Surgery or Angioplasty Viewed as Toss-Up for Mid-Level Disease

STANFORD, Calif., Oct. 15 -- In mid-level coronary artery disease, outcomes are about the same for either angioplasty or bypass graft surgery, found researchers here.

Five-year survival was 90.7% for bypass grafts and 89.7% for angioplasty, according to Mark A. Hlatky, M.D., of Stanford, and colleagues, in a systematic review of published randomized controlled trials.

Procedural survival rates were 98.2% for bypass and 98.9% for angioplasty, they reported online in the Oct. 16 issue of the Annals of Internal Medicine.

The researchers concluded that in this subgroup of patients with moderately advanced coronary artery disease, treatment decisions can safely defer to patients' preferences. The researchers described mid-range disease as "single-vessel, proximal left anterior descending disease; most forms of double-vessel disease, or less extensive forms of triple-vessel disease."

The investigators excluded patients with single-vessel disease outside the proximal left-anterior-descending artery, for whom angioplasty is the accepted choice, and patients with left-main or extensive triple-vessel disease, who are candidates for bypass surgery.

Dr. Hlatky emphasized in an interview that these conclusions do not apply to patients whose coronary disease is either much less or much worse than the patients included in the study.

But among coronary disease patients for whom there had been reasonable doubt as to which approach was best, his analysis "found relatively equivalent cardiac events in terms of outcomes over whatever time scale you wanted to look at, anywhere from zero to 10 years."

Patients with mid-level disease will need to weigh the higher upfront risk associated with surgery, including higher risk of strokes and longer postoperative recovery, against more durable angina relief and reduced need for a second operation, according to Dr. Hlatky and colleagues.

Angina relief at one year was 84% in bypass-treated patients and 75% in angioplasty-treated patients. The absolute rates of angina relief at five years were 79% after angioplasty and 84% after bypass graft. Procedural stroke rates were 1.2% after CABG and 0.6% after angioplasty (CI, 0.2% to 1%, P=0.002.)

Angioplasty had slightly less durable angina relief and was more likely to require a repeat procedure, the review found.

Repeated revascularization was more common after percutaneous coronary interventions than after bypass grafts. The absolute rates at five years were 46.1% after balloon angioplasty, 40.1% after percutaneous coronary interventions with stents, and 9.8% after bypass grafts.

The investigators analyzed data from 23 randomized clinical trials that included nearly 10,000 patients who had been randomized either to bypass or to angioplasty. None of the studies included patients treated with drug-eluting stents.

In a separate review of observational studies, the bypass graft-percutaneous coronary intervention hazard ration for death favored percutaneous interventions among patients with the least severe disease and bypass grafts among those with the most severe disease. In the patients with intermediate extent of disease who were most similar to patients enrolled in the randomized trials, the studies based on data from clinical registries reported bypass grafts-percutaneous coronary intervention hazard ratios close to 1.0

On the question of therapy for patients with diabetes, Dr. Hlatky noted that best care for coronary disease has been an area of concern since the 1995 Bypass Angioplasty Revascularization Investigation (BARI) investigators (including Dr. Hlatky) reported that such patients had better survival after bypass surgery than after angioplasty.

The BARI data prompted Dr. Hlatky and other researchers to re-examine data on diabetic patients from coronary disease registries and trials.

Survival did not differ between bypass grafts and percutaneous coronary intervention for patients with diabetes in the six trials that reported on this subgroup.

"We were surprised to find that when you put all the data together, the survival is not significantly different, even in patients with diabetes, between angioplasty and surgery," Dr. Hlatky said.

The disparate results confirm the need for larger, prospective trials in patients with diabetes, Dr. Hlatky said. This problem is being pursued in the FREEDOM (Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease) and VA CARDS (Coronary Artery Revascularization in Diabetes) trials.

Dr. Hlatky said in an interview that clinicians should interpret the current study as supporting a multi-step approach to treating coronary disease rather than a blanket indication that surgery or angioplasty are equally safe in all patients. Whether either is indicated for patients with mid-range disease beyond medical management should be carefully considered, he said,

If a patient is high-risk, heavily symptomatic despite drug therapy, or has intolerable drug side effects, examine the coronary anatomy to determine which procedure is technically feasible, he recommended. If both approaches look equally feasible, patient preference becomes a deciding factor.

This review did not include any data from the large ongoing trials using drug-eluting stents. Dr. Hlatky expressed doubt that the results of those studies will alter his conclusions. He said that previous comparisons of drug-eluting versus bare-metal stents revealed no significant differences in death or MI rates.