Reduction of exercise-induced myocardial ischemia during add-on treatment with the angiotensin-converting enzyme inhibitor enalapril in patients with normal left ventricular function and optimal beta blockade.
OBJECTIVE
We sought to study the effect of angiotensin-converting enzyme inhibition on exercise-induced myocardial ischemia.


BACKGROUND
Although angiotensin-converting enzyme inhibitors have been shown to reduce ischemic events after myocardial infarction, few data are available regarding their direct anti-ischemic effects in patients with coronary artery disease.


METHODS
We studied 43 patients (average age 63 +/- 8 years) with exercise-induced myocardial ischemia (> or =0.1 mV ST depression, despite optimal beta blockade) and normal left ventricular function (ejection fraction >0.50). In a double-blind, placebo-controlled parallel design, patients were treated with angiotensin-converting enzyme inhibitor (enalapril 10 mg twice daily) or placebo. Assessments were made after three weeks (short-term) and 12 weeks (long-term).


RESULTS
At baseline, the groups were well matched for all clinical characteristics. After three weeks, there was a slight but not significant increase in time to 0.1 mV ST depression in both groups (p = NS); rate pressure product (RPP = heart rate x systolic blood pressure) was also unaffected. After 12 weeks, however, time to 0.1 mV ST depression further increased in the enalapril group (5.6 +/- 1.9 min) but was unchanged in the placebo group (4.4 +/- 1.3 min; p < 0.05 between groups). In contrast, RPP was not affected. Concentrations of both atrial and brain natriuretic peptides at peak exercise tended to be lower by enalapril, if compared to placebo (p = NS).


CONCLUSIONS
Angiotensin-converting enzyme inhibition may reduce exercise-induced myocardial ischemia in patients with normal left ventricular function. Further studies are needed to elucidate the mechanisms involved.
van den Heuvel
A F
AF
Department of Cardiology/Thoraxcenter, University Hospital Groningen, The Netherlands.
Dunselman
P H
PH
Kingma
T
T
Verhorst
P
P
Boomsma
F
F
van Gilst
W H
WH
van Veldhuisen
D J
DJ
D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage* / Q000009:adverse effects; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000787:Angina Pectoris / Q000188:drug therapy*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects; D003327:Coronary Disease / Q000188:drug therapy*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D004562:Electrocardiography / Q000187:drug effects; D004656:Enalapril / Q000008:administration & dosage* / Q000009:adverse effects; D005080:Exercise Test / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000187:drug effects
D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D004656:Enalapril