Differences in treatment and outcomes among patients with ST-segment elevation myocardial infarction with and without standard modifiable risk factors: a systematic review and meta-analysis

Background:There are limited data available on outcomes and pathophysiology behind ST-segment elevation myocardial infarction (STEMI) in populations without standard modifiable risk factors (SMuRFs). The authors carried out this meta-analysis to understand the differences in treatment and outcomes of STEMI patients with and without SMuRFs. Methods:A systematic database search was performed for relevant studies. Studies reporting desired outcomes among STEMI patients with and without SMuRFs were selected based on predefined criteria in the study protocol (PROSPERO: CRD42022341389). Two reviewers independently screened titles and abstracts using Covidence. Full texts of the selected studies were independently reviewed to confirm eligibility. Data were extracted from all eligible studies via a full-text review of the primary article for qualitative and quantitative analysis. In-hospital mortality following the first episode of STEMI was the primary outcome, with major adverse cardiovascular events (MACE), repeat myocardial infarction (MI), cardiogenic shock, heart failure, and stroke as secondary outcomes of interest. Odds ratio (OR) with a 95% CI was used to estimate the effect. Results:A total of 2135 studies were identified from database search, six studies with 521 150 patients with the first STEMI episode were included in the analysis. The authors found higher in-hospital mortality (OR: 1.43; CI: 1.40-1.47) and cardiogenic shock (OR: 1.59; 95% CI: 1.55-1.63) in the SMuRF-less group with no differences in MACE, recurrent MI, major bleeding, heart failure, and stroke. There were lower prescriptions of statin (OR: 0.62; CI: 0.42-0.91) and Angiotensin converting enzyme inhibitor /Angiotensin II receptor blocker (OR: 0.49; CI: 0.28-0.87) at discharge in SMuRF-less patients. There was no difference in procedures like coronary artery bypass graft, percutaneous coronary intervention, and thrombolysis. Conclusion:In the SMuRF-less STEMI patients, higher in-hospital mortality and treatment discrepancies were noted at discharge.