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Clinical and Hemodynamic Factors Associated with Prognosis in Pulmonary Arterial Hypertension (PAH)

Garvan Kane


J. P. Slusser

C. G. Scott

H Maradit-Kremers

Michael McGoon


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Conference: 2008 International PHA Conference and Scientific Sessions

Release Date: 06.20.2008

Presentation Type: Abstracts

Kane G.C., Slusser J.P., Scott C.G., Maradit-Kremers H., McGoon M.D.

Mayo Clinic, Rochester, MN, USA

BACKGROUNDTreatment guidelines for PAH rely mainly on functional class in guiding aggressiveness of therapy. There is limited evidence as to the incremental prognostic value of clinical and hemodynamic factors. The purpose of our study was to examine the association between echocardiography (Echo), right heart catheterization (RHC) and pulmonary function test (PFT) findings and mortality in a large contemporary cohort of patients with PAH.

METHODSThis is a retrospective cohort study and included all adult PAH subjects treated at a large referral center in the USA between 1/1/1995–12/31/2004.  The original medical records of each subject were reviewed to collect data on demographics, disease etiology, clinical and hemodynamic characteristics.  Disease etiology was classified according to WHO classification and included idiopathic PAH (IPAH), PAH associated with connective tissue diseases (PAHc) and other conditions.  Predictors of mortality were assessed sequentially using Cox models, first considering only echo and PFT findings and finally RHC findings.   

RESULTSThe study included 657 PAH patients with a mean age of 53.6 (±15.9) years and 77% were female.  Mean disease duration at start of follow-up was 2.4 (±2.7) years. A total of 366 (55.7%) subjects had IPAH and 154 (23.4%) subjects had PAHc with median survival of 3.8 and 2.8 years, respectively. Females had a lower risk of death than males (HR: 0.67, 95% CI 0.53, 0.85).  In analyses adjusted for age, sex, functional class and baseline 6-min walk, various echo, RHC and PFT findings were significant predictors of mortality (Table).  In multivariable analyses that included age, sex, functional class and baseline 6-min walk test, RV enlargement (HR: 1.43, 95% CI 1.10, 1.86), pericardial effusion (HR: 1.37, 95% CI 1.07, 1.76) and % DLCO (HR: 0.98, 95% CI 0.97, 0.99) remained significant predictors of mortality. Upon inclusion of RHC findings, RA pressure (HR: 1.03, 95% CI 1.01, 1.06), pulmonary vascular resistance index (HR: 1.02, 95% CI 1.00, 1.04) and vasodilator response (HR: 0.93, 95% CI 0.88, 0.99 per 10% decrease in pvri) predicted mortality.  Concordance index (C statistic) showed that hemodynamic variables significantly improved the prediction of a model that already included functional class (0.686 vs. 0.734).

CONCLUSIONSThese findings indicate the additive predictive value of clinical, echocardiographic and invasive hemodynamic variables in the prediction of survival in PAH patients. There is a need to extend the treatment guidelines beyond functional class to also include these factors.  

Hazard ratio for death (95% CI)*

Echo & PFT findings

RHC findings

≥ mod RA enlargement

1.45 (1.16, 1.81)

RA pressure

1.05 (1.03, 1.08)

≥ mod RV enlargement

1.72 (1.36, 2.19)

Mean PA pressure

1.01 (1.00, 1.02)

≥ mod TV regurgitation

1.43 (1.15, 1.77)

Cardiac index

0.70 (0.59, 0.84)

Est. RA pressure (>10 versus ≤10 mmHg)

1.07 (1.05, 1.10)

PaO2 saturation

0.97 (0.96, 0.98)

≥ mod RV syst dysfunction

1.42 (1.14, 1.77)

PAP/syst BP ratio

3.09 (1.45, 6.60)

RV performance index

1.57 (1.02, 2.41)

Pulm vasc resistance index

1.03 (1.01, 1.04)

Pericardial effusion

1.69 (1.34, 2.12)

Vasodilator response

0.99 (0.65, 1.51)

DLCO (%)

0.97 (0.97, 0.98)

Vasodilator response (per 10% decrease in pvri)

1.00 (0.95, 1.05)

* Univariately adjusted for age, sex, functional class and 6 min walk test

 

Funding for this study was provided by Pfizer