Effects of long-term treatment with verapamil on left ventricular functionand myocardial blood flow in patients with dilated cardiomyopathy without overt heart failure

Myocardial blood flow (MBF) abnormalities are present in early stage dilate d cardiomyopathy (DCM) and have been attributed to coronary microvascular a bnormalities. The favorable effects of verapamil on coronary microcirculati on might indicate its use in early stage DCM. We assessed the safety of lon g-term combination therapy of verapamil and enalapril and its effects on bo th left ventricular function and myocardial perfusion compared with enalapr il alone in 18 patients with DCM (15 men, 3 women; mean age, 50 +/- 9 years ) without overt heart failure (NYHA class I-II). At baseline and after 6 mo nths of randomized treatment with either enalapril (10-20 mg) (nine patient s, group 1) or enalapril (10-20 mg) and verapamil (120-240 mg) (nine patien ts, group 2), left ventricular function was assessed at rest, during handgr ip, and during bicycle exercise by equilibrium radionuclide angiography. Me an MBF was measured at rest and after dipyridamole by positron emission tom ography (PET) and N-13-ammonia as a flow tracer. At baseline, the two group s had reduced left ventricular ejection fraction at rest, which was further impaired during isometric exercise, but increased at peak bicycle exercise . MBF was similarly reduced in the two groups at rest and during dipyridamo le. During treatment, no adverse events occurred in either group. After 6 m onths there was no significant difference in the main study variables eithe r between the two groups or within each group before and after treatment. L ong-term combination therapy with verapamil and enalapril is safe in patien ts with DCM without overt heart failure. Despite no favorable effect on myo cardial perfusion, combined treatment prevented deterioration of left ventr icular function, similarly to enalapril alone.