Goff, Zackary D.

Introduction: The right ventricle [RV] adapts to pulmonary hypertension [PH] by increasing contractility to maintain RV-PA coupling. With increased afterload, RV contractility cannot compensate, resulting in RV failure. TAPSE/RVSP ratio is a non-invasive measure of RV-PA coupling. We aim to assess TAPSE/RVSP ratio for predicting PH severity and survival across a spectrum of PH in the PVDOMICS cohort. Methods: PVDOMICS subjects from the 5 World Symposium PH groups and comparators were evaluated. TAPSE/RVSP ratio, in mm/mmHg, was derived for each group. PH subjects were stratified by TAPSE/RVSP ratio into low < 0.19, intermediate ≥ 0.19 to < 0.32, and high ratio > 0.32. The relationship between the ratio and RHC parameters (mean PA pressure [mPAP] and pulmonary vascular resistance [PVR]), and between-group differences were evaluated by one-way ANOVA. Kaplan-Meier curves and log-rank tests were used to characterize and compare survival between groups. Results: Data were available for 514 PH subjects (58 ± 15 yrs, 64% female) and 179 comparators (61 ± 13 yrs, 59% female). Mean TAPSE/RVSP ratio was 0.35 ± 0.18 in PH vs 0.63 ± 0.26 in comparators (p < 0.001). Mean TAPSE/RVSP across the PH groups 1-5 were similar, 0.33 ± 0.19, 0.33 ± 0.16, 0.37 ± 0.15, 0.41 ± 0.21 and 0.43 ± 0.29 (p=NS). Within PH subjects, 99 (19.2%) had low, 173 (33.7%) had intermediate and 242 (47.1%) had high ratio. Those with low ratio had higher mPAP (53.6 ± 11.8 mmHg), compared to intermediate (44.6 ± 11.7 mmHg) and high ratio (34.1 ± 10.2 mmHg) [p < 0.001]. Those with low ratio had higher PVR (10.1 ± 5.1 WU), compared to intermediate (6.8 ± 4.1 WU) and high ratio (4.1 ± 2.1 WU) [p < 0.001]. Survival was significantly higher for those with high TAPSE/RVSP ratio compared to those with low ratio (p < 0.001) [Figure]. Discussion: TAPSE/RVSP ratio correlates well with invasive markers to predict PH severity. This useful measure of RV-PA coupling also enables stratification for outcome, with ratio > 0.32 having the best survival rates.

Introduction: Assessment of right ventricular (RV) size and function by echo is challenging due to complex RV anatomy and requires integration of multiple measurements. We sought to compare accuracy of echo measures of RV size and function with cardiac MRI (CMR) in pulmonary hypertension (PH). Methods: We included patients with PH from the PVDOMICS Study who underwent both echo and CMR. Echo measures of RV size (basal dimension, area, 3D volume) and function (fractional area change [FAC], 3D RV ejection fraction [EF], RV global longitudinal strain [GLS], S’, TAPSE, Tei index) were compared to CMR derived RV volumes and RVEF. Agreement was assessed using Bland-Altman (BA) plots and Lin’s concordance correlation coefficients (ρ c ). Predictive trends were evaluated using linear regression. Results: The cohort included 446 subjects (58 ± 15 yrs, 36% male). Echo measures of RV size showed poor agreement with CMR, but substantial linear associations, when comparing CMR end diastolic volume (EDV) with: echo basal dimension (ρ c = 0.002; β = 60, R 2 = 0.47), end-diastolic area (ρ c = 0.04, β = 6.4, R 2 = 0.64), and 3D EDV (bias = 106, limits of agreement [LOA]: -14.1 to 225); and also when comparing CMR end-systolic volume (ESV) with: end-systolic area (ρ c = 0.08; β = 6.8, R 2 = 0.74) and 3D ESV (bias = 67.3, LOA: -31.8 to 166). Select echo measures of RV function demonstrated better agreement with CMR RVEF including: 3D RVEF (bias -0.23, LOA -17.9 to 17.5) and FAC (ρ c = 0.55; β = 0.89, R 2 = 0.50). Others exhibited modest or poor agreement including: RV GLS (ρ c = 0.11; β = -1.5, R 2 = 0.40), along with S’, TAPSE, and Tei index (ρ c ≤ 0.02; R 2 ≤ 0.19 for all). [Figure] Discussion: In this largest comparison of echo vs CMR measures of RV assessment in PH, echo measures of RV size agreed poorly with CMR, especially at larger RV volumes. RV functional assessment was best with echo 3D RVEF and FAC, which should be preferentially used for echo RV functional assessment. Consider CMR for more accurate volume assessment of RV size.