Prognostic significance of contractile reserve assessed by dobutamine-induced changes of Tei index in patients with idiopathic dilated cardiomyopathy.

Aims: To determine prognostic significance of global left ventricular (LV) contractile reserve, defined by dobutamine-induced changes of Tei index (Delta Tei), in patients with dilated cardiomyopathy (DCM).
Methods and Results: Thirty-eight patients with idiopathic DCM underwent high-dose (up to 40 microg/kg/min) dobutamine stress echocardiography. Prognostic value of different indices of LV contractile reserve, including Delta Tei, as well as changes of ejection fraction (Delta EF) and wall motion score index (Delta WMSi), was analysed. Patients were followed up for 5 years for cardiac mortality. Patients with preserved contractile reserve, defined by Delta Tei > -0.35, had significantly lower cardiac mortality when compared with those without it (38 vs. 77%, P = 0.02). Also, the Kaplan-Meier survival analysis revealed that patients with contractile reserve had better 5-year survival when compared with those without contractile reserve (log-rank = 6.01, P = 0.014). However, of all examined indices of contractile reserve, Cox's regression analysis identified Delta WMSi as the only independent predictor of 5-year mortality.
Conclusion: Our data indicate that the presence of contractile reserve assessed by Delta Tei may identify patients with favourable long-term prognosis. Prognostic value of Delta Tei appears to be similar to Delta EF, but less powerful than Delta WMSi.