RT Journal Article
SR Electronic
T1 Survival in patients with IPAH and peak exercise ventilatory limitation
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP PA2416
DO 10.1183/13993003.congress-2016.PA2416
VO 48
IS suppl 60
A1 Colm McCabe
A1 Rocco Rinaldi
A1 Luke Howard
YR 2016
UL http://erj.ersjournals.com/content/48/suppl_60/PA2416.abstract
AB Background: The broadening demographic of IPAH means classical outcome predictors may not universally apply. With increasing prevalence of lung disease in IPAH, we characterised haemodynamics and exercise parameters in patients with IPAH and ventilatory limitation (VL) to exercise.Methods: Contemporary cardiopulmonary exercise test (CPET) and haemodynamic data were analysed in IPAH patients at diagnosis. VL was defined by a residual %breathing reserve of <20% at peak exercise. Cox regression was used to determine survival predictors with adjustments for age, sex and drug treatment.Results: 76 patients had CPET and RHC data with survival calculated to over five years. Patients with IPAH and VL had worse survival compared to those with non-VL (p=0.048, Logrank) , despite similar peak exercise capacity (peak VO2:12.2±0.9vs11.7±0.6 ml/Kg) and haemodynamic profile (mPAP 48±2vs46±3mmHg (p=0.56), PVR 11.6±1.4vs11.4±0.8WU (p=0.92)). Improved survival was strongly predicted by high mixed venous oxygen saturation (p<0.001) and cardiac index (p=0.01). Resting lung function, Ve/VCO2 slope or Vd/Vt did not discriminate patients with VL and non-VL.Discussion: These data suggest a negative prognostic impact of VL in IPAH. IPAH patients are classically limited by impaired stroke volume relative to demand but factors affecting exercise ventilatory responses are less understood. Patients with IPAH and VL warrant wider evaluation to understand its long term relevance.