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Bypass Angioplasty Revascularization Investigation - BARI
Description:
CABG vs. PTCA for mortality in multivessel coronary disease.
Hypothesis:
An initial strategy of PTCA patients with multivessel coronary artery disease (CAD) and severe angina or ischemia does not compromise clinical outcome compared with CABG during a 5-year follow-up period.
Study Design
Study Design:
Patients Screened: Not given
Patients Enrolled: 1,829
Mean Follow Up: 5.4 years
Mean Patient Age: 61
Female: 26
Mean Ejection Fraction: 57.1-57.6
Patient Populations:
Clinically severe angina or objective evidence of ischemia that requires revascularization
Angiographically documented multivessel coronary disease
Suitability for both PTCA and CABG
Informed consent for random assignment.
Exclusions:
Absence of significant CAD: Insufficient angina or objective evidence of ischemia.
Primary congenital heart disease.
Primary valvular heart disease (including a ventricular aneurysm, which requires surgery).
Prior PTCA or CABG.
Single-vessel CAD.
Age < 17 years or > 80 years.
Geographically inaccessible or unable to return for follow-up.
Unstable angina or acute MI, which requires emergency revascularization.
Left main stenosis > 50% or of a character that precludes angioplasty.
Noncardiac illness that is expected to limit survival.
Extensive ascending aortic calcification.
Primary coronary spasm.
Inability to understand or cooperate with protocol requirements.
Coronary angiogram that is technically unsatisfactory.
Suspected or known pregnancy.
Enrollment in a competing clinical trial.
Contraindications to PTCA or CABG because of a preexisting clinical condition.
Concomitant major surgery that is required (e.g., aortic and/or mitral valve surgery, carotid endartectomy, and/or resection of left ventricular or abdominal aortic aneurysm).
Angiographic unsuitability in the judgment of the surgeon or angioplasty operator.
Primary Endpoints:
Mortality at 5 years.
Secondary Endpoints:
MI
Angina (stable or unstable)
Myocardial ischemia
Subsequent revascularization
Resource use (subsequent hospitalization)
Quality of life
Angiographic assessment at 5 years
Left ventricular function (ejection fraction) at 5 years
Drug/Procedures Used:
PTCA
CABG
Principal Findings:
Over 5 years of follow-up, there were 111 deaths in the CABG group and 131 in the PTCA group, not a statistically significant difference. Cumulative survival was 89.3% for CABG patients and 86.3% for PTCA patients (p = 0.19; 95% confidence interval [CI] of the difference in survival, -0.2% to 6.0%).
The 5-year cardiac mortality rate was 8.0% in patients assigned to PTCA compared with 4.9% in those assigned to CABG (relative risk [RR] of 1.55 with a 95% confidence interval [CI] of 1.07 to 2.23; P=.022).
Freedom from Q-wave MI occurred at similar rates in both groups: 80.4% for CABG, 78.7% for PTCA.
The median hospital stay after CABG was 7 days, vs 3 days for PTCA. The median total hospital stay was 12 days with CABG vs 7 days with PTCA.
In-hospital event rates were similar in the two groups: 1.3% with CABG, 1.1% with PTCA. CABG patients were more likely to have Q-wave MIs than PTCA patients (4.5% vs 2.1%, p = 0.01). The rate of stroke for CABG patients was 0.8%; for PTCA patients, 0.2%.
PTCA patients were more likely to need a repeat revascularization procedure in the hospital than CABG patients: 6.3% of PTCA patients underwent emergency CABG vs. 1 patient (0.01%) in the CABG group. 2.1% of PTCA patients underwent emergency PTCA; no CABG patients did so.
During the 5-year follow-up, 8% of CABG patients underwent repeat revascularization, vs. 54% for PTCA patients.
69% of patients assigned to PTCA did not subsequently undergo CABG.
The survival rate for diabetics was significantly lower than patients without diabetes. In addition, the survival rate of diabetics was much worse with PTCA than with CABG (65.5% vs 80.6%).
At 5 years, differences in angina-free rates between patients assigned to PTCA and CABG decreased from 73% vs 95% at 4 to 14 weeks (P<.001) to 79% vs 85% at 5 years (P=.007). Similar patterns were observed for exercise-induced angina and ischemia, except 5-year differences were not significant. Among patients angina-free at 5 years, 52% of patients who had PTCA required revascularization after the initial procedure vs 6% of patients who had CABG.
At follow-up of 1 year and later, quality of life, return to work, modification of smoking and exercise behaviors, and cholesterol levels were similar for the 2 treatments.
During the first 3 years of follow-up, functional-status scores on the Duke Activity Status Index improved more in patients assigned to surgery than in those assigned to angioplasty (P<0.05). The initial mean cost of angioplasty was 65 percent that of surgery ($21,113 vs. $32,347, P<0.001), but after 5 years the total medical cost of angioplasty was 95 percent that of surgery ($56,225 vs. $58,889), a difference of $2,664 (P = 0.047). After 5 years of follow-up, surgery had an overall cost-effectiveness ratio of $26,117 per year of life added, but unacceptable ratios of $100,000 or more per year of life added could not be excluded (P=0.13).
Interpretation:
The Bypass Angioplasty Revascularization Investigation (BARI) trial indicates 5-year cardiac mortality in patients with multivessel disease was significantly greater after initial treatment with PTCA than with CABG. For treated diabetics, 5-year survival was significantly better after CABG than after PTCA. The narrowing of treatment differences in angina and exercise-induced ischemia rates can be attributed to a return of symptoms among patients assigned to CABG and incremental surgical procedures among patients assigned to PTCA. There were no significant differences overall for the composite end point of cardiac mortality or MI between treatment groups or for cardiac mortality in nondiabetic patients. For patients with multivessel coronary disease, coronary artery bypass surgery is associated with a better quality of life for three years than coronary angioplasty, after the initial morbidity caused by the procedure.
References:
1. Am J Cardiol 1995; 75:9C-17C Baseline clinical and angio data
2. Am J Cardiol 1995;75:34C-41C Baseline economic and functional status
3. N Engl J Med 1996; 335: 217-225 Final results (5-year)
4. JAMA 1997;277:715-21 Clinical outcomes
5. New Engl J Med 1997;336:92-9 Cost and quality of life
6. Circulation 1997;96:1761-9 Diabetic subgroup
7. Circulation 1998;98:1279-85 Gender subgroups
8. Circulation 1997;96:2162-70 MI and cardiac mortality
Keywords: Cholesterol, Risk, Stroke, Follow-Up Studies, Return to Work, Quality of Life, Survival Rate, Confidence Intervals, Coronary Artery Bypass, Angioplasty, Balloon, Coronary, Diabetes Mellitus, Smoking
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