Long-term outcomes in acute coronary syndrome patients without standard modifiable risk factors: a multi-ethnic retrospective cohort study Of 5400 asian patients

A sizeable number of patients without standard modifiable cardiovascular risk factors (SMuRFs), such as hypertension, diabetes, hypercholesterolemia and smoking, suffer from acute coronary syndrome (ACS). These SMuRF-less patients have high short-term morbidity and mortality. We compared both short- and long-term outcomes of SMuRF-less and SMuRF ACS patients in a multi-ethnic Asian cohort. This was a retrospective study of patients with first ACS from 2011 to 2017. The primary outcome was long-term all-cause mortality. Secondary outcomes were 30-day all-cause mortality, cardiac-mortality, unplanned cardiac readmission, cardiogenic shock, heart failure, and stroke. Subgroup analysis was carried out by sex and ACS type. Of 5400 patients, 8.6% were SMuRF-less. The median follow-up time was 6.3 years (interquartile range [IQR] 4.2–8.2 years). SMuRF-less patients were younger and tended to present with ST-segment elevation myocardial infarction (STEMI). They were more likely to require inotropic support, intubation, and have cardiac arrest. At 30 days, SMuRF-less patients had higher rates of all-cause mortality, cardiac-related mortality and cardiogenic shock, but lower rates of heart failure. At 6 years, all-cause mortality was similar in both groups (18.0% versus 17.1% respectively, p = 0.631). Kaplan–Meier curves showed increased early mortality in the SMuRF-less group, but the divergence in survival curves was no longer present in the long-term. The absence of SMuRF was an independent predictor of mortality, regardless of sex or ACS type. In a multi-ethnic cohort of patients with ACS, SMuRF-less patients were observed to have higher mortality than SMuRF patients during the early stages which was attenuated over time.