Abstract 12735: Differences in the Tolerable Threshold of Right Ventricular Volume Predict Adverse Events in Patients With Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension
Introduction: Right ventricular (RV) volume measurements may predict short term prognosis in patients with pulmonary arterial hypertension (PAH) and chronic pulmonary thromboembolic pulmonary hypertension (PH) (CTEPH) but quantitative thresholds of RV volume that predict occurrence of adverse events (AE) may differ between both groups.
Hypothesis: To evaluate tolerance of RV volume in PAH and CTEPH patients by comparing quantitative thresholds of RV end diastolic (RVEDV) and end systolic volume (RVESV) by CT as predictors of AE.
Method: 43 confirmed PH patients (14 PAH (4 males, 49 ± 16 yrs) and 29 CTEPH patients (9 males, 58 ± 15 yrs) underwent retrospective ECG gated 320 slice CT (Aquilion one). CT images were reconstructed every 5% from 0-95% of ECG R-to-R interval and RVEDV and RVESV were measured. Subjects were followed for a median of 31.5 months for PAH and 21 months for CTEPH. AE included cardiac death and hospitalization due to heart failure.
Results: AE occurred in 2 PAH and 3 CTEPH patients. Receiver operating characteristic (ROC) curves of RVEDV and RVESV showed the best cutoff points to distinguish PAH patients with and without AEs were 264.8 cm3 for RVEDV(sensitivity 50%, specificity 100%) and 215.3 cm3 for RVESV (sensitivity 50%, specificity 100%) with AUC of 0.708 and 0.667, respectively. Other ROC curves of RVEDV and RVESV showed the best cutoff points to distinguish CTEPH patients with and without AEs were 210.3 cm3 for RVEDV(sensitivity 100%, specificity 92.3%) and 152.6 cm3 for RVESV (sensitivity 100%, specificity 92.3%) with AUC of 0.923 and 0.923, respectively. There were significant differences by Kaplan Meier analysis in incidence of AEs for PAH patients with RVEDV ≥ and < 264.8 cm3 (P=0.038) and with RVESV ≥ and < 215.3 cm3 (P=0.038) and for CTEPH patients with RVEDV ≥ and < 210.3 cm3 (P<0.001) and with RVESV ≥ and < 152.6 cm3 (P<0.001), respectively.
Conclusion: RVEDV and RVESV measurements by CT could predict short term prognosis in PAH and CTEPH patients. Quantitative thresholds of RVEDV and RVESV that predict occurrence of AE were greater in PAH than in CTEPH patients. This difference may be due to presence of specific and effective therapy, such as pulmonary endarterectomy in CTEPH, or etiological and pathological differences between groups.
Author Disclosures: K. Ozawa: None. N. Funabashi: None. H. Takaoka: None. N. Tanabe: None. K. Tatsumi: None. Y. Kobayashi: None.
- © 2014 by American Heart Association, Inc.