Impact of total occlusion of the infarct-related coronary artery on mortality of 2483 patients with acute myocardial infarction

BACKGROUND The electrocardiographic (ECG) presentation, with or without ST-segment elevation, has traditionally been the cornerstone for classifying and managing acute myocardial infarction (AMI). However, up to 20% of non-ST-segment elevation myocardial infarction (NSTEMI) patients may have a completely occluded infarct-related artery, which could have important prognostic implications regardless of ECG findings. AIM To determine the prevalence, predictors, and impact of total occlusion of the infarct-related coronary artery on short-term mortality. METHODS We conducted a prospective, single-center cohort study that included consecutive patients treated for AMI with percutaneous coronary intervention (PCI) at the University Hospital Centre Sestre Milosrdnice in Zagreb, Croatia, between 2011 and 2018. Patients were divided into two groups based on the patency of the infarct-related artery: Those with an occluded coronary artery (OCA) and those with a patent coronary artery (PCA). RESULTS Among the 2483 patients (71.6% male) treated with PCI for AMI, 67.9% had an OCA, while 32.1% had a patent artery (PCA). Notably, 35.5% of NSTEMI patients had an OCA. Patients with OCA were younger, had fewer chronic comorbidities, and presented with more severe clinical symptoms. In contrast, patients with PCA were older and exhibited more extensive chronic atherosclerotic disease. Thirty-day mortality was significantly higher in the OCA group (7.29%) compared to the PCA group (3.52%, P < 0.001). OCA was identified as an independent predictor of mortality [hazard ratio (HR) = 3.0367, 95% confidence interval (CI): 1.4543-6.3411]. Other independent predictors included age (HR = 1.0626; 95%CI: 1.0341-1.0919), Global Registry of Acute Coronary Events score (HR = 1.0065; 95%CI: 1.0011-1.0120), and ventricular tachycardia before or during PCI (HR = 3.8458; 95%CI: 1.4600-10.1299). ECG presentation (STEMI vs NSTEMI) was not an independent prognostic factor (HR = 1.0404; 95%CI: 0.5659-1.9128). Chronic statin therapy prior to AMI [odds ratios (OR) = 0.0168, 95%CI: 0.3674-0.9057], older age (OR = 0.0023, 95%CI: 0.9547-0.9900), and lower troponin I values (OR = 1.0000, 95%CI: 1.0000-1.0001) were associated with a lower likelihood of having an OCA. CONCLUSION Culprit-artery occlusion is a strong, independent determinant of short-term mortality. An occlusion-aware perspective refines risk stratification beyond ECG presentation and supports earlier invasive evaluation in NSTEMI patients with clinical/ECG signs of possible occlusion.