PURPOSE: In patients with chronic heart failure, the ventilatory equivalent for carbon dioxide (VE/CO2) measured during maximal cardiopulmonary exercise testing (CPET) can predict the mortality and the request for hospitalizations. The aim of this study was to assess the relationship between the VE/VCO2 and pulmonary function parameters, heart function at rest and clinical features in patients with dilated cardiomyopathy (DC).
METHODS: We studied 55 patients (41 M, age mean± SD: 55 yrs ±12) with DC in clinically stable conditions. All patients underwent pulmonary function testing, CPET and a transthoracic echocardiography (TE) with measurement of ejection fraction (EF). NYHA class was also recorded.
RESULTS: Mean ±SD values of FEV1, FEV1/VC, IC, TLC and TLCO were respectively: 92% pred. ± 16, 77% ± 6, 2.65 L ± 0.59, 91% pred ± 12, and 91± 24. Mean±SD values of V’O2 max, O2 pulse, VE/VCO2 and EF were respectively: 66% pred. ± 14, 11.6 mL/bpm ± 3.3, 32 ± 6 and 33 % ± 10. NYHA class ranged from I to III (median II). Correlations are shown in the table.
CONCLUSION: In patients with DC and impaired exercise capacity, the VE/VCO2 significantly correlated with pulmonary function parameters and the severity of disease, but not with EF.
CLINICAL IMPLICATIONS: Our findings showed that resting lung function rather than cardiac one is linked to the ventilatory equivalent for carbon dioxide in patients with dilatative cardiomyopathy.
DISCLOSURE: Antonio Castagnaro, None.