Clinical study
Asymptomatic cardiac ischemia pilot (ACIP) study: Outcome at 1 year for patients with asymptomatic cardiac ischemia randomized to medical therapy or revascularization*

https://doi.org/10.1016/0735-1097(95)00228-VGet rights and content
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Objectives

This report discusses the outcome at 1 year in patients in the Asymptomatic Cardiac Ischemia Pilot (ACIP) study.

Background

Comparative efficacy of medical therapy versus revascularization in treatment of asymptomatic ischemia is unknown. The ACIP study assessed the ability of three treatment strategies to suppress ambulatory electrocardiographic (ECG) ischemia to determine whether a large-scale trial studying the impact of these strategies on clinical outcomes was feasible.

Methods

Five hundred fifty-eight patients with coronary anatomy amenable to revascularization, at least one episode of asymptomatic ischemia on the 48-h ambulatory ECG and ischemia on treadmill exercise testing were randomized to one of three treatment strategies: 1) medication to suppress angina (angina-guided strategy, n = 183); 2) medication to suppress both angina and ambulatory ECG ischemia (ischemia-guided strategy, n = 183); or 3) revascularization strategy (angioplasty or bypass surgery, n = 192). Medication was titrated atenolol-nifedipine or diltiazemisosorbide dinitrate.

Results

The revascularization group received less medication and had less ischemia on serial ambulatory ECG recordings and exercise testing than those assigned to the medical strategies. The ischemia-guided group received more medication but had suppression of ischemia similar to the angina-guided group. At 1 year, the mortality rate was 4.4% in the angina-guided group (8 of 183), 1.6% in the ischemia-guided group (3 of 183) and 0% in the revascularization group (overall, p = 0.004; angina-guided vs. revascularization, p = 0.003; other pairwise comparisons, p = NS). Frequency of myocardial infarction, unstable angina, stroke and congestive heart failure was not significantly different among the three strategies. The revascularization group had significantly fewer hospital admissions and nonprotocol revascularizations at 1 year. The incidence of death, myocardial infarction, nonprotocol revascularization or hospital admissions at 1 year was 32% with the angina-guided medical strategy, 31% with the ischemia-guided medical strategy and 18% with the revascularization strategy (p = 0.003).

Conclusions

After 1 year, revascularization was superior to both angina-guided and ischemia-guided medical strategies in suppressing asymptomatic ischemia and was associated with better outcome. These findings require confirmation by a larger scale trial.

Cited by (0)

This study was funded by the National Heart, Lung. and Blood Institute, Cardiac Disease Branch, Division of Heart and Vascular Diseases, National Institutes of Health, Bethesda, Maryland by research contracts HV-90-07, HV-90-08, HV-91-05 to HV-91-14. Study medications and placebo were donated by ICI Pharmaceuticals Group (Zeneca Pharma Inc. after April 1993), Wilmington, Delaware: MarionMerrell 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. Some units had partial support from General Clinical Research Center grants, National Institutes of Health, Bethesda, Maryland. A list of participating centers and investigators appears in the Appendix.

*

See Correction on page 842.