Predictors of left ventricular thrombus formation in patients with anterior myocardial infarction: role of activated protein C resistance.

ABSTRACT

BACKGROUND: Left ventricular mural thrombus formation is a well-recognised consequence of acute anterior myocardial infarction. The vast majority of left ventricular thromboses occur in patients with anterior myocardial infarction and depressed left ventricular function. OBJECTIVE: To evaluate the factors predicting left ventricular thrombus formation in patients similar for left ventricular function and left ventricular score indexes. METHODS: We evaluated 45 consecutive patients who met the inclusion criteria of anterior myocardial infarction resulting in apical, anterior or septal asynergy (akinesia, dyskinesia), without non-Q-wave myocardial infarction, dilated cardiomyopathy, or renal or hepatic dysfunction. Patients were divided into two groups group I with, and group II without, left ventricular mural thrombus. The groups were compared for clinical, echocardiographic and hematologic parameters (activated protein C resistance (APC-R), protein S and antithrombin III). RESULTS: Smoking and ACP-R were significantly greater in group I than in group II (P < 0.05 and P < 0.005 respectively). Multivariate regression analysis showed that APC-R was an independent risk factor for left ventricular thrombus formation in the patient group selected. Antithrombin III and protein S concentrations were not statistically different between two groups. All other clinical and echocardiographic characteristics of the patients were similar in both groups. CONCLUSION: APC-R is an independent risk factor for left ventricular thrombosis in patients with anterior myocardial infarction resulting in septal or anterior and apical akinesia or dyskinesia.