Clinical Characteristics and Prognosis of Patients With No Standard Modifiable Risk Factors in Acute Myocardial Infarction

Background: Recently, the impact of the lack of standard modifiable risk factors, including hypertension, diabetes, dyslipidaemia, and current smoking, has been investigated in ST-segment elevation myocardial infarction (MI). The present study aimed to evaluate clinical characteristics and prognosis of the patients with no standard risk factors in acute MI.

Methods: This bi-centre registry included 1,093 patients with acute MI undergoing percutaneous coronary intervention. The participants were divided into two groups: patients having at least one of the four standard risk factors and those having none of the risk factors. The study endpoints included major adverse cardiovascular events (MACE) (death, recurrent MI, and stroke) and major bleeding events during hospitalisation. Any MACE and major bleeding events after discharge were also evaluated as an exploratory analysis.

Results: Of 1,093 patients, 64 (5.9%) had none of the four standard risk factors. The patients with no standard risk factors were likely to present with Killip class IV and cardiac arrest. The rate of in-hospital MACE was higher in patients with no risk factors than in their counterparts (25.0% vs 9.9%; p<0.001), whereas the incidence of in-hospital major bleeding was not significantly different between the two groups (9.4% vs 6.7%; p=0.44). Active cancer and autoimmune/inflammatory diseases were often found in patients with no standard risk factors. After discharge, no significant differences were observed in the risks of MACE and major bleeding events between the two groups.

Conclusions: No standard modifiable risk factors were not uncommon and were associated with poor short-term outcomes in patients with acute MI.