Changes in the Doppler myocardial performance index during dobutamine echocardiography: association with neurohormonal activation and prognosis after acute myocardial infarction.

OBJECTIVES

To test whether an increase in Doppler myocardial performance index (MPI) during dobutamine stress echocardiography, reflecting deterioration of overall left ventricular function, is associated with increased N-terminal pro-brain natriuretic peptide (NT-pro-BNP) concentration and provides prognostic information beyond conventional systolic wall motion analysis after acute myocardial infarction (AMI).

DESIGN

Prospective, observational study.

METHODS

Dobutamine-atropine stress echocardiography (DASE) and NT-pro-BNP were assessed five days after AMI in 109 consecutive patients. MPI was measured at rest and at low-dose (10 microg/kg/min) and peak dobutamine infusion (<or= 40 microg/kg/min with or without atropine).

MAIN OUTCOME MEASURES

End point was a composite of cardiac death or readmission for heart failure or reinfarction.

RESULTS

In 35 patients (32%), MPI increased at low-dose DASE. This was associated with higher NT-pro-BNP concentrations (beta = 0.30, p = 0.004). During a mean follow up of 27 (SD 7) months, 8 patients died of cardiac causes and 15 patients were readmitted for heart failure or reinfarction. On Cox regression analysis, an increase in MPI at low-dose DASE (p = 0.02) was an independent predictor of cardiac events. In contrast, traditional wall motion analysis during DASE provided no additional prognostic information.

CONCLUSIONS

An increase in MPI at low-dose DASE, reflecting early deterioration of overall left ventricular function, is associated with raised NT-pro-BNP concentration and provides prognostic information beyond conventional stress echocardiographic data after AMI.