[The effect of carvedilol on coronary flow reserve in patients with dilated cardiomyopathy].

Objective: To investigate the change of coronary flow reserve (CFR) in patients with dilated cardiomyopathy (DCM) with non-invasive transthoracic stress echocardiography before and after administration of carvedilol.

Methods: Seventy-five patients with DCM were included and divided into a group with heart failure (HF), a group without (non HF) and 30 healthy subjects with normal angiography and negative ECG exercise test were served as controls. In addition to traditional treatment, all patients were given enough carvedilol in 6 months. Doppler measurement of distal left anterior descending was recorded at rest and hyperemic state after adenosine infusion and CFR was calculated before and after the treatment.

Results: Compared with the controls, HF group and non HF group had greater left atrial diameter (LAd) and left ventricular diastolic diameter (LVDd) but less left ventricular ejection fraction (LVEF) and E/A than the controls before treatment (P < 0.05). LAd, LVDd and LVEF of the HF group and non HF group improved after treatment and there was significant difference of these indexes between the two groups (P < 0.05). Compared with the controls, HF group and non HF group had lower CFR before treatment (2.35 +/- 0.28 vs 2.57 +/- 0.31 vs 3.20 +/- 0.29, P < 0.05). After treatment with carvedilol, CFR rised in these two groups. Although CFR was still lower in the HF group than that in the control group (2.68 +/- 0.30 vs 3.20 +/- 0.29, P < 0.05), there was no difference between the non HF group and the controls (3.13 +/- 0.36 vs 3.20 +/- 0.29, P > 0.05).

Conclusions: CFR decreased in patients with DCM and patients with heart failure had lower CFR than those without. Carvedilol could not only reverse the ventricular remodeling due to DCM, but also improve CFR in those patients. Detection of CFR with stress echocardiography could evaluate the effect of carvedilol earlier than the index of traditional echocardiography.