@article {FerreiraP4445, author = {Eloara Ferreira and Roberta Ramos and Jaquelina Arakaki and Priscila Barbosa and Erika Treptow and L. Eduardo Nery and Fabr{\'\i}cio Valois and J. Alberto Neder}, title = {Exercise ventilatory inefficiency is an independent predictor of mortality in patients with pulmonary arterial hypertension}, volume = {40}, number = {Suppl 56}, elocation-id = {P4445}, year = {2012}, publisher = {European Respiratory Society}, abstract = {Rationale: An excessive ventilatory (V{\textasciiacute}E) response to CO2 output (V{\textasciiacute}CO2) during incremental exercise is a strong prognosticator in cardiovascular diseases. The role of ΔV{\textasciiacute}E/ΔV{\textquoteright}CO2 to predict mortality in pulmonary arterial hypertension (PAH), however, remains to be demonstrated. Objective: To investigate the value of increased ΔV{\textquoteright}E/ΔV{\textquoteright}CO2 as a negative prognostic marker in PAH. Methods: 80 patients with PAH who underwent a ramp-incremental cardiopulmonary exercise test (CPET) were followed-up for 5 yrs. ΔV{\textquoteright}E/ΔV{\textquoteright}CO2 slope was calculated to the respiratory compensation point (ΔV{\textquoteright}E/ΔV{\textquoteright}CO2(start-RCP)) or to peak exercise (ΔV{\textquoteright}E/ΔV{\textquoteright}CO2(start-PEAK)). Results: 14 patients (17.5 \%) died of PAH-related causes. Compared to survivors, deceased patients were younger and had lower peak O2 uptake, O2 pulse, and oxyhemoglobin saturation but, regardless the method of calculation, higher ΔV{\textquoteright}E/ΔV{\textquoteright}CO2 (p\<0.05). None of the other variables (including the six-minute walking distance) was related to mortality (p\>0.05). The best cutoff to death prediction was higher for ΔV{\textquoteright}E/ΔV{\textquoteright}CO2(start-PEAK) (\>55) than ΔV{\textquoteright}E/ΔV{\textquoteright}CO2(start-RCP) (\>45). An univariate analysis revealed that the former variable was superior to the later on this regard (p= 0.004 vs. 0.02).In fact, a multiple regression analysis showed that resting heart rate (hazard ratio (95\% CI)= 1.04 (1.00-1.08); p=0.03) and ΔV{\textquoteright}E/ΔV{\textquoteright}CO2(start-PEAK) (1.04 (1.01-1.07); p= 0.006) were the only independent predictors of mortality. Conclusions: A resting variable (heart rate) and an effort-independent marker of ventilatory inefficiency (ΔV{\textquoteright}E/ΔV{\textquoteright}CO2(start-PEAK)) are clinically-useful markers of poor prognosis in patients with PAH.}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/40/Suppl_56/P4445}, eprint = {https://erj.ersjournals.com/content/40/Suppl_56/P4445.full.pdf}, journal = {European Respiratory Journal} }