Abstract 21207: Comprehensive Assessment of Right Ventricular-Pulmonary Arterial Coupling Predicts Outcome in Pulmonary Hypertension
Background: Right ventricular (RV) dysfunction confers poor prognosis in pulmonary hypertension (PH). However, predicting which patients will do poorly and when remains difficult. Hemodynamic calculations of RV-pulmonary arterial (PA) coupling have been used to explain the altered physiology in PH. We hypothesized that such measures may be of prognositic value.
Methods: Patients (n=27) underwent right heart catheterization with a standard 7F fluid-filled (PA) catheter and ECG-gated multislice CT (MSCT) of the chest with IV contrast timed to opacify the RV. Tests were performed within 48 hours. RV volumes were assessed by MSCT. Primary outcome was time to death, lung transplant, or hospitalization. Cox proportional hazard ratio was calculated for each variable.
Results: Patient characteristics: age 52 ± 12, 9 males, mean PA pressure range 13–79 mmHg. Mean follow-up was 827 ± 137 days. There were 3 deaths and 7 lung transplants. Several variables were predictive of outcomes but with small effect (heart rate, baseline 6-minute walk, RVEF; table). However, the ratio of RV end-systolic elastance to RV effective arterial elastance (RV Ees/Ea, a measure RV-PA coupling) had a large protective effect on outcomes (HR 0.137). RV Ees/Ea was significantly lower in those reaching an endpoint (0.34 ± 0.19 vs. 0.84 ± 0.52, P = 0.002). Other variables were not significant (right atrial pressure, mean PA pressure, PVR, RV compliance, RV stroke volume/work, peak power index).
Conclusions: While some previously reported factors are predictive of outcomes in PH, their overall effect is relatively small. Hemodynamic calculations of RV-PA coupling offer a more thorough assessment and at least one such measure, RV Ees/Ea, had a large protective effect on outcomes in this pilot study. Reduced RV contractility (Ees) relative to arterial elastance (Ea) may clarify the link between observed RV function and outcomes in PH. Future studies of PH outcomes should utilize RV-PA coupling terms.
- © 2010 by American Heart Association, Inc.