Mortality After Procedural or Spontaneous Myocardial Infarction.

Background: It remains unclear whether procedural myocardial infarction (pMI) and spontaneous myocardial infarction (spMI) have a similar impact on prognosis.

Objectives: The aim of this study was to assess mortality after pMI and spMI.

Methods: Patients with chronic coronary syndrome (CCS) and baseline troponin ≤1× the upper reference level (URL) or with acute spMI who underwent percutaneous coronary intervention (PCI) were included. PMI was defined as post-PCI troponin increase >1× URL in patients with CCS. SpMI comprised any acute coronary syndrome with elevated troponin. The 1-year risk of all-cause death was assessed after pMI and spMI across 3 strata of troponin elevation (>1-5×, >5-35×, and >35× URL), with CCS patients having post-PCI troponin ≤1× URL as a reference group. Conventional troponin I was measured using the Architect methodology (Abbott).

Results: Among 10,707 patients undergoing PCI from 2012 to 2020, 8,515 patients presented with CCS and 2,192 with spMI. Among CCS patients, 913 (10.7%) had pMI. Troponin peaks >1-5×, >5-35×, and >35× URL were observed in 53%, 41%, and 6% of patients with pMI, and in 24%, 38%, and 37% of patients with spMI, respectively. Mortality at 1 year was higher after pMI (7.7%; adjusted HR: 4.40; 95% CI: 1.59-12.2), and spMI (8.5%; adjusted HR: 7.57; 95% CI: 5.44-10.5) with troponin peak >35× URL compared with no-MI (1.4%). Mortality was also increased after spMI with troponin peak >1-5× or >5-35× URL.

Conclusions: Mortality at 1 year was significantly increased after pMI and spMI with troponin peak >35× URL, whereas for troponin levels ≤35× only spMI had a relevant impact on mortality.