Worse outcomes of ACS patients without versus with traditional cardiovascular risk factors

Introduction: Up to 20% of patients presenting with acute coronary syndrome (ACS) have no traditional cardiovascular risk-factors (RFs). Data regarding the determinants, management, and outcomes of these patients are scarce. Objectives: To evaluate the management, outcomes, and time-dependent changes of ACS patients without RFs. Methods: Evaluation of clinical characteristics, management strategies, and outcomes as well as time-dependent changes [by 3 time periods: early (2000-2006), mid (2008-2013), and late (2016-2018)] of ACS patients without RFs (diabetes mellitus, hypertension, dyslipidemia, family history of ischemic heart disease, and smoking) or known coronary artery disease, enrolled in the biennial ACS Israeli Surveys (ACSIS) between 2000 and 2018. We compared ACS patients without RFs (no-RF group) to those with ≥1 RFs (RF group). Results: Overall, 554/9,683 (5.7%) eligible ACS patients did not have any RFs [median age 63 (IQR 52-76) years, 25% females]. The no-RF group were older, with lower body mass index and prevalence of other cardiovascular comorbidity and chronic kidney disease compared with the RF group. The in-hospital percutaneous coronary intervention rates were lower among the no-RF vs. the RF group (55% vs. 66%, respectively p<0.001). Furthermore, lower rate of guideline-recommended medical therapy upon discharge was prescribed in the no-RF group. The rate of in-hospital complications was greater in the no-RF vs. RF group (31.6% vs. 26.1%, respectively p=0.005). The rates of 30-day major adverse cardiovascular events (MACE; 17.6% vs.12.8%, respectively, p=0.002) and of 30-day and 1-year all-cause mortality (8.4% vs. 4.2%, p<0.001 and 11.4% vs. 7.7%, p=0.003 respectively) were higher among patients with no-RF vs. RF. Following propensity score matching 30-day MACE, 30-day and 1-year mortality risk remained higher in the no-RF group. The rate of 30-day MACE decreased between the early and the late study period in the no-RF group (21.5% vs. 10.5%, p=0.003, respectively). Conclusions: ACS patients without traditional cardiovascular risk-factors comprise a unique group with reduced prevalence of comorbidities yet significantly worse outcomes. Additional research to identify unique risk-factors and targets for interventions to improve outcomes of this group of patients is warranted.