Author + information
- Received December 12, 1994
- Accepted April 24, 1995
- Published online September 1, 1995.
- Martial G. Bourassa, MD, FACC1,
- Carl J. Pepine, MD, FACC,
- Sandra A. Forman, MA,
- William J. Rogers, MD, FACC,
- Ihor Dyrda, MD, FACC,
- Peter H. Stone, MD, FACC,
- Bernard R. Chaitman, MD, FACC,
- Barry Sharaf, MD, FACC,
- John Mahmarian, MD, FACC,
- Richard F. Davies, MD, FACC,
- Genell L. Knatterud, PhD,
- Michael Terrin, MD,
- George Sopko, MD,
- C. Richard Conti, MD, FACC and
- ACIP Investigators1
Objectives The Asymptomatic Cardiac Ischemia Pilot (ACIP) study showed that revascularization is more effective than medical therapy in suppressing cardiac ischemia at 12 weeks. This report compares the relative efficacy of coronary angioplasty or coronary artery bypass graft surgery in suppressing ambulatory electrocardiographic (ECG) and treadmill exercise cardiac ischemia between 2 and 3 months after revascularization in the ACIP study.
Background Previous studies have shown that coronary angioplasty and bypass surgery relieve angina early after the procedure in a high proportion of selected patients. However, alleviation of ischemia on the ambulatory ECG and treadmill exercise test have not been adequately studied prospectively after revascularization.
Methods In patients randomly assigned to revascularization in the ACIP study, the choice of coronary angioplasty or bypass surgery was made by the clinical unit staff and the patient.
Results Patients assigned to bypass surgery (n = 78) had more severe coronary disease (p = 0.001) and more ischemic episodes (p = 0.01) at baseline than those assigned to angioplasty (n = 92). Ambulatory ECG ischemia was no longer present 8 weeks after revascularization (12 weeks after enrollment) in 70% of the bypass surgery group versus 46% of the angioplasty group (p = 0.002). ST segment depression on the exercise ECG was no longer present in 46% of the bypass surgery group versus 23% of the angioplasty group (p = 0.005). Total exercise time in minutes on the treadmill exercise test increased by 2.4 min after bypass surgery and by 1.4 min after angioplasty (p = 0.02). Only 10% of the bypass surgery group versus 32% of the angioplasty group still reported angina in the 4 weeks before the 12-week visit (p = 0.001).
Conclusions Angina and ambulatory ECG ischemia are relieved in a high proportion of patients early after revascularization. However, ischemia can still be induced on the treadmill exercise test, albeit at higher levels of exercise, in many patients. Bypass surgery was superior to coronary angioplasty in suppressing cardiac ischemia despite the finding that patients who underwent bypass surgery had more severe coronary artery disease.
This study was funded by research contracts HV-90-07, HV-90-08, HV-91-05 to HV-91-14 from the National Heart, Lung, and Blood Institute, Cardiac Diseases Branch, Division of Heart and Vascular Diseases, National Institutes of Health, Bethesda, Maryland. Study medications and placebo were donated by Zeneca Pharma Inc., Wilmington, Delaware; Marion-Merrell Dow, Kansas City, Missouri; and Pfizer, New York, New York. Support for electrocardiographic data collection was provided in part by Applied Cardiac Systems, Laguna Hills, California; Marquette Electronics, Milwaukee, Wisconsin; and Quinton Instruments, Seattle, Washington. A list of participating centers and investigators appears in reference 32.
* See Correction on page 842.
- Received December 12, 1994.
- Accepted April 24, 1995.
- American College of Cardiology