BACKGROUND Previous studies have reported controversial results regarding the clinical and angiographic factors involved in the left ventricular aneurysm (LVA) formation after myocardial infarction (MI). OBJECTIVE This study was performed to determine the clinical and angiographic factors that are priori predictors of LVA following anterior myocardial infarction and so to provide a paradigm which may identify patients who were candidates for aneurysm formation. METHODS Of the patients who underwent coronary angiography during the interval between 1995 and 2000 in our clinic, 809 were found to have anterior MI and LVA (aneurysm group) (677 men, 132 women, mean age 53.3+/-11.4 years). The clinical and the angiographic data of these patients were compared with those of 446 patients (399 men, 47 women, mean age 55.2+/-10.5 years) with previous anterior MI and without LVA (control group). RESULTS LVA was found to occur more frequently in females (16.3% in women and 10.4%, in men, P=0.03) and in patients without previous angina (23.5 vs. 8.2%, P<0.0001). Major cardiovascular risk factors, previous anti-anginal medication and thrombolytic therapy did not show a significant difference between the two groups. Angiographic examination revealed that single-vessel disease, proximal left anterior descending artery (LAD) stenosis, total LAD occlusion, mean stenosis in LAD artery, end-diastolic pressure and left ventricular score were all higher in the aneurysm group compared to control group. After adjustment for other clinical and angiographic variables, single-vessel disease [odds ratio (OR) 5.89, 95% confidence interval (CI)=3.68-9.28, P<0.0001), absence of previous angina (OR=4.21, 95% CI=2.1-7.48, P=0.0003), total LAD occlusion (OR=2.63, 95% CI=1.97-3.53, P<0.0017) and female gender (OR=1.60, 95% CI=1.20-2.28, P=0.043) remained the independent determinants of LVA formation after anterior MI. CONCLUSIONS In patients with LVA, logistic regression analysis revealed that (1) single-vessel disease, (2) absence of previous angina, (3) total LAD occlusion and (4) female gender were independent determinants in the formation of LVA after anterior MI. Coronary collateral status and risk factors, such as hypertension, diabetes mellitus, hypercholesterolemia, smoking and family history of CAD were not found to be important determinants in the aneurysm formation.