Correlation between short-term quality of life improvement and clinical outcomes - a post-hoc ISCHEMIA trial analysis

Abstract Background Patients with symptomatic coronary artery disease (CAD) exhibit improvement in quality of life (QoL) after invasive management (percutaneous coronary intervention [PCI] and coronary artery bypass grafting [CABG]). However, it is not clear how QoL improvements after intervention are related to clinical outcomes. Purpose Using the International Study of Comparative Health Effectiveness With Medical and Invasive Approaches (ISCHEMIA) population, we sought to assess the relationship between short-term QoL improvement and long-term clinical outcomes. Methods All participants in the ISCHEMIA trial who were randomized to the invasive arm and who had QoL scores available were included in the analysis. QoL improvement was calculated using the difference between the Seattle Angina Questionnaire (SAQ) score at baseline and at six months regarding randomization. The primary outcome was the trial-defined composite outcome (cardiovascular death, myocardial infarction, cardiac arrest or hospitalization for unstable angina/heart failure) and all-cause death. The secondary outcome was all-cause mortality. Median follow-up was 3.3 years. Cox proportional hazards models included clinically relevant demographic and angiographic covariates. Results After the exclusion of the conservative treatment arm and patients without QoL follow-up or covariate data, 1,577 patients were selected for the final analysis (Fig.1). The median baseline SAQ score was 74 (interquartile range, IQR: 60-88), the change in score at six months was 14 (IQR: 2-26), and 76.1% of patients experienced improvement in QoL. Six-month QoL improvement was not associated with a lower risk of the primary outcome (hazard ratio [HR]: 0.961, 95% confidence interval [CI], 0.920-1.005, p=0.081 – Table 1), but was associated with all-cause mortality (HR: 0.919, 95% CI, 0.859-0.982, p=0.013 – Table 1). In this population, increased age (HR: 2.370, 95% CI, 1.710-3.287, p<0.001, per 10 years) was also associated with higher risk of all-cause mortality. Conclusions Among invasive treated patients in ISCHEMIA trial, six-month QoL improvement was associated with a lower risk of long-term all-cause mortality, but not with a lower risk of major adverse events.Figure 1.Study population.