Risk of cardiovascular comorbidity in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

Background Chronic obstructive pulmonary disease (COPD) is a systemic inflammatory disorder associated with increased comorbid prevalence of cardiovascular diseases. We aimed to quantify the magnitudes of association between overall and specific types of cardiovascular disease, major cardiovascular risk factors, and COPD. Methods We searched Cochrane, Medline, and Embase databases for studies published between Jan 1, 1980, and April 30, 2015, on the prevalence of cardiovascular disease and its risk factors in patients with COPD versus matched controls or random samples from the general public. We assessed associations with random-effects meta-analyses. We studied heterogeneity and biases with random-effects meta-regressions, jackknife sensitivity analyses, assessment of funnel plots, and Egger tests. Findings We identified 18 176 unique references and included 29 datasets in the meta-analyses. Compared with the non-COPD population, patients with COPD were more likely to be diagnosed with cardiovascular disease (odds ratio [OR] 2 . 46; 95% CI 2 . 02-3 . 00; p<0 . 0001), including a two to five times higher risk of ischaemic heart disease, cardiac dysrhythmia, heart failure, diseases of the pulmonary circulation, and diseases of the arteries. Additionally, patients with COPD reported hypertension more often (OR 1 . 33, 95% CI 1 . 13-1 . 56; p=0 . 0007), diabetes (1 . 36, 1 . 21-1 . 53; p<0 . 0001], and ever smoking (4 . 25, 3 . 23-5 . 60; p<0 . 0001). The associations between COPD and these cardiovascular disease types and cardiovascular disease risk factors were consistent and valid across studies. Enrolment period, age, quality of data, and COPD diagnosis partly explained the heterogeneity. Interpretation The coexistence of COPD, cardiovascular disease, and major risk factors for cardiovascular disease highlights the crucial need for the development of strategies to screen for and reduce cardiovascular risks associated with COPD.