PROGNOSTIC VALUE OF NONINVASIVELY OBTAINED LEFT-VENTRICULAR CONTRACTILE RESERVE IN PATIENTS WITH SEVERE HEART-FAILURE

Objectives. The present study sought to evaluate the prognostic value of contractile reserve measured noninvasively during dobutamine infusi on in patients with severe heart failure. Background. In patients with severe heart failure there is a great need for objective criteria to define candidates for heart transplantation or intensive medical treat ment, Cardiac pumping performance reserve has been shown to have excel lent prognostic value in patients with cardiogenic shock. Methods. Car diac peak power, an afterload-independent contractility index, was mea sured noninvasively at rest and at peak dobutamine inotropic stimulati on, Contractile reserve was defined as the difference between maximal cardiac power at peak dobutamine dose and baseline value, Maximal card iac power was calculated from the maximal product of validated central arterial pressure and aortic flow. Results. Results were obtained fro m 52 subjects (42 patients, 10 control subjects), Twenty-two patients were in New York Heart Association functional classes III and IV, Of n ine patients with a contractile reserve <1.5 W/ml, eight died during t he 3 year follow-up period. In contrast, all survivors had a contracti le reserve >1.5 W/ml. Using multiple logistic regression analysis, con tractile reserve was shown to be the only predictor of survival. Concl usions. Contractile reserve measured noninvasively during dobutamine i nfusion is a valuable prognostic indicator in patients with severe hea rt failure, with added value to ejection fraction. (C) 1997 of the Ame rican College of Cardiology.