Quality of life after PCI vs CABG among patients with diabetes and multivessel coronary artery disease: a randomized clinical trial

Abstract

Importance: The FREEDOM trial demonstrated that among patients with diabetes mellitus and multivessel coronary artery disease, coronary artery bypass graft (CABG) surgery resulted in lower rates of death and myocardial infarction but a higher risk of stroke when compared with percutaneous coronary intervention (PCI) using drug-eluting stents. Whether there are treatment differences in health status, as assessed from the patient's perspective, is unknown.

Objectives: To compare the relative effects of CABG vs PCI using drug-eluting stents on health status among patients with diabetes mellitus and multivessel coronary artery disease.

Design, setting, and participants: Between 2005 and 2010, 1900 patients from 18 countries with diabetes mellitus and multivessel coronary artery disease were randomized to undergo either CABG surgery (n = 947) or PCI (n = 953) as an initial treatment strategy. Of these, a total of 1880 patients had baseline health status assessed (935 CABG, 945 PCI) and comprised the primary analytic sample.

Interventions: Initial revascularization with CABG surgery or PCI.

Main outcomes and measures: Health status was assessed using the angina frequency, physical limitations, and quality-of-life domains of the Seattle Angina Questionnaire at baseline, at 1, 6, and 12 months, and annually thereafter. For each scale, scores range from 0 to 100 with higher scores representing better health. The effect of CABG surgery vs PCI was evaluated using longitudinal mixed-effect models.

Results: At baseline, mean (SD) scores for the angina frequency, physical limitations, and quality-of-life subscales of the Seattle Angina Questionnaire were 70.9 (25.1), 67.3 (24.4), and 47.8 (25.0) for the CABG group and 71.4 (24.7), 69.9 (23.2), and 49.2 (25.7) for the PCI group, respectively. At 2-year follow-up, mean (SD) scores were 96.0 (11.9), 87.8 (18.7), and 82.2 (18.9) after CABG and 94.7 (14.3), 86.0 (19.3), and 80.4 (19.6) after PCI, with significantly greater benefit of CABG on each domain (mean treatment benefit, 1.3 [95% CI, 0.3-2.2], 4.4 [95% CI, 2.7-6.1], and 2.2 [95% CI, 0.7-3.8] points, respectively; P < .01 for each comparison). Beyond 2 years, the 2 revascularization strategies provided generally similar patient-reported outcomes.

Conclusions and relevance: For patients with diabetes and multivessel CAD, CABG surgery provided slightly better intermediate-term health status and quality of life than PCI using drug-eluting stents. The magnitude of benefit was small, without consistent differences beyond 2 years, in part due to the higher rate of repeat revascularization with PCI.

Trial registration: clinicaltrials.gov Identifier: NCT00086450.

Figures

Figure 1. Study population

Consort diagram showing patient flow for the FREEDOM trial. Black boxes indicate the primary analytic population for the quality of life study.

Figure 2. Seattle Angina Questionnaire Results

Mean scores (with 95% C.I. error bars) for the angina frequency, physical limitation, and quality of life subscales of the Seattle Angina Questionnaire (SAQ). Scores for each subscale range from 0 to 100, with higher scores representing better health status or quality of life.

Figure 3. Angina Frequency

Frequency of angina by treatment group according to the SAQ angina frequency (AF) scale. Categories were defined as no angina (SAQ-AF score 100), monthly angina (SAQ-AF score 70-90), weekly angina (SAQ-AF score 40-60), or daily angina (SAQ-AF score

Figure 4. Dyspnea

Frequency of dyspnea-related limitation in physical activity according to the Rose Dyspnea Scale (RDS; range 0-4; higher scores represent more dyspnea).

Figure 5. Subgroup Analysis of the Mean Treatment Effect of CABG vs. PCI on the SAQ Angina Frequency Subscale

Treatment effects at 12 months (Figure 5A) and 24 months (Figure 5B) along with associated 95% confidence intervals and interaction P values were derived from longitudinal random effect growth curve models.

Figure 5. Subgroup Analysis of the Mean Treatment Effect of CABG vs. PCI on the SAQ Angina Frequency Subscale

Treatment effects at 12 months (Figure 5A) and 24 months (Figure 5B) along with associated 95% confidence intervals and interaction P values were derived from longitudinal random effect growth curve models.