Current issues of ACP Journal Club are published in Annals of Internal Medicine


Therapeutics

Bypass surgery and angioplasty were similarly effective in relieving angina

ACP J Club. 1995 Mar-April;122:30. doi:10.7326/ACPJC-1995-122-2-030


Source Citation

Hamm CW, Reimers J, Ischinger T, et al. A randomized study of coronary angioplasty compared with bypass surgery in patients with symptomatic multivessel coronary disease. N Engl J Med. 1994 Oct 20;331:1037-43.


Abstract

Objective

To compare the effectiveness of coronary artery bypass grafting (CABG) with percutaneous transluminal coronary angioplasty (PTCA) in patients with symptomatic 2- or 3-vessel coronary artery disease (CAD) requiring complete revascularization.

Design

Randomized controlled trial with 1-year follow-up.

Setting

8 clinical sites in Germany.

Patients

8981 patients with multivessel disease were screened for clinical and angiographic eligibility. 359 patients (80% men) younger than age 75 years with symptomatic multivessel coronary disease requiring complete revascularization met the inclusion criteria. Exclusion criteria were totally occluded vessels, lesions of the left main coronary artery, lesions > 2 cm in length, diffuse peripheral coronary disease, aneurysms, myocardial infarction (MI) within the previous 4 weeks, previous CABG or PTCA, or the risk that > 50% of the left ventricular circumference would be in jeopardy should abrupt closure of 1 of the target vessels occur.

Intervention

177 patients were assigned to CABG, and 182 patients were assigned to PTCA.

Main outcome measures

Angina pectoris, death, MI, procedure-related complications, and the need for further interventions.

Main results

337 patients (94%) had the assigned treatment. 74% of patients in the CABG group were free of angina at 12 months compared with 71% of those in the PTCA group (Table). 22% of patients in the CABG group compared with 12% of those in the PTCA group, however, were not using antianginal medications (P = 0.04). In-hospital mortality did not differ between the groups (Table). The median hospital stay was 5 days after PTCA and 19 days after CABG. Q-wave MI in relation to the procedure was more frequent in patients in the CABG group (Table). 44% of patients in the PTCA group required further interventions during the first year of follow-up (repeat PTCA in 23%, CABG in 18%, and both PTCA and CABG in 3%) compared with 6% of patients in the CABG group (repeat CABG in 1% and repeat PTCA in 5%) (P < 0.001).

Conclusions

Coronary artery bypass surgery and percutaneous transluminal coronary angioplasty achieved similar improvement in angina after 1 year in patients with symptomatic multivessel coronary artery disease. Patients treated with angioplasty, however, were more likely to require further interventions and antianginal drugs, whereas patients treated with bypass surgery were more likely to have a myocardial infarction during the procedure.

Source of funding: Bundesministerium für Forschung und Technologie, Bonn, Germany.

For article reprint: Dr. C.W. Hamm, Department of Cardiology, Medical Clinic, University Hospital Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany. FAX 49-6032-996-2298.


Table. Percutaneous transluminal coronary angioplasty (PTCA) vs coronary artery bypass grafting (CABG) in patients with symptomatic 2- or 3-vessel coronary artery disease*

Outcomes at 1 y PTCA CABG RBI (95% CI) NNT (CI)
Free of angina 71% 74% 4% (-10 to 16) Not significant
RRR (95% CI)
In-hospital mortality 1% 2% 54% (-111 to 90) Not significant
Q-wave myocardial infarction 2% 8% 72% (20 to 90) 18 (9 to 83)

*Abbreviations defined in Glossary; RBI, RRR, NNT, and CI calculated from data in article.


Commentary

Bypass surgery and angioplasty were comparable for preventing ischemic outcomes

Medical therapy, PTCA, and CABG are competitive and complementary techniques for treating symptomatic CAD. Medical therapy includes nitrate, β-blockers, and calcium channel blockers. Balloon angioplasty is superior to these drugs to relieve angina and improve exercise duration (1) but is not very successful for diffuse disease or chronic total occlusions and is limited by acute closure and restenosis. CABG has the same advantages as angioplasty relative to drug therapy and also has been shown to reduce mortality in patients with significant left main disease or 3-vessel disease and left ventricular dysfunction. Surgery is superior to angioplasty for revascularizing arteries that are diffusely diseased or chronically occluded but is limited by perioperative complications, prolonged convalescence, and bypass graft atherosclerosis. Increasing data support the use of coronary revascularization rather than medical therapy for selected patients with CAD, but the choice of angioplasty or surgery has only recently been studied in 6 randomized studies, 2 of which are abstracted here and 4 of which are reported elsewhere (2-5).

The early results from these trials have produced no major surprises. No differences existed in mortality, MI, left ventricular ejection fraction, exercise time, or employment status. Angioplasty was easier to schedule, required shorter hospital stays and convalescent periods, and was less expensive initially. Patients were, however, more likely to have recurring angina, increased need for antianginal medications, and repeat revascularizations. Surgery resulted in more complete and sustained revascularization but was associated with more in-hospital complications and longer recovery periods.

The patients enrolled in these studies were carefully selected, representing < 10% of those screened. Patients with left main disease, significant valvular heart disease, previous angioplasty or surgery, recent MI, total occlusions, long lesions, or significant left ventricular dysfunction were excluded. Thus, the results only apply to patients who are suitable candidates for either procedure.

Individually, these trials are underpowered for addressing several important revascularization questions, but future analysis of the pooled results and the nonrandomized registries may prove enlightening. Does partial revascularization give the same clinical outcome as total revascularization for large subsets of patients? Are the techniques equivalent in patients with left ventricular dysfunction? How does vein graft failure 5 to 10 years after surgery influence the long-term comparison? Will the early economic advantage for angioplasty be maintained? The potential benefit of selectively using coronary atherectomy or endoluminal stenting to improve the angioplasty results is not addressed by these studies.

Clinically, it continues to seem reasonable to offer angioplasty initially to patients with low-risk anatomy (1-vessel disease, multivessel disease with dilatable lesions, reasonable left ventricular function) who wish to avoid major surgery and are willing to risk the need for further interventions. Patients with left main disease, complex multivessel disease, and significant left ventricular dysfunction have a proven survival benefit with surgery. Another important role for angioplasty is in revascularizing patients who are at high risk for surgery because of cerebrovascular, renal, or pulmonary disease or who have poor target arteries, inoperable valvular heart disease, or severe left ventricular dysfunction.

Eric Bates, MD
The University of Michigan Medical CenterAnn Arbor, Michigan, USA


Commentary Update

The results of the 8-year follow-up of the trial by King and colleagues confirm the 1994 results (6).


References

1. Parisi AF, Folland ED, Hartigan P. A comparison of angioplasty with medical therapy in the treatment of single-vessel coronary artery disease. Veterans Affairs ACME Investigators. N Engl J Med. 1992;326:10-6.

2. Protocol for the Bypass Angioplasty Revascularization Investigation. Circulation. 1991;84 (Suppl V):V1-27.

3. RITA Trial Participants. Coronary angioplasty versus coronary artery bypass surgery: the Randomized Intervention Treatment of Angina (RITA) trial. Lancet. 1993;341:573-80.

4. Rickards A. Coronary Angioplasty vs Bypass Revascularization Investigation (CABRI). Presented at the European Society of Cardiology XVth Congress. Nice, France; September 1993.

5. Rodriguez A, Boullon F, Perez-Baliño N, et al. Argentine randomized trial of percutaneous transluminal coronary angioplasty versus coronary artery bypass surgery in multivessel disease (ERACI): in-hospital results and 1-year follow-up. ERACI Group. J Am Coll Cardiol. 1993;22:1060-7.

6. King SB 3d, Kosinski AS, Guyton RA, Lembo NJ, Weintraub WS. Eight-year mortality in the Emory Angioplasty versus Surgery Trial. J Am Coll Cardiol. 2000;35:1161-21.