Purpose
It is unclear whether left ventricular (LV) contractile reserve assessed by low-dose dobutamine stress echocardiography (DSE) can predict the long-term prognosis together with LV functional changes in patients with idiopathic dilated cardiomyopathy (DCM).
Methods and results
Contractile reserve was determined in 28 patients with DCM, and was then compared with changes in LV fractional shortening (FS) and cardiac events during a follow-up period of 68 ± 43 months. Nine events (2 sudden deaths, 5 heart failure deaths, and 2 rehospitalizations for heart failure) were observed. FS at peak dose was lower in patients with events (events group) than in those without events (no-events group) (20 ± 6 vs. 27 ± 7%; P < 0.05), although there were no differences in FS at baseline between the two groups. FS at follow-up was lower in the events group than in the no-events group (14 ± 7 vs. 21 ± 8%; P < 0.05). The change in FS during DSE (FS at peak dose/baseline) correlated with the change in FS during the follow-up time (FS at follow-up/baseline), and it was a predictor of events by multiple regression analysis.
Conclusions
LV contractile reserve assessed by low-dose DSE is a useful marker not only to predict LV functional improvement, but also to determine the long-term prognosis in patients with DCM.