Abstract
Left main (LM) percutaneous coronary interventions (PCI) are challenging and highly invasive procedures. Periprocedural myocardial injury (Troponin (Tn) elevation > 99th percentile) is frequently detected after LM PCI, being identified even in up to 67% of patients. However, the prognostic implications of periprocedural Tn elevation after LM PCI remain controversial. We aim to assess the impact and prognostic significance of the periprocedural troponin elevation on long-term outcomes in patients undergoing LM PCI in a real-world setting. Consecutive 673 patients who underwent LM PCI in our department between January 2015 to February 2021 were included in a prospective registry. The first group consisted of 323 patients with major cardiac Troponin I elevation defined as an elevation of Tn values > 5× the 99th percentile in patients with normal baseline values or post-procedure Tn rise by >20% in patients with elevated pre-procedure Tn in whom the Tn level was stable or falling (based on the fourth universal definition of myocardial infarction). The second group consisted of patients without major cardiac Troponin I elevation. Seven-year long-term all-cause mortality was not higher in the group with major Tn elevation (36.9% vs. 40.6%; p = 0.818). Naturally, periprocedural myocardial infarction was diagnosed only in patients from groups with major Tn elevation (4.9% of all patients). In-hospital death and other periprocedural complications did not differ significantly between the two study groups. The adjusted HRs for mortality post-PCI in patients with a periprocedural myocardial infarction were not significant. Long-term mortality subanalysis for the group with criteria for cardiac procedural myocardial injury showed no significant differences (39.5% vs. 38.8%; p = 0.997). The occurrence of Tn elevation (>1×; >5×; >35× and >70× URL) after LM PCI was not associated with adverse long-term outcomes. The results of the study suggest that the isolated periprocedural troponin elevation is not clinically significant.