Smetana, Michael Robert

Background Heart failure (HF) is associated with impaired exercise pulmonary gas exchange (PGX) that is likely related to the development and severity of pulmonary hypertension (PH). Purpose To determine whether PGX measures differentiate HF patients with reactive PH from patients with passive PH or no PH. Methods/Results Pulmonary arterial pressure (P AP ), pulmonary wedge pressure (P WP ), transpulmonary pressure gradient (TPG) and PGX indices [end‐tidal CO 2 (P ET CO 2 ), ventilatory efficiency (V E /VCO 2 ), O 2 pulse, estimated pulmonary arterial capacitance (GX CAP )] were assessed simultaneously at rest and during cycle exercise in 38 HF patients undergoing right heart catheterization. Post hemodynamic evaluation, patients were classified as having no PH ( n = 12), passive PH ( n = 10) or reactive PH ( n = 16). TPG increased during exercise in all groups but was greater at end exercise in the reactive PH vs. the passive PH and no PH patients (21±9 vs. 14±7 vs. 12±7 mmHg). At an equivalent VO 2 , P ET CO 2 , O 2 pulse and GX CAP were higher and V E /VCO 2 ratio lower in the no PH and, to a lesser extent, in the passive PH vs. the reactive PH subjects (Figure 1). Conclusion Noninvasive measures of PGX during exercise appear to differentiate HF patients with reactive PH from patients with passive PH or no PH and may be a useful adjunct to invasive catheterization in assessing PH type and severity. HL71478, AHA12POST12070084, Gilead Science