NEJM: CABG leads to greater angina relief than PCI in high-risk patients

Among patients with three-vessel or left main coronary artery disease (CAD), there was greater relief from angina after CABG than after PCI at six and 12 months, although the extent of the benefit was small, according to the quality-of-life data that emerged from the SYNTAX trial, which was published in the March 17 issue of the New England Journal of Medicine.

Previous studies have shown that among patients undergoing multivessel revascularization, CABG as compared with PCI either by means of balloon angioplasty or with the use of bare-metal stents, results in greater relief from angina and improved quality of life, wrote the study authors. However, they noted that the effect of PCI with the use of drug-eluting stents on these outcomes is “unknown.”

Therefore, David J. Cohen, MD, from St. Luke’s Mid America Heart Institute in Kansas City, Mo., and the SYNTAX (Synergy between PCI with Taxus and Cardiac Surgery) investigators assigned 1,800 patients with three-vessel or left main CAD to undergo either CABG (897 patients) or PCI with Boston Scientific’s Taxus paclitaxel-eluting stents (903 patients).

They assessed the health-related quality of life at baseline and at one, six and 12 months with the use of the Seattle Angina Questionnaire (SAQ) and the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). The primary endpoint was the score on the angina-frequency subscale of the SAQ (on which scores range from 0 to 100, with higher scores indicating better health status).

The scores on each of the SAQ and SF-36 subscales were significantly higher at six and 12 months than at baseline in both groups, the authors reported. The score on the angina-frequency subscale of the SAQ increased to a greater extent with CABG than with PCI at both six and 12 months, but the between-group differences were small (mean treatment effect of 1.7 points at both time points).

The proportion of patients who were free from angina was similar in the two groups at one month and six months and was higher in the CABG group than in the PCI group at 12 months (76.3 vs. 71.6 percent), Cohen and colleagues reported. Scores on all the other SAQ and SF-36 subscales were either higher in the PCI group (mainly at one month) or were similar in the two groups throughout the follow-up period.

“Subgroup analyses showed that the benefits of CABG with respect to relief from angina were consistent over a broad range of patient characteristics,” the study authors wrote. “There was, however, evidence of heterogeneity according to the frequency of angina at baseline. Among patients with daily or weekly angina, CABG was associated with greater relief from angina than was PCI at both six months and 12 months, whereas there was no significant between-group difference in relief from angina among the two-thirds of the study population with less frequent angina at baseline.”

In contrast to the small differences in disease-specific quality of life at six and 12 months, they pointed out that the early benefits of PCI on general health status in the study were “large.” For example, the difference of 7.8 points between PCI and CABG in the SF-36 physical-component summary score at one month exceeds the effect on physical health of a variety of chronic conditions, including sciatica (3.8 points), chronic lung disease (3.1 points) and heart failure (7.2 points).

At both six and 12 months, there was a small but significant reduction in angina frequency with CABG as compared with PCI in the overall population. Cohen et al concluded that these symptomatic benefits of CABG were counterbalanced by the more rapid recovery and improved short-term health status achieved with PCI.