Abstract 11: Comparison of Patient Reported Angina with Provider Assigned Canadian Cardiovascular Society Angina Class Before and After Revascularization

Abstract

Background: The Canadian Cardiovascular Society (CCS) classification system for angina is a critical determinant of revascularization appropriateness. A major limitation of CCS is that it rates patients’ symptoms from the perspective of providers, rather than patients themselves. Accordingly, we sought to evaluate the correlation of physician-assigned CCS class with patient-reported Seattle Angina Questionnaire (SAQ), before and after revascularization. Methods: Using data from the FREEDOM trial, which randomized 1900 patients from over 160 international sites to either PCI or CABG, CCS was reported by physicians and the SAQ was completed by patients prior to randomization and 1 year later. SAQ angina frequency (SAQ AF) scores were considered to correspond to CCS class per the following: SAF AF: 100=CCS 0, 61-99=CCS I, 31-60=CCS II, 0-30=CCS III/IV. Agreement between physician- and patient-reported angina categories was compared using chi square tests. Results: Among 1640 patients who had CCS and SAQ data at both baseline and 1-year, the mean age was 63.1 years, 71% were male, and 83% had 3-vessel coronary disease. Before revascularization, physicians correctly reported the burden of angina in 25.5% of patients and overestimated the burden of angina in 62.1%. Among 1194 patients who reported monthly or no angina, 229 (19.2%) were classified by their physicians as having CCS III/IV. In contrast, at follow-up, 71.2% of patients had their angina correctly estimated by their physicians and only 0.6% among the 1568 patients with monthly/no angina were assigned CCS III/IV by their physicians. Among the 28.8% misclassified by CCS at 1 year, 20.8% had less angina than reported by physicians and 8.0% had more (Figure; p=0.01). Findings were similar when the analysis was repeated in patients who were treated with PCI or CABG. Conclusions: In a large cohort of patients with stable coronary disease undergoing revascularization, clinicians often overestimated the amount of angina patients were having prior to revascularization but were significantly more accurate at follow-up. Given that importance placed on CCS for enrollment in clinical trials, or assigning appropriateness of revascularization in clinical practice, using patient-reported symptom burden as a more unbiased measure should be considered.