Long-term benefit of dobutamine in patients with congestive cardiomyopathy

Dobutamine was given intravenously for three days to 38 patients with congestive cardiomyopathy. The patients were followed by serial determinations of functional class and by non-invasive measurements of left ventricular function-systolic time intervals ($\text{PEP}\text{LVET}$) and echocardiogram (%ΔD). The average functional class (FC) of this group was 3.8 prior to dobutamine, but two days after completion, the average FC was 2.7, by four weeks the average FC was 3.1, and by 10 weeks it was 3.4.The average $\text{PEP}\text{LVET}$ declined significantly (p < 0.001) at three days, four and nine weeks, and at 10 months after the discontinuation of dobutamine infusion. Also, 67% (20 of 30) of patients had improvement of the $\text{PEP}\text{LVET}$ by greater than ?0.04 at seven days. Even two and six months after dobutamine, 58% (15 of 26) and 39% (seven of 18) were improved. Similarly, the %ΔD was improved by at least 2% in 60% (18 of 30) at seven days and 55% (16 of 29) at four weeks. At two and six months, 50% (14 of 28) and 42% (10 of 24) were improved. Those patients who did not improve their FC were more likely (five of nine) to have left ventricular free wall thickness (by echocardiogram) less than 0.5 cm./M². Those who responded usually (22 of 29) had a ventricular wall thickness greater than 0.5 cm./M². Although the mechanism of the prolonged improvement after a three day infusion of dobutamine is not understood, this study suggests that dobutamine has a role in the therapy of chronic congestive heart failure.