Mortality and Cardiovascular Outcomes in Patients Presenting With Non-ST Elevation Myocardial Infarction Despite No Standard Modifiable Risk Factors: Results From the SWEDEHEART Registry.

Abstract

BACKGROUND: A significant proportion of patients with ST-segment– elevation myocardial infarction (MI) have no standard modifiable cardiovascular risk factors (SMuRFs) and have unexpected worse 30-day outcomes compared with those with SMuRFs. The aim of this article is to examine outcomes of patients with non–ST- segment– elevation MI in the absence of SMuRFs. METHODS AND RESULTS: Presenting features, management, and outcomes of patients with non–ST- segment– elevation MI without SmuRFs (hypertension, diabetes, hypercholesterolemia, smoking) were compared with those with SmuRFs in the Swedish MI registry SWEDEHEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies; 2005–2018). Cox proportional hazard models were used. Out of 99 718 patients with non–ST- segment– elevation MI, 11 131 (11.2%) had no SMuRFs. Patients without SMuRFs had higher all-cause and cardiovascular mortality at 30 days (hazard ratio [HR], 1.20 [95% CI, 1.10–1.30], P<0.0001; and HR, 1.25 [95% CI, 1.13–1.38]), a difference that remained after adjustment for age and sex. SMuRF-less patients were less likely to receive secondary prevention statins (76% versus 82%); angiotensin-converting enzyme inhibitors/angiotensin receptor blockade (54% versus 72%); or β-blockers (81% versus 87%, P for all <0.0001), with lowest rates observed in women without SMuRFs. In patients who survived to 30 days, rates of all-cause and cardiovascular death were lower in patients without SMuRFs compared with those with risk factors, over 12 years. CONCLUSIONS: One in 10 patients presenting with non–ST- segment– elevation MI present without traditional risk factors. The excess 30-day mortality rate in this group emphasizes the need for both improved population-based strategies for prevention of MI, as well as the need for equitable evidence-based treatment at the time of an MI.