The Clinical Significance of PCI-Related Myocardial Infarction in Stable Ischaemic Heart Disease Patients in the Era of hs-Troponin.

Background & Aim: The definition and clinical relevance of percutaneous coronary intervention (PCI)-related myocardial infarction (MI) has been a topic of significant debate and controversy. It has particularly garnered widespread attention recently due to a contemporary trend of including it as a component of primary end points in major trials. The study aimed to assess the clinical relevance of PCI-related MI (PMI) according to the Fourth Universal Definition of MI using a high-sensitivity troponin (hs-Tn) assay in a real-world setting.

Methods: This was a single centre, retrospective registry analysis of consecutive patients who underwent elective PCI for stable ischaemic heart disease between January 2014 to December 2018. The primary end point was major adverse cardiovascular events (MACEs)-the composite of death, spontaneous MI, stent thrombosis and the need for repeat revascularisation within 12 months from the index procedure.

Results: We treated 858 patients with a mean age of 67.6 years and 78.3% were men. The incidence of PMI in our cohort was 12.8%. On univariable analysis, contrast volume >150 mL, prior coronary artery bypass graft, final thrombolysis in MI flow 0-2, total stent length and stent length >20 mm were significantly associated with increased risk of PMI. There were 46 (5.4%) MACE in total with seven (6.4%) in the PMI group and 39 (5.2%) in the non-PMI group (p=0.6). Kaplan-Meier survival curves were used to estimate 1-year MACE-free survival for the patients with PMI versus non-PMI and there was no significant difference. On multivariable Cox proportional hazards analysis, contrast volume >150 mL, prior coronary artery bypass graft and estimated glomerular filtration rate <60 (mL/min/1.73 m) were independent predictors of MACE during 1-year follow-up, whereas PMI was not an independent predictor.

Conclusions: PMI defined according to the Fourth Universal Definition of MI and using hs-Tn was common, occurring in 12.8% of patients, but not independently predictive of MACE in 1 year. As PMIs are increasingly used as a component of composite primary end points in major, practice-changing trials, establishing a clinically relevant definition of PMI is of utmost importance.