Cardio-pulmonary-exercise testing, stress-induced right ventricular diastolic dysfunction and exercise capacity in non-severe chronic obstructive pulmonary disease

Abstract

Abstract Background Data regarding echocardiographic structural and functional abnormalities in right ventricular diastolic dysfunction (RVDD), cardio-pulmonary exercise testing (CPET) abnormalities and their association with exercise capacity among non-severe chronic obstructive pulmonary disease (COPD) patients without pulmonary arterial hypertension (PAH) at rest is limited. Purpose The aim of the study was to find echocardiographic parameters of the right ventricle that may be predictors for stress RVDD in non-severe COPD patients without PAH and to determine their correlation with the 6-minute walking test (6-MWT). Methods We applied a ramp protocol of CPET in 104 patients. Dynamic hyperinflation (ICdyn) was measured. Emphysema was evaluated by Goddard score. Echocardiography was performed before and 1–2 minutes after peak CPET. Stress RVDD was assumed if peak E/e'>6.0. Exercise capacity was evaluated by the 6-MWT. ROC analysis detected the best cut-off values of the RV echocardiographic predictors for stress RVDD. Multivariate analysis with covariates left ventricle (LV) (LV E/A at rest; LV E/e' at rest; stress LV E/A; stress LV E/e'), lung function (FEV1), ICdyn, Goddard score, age, sex, and BMI was performed. A p-value <0.05 was accepted of statistical significance. Results 78% of the patients had stress RVDD. RV wall thickness (RVWT), right atrial volume index (RAVI) and exercise systolic PAH were significantly higher in COPD patients with stress RVDD. After multivariable regression analysis RAVI and rest RV E/e' ratio >5.1 remained independent predictors for stress RVDD; RAVI and RVWT were independent predictors for diminished exercise capacity (6-MWT). Conclusion There is a high prevalence of stress induced RVDD in non-severe COPD patients without PAH at rest. RAVI and rest RV E/e'>5.1 are the best predictors for stress E/e' >6; RAVI and RVWT are associated with decrements in exercise capacity. Funding Acknowledgement Type of funding source: None