Post-treatment pulmonary arterial compliance best predicts PAH prognosis
medwireNews: Evaluation of pulmonary arterial compliance (PCa) after initiation or escalation of therapy for pulmonary arterial hypertension (PAH) more accurately predicts prognosis than conventional right heart hemodynamic parameters, Italian study findings indicate.
The researchers say that their “study reinforces the concept that repeated hemodynamic evaluations are clinically important in the follow-up of PAH patients hospitalized to initiate or to escalate PAH-specific therapy and strongly supports the calculation of PCa, since failure to improve PCa above 1.4 mL/mmHg after therapy appears to be a strong hemodynamic predictor of poor prognosis.”
A total of 419 consecutive PAH patients admitted to four pulmonary hypertension referral centers in Italy underwent right heart catheterization (RHC) prior to initiating (n=308) or escalating (n=111) PAH-targeted therapy between 2004 and 2012.
Of these, 255 (61%) underwent a follow-up RHC within 1 year (median 8 months), 62 (15%) died, and 102 (24%) did not receive follow-up RHC.
During the subsequent 39-month median follow-up period, 63 of the patients who received a second RHC died.
Multivariate analysis showed that poor prognosis after therapy initiation or escalation was significantly associated with being over 50 years of age (hazard ratio [HR]=2.03, p=0.050), male gender (HR=1.92, p=0.048), etiology associated with systemic sclerosis (HR=2.26, p=0.016), persistence of World Health Organization class III/IV (HR=2.06, p=0.033), and reduced PCa at follow-up RHC (HR=0.40, p<0.001).
By contrast, there was no significant association with mean pulmonary artery pressure, right atrial pressure, cardiac index (CI), or pulmonary vascular resistance (PVR).
The optimal cutoff for PCa to predict survival, calculated by receiver operating characteristic curve analysis, was 1.4 mL/mmHg at follow-up RHC.
At this cutoff, the sensitivity and specificity for predicting survival were 81.8% and 58.8%, respectively, while the Kaplan-Meier probability of survival was around 95% at 24 months for patients with PCa at or above 1.4 mL/mmHg compared with 80% for those with lower PCa at follow-up RHC.
Writing in the International Journal of Cardiology, Stefano Ghio (Fondazione IRCCS Policlinico S.Matteo, Pavia) and co-authors stress that their study “does not deny the role of other hemodynamic predictors of prognosis, in particular of CI, which was confirmed as an independent predictor in the present population when analyzing baseline data.”
Furthermore, PCa was not a statistically better prognostic indicator than CI at baseline, “thus, it could be hypothesized that the prognostic relevance of PCa calculated after therapy initiation or escalation resides in its apparent ability to describe the effects of targeted therapy on [right ventricular] afterload more precisely than the changes in PVR or CI,” the researchers remark.
By Laura Cowen
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