Long-Term Oral Administration of Dipyridamole Improves Both Cardiac and Physical Status in Patients with Mild to Moderate Chronic Heart Failure: A Prospective Open-Randomized Study

Adenosine is known as an endogenous cardioprotectant. We previously reported that plasma adenosine levels increase in patients with chronic heart failure (CHF), and that a treatment that further elevates plasma adenosine levels may improve the pathophysiology of CHF. Therefore, we performed a prospective, open-randomized clinical trial to determine whether or not exposure to dipyridamole for 1 year improves CHF pathophysiology compared with conventional treatments. The study enrolled 28 patients (mean+/-SEM: 66+/-4 years of age) attending specialized CHF outpatient clinics with New York Heart Association (NYHA) class II or III, no major complications, and stable CHF status during the most recent 6 months under fixed medications. They were randomized into three groups with or without dipyridamole (Control: n=9; 75 mg/day: n=9; 300 mg/day: n=10) in addition to their original medications and were followed up for 1 year. The other drugs were not altered. Among the enrolled patients, 100%, 4%, 100%, and 79% received angiotensin-converting enzyme inhibitors, aldosterone analogue, loop diuretics, and beta-adrenoceptor blocker, respectively. Fifteen patients suffered from dilated cardiomyopathy, and 7/3/3 patients suffered from ischemic/valvular/hypertensive heart diseases, respectively. Mean blood pressure was comparable among the groups. While the baseline conditions were comparable, we found that echocardiographic ejection fraction (p<0.01 vs. baseline, p<0.01 vs. Control), left ventricular systolic diameter (p<0.05, p<0.05), Specific Activity Scale (SAS) score (p<0.05, p<0.01), maximal oxygen consumption (p<0.05, p<0.05) and plasma B-type natriuretic peptide level (p<0.01, p<0.01) were significantly improved in patients with dipyridamole after 1 year, generally in a dose-dependent manner. Therefore, we suggest that an additional administration of dipyridamole further improves CHF pathophysiology.