Cardiopulmonary Exercise Testing as a Diagnostic Tool for the Detection of Left-sided Pulmonary Hypertension in Heart Failure

Background: Recently, it has become increasingly recognized that pulmonary hypertension (PH) is a particularly ominous consequence of left-sided heart failure (HF). The primary aim of this investigation was to assess the ability of key cardiopulmonary exercise testing (CPX) variables to detect elevated pulmonary pressures in a HF cohort. Methods: This was a retrospective analysis of a prospectively collected database. Two hundred ninety-three subjects with HF (63 +/- 10 years old, 79% male) underwent Doppler echocardiography to estimate resting pulmonary artery systolic pressure (PASP). Peak oxygen consumption (VO2), the minute ventilation/carbon dioxide production (VE/VCO2) slope, peak partial pressure of end-tidal CO2 (PETCO2) and exercise oscillatory ventilation (EOV) were determined. Results: Forty-six percent (n = 134) of the subjects presented with a PASP >= 40 mm Hg. A VE/VCO2 slope = 36.0 was the best predictor of a PASP >= 40 mm Hg (odds ratio [OR] 12.1, 95% confidence interval [CI] 6.8-21.4; P < .001). Peak PETCO2 <= 34 mm Hg (OR 3.8, 95% CI 1.3-11.2; P < .001) and the presence of EOV (OR 3.2, 95% CI 1.8-5.8; P < .001) added significant diagnostic value. Conclusions: Although CPX is an established prognostic assessment in the HF population, the results of the present investigation indicate that it may also have important diagnostic utility for PH.