To assess the prognostic role of isolated troponin I
(TnI) elevation after elective percutaneous coronary intervention
(PCI) in patients with stable coronary artery disease.
The prognostic role of minor troponin elevation after PCI is controversial.
A total of 1532 consecutive patients who underwent elective PCI were included. Follow-up data were obtained for 1432 of 1532 (93.4%) patients. The events taken into account in the follow-up included total mortality, cardiac death, hospitalization for acute myocardial infarction and/or unstable angina.
The following variables were identified as predictive of major adverse cardiac events (MACE) by univariate analysis: age 75 years at least (P
= 0.012), ejection fraction less than 50% (P
= 0.001), prior myocardial infarction (P
= 0.031) and TnI 1.0 ng/ml at least after PCI (P
= 0.04). The Cox-regression model identified the TnI elevation after PCI, the older age and the ejection fraction as independent predictors of MACE during follow-up (TnI: P
= 0.042; older age: P
= 0.001; ejection fraction: P
= 0.003). In a subgroup of patients with preserved ejection fraction, the incidence of MACE was significantly higher in those with TnI of at least 1.0 ng/ml at least than in the ones with TnI less than 1.0 ng/ml, with the highest incidence among the older cohort. The multivariate analysis confirmed the TnI elevation 1.0 ng/ml at least after PCI and the older age as predictors of MACE.
This study documented that in clinically stable patients, minor TnI elevations after elective PCI are independent predictors of MACE during follow-up, as are older age and reduced ejection fraction. Additionally, TnI elevation was a predictor of MACE during follow-up in a subset of patients with preserved ejection fraction. The combination of TnI elevation and older age confers the highest risk of MACE.