Background: Chronic obstructive pulmonary disease (COPD) is associated with heart failure (HF), independent of shared risk factors. The underlying pathophysiological mechanism is unknown.
Objectives: To determine why COPD is associated with HF. Specifically, whether COPD is associated with myocardial fibrosis, whether myocardial fibrosis is associated with hospitalisation for HF and death in COPD and whether COPD and smoking are associated with myocardial inflammation.
Methods: A prospective, multicentre, longitudinal cohort study of 572 patients undergoing cardiac magnetic resonance imaging (MRI), including 450 patients with COPD and 122 age- and sex-matched patients, with median (interquartile range) 726 (492-1160) day follow-up. Multivariable analysis examined the relationship between COPD and myocardial fibrosis, measured using cardiac MRI. Cox regression examined the relationship between myocardial fibrosis and outcomes; primary endpoint: composite of hospitalisation for HF or all-cause mortality; secondary endpoints: hospitalisation for HF and all-cause mortality. Fifteen patients with COPD, 15 current smokers and 15 healthy volunteers underwent evaluation for myocardial inflammation, including ultrasmall superparamagnetic particles of iron oxide MRI.
Results: COPD was independently associated with myocardial fibrosis (p<0.001). Myocardial fibrosis was independently associated with the primary outcome (hazard ratio (HR) 1.14; 95% confidence interval 1.08-1.20; p<0.001), hospitalisation for HF (HR 1.25 [1.14-1.36]); p<0.001) and all-cause mortality. Myocardial fibrosis was associated with outcome measurements more strongly than any other variable. Acute and stable COPD were associated with myocardial inflammation.
Conclusions: The association between COPD, myocardial inflammation and myocardial fibrosis, and the independent prognostic value of myocardial fibrosis, elucidate a potential pathophysiological link between COPD and HF.