Pulmonary Vascular Response Patterns During Exercise in Left Ventricular Systolic Dysfunction Predict Exercise Capacity and Outcomes

Abstract

Elevated resting pulmonary arterial pressure (PAP) in patients with left ventricular systolic dysfunction (LVSD) purports a poor prognosis. However, PAP response patterns to exercise in LVSD and their relationship to functional capacity and outcomes have not been characterized. Sixty consecutive patients with LVSD (age 60±12 years, left ventricular ejection fraction 0.31±0.07, mean±SD) and 19 controls underwent maximum incremental cardiopulmonary exercise testing with simultaneous hemodynamic monitoring. During low-level exercise (30 W), LVSD subjects, compared with controls, had greater augmentation in mean PAPs (15±1 versus 5±1 mm Hg), transpulmonary gradients (5±1 versus 1±1 mm Hg), and effective pulmonary artery elastance (0.05±0.02 versus −0.03±0.01 mm Hg/mL, P P 2 (10.6±2.6 versus 13.1±4.0 mL · kg ⁻¹ · min ⁻¹ , P =0.005), lower right ventricular stroke work index augmentation with exercise (5.7±3.8 versus 9.7±5.0 g/m ² , P =0.002), and increased mortality (hazard ratio 8.1, 95% CI 2.7 to 23.8, P <0.001). A steep increment in PAP during exercise and failure to augment PAP throughout exercise are associated with decreased exercise capacity and survival in patients with LVSD, and may therefore represent therapeutic targets. URL: http://www.clinicaltrials.gov . Unique identifier: NCT00309790.