Chronic Obstructive Pulmonary Disease: The Role of Myocardial Deformation Indices and Right Ventricle Three-Dimensional Echocardiography

Abstract Background: Right ventricular dysfunction is a major complication in chronic obstructive pulmonary disease (COPD) and, despite its prognostic implications, is rarely considered in routine clinical analysis. Objectives: To compare RV function variables with standard and advanced echocardiographic techniques in patients with stable COPD and controls. Methods: Twenty COPD patients classified as GOLD ≥ II (13 men aged 68.4 ± 8.3 years) and 20 matched controls were compared. Myocardial strain/strain rate indices were obtained by tissue Doppler and two-dimensional speckle tracking echocardiography. Right ventricular ejection fraction was obtained with three-dimensional software. Free wall myocardial thickness (FWMT) and tricuspid annular systolic excursion (TAPSE) were also measured. Numerical variables were compared between groups with Student's t-test or the Mann-Whitney test. Associations between categorical variables were determined with Fisher's exact test. P-values < 0.05 were considered statistically significant. Results: All myocardial deformation indices, particularly global longitudinal strain (-17.2 ± 4.4 vs -21.2: ± 4.4 = 0.001) and 3D right ventricular ejection fraction (40.8 ± 9.3% vs 51.1 ± 6.4% p <0.001) were reduced in COPD patients. These patients presented higher right ventricular FWMT and lower TAPSE values than controls. Conclusion: Myocardial deformation indices, either tissue Doppler or speckle tracking echocardiography and 3D right ventricular ejection fraction, are robust markers of right ventricular dysfunction in patients with stable COPD. Assessing global longitudinal strain by speckle tracking echocardiography is a more practical and reproducible method.

Right Ventricular Functional Improvement after Pulmonary Rehabilitation Program in Patients with COPD Determined by Speckle Tracking Echocardiography / Melhora da Função Ventricular Direita após Programa de Reabilitação Pulmonar em Pacientes com DPOC Avaliada por Ecocardiografia Speckle Tracking

Abstract Background: Although right ventricular (RV) dysfunction in pulmonary diseases has been associated with increased morbidity, tools for RV dysfunction identification are not well defined. Objective: The aim of this study was to evaluate the magnitude of RV dysfunction by means of speckle tracking echocardiography (STE) in patients with chronic obstructive pulmonary disease (COPD) and to investigate whether STE could be used as an index of RV improvement after a pulmonary rehabilitation (PR) program. Methods: Forty-six patients with COPD undergoing PR program and 32 age-sex matched healthy subjects were enrolled. RV function was evaluated at admission and after PR program by conventional two-dimensional echocardiography (2DE) and STE. In addition, exercise tolerance of subjects was evaluated using the six-minute walk test (6MWT). Results: COPD patients had worse RV function according to STE and 2DE as well. STE was more sensitive than conventional 2DE in determining RV improvement after PR program - RV global longitudinal strain (LS): 20.4 ± 2.4% vs. 21.9 ± 2.9% p < 0.001 and RV free wall LS: 18.1 ± 3.4% vs. 22.9 ± 3.7%, p < 0.001). RV free wall LS was directly related to distance walked at baseline 6MWT (r = 0.58, p < 0.001) and to the change in the 6MWT distance (6MWTD ∆) (r = 0.41, p = 0.04). Conclusions: We conclude that STE might be as effective as 2DE for evaluation of global and regional RV functions. STE may become an important tool for assessment and follow-up of COPD patients undergoing PR program to determine the relationship between RV function and exercise tolerance.

Resumo Fundamento: Embora a disfunção do ventrículo direito (VD) nas doenças pulmonares tenha sido associada ao aumento da morbidade, as ferramentas para a identificação da disfunção do VD não estão bem definidas. Objetivo: O objetivo deste estudo foi avaliar a disfunção do VD por ecocardiografia speckle tracking (STE) em pacientes com doença pulmonar obstrutiva crônica (DPOC), e se a STE pode ser usada como indicador de melhora da função ventricular direita após um programa de reabilitação pulmonar (RP). Métodos: Quarenta e seis pacientes com DPOC submetidos ao programa de RP e 32 controles sadios pareados por sexo e idade foram incluídos no estudo. A função do VD foi avaliada na admissão e após o programa de RP por ecocardiografia bidimensional convencional e por STE. Além disso, a tolerância ao exercício foi avaliada pelo teste de caminhada de seis minutos (TC6M). Resultados: Pacientes com DPOC apresentaram pior função do VD segundo STE e ecocardiografia bidimensional convencional. Em comparação ao método convencional, a STE mostrou maior sensibilidade em determinar melhora da função ventricular direita após o programa de RP - strain longitudinal (SL) global do VD: 20,4 ± 2,4% vs. 21,9 ± 2,9% p < 0,001; SL da parede livre do VD: 18,1 ± 3,4% vs. 22,9 ± 3,7%, p < 0,001. O SL da parede livre do VD relacionou-se diretamente com a distância percorrida no TC6M basal (r = 0,58, p < 0,001) e com a variação no TC6M ∆ (TC6M) (r = 0,41, p = 0,04). Conclusões: Concluímos que a STE pode ser tão eficaz como a ecocardiografia bidimensional convencional na avaliação das funções globais e regionais do VD. Ainda, a STE pode se tornar uma importante ferramenta de avaliação e acompanhamento de pacientes com DPOC submetidos à RP para determinar a relação entre função ventricular direita e tolerância ao exercício.