BACKGROUND

The author recently reported ∼50% excess early mortality in patients with first-presentation ST-segment elevation myocardial infarction (STEMI) without standard modifiable cardiovascular risk factors (SMuRFs); the cause of this is not clear.

OBJECTIVES

The aim of this study was to examine differences in infarct characteristics and clinical outcomes in patients with versus without SMuRFs (dyslipidemia, hypertension, diabetes mellitus, and smoking).

METHODS

Individual-level data were pooled from 10 randomized percutaneous intervention (PCI) trials in which infarct size was measured within 1 month by either cardiac magnetic resonance or technetium-99m sestamibi single-photon emission computed tomography imaging. First-presentation STEMI was classified into 2 groups according to the presence or absence of at least 1 SMuRF.

RESULTS

Among 2,862 patients, 524 (18.3%) were SMuRF-less. After adjusting for study effect, SMuRF-less patients had more frequent poor pre-PCI flow Thrombolysis In Myocardial Infarction 0/1 compared with patients with at least 1 SMuRF (72.0% vs 64.1%; OR: 1.35; 95% CI: 1.08-1.70). There were no independent associations between the presence or absence of SMuRFs at baseline and infarct size (estimate = -0.35; 95% CI: -1.93 to 1.23), left ventricular ejection fraction (estimate = -0.06; 95% CI: -1.33 to 1.20), or mortality at 30 days (HR: 0.46; 95% CI: 0.19-1.07) and 1 year (HR: 0.74; 95% CI: 0.43-1.29).

CONCLUSIONS

First-presentation STEMI patients with no identifiable baseline SMuRFs had a higher risk of Thrombolysis In Myocardial Infarction flow grade 0/1 pre-PCI. However, after adjustment, there were no significant associations between SMuRF-less status and infarct size, left ventricle ejection fraction, or mortality.