Simple Score Shown to Predict Early and Late Mortality After TAVR

July 18, 2016—Findings from a study that analyzed patients from the Medtronic CoreValve United States Pivotal Trial program were used to develop a simple scoring system that incorporates standard and novel predictor variables after transcatheter aortic valve replacement (TAVR). The data were published by James B. Hermiller, Jr, MD, et al in Journal of the American College of Cardiology (JACC. 2016;68:343–352).

The investigators noted that few studies have examined the impact of novel indices of comorbidity, frailty, and disability on TAVR outcomes. The CoreValve pivotal trial evaluated the safety and efficacy of the CoreValve system (Medtronic) in the treatment of symptomatic severe aortic stenosis in high-risk and very high-risk patients who need aortic valve replacement.

In this investigation, a multidisciplinary heart team used objective criteria, such as the Society of Thoracic Surgeons Predicted Risk of Mortality (STS PROM), and subjective criteria to assess patients’ eligibility for TAVR. The analysis included 3,687 patients randomly divided (2:1) into a derivation cohort (n = 2,482) and a validation cohort (n = 1,205). The study evaluated predictors of all-cause death, which were used to calculate a risk score for each patient.

As summarized in JACC, the overall mortality rate was 5.8% at 30 days and 22.8% at 1 year. Home oxygen use, assisted living, albumin levels < 3.3 g/dL, and age > 85 years predicted death at 30 days. Home oxygen use, albumin levels < 3.3 g/dL, falls in the past 6 months, STS PROM score > 7%, and severe (≥ 5) Charlson comorbidity score predicted death at 1 year. 

A simple scoring system created on the basis of these multivariable predictors effectively stratified risk at 30 days and 1 year into low-risk, moderate-risk, and high-risk subsets. This score showed a threefold difference in mortality rates for the low-risk and high-risk subsets at 30 days (3.6% and 10.9%, respectively) and 1 year (12.3% and 36.6%, respectively). The 1-year mortality model was more stable than the 30-day model (C-statistics, 0.79 vs 0.75).

The investigators concluded in JACC that the simple score dominated by novel predictors of outcome effectively stratified early and late mortality rates in extreme-risk and high-risk patients and may assist in selecting appropriate candidates for TAVR.