Coronary Angioplasty versus Bypass Revascularization Investigation - CABRI


CABG vs. PTCA for mortality in multivessel coronary disease.


There is no difference in clinical outcomes for patients undergoing revascularization by coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA) in patients with symptomatic multivessel coronary disease.

Study Design

Study Design:

Patients Screened: Not given
Patients Enrolled: 1,054
Mean Follow Up: 1 year
Mean Patient Age: Males: 58.9; Females 63.2
Female: 22
Mean Ejection Fraction: 0.63

Patient Populations:

Patients undergoing coronary angiography who needed revascularization
<76 years of age
Typical angina pectoris or unstable angina, or unequivocal evidence of myocardial ischemia on 12-lead exercise electrocardiography (ECG) or isotope scintigraphy
> 50% reduction of luminal diameter viewed from two projections in two or more major epicardial vessels
At least one lesion suitable for PTCA (could include total and subtotal occlusion) and the vessel distal to the lesion > 2 mm in diameter
Cardiologist and surgeon believed that either PTCA or CABG could effect clinical improvement


Single vessel coronary disease
Left main coronary disease or severe triple vessel disease
Left ventricular ejection fraction < 0.35
Overt cardiac failure or acute myocardial infarction within previous 10 days
Recent cerebrovascular event
Previous CABG or PTCA
Severe concomitant cardiac illness such as valvular heart disease, aortic aneurysm, or other conditions affecting short-term survival
Participation in other clinical trials

Primary Endpoints:

Mortality and symptom (based on angina) status at 1 year

Secondary Endpoints:

Myocardial infarction
Requirement for medication
Subsequent revascularization procedures after initial revascularization

Drug/Procedures Used:


Concomitant Medications:

Calcium agonist
Combinations of the above 3

Principal Findings:

After 1 year of follow-up, 2.7% of patients randomized to CABG and 3.9% of patients randomized to PTCA had died. Relative risk of death was 1.42 in patients receiving PTCA (95% CI 0.73-2.76).

There was no significant difference between the groups in the risk of non-fatal MI during the first year.

Patients randomized to receive PTCA required more reinterventions later, with only 66.4% of them reaching 1-year follow-up with a single revascularization procedure, compared with 93.5% of patients randomized to CABG (RR=5.23, 95% CI 3.90-7.03, p < 0.001).

Patients randomized to PTCA took significantly more medication at 1 year (RR=1.30, 95% CI 1.18-1.43, p <0.001).

Patients randomized to PTCA were more likely to have clinically significant in angina (RR=1.54, 95% CI 1.09-2.16, p=0.012); this association was present in all patients, but only significant for females.

At 1 year, the restenosis rate was 9.3% ± 5.9% overall and 9.5% ± 6.5% in those patients with an optimal PTCA result (p=NS).


In symptomatic patients with multivessel coronary disease, both CABG and PTCA were effective in relieving angina at equivalent risk of death or MI.

Patients undergoing PTCA were more likely to require reintervention, were more likely to have clinically significant angina, and more likely to require medication during the year after the procedure.


1. Lancet 1995; 346:1179-1184. 1-year interim results
2. Am Heart J 1998;135(4):703-8 Restenosis rates
3. Am J Cardiol 82(3):272-6, 1998 Restenosis subgroup analysis

Keywords: Risk, Coronary Artery Disease, Coronary Angiography, Electrocardiography, Coronary Artery Bypass, Angioplasty, Balloon, Coronary

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