Abstract
Background. There is reason to believe that unfavourable outcomes of non-ST-elevation acute coronary syndrome (NSTE-ACS) is due to the «risk-treatment» paradox (RTP). However, the true prevalence, types and causes of RTP have not been studied, and data from previous studies have shown an equivocal effect of RTP on outcomes of NSTE-ACS. Methods. The retrospective analysis included 600 patients with an initial diagnosis of NSTE-ACS. All patients were re-stratified into four groups according to their risk of adverse ischaemic events on admission to hospital. RTP was defined as situations where the risk did not match the recommended timing of invasive treatment strategy. Results. RTP identified in 321 cases (53.5%), was most characteristic of the intermediate risk (74%), and was least common in high-risk patients (28.5%). In a generalised comparison across all risk categories, no effect of RTP was found on hospital outcomes, length of hospital stay and incidence of adverse cardiovascular events during hospital follow-up. After adjusting for RTP in each risk group, only the high-risk group showed increase in adverse outcomes in the presence of RTP (5.4% mortality vs. 2.9% (OR 1. 9 (95% CI 0.5–8.9), p = 0.037) and a negative effect of RTP on the risk of recurrent myocardial ischaemia (RMI) after 24 hours (7.1% vs. 0.7%, OR 10.7 (95% CI 1.2–97.9), p = 0.01). Conclusions. RTP in relation to the timing of invasive treatment is common in patients with NSTE-ACS (53.5%). For high-risk patients, RTP worsened in-hospital outcome and influenced the risk of RMI after 24 hours. Clinical Trial Number This research is a retrospective observational study, which does not require mandatory registration as defined by the ICMJE.