Clinical outcomes of patients undergoing percutaneous coronary intervention for coronary artery disease without standard modifiable cardiovascular risk factors according to clinical presentation

Abstract Background Recent studies have reported that patients with acute coronary syndrome (ACS) in the absence of standard modifiable cardiovascular risk factors (SMuRFs), including diabetes mellitus, dyslipidemia, hypertension, and smoking, exhibit higher mortality than those with risk factors. However, data on clinical outcomes were conflicting across studies and direct comparisons of prognosis between SMuRF-less patients with ACS and chronic coronary syndrome (CCS) are lacking. Purpose We aimed to investigate the impact of clinical presentation (i.e. ACS vs. CCS) on prognosis in SMuRF-less patients undergoing PCI. Methods Between August 2012 and July 2013, consecutive patients undergoing PCI for coronary artery disease were enrolled in the SHINANO registry, a prospective, observational, multicenter study in Japan. The primary outcome of the current study was major adverse cardiovascular events (MACE), defined as a composite of cardiovascular death, nonfatal myocardial infarction, and stroke, at 2 years. Results Among 1638 patients, 694 (42.4%) presented with ACS. Overall, a total of 124 (7.6%) patients had no SMuRFs, with a higher proportion in the ACS group (ACS: 9.2% vs. CCS: 6.4%, P=0.037). The median age of the cohort was 72 years and 23.5% of patients were female. Compared with patients with SMuRFs, SMuRF-less patients were older (74 years IQR 66-80 vs. 71 years 63-79, P = 0.02) and were less likely to receive secondary prevention medications such as statins, renin-angiotensin system inhibitors, and β-blockers at discharge. In the ACS group, SMuRF-less patients had a higher 2-year rate of MACE (18.2% vs. 9.5%, log-rank P=0.046), mainly driven by an increased risk of stroke (13.9% vs. 3.6%, P0.001), while there was no significant difference in MACE in the CCS group (3.4% vs. 5.4%, P=0.536) (Figure). Multivariable Cox analysis demonstrated that the absence of SMuRFs emerged as an independent predictor for MACE at 2 years in the ACS group (HR 2.20, 95% CI 1.14-4.23, P = 0.018), but not in the CCS group (HR 0.71, 95% CI 0.17-2.94, P = 0.636). Conclusions The absence of SMuRFs was associated with an increased risk of cardiovascular event in patients with ACS, which deserves particular attention. Further studies should explore the underlying mechanisms of the worse outcomes in this population.Figure