Dipyridamole in heart failure due to dilated cardiomyopathy: A pilot study

Abstract

Introduction: Dipyridamole (DIP) might be beneficial in heart failure (HF). It
has been reported to improve symptoms in observational, small‑scale studies. The
PRoFESS study for secondary prevention of stroke observed a reduction in the risk
of HF with acetylsalicylic acid (ASA) plus DIP in comparison with clopidogrel. The
present pilot study was aimed at assessing the clinical effects of DIP and ASA in dilated
cardiomyopathy. Materials and Methods: Nineteen outpatients with nonischemic
HF, New York Heart Association (NYHA) Class II, ejection fraction (EF) <40%,
were randomized to ASA 25 mg, or ASA 25 mg plus DIP 200 mg (ASA + DIP),
twice daily. They were evaluated at baseline and after 6 months for symptoms, EF, and
exercise capacity through 6‑min walk test. Results: Eleven subjects were in the ASA
group and 8 in the ASA + DIP. Dyspnea improved, without differences between the
two arms: n = 6/5/0/0 for NYHA I/II/III/IV in ASA, n = 4/3/1/0 in ASA + DIP. EF
increased in both groups (ASA: from 34 [28–35%] to 40 [32–46%]; ASA + DIP from
32.5 [25.75–34%] to 36 [31.5–46%]). No change in meters walked or points in the
Borg scale was observed. In a similar population, an adequately powered study would
need to recruit 38 subjects. Conclusion: The study, although underpowered, did not
show any difference between the two treatment strategies. While this appears in contrast
with previous studies, the strict inclusion criteria, the randomized, double‑blind design,
and the clinical end‑points give strength to our findings. A properly sized trial would
be within the capabilities of a single center.