Troponin I elevation and all-cause mortality after elective percutaneous coronary interventions

Although troponin I (TnI) elevation and myocardial injury after percutaneous coronary interventions (PCI) are frequent findings, their prognoses remain controversial. We aimed to determine the association between any or ≥5 times TnI elevation after elective PCI and subsequent one year mortality rates and long term survival.

Consecutive patients admitted for elective PCI between January 2013 and December 2014 were retrospectively analyzed by chart review in two hospitals in Rio de Janeiro. Only patients with post-PCI TnI measurements were included. Clinical, angiographic and procedural characteristics were correlated with any or ≥5 times TnI elevation, as well as 1year mortality and long term survival.

A total of 407 interventions were included in the analysis. Post-PCI TnI elevation was observed in 74.7% of cases and ≥5 times elevations occurred in 41.3%. Age≥70years, female gender and multistenting were predictors of enzyme elevation. Prior aspirin or hypoglycemic therapy were protective factors. One year mortality was significantly associated with any TnI elevation (6.6% vs 1.05%, p=0.035) and values ≥5 times above the normal limit predicted the highest mortality rates (8.13% vs 3.14%, p=0.031). Survival of patients with single vessel disease was also adversely affected by ≥5 times enzyme elevation (log-rank: p=0.039).

Troponin I elevation after elective PCI is frequent and associated with progressively higher mortality rates at 1year. A cutoff value ≥5 times the 99th percentile, currently defined as myocardial injury, appears to be an even more significant predictor of this outcome, even in lower risk subgroups.