The Effects of Quinapril on Vascular ACE and Determinants of Ischemia - QUO VADIS

Description:

Quinapril for ischemic events after CABG.

Hypothesis:

To test the clinical efficacy of ACE inhibitors on frequency of myocardial ischemia and ischemic events post-coronary artery bypass graft (CABG) surgery.

Study Design

Study Design:

Patients Screened: 150
Patients Enrolled: 149
Mean Follow Up: 1 year

Patient Populations:

Scheduled for elective CABG
Exercise-induced ischemia

Exclusions:

Prior use of ACE inhibitors or diuretics
LV dysfunction

Primary Endpoints:

Change in total exercise time during symptom-limited exercise test.

Secondary Endpoints:

Change in time to exercise-induced ischemia, presence of exercise-induced ischemia 1-year post-CABG surgery, ischemic episodes detected on 48-hour Holter monitoring, and ischemic events (recurrence of angina pectoris, MI, ischemic stroke, or transient ischemic attack), revascularization.

Drug/Procedures Used:

Quinapril (40 mg/day) or placebo, beginning 4 weeks before CABG surgery.

Principal Findings:

Seventy-five patients received quinapril and 73 patients received a placebo for 1 year following CABG surgery. (An additional patient was not included in the analysis since the patient did not undergo CABG surgery.) The groups were well-matched at baseline.

Total exercise time, as well as time to exercise-induced ischemia, both increased during symptom-limited exercise testing in the quinapril group, but this difference was not statistically significant.

On an intention-to-treat basis, there was no difference in the incidence of ischemic episodes detected during Holter monitoring at 1 year. However, among those patients who remained on assigned therapy throughout the trial, more placebo patients showed 1 or more ischemic episodes during Holter monitoring (20% vs. 13%), but this did not reach statistical significance.

There was a significant reduction in ischemic events among the quinapril group at 1-year follow up (3 events vs. 11 events, p=0.002).

Interpretation:

There is good evidence angiotensin-converting enzyme (ACE) inhibition decreases ischemic events post-myocardial infarction (MI) and improves endothelial function. However, the precise antianginal effects of this class of compounds remains to be determined, and are often confounded by concomitant anti-anginal therapy.

References:

1. Circulation 1998;98(Suppl I):I-636

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Cardiac Surgery and Arrhythmias

Keywords: Isoquinolines, Myocardial Infarction, Follow-Up Studies, Intention to Treat Analysis, Tetrahydroisoquinolines, Electrocardiography, Ambulatory, Coronary Artery Bypass


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