Impact of Myocardial Viability on Long-term Outcomes after Surgical Revascularization

Abstract

Background This study was conducted to evaluate whether myocardial viability assessed with cardiac magnetic resonance (CMR) affected long-term clinical outcomes after coronary artery bypass grafting (CABG) in patients with ischemic cardiomyopathy (ICMP).

Methods Preoperative CMR with late gadolinium enhancement (LGE) was performed in 103 patients (64.9 ± 10.1 years, male:female = 82:21) with 3-vessel disease and left ventricular dysfunction (ejection fraction ≤ 0.35). Transmural extent of LGE was evaluated on a 16-segment model, and transmurality was graded on a 5-point scale: grades—0, absence; 1, 1 to 25%; 2, 26 to 50%; 3, 51 to 75%; 4, 76 to 100%. Median follow-up duration was 65.5 months (interquartile range = 27.5–95.3 months). Primary endpoint was the composite of all-cause mortality or hospitalization for congestive heart failure.

Results Operative mortality was 1.9%. During the follow-up, all-cause mortality and readmission for congestive heart failure occurred in 29 and 8 patients, respectively. The cumulative incidence of the primary endpoint was 31.3 and 46.8% at 5 and 10 years, respectively. Multivariable analysis demonstrated that the number of segments with LGE grade 4 was a significant risk factor (hazard ratio 1.42, 95% confidence interval 1.10–1.83, p = 0.007) for the primary endpoint among the variables assessed by CMR. Other risk factors included age, dialysis, chronic obstructive pulmonary disease, and EuroSCORE II.

Conclusion The number of myocardial segments with transmurality of LGE >75% might be a prognostic factor associated with the composite of all-cause mortality or hospitalization for congestive heart failure after CABG in patients with 3-vessel disease and ICMP.

Keywords

coronary artery bypass grafting - ischemic cardiomyopathy - cardiac magnetic resonance - late gadolinium enhancement - long-term outcomes

• References

• 1 Velazquez EJ, Lee KL, Jones RH. et al; STICHES Investigators. Coronary-artery bypass surgery in patients with ischemic cardiomyopathy. N Engl J Med 2016; 374 (16) 1511-1520
• 2 McDonagh TA, Metra M, Adamo M. et al; ESC Scientific Document Group. 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure. Eur Heart J 2021; 42 (36) 3599-3726
• 3 Ezekowitz JA, O'Meara E, McDonald MA. et al. 2017 Comprehensive Update of the Canadian Cardiovascular Society Guidelines for the Management of Heart Failure. Can J Cardiol 2017; 33 (11) 1342-1433
• 4 Lee SA, Yoon YE, Kim JE. et al. Long-term prognostic value of late gadolinium-enhanced magnetic resonance imaging in patients with and without left ventricular dysfunction undergoing coronary artery bypass grafting. Am J Cardiol 2016; 118 (11) 1647-1654
• 5 Kancharla K, Weissman G, Elagha AA. et al. Scar quantification by cardiovascular magnetic resonance as an independent predictor of long-term survival in patients with ischemic heart failure treated by coronary artery bypass graft surgery. J Cardiovasc Magn Reson 2016; 18 (01) 45
• 6 Amado LC, Gerber BL, Gupta SN. et al. Accurate and objective infarct sizing by contrast-enhanced magnetic resonance imaging in a canine myocardial infarction model. J Am Coll Cardiol 2004; 44 (12) 2383-2389
• 7 Klein C, Nekolla SG, Bengel FM. et al. Assessment of myocardial viability with contrast-enhanced magnetic resonance imaging: comparison with positron emission tomography. Circulation 2002; 105 (02) 162-167
• 8 Selvanayagam JB, Kardos A, Francis JM. et al. Value of delayed-enhancement cardiovascular magnetic resonance imaging in predicting myocardial viability after surgical revascularization. Circulation 2004; 110 (12) 1535-1541
• 9 Kim RJ, Wu E, Rafael A. et al. The use of contrast-enhanced magnetic resonance imaging to identify reversible myocardial dysfunction. N Engl J Med 2000; 343 (20) 1445-1453
• 10 Oh SJ, Park EA, Lee W, Hwang HY, Kim KB. Improved wall motion of late gadolinium-enhanced myocardium after complete surgical revascularization. Ann Thorac Surg 2015; 99 (05) 1554-1560
• 11 Hwang HY, Yeom SY, Park EA, Lee W, Jang MJ, Kim KB. Serial cardiac magnetic resonance imaging after surgical coronary revascularization for left ventricular dysfunction. J Thorac Cardiovasc Surg 2020; 159 (05) 1798-1805
• 12 Kim KB, Choi JW, Oh SJ. et al. Twenty-year experience with off-pump coronary artery bypass grafting and early postoperative angiography. Ann Thorac Surg 2020; 109 (04) 1112-1119
• 13 Hwang HY, Lee KH, Han JW, Kim KB. Equivalency of saphenous vein and arterial composite grafts: 5-year angiography and midterm clinical follow-up. Ann Thorac Surg 2016; 102 (02) 580-588
• 14 Cerqueira MD, Weissman NJ, Dilsizian V. et al; American Heart Association Writing Group on Myocardial Segmentation and Registration for Cardiac Imaging. Standardized myocardial segmentation and nomenclature for tomographic imaging of the heart. A statement for healthcare professionals from the Cardiac Imaging Committee of the Council on Clinical Cardiology of the American Heart Association. Circulation 2002; 105 (04) 539-542
• 15 Schvartzman PR, Srichai MB, Grimm RA. et al. Nonstress delayed-enhancement magnetic resonance imaging of the myocardium predicts improvement of function after revascularization for chronic ischemic heart disease with left ventricular dysfunction. Am Heart J 2003; 146 (03) 535-541
• 16 Assomull RG, Prasad SK, Lyne J. et al. Cardiovascular magnetic resonance, fibrosis, and prognosis in dilated cardiomyopathy. J Am Coll Cardiol 2006; 48 (10) 1977-1985
• 17 Wu KC, Weiss RG, Thiemann DR. et al. Late gadolinium enhancement by cardiovascular magnetic resonance heralds an adverse prognosis in nonischemic cardiomyopathy. J Am Coll Cardiol 2008; 51 (25) 2414-2421
• 18 Kwon DH, Halley CM, Carrigan TP. et al. Extent of left ventricular scar predicts outcomes in ischemic cardiomyopathy patients with significantly reduced systolic function: a delayed hyperenhancement cardiac magnetic resonance study. JACC Cardiovasc Imaging 2009; 2 (01) 34-44
• 19 Kwong RY, Chan AK, Brown KA. et al. Impact of unrecognized myocardial scar detected by cardiac magnetic resonance imaging on event-free survival in patients presenting with signs or symptoms of coronary artery disease. Circulation 2006; 113 (23) 2733-2743
• 20 Wu E, Ortiz JT, Tejedor P. et al. Infarct size by contrast enhanced cardiac magnetic resonance is a stronger predictor of outcomes than left ventricular ejection fraction or end-systolic volume index: prospective cohort study. Heart 2008; 94 (06) 730-736
• 21 Cheong BY, Muthupillai R, Wilson JM. et al. Prognostic significance of delayed-enhancement magnetic resonance imaging: survival of 857 patients with and without left ventricular dysfunction. Circulation 2009; 120 (21) 2069-2076
• 22 Kirschbaum SW, Springeling T, Boersma E. et al. Complete percutaneous revascularization for multivessel disease in patients with impaired left ventricular function: pre- and post-procedural evaluation by cardiac magnetic resonance imaging. JACC Cardiovasc Interv 2010; 3 (04) 392-400
• 23 Saeed M, Lund G, Wendland MF, Bremerich J, Weinmann H, Higgins CB. Magnetic resonance characterization of the peri-infarction zone of reperfused myocardial infarction with necrosis-specific and extracellular nonspecific contrast media. Circulation 2001; 103 (06) 871-876
• 24 Park EA, Lee W, Oh SJ, Kim KB. Magnetic resonance imaging of reverse remodeling after coronary revascularization in ischemic heart disease- morphologic evaluation. Circ J 2016; 80 (12) 2513-2519
• 25 Park H, Kang DY, Ahn JM. et al. Myocardial scar and revascularization on mortality in ischemic cardiomyopathy (from the Late Gadolinium Enhancement Cardiac Magnetic Resonance Study). Am J Cardiol 2023; 192: 212-220
• 26 de Haan S, Meijers TA, Knaapen P, Beek AM, van Rossum AC, Allaart CP. Scar size and characteristics assessed by CMR predict ventricular arrhythmias in ischaemic cardiomyopathy: comparison of previously validated models. Heart 2011; 97 (23) 1951-1956
• 27 Scott PA, Morgan JM, Carroll N. et al. The extent of left ventricular scar quantified by late gadolinium enhancement MRI is associated with spontaneous ventricular arrhythmias in patients with coronary artery disease and implantable cardioverter-defibrillators. Circ Arrhythm Electrophysiol 2011; 4 (03) 324-330
• 28 Alexandre J, Saloux E, Dugué AE. et al. Scar extent evaluated by late gadolinium enhancement CMR: a powerful predictor of long term appropriate ICD therapy in patients with coronary artery disease. J Cardiovasc Magn Reson 2013; 15 (01) 12
• 29 Bonow RO, Maurer G, Lee KL. et al; STICH Trial Investigators. Myocardial viability and survival in ischemic left ventricular dysfunction. N Engl J Med 2011; 364 (17) 1617-1625