Impact of non-cardiovascular disease comorbidity on cardiovascular disease symptom severity: a population-based study.

OBJECTIVES: Non-cardiovascular comorbidity is common in cardiovascular disease (CVD) populations but its influence on chest pain (CP) and shortness of breath (SOB) symptom-specific physical limitations is unknown. We wanted to test the a priori hypothesis that an unrelated comorbidity would influence symptom-specific physical limitations and to investigate this impact in different severities of CVD. METHOD AND RESULTS: The study was based on 5426 patients from ten family practices, organised into eight a priori exclusive severity groups: (i) no CVD or osteoarthritis (OA) (reference), (ii) index hypertension, ischaemic heart disease (IHD) and heart failure (HF) without OA, (iii) index OA without CVD and (iv) same CVD groups with comorbid OA. The measure of CP physical limitations was Seattle Angina Questionnaire and for SOB physical limitations was the Kansas City Cardiomyopathy Questionnaire. Adjusted baseline associations between the cohorts and symptom-specific physical limitations were assessed using linear regression methods. In the study population, 1443 (27%) reported CP and 2097 (39%) SOB. CP and SOB physical limitations increased with CVD severity in the index and comorbid groups. Compared with the respective index CVD group, the CP physical limitation scores for comorbid CVD groups with OA were lower by: -14.7 (95% CI -21.5, 7.8) for hypertension, -5.5 (-10.4, -0.7) for IHD and -22.1 (-31.0, -6.7) for HF. For SOB physical limitations, comorbid scores were lower by: -9.2 (-13.8, -4.6) for hypertension, -6.4 (-11.1, -1.8) for IHD and -8.8 (-19.3, 1.65) for HF. CONCLUSIONS: CP and SOB are common symptoms, and OA increases the CVD symptom-specific physical limitations additively. Comorbidity interventions need to be developed for CVD specific health outcomes.