Venous thromboembolic (VTE) disease in people with chronic obstructive pulmonary disease (COPD): A matched case-control study

Abstract

Background: People with COPD are at increased risk of vascular disease, including VTE.1 While some researchers have tested the hypothesis that certain subgroups of COPD patients, e.g. frequent exacerbators, are at even greater risk of cardiovascular events, large-scale investigations of the relationship between exacerbation frequency or disease severity and VTE risk are lacking. Methods: 3,594 COPD patients recording a first VTE event between 1 January 2004 and 31 December 2013 were identified in Clinical Practice Research Datalink (CPRD GOLD) (cases) and matched (1:3) on age, sex and GP practice to 10,782 VTE-free COPD patients (controls). COPD severity was staged by degree of airflow limitation (GOLD stage) and by COPD medication history (very severe, severe, moderate/mild). Patients experiencing ≥2 exacerbations per year were classed as frequent exacerbators and as infrequent exacerbators otherwise. Analyses were conducted in STATA using conditional logistic regression. Results: After controlling for smoking and BMI, as well as the matching variables, there was an association between increased disease severity and VTE when severity was measured in terms of lung function impairment (ORmoderate/mild=1.16; 95% CIs 1.03, 1.32; p=0.018) and in terms of medication history (ORsevere/moderate+mild=1.17; 95% CIs 1.06, 1.26; p=0.001). There was no evidence that frequent exacerbators were at greater risk of VTE than infrequent exacerbators (OR=1.06; 95% CIs 0.97, 1.15; p=0.18). Conclusion: Severity of disease but not frequent exacerbation appears to be associated with VTE events in COPD patients. 1 Bertoletti L et al. (2012) EuropeanRespiratory Journal, 30(4):862–868.