Prognostically significant myocardial injury in patients undergoing TAVR

Sharma, Vikram

Background
Troponin (TnT) elevation occurs commonly in the setting of TAVR. The cutoff for TnT elevation post TAVR that is prognostically significant , in its association with long-term mortality, is unclear. We assessed the optimal cutoff for post TAVR TnT elevation that correlates with long-term prognosis. We also examined whether severity of coronary artery disease, presence of significant left main stem disease or presence of unrevascularized coronary disease correlates with occurrence of prognostically significant myocardial injury in TAVR.

Methods
This is a retrospective, observational single center study using a prospectively collected registry database of all patients who underwent TAVR at Cleveland Clinic between 2010 and 2015.

Results
The final analysis included 510 patients with a mean follow-up of 2.6 +/- 1.3 years. ROC analysis showed that TnT elevation ≥ 3x ULN was the best predictor of long-term mortality post TAVR with AUC of 0.56 for the whole study population and 0.57 with transapical TAVR patients excluded. Univariate and multivariate analyses confirmed that TnT elevation ≥ 3x ULN was significantly associated with increased long-term mortality post TAVR (HR 1.64, CI 1.05-2.56, p = 0.029 ), particularly when transapical TAVR patients were excluded. The most common causes for the presence of unrevascularized coronary disease included the presence of chronic total occlusion in the native or graft vessels (49.7%) and diffuse / complex CAD not suitable for PCI (24.6%). The presence of unrevascularized coronary disease and significant left main stem disease correlated with increased mortality, but not to the presence of prognostically significant myocardial injury.

Conclusions
Troponin T elevation of ≥ 3x ULN is associated with increased long-term mortality after TAVR, except for the transapical approach. The association between CAD/revascularization status and mortality in TAVR patients does not appear to be secondary to increased risk of myocardial injury. TnT elevation ≥ 3x ULN, which correlated with increased long-term mortality post TAVR in our study, does not appear to be secondary to underlying coronary artery disease, but rather is more closely associated with other factors, such as post TAVR complications.