Toward Improved Risk Stratification in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is progressive and evetually results in right ventricular (RV) failure and death. RV function primarily determines prognosis. There are limited clinical measurements available to guide risk stratification for PAH patients.

Pulmonary arterial proportional pulse pressure (PAPP) reflects the RV adaptive response to increased afterload and there is some evidence to suggest that low PAPP is a powerful predictor of poor prognosis in advanced HF.¹

The slides that follow summarize a recent study that investigates the use of PAPP as a novel and easily measured index to guide risk stratification in PAH. 

Data from the NIH Primary Pulmonary Hypertension Registry; 262 patients with WHO group 1 pulmonary HTN; assessed ability of PAPP to predict 5-year mortality; also used Pulmonary Hypertension Connection risk equation; validated in prediction of PAH survival. (3)

Results: Pulmonary arterial proportional pulse pressure </= .47 linked to significanlty worse right ventricular function.

Results: PAPP ≤ .47 linked to 58% increased risk of 5-year mortality, vs PAPP > .47; independent association remained after adjusting for the PHC equation. Adding PAPP to PHC risk equation improved predictive value by 56%.

Study limitations include: retrospective analysis; no ECHO images available; results may not generalize to current patient groups.

Authors' comment: "PAPP is independently associated with survival in WHO group 1 PH and adds significant predictive power for all-cause mortality when used in combination with the PHC equation. ..."

Study Take-home Points: Retrospective analysis of NIH data suggests low PAPP, an index of ventricular-arterial coupling, is independently linked to worse survival in WHO group 1 pulmonary hypertension. Adding PAPP to the PHC equation may increase power to predict 5-year mortality; further studies are needed  .