Outcomes of ST Segment Elevation Myocardial Infarction without Standard Modifiable Cardiovascular Risk Factors – Newer Insights from a Prospective Registry in India

Objectives: Patients with ST elevation myocardial infarction (STEMI) without standard modifiable cardiovascular risk factors (SMuRFs; dyslipidaemia, hypertension, diabetes mellitus and smoking) are reported to have a worse clinical outcome compared to those with SMuRFs. However, robust prospective data and low-and middle-income country perspective are lacking. We aimed to study the patients with first STEMI and assess the influence of SMuRFs on clinical outcomes by comparing the patients with and without SMuRFs. Methods: We included all consecutive STEMI patients without prior coronary artery disease enrolled in the Madras Medical College STEMI Registry from September 2018 to October 2019. We collected baseline clinical characteristics, revascularisation strategies and clinical outcome. We analysed suboptimal self-reported sleep duration as a 5th extended SMuRF (eSMuRF). Primary outcome was in-hospital mortality. Secondary outcomes included in-hospital complications and one-year all-cause mortality. Results: Among 2,379 patients, 605 patients (25.4%) were SMuRF-less. More women were SMuRF-less than men (27.1% vs 22.1%; P = 0.012). SMuRF-less patients were older (57.44 ± 13.95 vs 55.68 ± 11.74; P < 0.001), more often former tobacco users (10.4% vs 5.0%; P < 0.001), with more anterior wall MI (62.6% vs 52.1%; P = 0.032). The primary outcome [in-hospital mortality (10.7% vs 11.3%; P = 0.72)] and secondary outcomes [in-hospital complications (29.1% vs 31.7%; P = 0.23) and one-year all-cause mortality (22.3% vs 22.7%; P = 0.85)] were similar in both groups. Addition of suboptimal self-reported sleep duration as a 5th eSMuRF yielded similar results. Conclusions: 25% of first STEMI patients were SMuRF-less. Clinical outcomes of patients without SMuRFs were similar to those with SMuRFs. Suboptimal sleep duration did not account for the risk associated with the SMuRF-less status.