Dobutamine-induced augmentation of left ventricular ejection fraction predicts survival of heart failure patients with severe non-ischaemic cardiomyopathy

Aims The prognosis of patients with severe non-ischaemic dilated cardiomyopathy is variable. The predictive value of currently utilized tests is suboptimal. The purpose of this study was to determine the prognostic value of dobutamineinduced augmentation of left ventricular ejection fraction in patients with non-ischaemic dilated cardiomyopathy. Methods and Results Sixty-two patients with left ventricular ejection fraction ≤0·30 underwent exercise testing with gas exchange analysis and assessment of left ventricular ejection fraction at rest and after a 10-min intravenous infusion of dobutamine at 10μg.kg−1min−1, using equilibrium radionuclide ventriculography. Age was 48±11 years, 32% females, functional class 2·6±0·6, resting left ventricular ejection fraction 0·20±0·06, and peak exercise oxygen consumption (mVO2) 19±6ml.kg−1min−1. Mean dobutamine-induced augmentation of left ventricular ejection fraction (ΔLVEF) was 0·09±0·06 (median 0·08, range −0·03 to 0·26). Follow-up was 25±15 months during which there were 12 deaths and five transplantations. Patients were divided into two groups based on median ΔLVEF. The transplant-free survival was better in the group with higher ΔLVEF (94% vs 64%, P <0·008). In multivariate analysis incorporating age, gender, duration of chronic heart failure, functional class, right and left ventricular ejection fraction, ΔLVEF, left ventricular end-diastolic volume index, and mVO2, only ΔLVEF was predictive of 1-year, 3-year, and overall transplant-free survival (RR0·09, 0·03, and 0·13; P 0·03, 0·09, and 0·08 respectively). The linear correlation between ΔLVEF and mVO2(r=0·3) and between ΔLVEF and left ventricular ejection fraction (r=0·5) was weak. Conclusion Dobutamine-induced augmentation of left ventricular ejection fraction is a strong prognostic variable, independent of exercise capacity and resting ventriculographic variables, in severe non-ischaemic systolic dysfunctional heart failure.