Improvement of myocardial performance (Tei) index closely reflects intrinsic improvement of cardiac function: assessment in revascularized hibernating myocardium.

Background: Myocardial performance index (MPI), or Tei index, is an indicator of systolic and diastolic myocardial function. MPI increases in case of cardiac dysfunction; however, whether reversal of left ventricular dysfunction is also reflected by concomitant improvement (i.e., decrease) of MPI is unknown.

Methods: Fifty-two patients with chronic ischemic cardiomyopathy and viable myocardium by dobutamine stress echocardiography were studied by echocardiography before and more than 4 months after cardiac revascularization. Patients were in optimal medical therapy, which remained unchanged following revascularization.

Results: At baseline, ejection fraction (EF: 32 ± 6%) and wall motion score index (WMSI: 2.37 ± 0.32) were impaired, and MPI averaged 0.71 ± 0.19. Revascularization markedly improved EF (44 ± 10%, P < 0.0001) and WMSI (1.77 ± 0.44, P < 0.0001). MPI also improved (0.59 ± 0.26, P < 0.0001), and its decrease was significantly correlated with the improvement in EF (r =-0.68, P < 0.0001) and to the extent of viable myocardium (r =-0.45, P = 0.0007). Responders to revascularization (≥5% increase in EF at follow-up, n = 40% and 77%) achieved a significant improvement in MPI at follow-up in contrast with nonresponders (-23 ± 25% vs. 0.02 ± 0.18%, P = 0.001). Improvement in MPI was largely driven by a significant reduction in isovolumic contraction time (P < 0.001) with consequent prolongation of the ejection phase.

Conclusion: In patients with chronic ischemic cardiomyopathy, MPI improves along with recovery of function, reflecting the intrinsic improvement of viable segments induced by revascularization.