High Risk or Intermediate Risk? The Dilemma of Established Scoring Systems Used in Transcatheter Aortic Valve Implantation

Objectives: There is increasing debate about the role of transcatheter aortic valve implantation (TAVI) to intermediate-risk patients younger than 80 years of age and randomized studies are ongoing. We analyzed outcomes of a real-world cohort of TAVI patients formally meeting the criteria of intermediate-risk.

Methods: All TAVI patients treated from 2015 to 02/2017 were analyzed. Those aged < 80 years with a logistic EuroSCORE < 20% and STS Score < 6% were included and results presented in accordance with the VARC-2 criteria. All patients were considered high-risk for surgery as per heart team decision due to comorbidities not included in the risk score calculators.

Results: Out of 324 patients, 67 patients formally met the criteria of intermediate-risk by age and predictive risk scoring systems (20.7%). Mean age in this cohort was 73.3 ± 7.8y, mean logistic EuroSCORE I and STS scores were 9.6 ± 4.6% and 2.8 ± 1.3% respectively. Mean EuroSCORE II was 4.3 ± 3.2%. The decision in favor of TAVI was based on (more than one per patient): Frailty (59.7%, 40/67), intact bypass grafts (14.9%, 10/67), chronic malignant disease (29.8%, 20/67), porcelain aorta (17.9%, 12/67), COPD III/IV (5.9%, 4/67), hostile chest anatomy (5.9%, 4/106) and severe liver disease (2.9%, 2/67). Access was transfemoral in 79.1% (53/67). Transcatheter heart valves used were the Edwards Sapien 3 in 97.0% (65/67) and the CoreValve Evolut R in 2.9% (2/67). Device success was achieved in 98.5% (66/67). Mean transvalvular gradient was 15.1 ± 8.8mmHg and >mild paravalvular regurgitation occurred in 1.5% (1/67). Mortality at 30-days was 0% (0/67). Manifest strokes occurred in 4.5% (3/67) which were ischemic in ⅔ of cases. Pacemaker implantation rate was 11.9% (8/67).

Conclusion: In a routine TAVI cohort, a substantial share of patients (20.7%) does not meet formal criteria of high-risk assessed by scoring systems but have substantial risk factors affecting surgical outcome. Other scoring systems, validated for TAVI, should be implemented to improve discrimination between low-/intermediate and high-risk TAVI populations. When increasingly applying TAVI to a younger population, the considerable rate of neurological events and conduction disturbances with need for pacemaker implantation remain of concern.