outcomes in 6,526 patients was published.[111] TAR was associated with higher 30-day mortality (OR 1.79, CI 1.29–2.49), increased risk of renal failure requiring dialysis, and a trend toward higher stroke rates, but showed a potential benefit in freedom from long-term aortic reoperation.[111] For acute type A aortic intramural hematoma, surgery as the initial approach was associated with better late survival and lifetime gain in comparison with medical therapy alone.[112] Finally, a meta-analysis showed that ECLS after surgical repair for ATAAD remains associated with high rates of in-hospital death and complications, but it still represents a chance of survival in critical situations.[113]
