Association of right ventricle diastolic diameter with pulmonary function, exercise tolerance and exacerbation period in patients with chronic obstructive pulmonary disease: A prospective study

Abstract

Background: The echocardiogram is a useful method for monitoring the cardiovascular complications of chronic obstructive pulmonary disease (COPD), but it is not clear if morphological and functional cardiac variables are able to identify patients with unfavorable COPD progression.

Objective: The aim of this study was to investigate morphological and functional echocardiographic variables associated with exacerbation of the disease, pulmonary function parameters and functional capacity evaluation in COPD patients.

Method: A longitudinal observational study including 91 patients diagnosed with COPD, who were stratified in two groups according to their basal right ventricle diastolic diameter (RVDD) measuring greater and less than 35 mm. They underwent clinical evaluation, echocardiography, spirometry and 6-minute walking-test (6MWT).

Results: The study found that patients with RVDD greater than 35 mm showed worse functional capacity in the 6MWT (p = 0.05) and more exacerbation of the disease during the one-year follow-up (p = 0.05). There were correlations of greater RVDD vs forced vital capacity (R = -0.27; p = 0.02) and distance in the 6MWT (R = 0.55; p = 0.03) in patients with exacerbation. In the univariate regression analysis, the RVDD was responsible for 55% of the variation in distance in the 6MWT (-0.75 m) in COPD patients.

Conclusion: The RV dilation is associated with unfavorable prognostic markers in COPD, such as the worsening of the functional capacity and more frequent exacerbations. The echocardiogram may be a useful tool to identify patients who need more aggressive strategies to control the evolution of the disease with potential impact in pulmonary rehabilitation.

Keywords: COPD; Exercise tolerance; Pulmonary heart disease; Respiratory function tests; Ventricular dysfunction.