Aspirin inhibits the acute arterial and venous vasodilator response to captopril in patients with chronic heart failure.
OBJECTIVE
The potentially beneficial hemodynamic effects of angiotensin-converting enzyme (ACE) inhibitors in heart failure may relate, in part, to their ability to increase the production of vasodilator prostanoids. Low dose aspirin is commonly prescribed in CHF and may attenuate the vasodilator effects of ACE inhibitors. We sought to determine the effects of low dose aspirin on the peripheral hemodynamic effects of captopril in patients with chronic heart failure (CHF).


METHODS
Nine patients with chronic heart failure were randomized in a placebo controlled, cross over study, to 75 mg of aspirin daily or placebo. After 7 days treatment the response to 25 mg of captopril was evaluated over 180 min using venous occlusion plethysmography. Forearm blood flow (FBF) and forearm venous capacitance (FVC) were measured.


RESULTS
Mean arterial pressure and heart rate did not change. After placebo, FBF increased in response to captopril (+18%, 95%CI 24.2, 11.8), a response inhibited by aspirin (-1.4%, 2.9, -5.7), p < 0.005. After placebo, FVC increased in response to captopril (+7.6%, 9.8, 5.4), which was also inhibited by aspirin (+2.0%, 4.6, -0.6), aspirin vs. placebo, p = 0.02).


CONCLUSIONS
In patients with chronic heart failure even low dose aspirin inhibits both the acute arterial and venous dilator responses to captopril. This action of aspirin may reduce the long-term clinical benefits of ACE inhibitors.
MacIntrye
Iain M
IM
Division of Cardiovascular and Medical Sciences, University of Glasgow, UK.
Jhund
Pardeep S
PS
McMurray
John J V
JJ
D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D001241:Aspirin / Q000009:adverse effects; D002216:Captopril / Q000627:therapeutic use*; D018592:Cross-Over Studies; D016861:Cyclooxygenase Inhibitors / Q000009:adverse effects; D004311:Double-Blind Method; D004347:Drug Interactions; D005343:Fibrinolytic Agents / Q000009:adverse effects; D005542:Forearm / Q000098:blood supply; D006333:Heart Failure / Q000188:drug therapy* / Q000503:physiopathology; D006801:Humans; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects; D010991:Plethysmography; D014664:Vasodilation / Q000187:drug effects*; D014680:Veins / Q000187:drug effects / Q000502:physiology
D000806:Angiotensin-Converting Enzyme Inhibitors; D016861:Cyclooxygenase Inhibitors; D005343:Fibrinolytic Agents; D010975:Platelet Aggregation Inhibitors; D002216:Captopril; D001241:Aspirin