Predictors of cardiopulmonary exercise testing in COPD patients according to Weber classification.

Caruso FR; Goulart CDL;Jr JCB; de Oliveira CR; Mendes RG; Arena R; Borghi-Silva A;

Heart & lung : the journal of critical care [Heart Lung] 2023 Jun 24; Vol. 62, pp. 95-100.
Date of Electronic Publication: 2023 Jun 24.

Background: Weber classification stratifies cardiac patients based on peak oxygen consumption (V̇O 2 ), the gold-standard measure of exercise capacity.
Objective: To determine if Weber classification is a useful tool to discriminate clinical phenotypes in COPD patients and to evaluate if disease severity and other clinical measures can predict V̇O 2peak .
Methods: Three hundred and six COPD patients underwent cardiopulmonary exercise testing (CPX) and were divided according to Weber class: 1) Weber A (n = 34); 2) Weber B (n = 88); 3) Weber C (n = 138); and 4) Weber D (n = 46).
Results: Weber class D patients demonstrated a reduced V̇O 2 peak , heart rate (HR), minute ventilation (V̇ E ) , oxygen (O 2 ) pulse, circulatory power (CP), oxygen uptake efficiency slope (OUES), oxygen saturation (SpO 2 %), delta (Δ)HR and ΔSpO 2 when compared to Weber A and B (p<0.05). Moreover, Dyspnea and the V̇ E /carbon dioxide production (V̇CO 2 ) slope were higher in Weber D compared with Weber C and A (p<0.001). Hierarchical regression analysis demonstrated significant predictors of V̇O 2peak (R 2 = 0.131; Adj R 2  = 1.25), including HR (β=0.5757; t = 5.7; P<0.001) and forced expiratory volume in one second (FEV 1 ) (β=0.119; t = 2.16; P<0.03). Among the Weber C + D groups, predictors of V̇O 2peak (R = 0.78; R 2 = 0.60; Adj R 2 =0.59), dyspnea (β=0.076; t = 1.111; P<0.27) and maximal voluntary ventilation (MVV) (β=0.75; t = 1.14; P<0.00).
Conclusion: Weber classification may be a useful tool to stratify cardiorespiratory fitness in COPD patients. Other clinical measures may be useful in predicting peak V̇O 2 in mild-to-severe COPD, moreover different phenotypes may be important tool to improve physical capacity of chronic disease patients.