ACE Inhibitor Boosts
Coronary Circulation in Diabetics
posted 04/25/2006
Researchers reported that
angiotensin-converting enzyme (ACE) inhibitors can improve coronary flow
velocity reserve (CFVR) in patients with type 2 diabetes.
However, the researchers found that treatment with the angiotensin II type 1
receptor antagonist candesartan did not affect CFVR.
Both types of drugs have shown evidence of benefit in diabetic patients, Dr.
Takayuki Kawata of Chiba University Graduate School of Medicine and colleagues
write. Acute infusion of ACE inhibitors has been shown to increase coronary
perfusion in diabetic patients, they add, but it is not clear whether the two
drugs' effects on coronary circulation in these patients are similar.
To investigate, the researchers randomly assigned 24 patients with type 2
diabetes to 2 mg per day of the ACE inhibitor temocapril or 8 mg per day of
candesartan. CFVR was calculated at the beginning of the study and after four
weeks of treatment. It was also measured in eight healthy controls.
CFVR before treatment was 2.74 for patients in the temocapril group and 2.65
for patients on candesartan. It was 3.53 in the controls. After treatment, CFVR
rose to 3.31 in the temocapril group, but remained the same in the candesartan
group. Both drugs produced a similar reduction in blood pressure.
The findings suggest that temocapril's effects on coronary circulation in
diabetic patients are independent of angiotensin antagonism, Dr. Kawata and his
team note. The drug could improve coronary circulation by increasing bradykinin
availability, the researchers suggest.
Thus they conclude that ACE inhibitors, but not angiotensin II type 1
receptor antagonists "may have beneficial effects on the coronary
microangiopathy associated with type 2 diabetes mellitus."