Pulsed wave tissue Doppler-derived myocardial performance index for the assessment of left ventricular thrombus formation risk after acute myocardial infarction

Background

Assessment of left ventricular (LV) thrombosis risk after acute myocardial infarction (AMI) is important because of potential embolic sequelae that are reduced by oral anticoagulant agents. The goal of this study was to investigate whether early assessment of LV systolic and diastolic performance with pulsed wave tissue Doppler ultrasound scanning (PWTD) predicts LV thrombosis after AMI.

Methods

Two-dimensional and Doppler ultrasound scanning echocardiographic examinations were performed in 92 consecutive patients (age, 58 ± 10 years; 11 women) with first anterior AMI within 24 hours after arrival to the coronary care unit. From the apical 4-chamber view, the mitral annular velocities were recorded at the lateral corner of the mitral annulus with PWTD. The myocardial performance index (MPI), which combines parameters of both systolic and diastolic ventricular function, was calculated from the PWTD recordings. To analyze LV thrombus formation, the 2-dimensional echocardiographic examination was repeated on days 3, 7, 15, and 30. The patients were divided in 2 groups according to LV thrombus formation.

Results

LV thrombus was found in 32 of 92 patients (35%; group 1) and was not found in 60 patients (65%; group 2). The MPI was significantly higher in group 1 than in group 2 (0.73 ± 0.20 vs 0.53 ± 0.14; P <.001). When an MPI >0.6 was used as the cutoff, LV thrombus formation could be predicted with a sensitivity rate of 81%, a specificity rate of 73%, a positive predictive value of 62%, and a negative predictive value of 88%. In multivariate analyses, only MPI and LV wall motion score index were independent predictors of LV thrombus formation (P = .038 and P = .047, respectively).

Conclusions

The MPI derived with PWTD soon after admission appears to be a useful parameter for assessing the risk of LV thrombosis after AMI. Patients with an MPI >0.6 after AMI seem to be at a higher risk for thrombus formation.