Relationship of pulmonary arterial capacitance and mortality in idiopathic pulmonary arterial hypertension

J Am Coll Cardiol. 2006 Feb 21;47(4):799-803. doi: 10.1016/j.jacc.2005.09.054. Epub 2006 Jan 26.


Objectives: The purpose of this study was to determine if pulmonary vascular capacitance predicts survival in patients with idiopathic pulmonary arterial hypertension (IPAH).

Background: The prognosis of patients with IPAH is difficult to predict, despite knowledge of clinical and hemodynamic parameters previously identified as predictors.

Methods: We proposed a capacitance index of stroke volume divided by pulmonary pulse pressure (SV/PP) and prospectively gathered data on IPAH patients who underwent a right heart catheterization. SV/PP was analyzed as a predictor of mortality after adjusting for other modifiers of risk.

Results: During 4-year follow-up of 104 patients, 21 patients died. When compared with conventional markers, SV/PP was the strongest univariate predictor of mortality (hazard ratio 17.0 per Hg(-1) decrease, 95% confidence interval 13.0 to 22.0; p < 0.0001). In successive bivariate analysis, SV/PP was the only predictor of mortality. In quartile analysis, the lowest SV/PP quartile had a 4-year mortality of 61%; the highest SV/PP had no deaths.

Conclusions: The capacitance index (SV/PP) is a strong independent predictor of mortality in patients with IPAH.

MeSH terms

  • Adult
  • Cardiac Catheterization
  • Female
  • Hemodynamics
  • Humans
  • Hypertension, Pulmonary / mortality
  • Hypertension, Pulmonary / physiopathology*
  • Male
  • Middle Aged
  • Models, Statistical
  • Pulmonary Artery / physiopathology*
  • Stroke Volume
  • Survival Analysis
  • Survival Rate
  • Vascular Capacitance*