Beneficial effects of angiotensin-converting enzyme inhibitors during acute revascularization.
BACKGROUND
This experimental study was undertaken to determine whether using angiotensin-converting enzyme inhibitors during surgical revascularization of acutely ischemic myocardium would improve wall motion and limit infarct size.


METHODS
Twenty pigs underwent 90 minutes of occlusion of the second and third diagonal arteries followed by 45 minutes of cardioplegic arrest and 180 minutes of reperfusion. In 10 animals, the angiotensin-converting enzyme inhibitor enalaprilat (0.05 mg/kg) was infused intravenously during coronary occlusion; 10 other animals received no angiotensin-converting enzyme inhibitors. Ischemic damage was assessed by the number of cardioversions required for ventricular tachycardia or fibrillation; wall motion scores using echocardiography (4=normal to -1=dyskinesia); and infarct size using histochemical staining. Epicardial coronary artery vasomotor function was assessed using standard organ chamber methodology.


RESULTS
Enalaprilat-treated hearts had the least amount of ventricular irritability (0.84+/-0.24 versus 2.77+/-0.22 cardioversions; p < 0.01), the best recovery of wall motion score (3.20+/-0.15 versus 1.52+/-0.07; p < 0.0001), and the lowest infarct size (22.6%+/-1.4% versus 37.7%+/-3.0%; p < 0.001). Endothelium-independent relaxation was preserved in all hearts; however, endothelium-dependent relaxation was impaired in both groups.


CONCLUSIONS
Angiotensin-converting enzyme inhibitors reduce myocardial damage during surgical revascularization of acutely ischemic myocardium.
Lazar
H L
HL
Department of Cardiothoracic Surgery, Boston Medical Center, Boston University School of Medicine, Massachusetts 02118, USA.
Volpe
C
C
Bao
Y
Y
Rivers
S
S
Vita
J A
JA
Keaney
J F
JF
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D000818:Animals; D001794:Blood Pressure; D003331:Coronary Vessels / Q000502:physiology; D004452:Echocardiography; D004554:Electric Countershock; D015773:Enalaprilat / Q000008:administration & dosage / Q000627:therapeutic use*; D006324:Heart Arrest, Induced; D006339:Heart Rate; D007262:Infusions, Intravenous; D009204:Myocardial Revascularization / Q000379:methods*; D013552:Swine; D017180:Tachycardia, Ventricular / Q000628:therapy; D014666:Vasomotor System / Q000502:physiology; D014693:Ventricular Fibrillation / Q000628:therapy
D000806:Angiotensin-Converting Enzyme Inhibitors; D015773:Enalaprilat