Use of Cardiopulmonary Exercise Testing to Assess Pulmonary Hypertension in Patients With Rheumatic Mitral Valve Disease: A Comparative Study With Echocardiography.

Rheumatic mitral stenosis (RMS) is still a significant public health problem in low- and middle-income countries. Pulmonary hypertension (PH) is a common consequence of RMS and may be used as a surrogate of disease severity. Cardiopulmonary exercise testing (CPET) provides a comprehensive assessment of the cardiorespiratory systems and can identify indirect signs of PH. To evaluate the relationship between CPET parameters and PH quantified by echocardiography in patients with RMS. This cross-sectional study retrospectively included thirty patients with RMS referred for CPET from 2012 to 2020. Two groups of patients were defined according to echocardiographic-derived pulmonary systolic arterial pressure (PASP): significant PH group (PSAP ≥ 50 mmHg); and non-significant PH group (PSAP < 50 mmHg). A decrease in peak oxygen consumption (VO2) and oxygen pulse predicted (O2PP) was observed in the PH group compared to the non-significant PH group (11.1±2.8 mL/kg/min vs 14.1±2.9 mL/kg/min; P = 0.02; 54±9% vs 67.8±15%; P = 0.02). The PH group exhibited a greater VE/VCO2 nadir rather than non-significant PH group (38±5 vs 32±3; P < 0.001). Receiver operating characteristic (ROC) analysis with O2PP <54% showed sensitivity and specificity of 67% and 90%, respectively. VE/VCO2 nadir ≥ 40 and VO2 peak < 10.8 mL/kg/min showed 44% and 56% of sensitivity and 100% and 90% of specificity respectively. CPET can improve the assessment of disease severity in patients with RMS with high specificity. The presence of higher O2PP, higher VO2 peak, and lower VE/VCO2 nadir highly suggests the absence of significant PH.