Postprocedural Troponin Elevation and Mortality After Transcatheter Aortic Valve Implantation

Abstract

Background This study sought to investigate the role of postprocedural troponin elevations in mortality prediction after transcatheter aortic valve implantation and to define the threshold at which clinically relevant postprocedure myocardial injury determines mortality. Methods and Results A total of 1333 consecutive patients with transcatheter aortic valve implantation with available postprocedural high-sensitivity cardiac troponin T measurements were included in the analysis. The threshold at which postprocedure myocardial injury determines long-term mortality was identified using restricted cubic spline analysis. A >18.3-fold increase of troponin above the upper reference limit was identified as threshold for relevant postprocedure myocardial injury. Associations remained significant in a landmark analysis between 30 days and 2 years (hazard ratio [HR], 1.61, [95% CI, 1.13-2.28]; P=0.01), after adjusting for known confounders (adjusted HR, 1.90 [95% CI, 1.40-2.57]; P<0001), and in subgroups of patients with coronary artery disease (adjusted HR, 2.17 [95% CI, 1.44-3.29]; P<0.001), renal dysfunction (adjusted HR, 1.88 [95% CI, 1.35-2.62]; P<0.001), and intermediate/high surgical risk (adjusted HR, 2.70 [95% CI, 1.40-5.22]; P=0.003). Conclusions This study determined a troponin threshold for the identification of patients at increased mortality risk after transcatheter aortic valve implantation. The proposed definition of postprocedure myocardial injury advances risk stratification in patients with transcatheter aortic valve implantation and may assist in postprocedural patient management.

Keywords: aortic stenosis; myocardial infarction; risk stratification; transcatheter aortic valve implantation.

Figure 1. Restricted cubic spline analysis to determine the threshold at which postprocedural myocardial injury determines mortality.

Green and red areas represent the 95% CI. Univariable Cox proportional hazard regression with restricted cubic splines was used to flexibly model the association of peak hs‐cTnT levels above URL with mortality at 2 years after transcatheter aortic valve implantation. The minimal threshold at which hs‐cTnT is significantly associated with mortality at 2 years was identified at 18.3‐fold increase above URL. HR indicates hazard ratio; hs‐cTnT, high‐sensitivity cardiac troponin T; and URL, upper reference limit.

Figure 2. Kaplan–Meier estimates of survival according to the presence/absence of postprocedural myocardial injury.

The HR was adjusted for age, sex, chronic obstructive pulmonary disease, atrial fibrillation, peripheral artery disease, and Society of Thoracic Surgeons Predicted Risk of Mortality (STS‐PROM) Score. aHR indicates adjusted hazard ratio; HR, hazard ratio; and PPMI, postprocedural myocardial injury.

Figure 3. Increases of high‐sensitivity cardiac troponin T levels following transcatheter aortic valve implantation.

Proportion of patients across categories of postprocedural increases of hs‐cTnT above the URL. hs‐cTnT indicates high‐sensitivity cardiac troponin T; and URL, upper reference limit.

Figure 4. Kaplan–Meier estimates of survival according to the presence/absence of postprocedural myocardial injury stratified for coronary artery disease, renal dysfunction, and surgical risk.

A, Kaplan–Meier estimates of survival in patients with and without PPMI stratified according to the presence/absence of coronary artery disease. B, Kaplan–Meier estimates of survival in patients with and without PPMI stratified according to the presence/absence of renal dysfunction. C, Kaplan–Meier estimates of survival in patients with and without PPMI stratified according to low or intermediate/high surgical risk. The hazard ratio in (A through C) was adjusted for age, sex, chronic obstructive pulmonary disease, atrial fibrillation, peripheral artery disease, and Society of Thoracic Surgeons Predicted Risk of Mortality score. aHR indicates adjusted hazard ratio; CAD, coronary artery disease; PPMI, postprocedural myocardial injury; and RF, renal failure.

Figure 5. Landmark analysis of survival between 30 days and 2 years according to the presence/absence of postprocedural myocardial injury.

CI = confidence interval, HR, hazard ratio; PPMI, post‐procedural myocardial infarction.

Figure 6. Schematic illustration of pathophysiological mechanisms contributing to increases of cardiac troponin levels in patients undergoing transcatheter aortic valve implantation.