Medicina Pulmonar e Respiratória

Undiagnosed COPD in Patients with Established Cardiovascular Diseases:Prevalence, Symptoms Profiling and Functional Status

Abstract

Li-Cher Loh, Narentharen Selvarajah, Shanthiny Mohan, Wai-Sun Choo and Ismail Omar

Background: COPD is associated with cardiovascular co-morbidities. We examined the prevalence of undiagnosed COPD in our local population of patients with stable cardiovascular diseases and the profile of their respiratory symptoms and functional status.

Methods: Eligible patients with established stable cardiovascular diseases were prospectively recruited from the cardiology outpatient clinic of an urban-based university teaching hospital and evaluated with pre- and post- bronchodilator spirometry testing and interview using standard questionnaire.

Results: Of the 501 subjects recruited, 113 (22.6%) had COPD defined on post-bronchodilator fixed FEV 1 /FVC ratio <70%. 109 (96.5%) had moderate severity while only 4 (3.5%) had severe disease by GOLD classification. Compared to non-COPD, proportionately more COPD patients were older, males, exposed to cigarette smoking (including passive smoking) and had congestive cardiac failure and pulmonary hypertension. Also proportionately more COPD subjects had more cough, sputum and dyspnoae, and poorer scores in MRC dyspnoae scale, NYHA functional class and SGRQ quality of life. These symptoms were generally worst in the evening. They also had significantly higher mean number of unscheduled visits to outpatient clinics, emergency departments and of hospital admissions over the past 12 months. After multivariate analysis, only dyspnoae [odd ratio (95%CI): 4.2 (1.8-9.7); p=0.001] and cigarette smoking [2.8 (1.1-6.80); 0.018] remained independently associated with COPD.

Conclusions: A significant proportion of patients with established cardiovascular diseases have undiagnosed COPD of moderate severity. Dyspnoae and cigarette smoking appear highly predictive of COPD.