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.
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.
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.
In patients who underwent elective PCI, post-PCI cTnI elevation is not independently associated with cardiac mortality.