Abstract
OBJECTIVE: The prognostic significance of troponin elevation following percutaneous coronary intervention (PCI) remains debated. This study aimed to evaluate the association between different thresholds of post-PCI cardiac troponin I (cTnI) and mortality. METHODS: From January 2012 to July 2017, 5,218 consecutive patients undergoing elective PCI with pre-PCI cTnI < 99th percentile of the upper reference limit (URL) were included. Levels of cTnI were measured before PCI and every 8 h for 24 h after procedural. The outcomes were 3-year cardiac mortality. RESULTS: Patients had a mean age of 66.2 years, 27.6% were women, 67.0% had hypertension, and 26.2% had diabetes mellitus. During the 3 years of follow-up, cardiac death occurred in 0.86%, 1.46%, 1.69%, 2.36%, and 2.86% of patients with cTnI < 1, ≥ 1 to < 5, ≥ 5 to < 35, ≥ 35 to < 70, and ≥ 70 times URL. The cardiac mortality rate was moderately increased with higher peak cTnI values, but the Kaplan-Meier curve demonstrated no significant association between any increment of cTnI and either cardiac or non-cardiac mortality. Isolated cTnI increment of ≥ 5 × URL, ≥ 35 × URL, and ≥ 70 × URL was occurred in 1,379 (26.4%), 197 (3.8%), and 70 (1.3%) patients, respectively. In multivariate Cox regression analysis and Fine-Gray model, none of the above cTnI thresholds was significantly associated with an increased risk of cardiac death. CONCLUSION: In patients who underwent elective PCI, post-PCI cTnI elevation is not independently associated with cardiac mortality.