For diabetic patients who have multivessel coronary artery disease, bypass surgery provides slightly better quality of life and cardiovascular-related health status than does stenting for roughly 2 years, according to a substudy of the FREEDOM trial reported online Oct. 15 in JAMA.
Beyond 2 years, there are no significant differences between the two approaches regarding health status and quality of life in this patient group, said Dr. Mouin S. Abdallah of St. Luke’s Mid America Heart Institute, Kansas City, Mo., and his associates.
Both revascularization strategies yield substantial and sustained improvements for patients who have concomitant multivessel coronary artery disease (CAD) and diabetes, but coronary artery bypass graft surgery generally is preferred because it has a small but significant edge in reducing morbidity and mortality, is less expensive, and produces markedly more durable results. However, the risk of stroke is higher with CABG, and it requires a longer recovery period because it is more invasive, "which may be particularly relevant to patients who are more concerned about quality rather than duration of life," the investigators noted.
"For such patients, our study provides reassurance that there are not major differences in long-term health status and quality of life between the two treatment strategies," they said.
Dr. Abdallah and his colleagues performed a prospective substudy of quality-of-life issues alongside the FREEDOM (Future Revascularization Evaluation in Patients With Diabetes Mellitus: Optimal Management of Multivessel Disease) clinical trial. In FREEDOM, 1,900 patients from 18 countries were randomly assigned to undergo either CABG or percutaneous coronary intervention with drug-eluting stents during 2005-2010.
For their substudy, Dr. Abdallah and his associates assessed 935 participants who were assigned to CABG and 945 assigned to PCI. The mean patient age was 63 years, and 72% were men. Median follow-up was 44-47 months.
Patients in both study groups reported substantial and long-lasting improvements in cardiovascular-specific health status, as measured by the Seattle Angina Questionnaire and the Rose Dyspnea Scale. Scores on these instruments improved markedly within 1 month of both procedures and remained high throughout follow-up.
Patients in the PCI group showed more rapid improvement following the procedure, "but these benefits were transient and largely restricted to the first month of follow-up," the researchers said.
"Between 6 months and 2 years, health status was slightly better with CABG across a range of cardiac-specific domains including angina relief, physical function, and overall quality of life. Beyond 2 years, there were no consistent differences in any health status or quality-of-life domains between the CABG and PCI strategies," they reported (JAMA 2013;310:1581-90).
For example, the proportion of angina-free patients was slightly but significantly greater with CABG than with PCI at 6 months (83.7% vs. 78.1%) and at 12 months (83.5% vs. 79.5%), but was not significantly different thereafter.
Similarly, measures of physical limitations imposed by CAD were "modestly" higher with CABG than with PCI for 3 years after the procedure, but there were no significant between-group differences after year 3.
And dyspnea improved faster after PCI than after CABG, but by 6 months this difference had disappeared. By 1 year, the proportion of patients who reported moderate dyspnea was only 9% in both groups, and that proportion stayed fairly steady at 10%-12% in both groups for the remainder of follow-up.
The findings were similar in a sensitivity analysis and in a further analysis restricted only to patients who had reported daily or weekly angina at baseline.
In the FREEDOM trial, CABG showed a clear benefit over PCI for the composite endpoint of death, myocardial infarction, or stroke in patients with concomitant multivessel CAD and diabetes. CABG also afforded slightly better angina relief, especially in patients who had the most severe angina at baseline.
Moreover, patients in the PCI group were more likely to require continuing antianginal medication and twice as likely to undergo repeat revascularization procedures than those in the CABG group.
However, the study findings demonstrate that PCI is clearly beneficial for patients who want to avoid the acute risks of CABG surgery, and is an excellent alternative for those who want a less invasive treatment, Dr. Abdallah and his associates said.
This study was supported by the National Heart, Lung, and Blood Institute. Cordis and Boston Scientific provided the drug-eluting stents, Eli Lilly provided abciximab and research funds, and Sanofi-Aventis and Bristol-Myers Squibb provided clopidogrel. Dr. Abdallah reported no relevant financial conflicts of interest; his associates reported numerous ties to industry sources.