Characteristics and in-hospital outcomes of female patients presenting with ST-segment-elevation myocardial infarction without standard modifiable cardiovascular risk factors

Background

Standard Modifiable Cardiovascular Risk Factors (SMuRF) such as hypertension, diabetes mellitus, hyperlipidemia, and smoking have long been established in the etiology of atherosclerotic disease. We evaluate in-hospital outcomes of female STEMI patients without these risk factors.

Methods

The National Inpatient Sample databases (2016 to 2021) were queried to identify STEMI admissions as a principal diagnosis using ICD 10 codes. Patients with a history of coronary artery disease, myocardial infarction, coronary bypass graft, percutaneous coronary intervention, takotsubo cardiomyopathy, cocaine abuse, and spontaneous coronary dissection and males were excluded from our study population. A final study population aged >18 years was divided into cohorts of SMuRF and SMuRF-less based on the presence of ≥1 risk factor. Multivariate logistic regression model adjusting for baseline characteristics and comorbidities. The primary outcome was in-hospital mortality. The secondary outcomes are STEMI-related complications and the use of mechanical circulatory support devices.

Results

200,980 patients were identified. 187,776 (93.4 %) patients were identified as having ≥1 SMuRF, and 13,205 (6.6 %) patients were SMuRF-less. Compared to SMuRF patients, SMuRF-less patients are more likely to be white (75.6 % vs. 73.1 %, p < 0.01) and older median age (69 years [IQR: 58–78] vs 67 years [IQR: 57–81], p < 0.01). In comparing co-morbidities, SMuRF-less patients were less likely to have heart failure (28.0 % vs. 23.4 %, p < 0.01), atrial fibrillation/flutter (16.1 % vs. 14.6 %, p = 0.03), chronic pulmonary disease (18.9 % vs. 9.5 %, p < 0.01), obesity (20.7 % vs. 9.2 %, p < 0.01) and aortic disease (1.1 % vs. 0.6 %, p < 0.01). They were however more likely to have dementia (6.9 % vs. 5.7 %, p < 0.01). In evaluating outcomes, SMuRF-less patients had higher in-hospital mortality (aOR 3.2 [95 % CI, 2.9–3.6]; p < 0.01), acute heart failure (aOR 1.6 [95 % CI, 1.4–1.8]; p < 0.01), acute kidney injury (aOR 1.8 [95 % CI, 1.7–2.1]; p < 0.01), and Intra-aortic balloon pump (aOR 1.7 [95 % CI, 1.5–1.9]; p < 0.01). Predictors of higher mortality in SMuRF-less patients include chronic liver disease (OR 6.8, CI 2.4–19.4, p < 0.01), and Hispanic race (OR 1.62, CI 1.1–2.5, p < 0.01). We also found that SMuRF-less patients were less likely to undergo coronary angiography (aOR 0.5 [95 % CI, 0.4–0.5]; p < 0.01) and percutaneous coronary intervention (aOR 0.7 [95 % CI, 0.6–0.8]; p < 0.01).

Conclusion

Female SMuRF-less patients presenting with STEMI have worse in-hospital outcomes when compared to patients with ≥1SMuRF.