LAUSR

Background Both unstable angina and non-ST-segment elevation myocardial infarction (NSTEMI) are still classified together in non-ST-elevation acute coronary syndromes despite the fact they substantially differ in both clinical profile and prognosis. The aim of the present study was to evaluate contemporary clinical characteristics and outcomes of unstable angina patients after percutaneous coronary intervention (PCI) in comparison with stable angina and NSTEMI in Swietokrzyskie District of Poland in years 2015–2017. Methods A total of 7187 patients after PCI from ORPKI Registry (38% with diagnosis of unstable angina) were included into the analysis. Impact of clinical presentation (unstable angina, stable angina, NSTEMI, STEMI) on three-year outcomes were determined. Results Unstable angina patients were older than stable angina but younger than NSTEMI individuals. In unstable angina group, the percentage of previous myocardial infarction (MI), PCI or coronary artery bypass grafting (CABG) was the highest among all analyzed groups. In three-year observation, the risk of death as well as MI and MACE in unstable angina after PCI was higher than stable angina angina but considerably lower than in the NSTEMI group. Multivariate analysis confirmed that prognosis in NSTEMI was substantially worse in comparison with unstable angina [relative risk (RR) 1.365, 95% confidence interval (CI): 1.126–1.655, P = 0.0015]. On the contrary in unstable angina and stable angina patients, the impact of diagnosis on mortality risk was similar (RR 1.189, 95% CI: 0.932–1.518, P = 0.1620). Parallel results were observed in respect of MI and MACE. Independent predictors of death or MACE were: age, kidney disease, hypertension, diabetes, previous stroke or previous PCI. Conclusion Three-year prognosis in unstable angina was considerable better in comparison with NSTEMI. On the contrary, after adjustment for baseline differences, the outcomes (death, MI, MACE) in unstable angina and stable angina patients were comparable.