Clinical characteristics, aetiological factors and long-term prognosis of myocardial infarction with an absolutely...

Area of Science:

• Cardiology
• Internal Medicine
• Clinical Research

Background:

• Limited data exist on the outcomes and etiological factors for patients experiencing myocardial infarction (MI) with angiographically normal coronary arteries.
• Understanding these factors is crucial for accurate diagnosis and prognosis.

Purpose of the Study:

• To evaluate the clinical outcomes of patients with acute myocardial infarction (MI) and normal epicardial coronary arteries.
• To analyze the etiological and prognostic factors in this specific patient population.

Main Methods:

• A cohort of 91 patients with normal coronary arteries (NC) post-MI was prospectively evaluated and compared to 91 patients with coronary artery stenosis (SC).
• Systematic search for etiological factors was performed, and patients were matched for age, sex, and MI onset.
• Follow-up was conducted for a mean of 35 months to assess clinical events.

Main Results:

• While traditional coronary heart disease risk factors were less prevalent in NC patients, specific causes like coronary spasm (15.5%) and coagulation disorders (12.8%) were identified.
• Left ventricular ejection fraction was higher in NC patients (60% vs. 55%).
• Event-free survival was significantly better in NC patients (75% vs. 50%, P<0.0001), with similar survival rates between groups.

Conclusions:

• Etiological factors for MI in normal coronary arteries are found in only about one-third of cases, with coronary spasm and coagulation disorders being prominent.
• Patients with normal coronary arteries experience lower morbidity but similar mortality compared to those with coronary artery stenosis.
• Left ventricular function and diabetes mellitus are independent predictors of poor long-term outcomes in MI patients with normal coronary arteries.