To identify better predictors of early death in patients with chronic obstructive pulmonary disease (COPD) using potential predictors derived from key measures obtained from cardiopulmonary exercise testing (CPET).
This is a prospective, cohort study with 42-month follow-up in 126 COPD patients. Every patient completed the clinical evaluation, followed by a pulmonary function test and CPET. CPET was performed on a cycle ergometer with electromagnetic braking and ventilatory expired analysis was measured breath-by-breath using a computer-based system. Peak oxygen consumption (V̇O mlO kg min), minute ventilation/carbon dioxide production and the, minute ventilation (V̇, L/min), and the V̇/carbon dioxide production (V̇/V̇CO) slope were obtained from CPET.
48 (38%) patients died during the 42-month follow-up. Kaplan Meier analysis revealed a V̇/V̇CO slope ≥30, peak V̇ ≤ 25.7L/min and peak V̇O ≤ 13.8 mlO kg minwere strong predictors of mortality in COPD patients. Cox regression revealed that the V̇O peak ≤13.8 mlO kg min (CI 95% 0.08-0.93), V̇/V̇CO slope ≥30 (CI 95% 0.07-0.94), V̇ peak ≤25.7 L/min (CI 95% 0.01-0.15), Sex (CI 95% 0.04-0.55) and Age (CI 95% 1.03-1.2) were the main predictors of mortality risk.
Diminished exercise capacity and peak ventilation as well as ventilatory inefficiency are independent prognostic markers. Similar to patients with heart failure, CPET may be a valuable clinical assessment in the COPD population.

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