BARI 2D: Prompt Revascularization Improves Angina Symptoms in Diabetics

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In diabetic patients with stable ischemic heart disease, a strategy of early coronary artery revascularization and optimal medical therapy reduces the rates of new and worsening angina and increases the proportion of those who are angina free compared with optimal medical therapy alone. The results, from a fresh look at the BARI 2D study, were published online March 28, 2011, ahead of print in Circulation.

The original BARI 2D (Bypass Angioplasty Revascularization Investigation 2 Diabetes) trial found that a strategy of prompt revascularization did not reduce all-cause mortality or the composite of cardiovascular death, MI, and stroke in patients with type 2 diabetes and stable ischemic heart disease.

For the new analysis, researchers led by Gilles R. Dagenais, MD, of Laval University (Quebec, Canada), evaluated the effect of both strategies on angina symptoms in 2,364 patients from the BARI 2D cohort.

Greater, Sustained Reduction in Angina Symptoms

Overall, 1,434 patients (61%) had angina, 506 (21%) had anginal equivalents, and 424 (18%) had neither of those diagnoses. PCI was recommended in 1,602 patients and CABG in 762. Subsequently, patients in each group were randomized to receive either prompt revascularization or medical therapy alone.

Compared with optimal medical therapy alone, patients who received prompt revascularization had a lower rate of worsening angina, new angina, and subsequent coronary revascularization and were more likely to be angina free at 3-year follow-up.

Table 1. Three-Year Follow-up

 

Prompt Revascularization
(n = 1,173)

Medical Therapy Alone
(n = 1,191)

P Value

Worsening Angina

8%

13%

< 0.001

New Angina

37%

51%

0.001

Subsequent Revascularization

18%

33%

0.001

Angina-Free Status

66%

58%

0.003


Subgroups analyses showed that patients who had not undergone prior revascularization obtained greater improvements in each of these 4 outcomes. In addition, patients with triple-vessel disease fared better with regard to angina symptoms and repeat procedures after prompt revascularization than those with single- or double-vessel disease.

Neither angina nor subsequent revascularization rates differed by randomized treatment when patients were analyzed according to their glucose-lowering strategies, whether insulin sensitizers or insulin providers.

By 5 years, a first subsequent revascularization was required in 38% of the medical therapy group and in 20.5% of the prompt revascularization group. The main reasons for revascularization were ACS, severe angina, or documentation of worsening myocardial ischemia. Over the same time frame, the cumulative rate of subsequent revascularization was significantly higher after medical therapy than prompt revascularization, with CABG patients showing the greatest benefit.

New Findings Have Clinical Implications

The study authors point out that the reduction in each of the 4 outcomes was driven mostly by the benefits of prompt revascularization in the CABG group.

“Although it is known that CABG reduces angina more than medical management alone, the present observations constitute new findings in a population like BARI 2D because previous studies enrolled more symptomatic patients, most of them without diabetes mellitus,” they write.

In addition, Dr. Dagenais and colleagues say the benefits for the entire cohort also should be considered in the context of the main findings of BARI 2D, which show that prompt revascularization with CABG reduced cardiovascular events but not mortality.

“Patients, particularly those with triple-vessel disease, randomized to the [prompt revascularization] strategy had more relief from symptoms and fewer subsequent revascularizations than those with single- or double-vessel disease. Such patients may benefit from prompt revascularization. For the other patients, optimal medical management is a reasonable initial strategy, and revascularization can be done subsequently if patients are limited by their symptoms despite an optimal medical regimen,” the researchers write.

Important, Unsettled Issues Remain

But in an accompanying editorial, Steven P. Marso, MD, of the University of Missouri-Kansas City (Kansas City, MO), cautions that although the overall findings suggest PCI is superior to medical therapy alone, the debate over the relative merits of initial revascularization in low-risk stable angina patients with type 2 diabetes is not over.

To begin with, establishing a clinically meaningful difference in angina severity is difficult, Dr. Marso says, because it “requires the use of arbitrary cut points in health-status assessment tools” and because the concept “varies materially between patients.”

Other important issues to consider include the steady improvement in quality of life seen in both treatment groups, the fact that the magnitude of benefit initially seen in the PCI group diminished over time, and the significant crossover from medical therapy to revascularization in patients with the most symptoms. In all, 38% of patients in the medical therapy arm crossed over to revascularization by 12 months.

But, Dr. Marso says, the findings should be considered in clinical decision making and in patient communication.

“If shared decision making is valued, it would be inappropriate for physicians not to include coronary revascularization in the discussion of treatment options for relief of chronic angina in patients with type 2 diabetes mellitus,” he writes.

Study Details

There were 1,602 patients in the PCI stratum (806 randomized to medical therapy and 796 randomized to prompt revascularization) and 762 in the CABG stratum (385 randomized to medical therapy and 377 randomized to prompt revascularization). The mean age was 62.4 years.

There was no significant difference in baseline characteristics between the prompt revascularization and medical therapy groups. However, compared with PCI patients, those who received CABG were older, more often men, had higher blood pressure, had higher rates of previous MI and triple-vessel disease, had a higher myocardial jeopardy index, and were taking more beta-blockers. Patients in the CABG group had a smaller body mass index, less history of coronary revascularization, and were taking fewer diuretics and antiplatelet agents other than aspirin compared with patients in the PCI group. Both groups had similar LVEF (57.1 ± 11.0% vs. 57.4 ± 11.0%; P = 0.6).

Of those undergoing PCI, nearly one-third received DES.

 


Sources:
1. Dagenais GR, Lu J, Faxon DP, et al. Effects of optimal medical treatment with or without coronary revascularization on angina and subsequent revascularizations in patients with type 2 diabetes mellitus and stable ischemic heart disease. Circulation. 2011;Epub ahead of print.

2. Marso SP. Revascularization trumps medicine for patients with type 2 diabetes mellitus and chronic angina (or does it?). Circulation. 2011;Epub ahead of print.

 

 

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Disclosures
  • BARI 2D was funded by the National Heart, Lung, and Blood Institute and the National Institute of Diabetes and Digestive and Kidney Diseases. The study received significant supplemental funding provided by Abbott Laboratories, Astellas Pharma US, GlaxoSmithKline, Lantheus Medical Imaging (formerly Bristol-Myers Squibb Medical Imaging), Merck, and Pfizer.
  • Dr. Dagenais reports receiving lecture fees from GlaxoSmithKline and consulting fees from Abbott.

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