Incidence and prognostic value of electrocardiographic changes in patients with myocardial injury after elective PCI

Myocardial injury after percutaneous coronary intervention (PCI) is common and associated with adverse outcomes. Contemporary definitions of periprocedural myocardial infarction require biomarker elevation with or without ischemic electrocardiographic (ECG) findings. However, the incremental prognostic value of ECG beyond biomarker-defined injury alone remains uncertain.

To determine the incidence and independent prognostic value of ischemic ECG changes after elective PCI.

Consecutive adults age ≥ 18 years undergoing elective PCI at NYU Langone Health between 2011 and 2020 were included. Creatine kinase-myocardial band (CKMB) concentrations were measured at 1 and 3 h post-PCI. Among patients with myocardial injury, baseline and post-PCI ECGs (within 24 h) were reviewed to identify development of ischemic ECG changes (ST segment abnormalities, T wave abnormalities, and Q waves). Relationships between ischemic ECG findings and mortality were evaluated in Cox proportional hazards models adjusted for age, sex, and assay-normalized CKMB.

Among 10,735 patients, 1741 (16.2%) developed post-PCI myocardial injury. New ischemic ECG changes occurred in 18.4% of patients with myocardial injury and increased stepwise with higher concentrations of CKMB. New T wave abnormalities were most common (11%), followed by ST depressions (4.9%), Q waves (3.0%), and ST elevations (1.5%). Over a median follow-up of 5.3 years, new ischemic ECG changes were not independently associated with increased mortality among patients with myocardial injury (aHR 1.27, 95% CI 0.82-1.96).

Among patients with myocardial injury after elective PCI, new ischemic ECG changes were uncommon and did not confer independent prognostic value for long-term mortality.