T1 measurements for detection of expansion of the myocardial extracellular volume in chronic obstructive pulmonary disease

Abstract

Background: We aimed to assess whether chronic obstructive pulmonary disease (COPD) is associated with expansion of the myocardial extracellular volume (ECV) using T1 measurements.

Methods: Adult COPD patients Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage 2 or higher and free of known cardiovascular disease were recruited. All study patients underwent measures of pulmonary function, 6-minute walk test, serum measures of inflammation, overnight polysomnography, and a contrast cardiac magnetic resonance study.

Results: Eight patients with COPD were compared with 8 healthy control subjects. The mean predicted forced expiratory volume at 1 second of COPD subjects was 68%. Compared with control subjects, patients had normal left ventricular (LV) and right ventricular size, mass, and function. However, compared with control subjects, the LV remodelling index (median, 0.87; interquartile range [IQR], 0.71-1.14; vs median, 0.62; IQR, 0.60-0.77; P ¼ 0.03) and active left atrial emptying fraction was increased (median, 46; IQR, 41-49; vs median, 38; IQR, 33-43; P ¼ 0.005), and passive left atrial emptying fraction was reduced (median, 24; IQR, 20-30; vs median, 44; IQR, 31-51; P ¼ 0.007). The ECV was increased in patients with COPD (median, 0.32; IQR, 0.05; vs median, 0.27; IQR, 0.05; P = 0.001). The ECV showed a strong positive association with LV remodelling (r = 0.72; P = 0.04) and an inverse association with the 6-minute walk duration (r = -0.79; P = 0.02) and passive left atrial emptying fraction (r = -0.68; P = 0.003).

Conclusions: Expansion of the ECV, suggestive of diffuse myocardial fibrosis, is present in COPD and is associated with LV remodelling, and reduced left atrial function and exercise capacity.