Yu, Shilin

Abstract Aims Patients with pulmonary hypertension (PH) are grouped based upon clinical and haemodynamic characteristics. Groups 2 (G2, left heart disease [LHD]) and 3 (G3, lung disease or hypoxaemia) are most common. Many patients display overlapping characteristics of heart and lung disease (G2–3), but this group is not well-characterized. Methods and results Patients with PH enrolled in the prospective, NHLBI-sponsored PVDOMICS network underwent intensive clinical, biomarker, imaging, gas exchange and exercise phenotyping. Patients with pure G2, pure G3, or overlapping G2–3 PH were compared across multiple phenotypic domains. Of all patients with predominant G2 (n = 136), 66 (49%) were deemed to have secondary lung disease/hypoxaemia contributors (G2/3), and of all patients categorized as predominant G3 (n = 172), 41 (24%) were judged to have a component of secondary LHD (G3/2), such that 107 had G2–3 (combined G2/3 and G3/2). As compared with G3, patients with G2 and G2–3 were more obese and had greater prevalence of hypertension, atrial fibrillation, and coronary disease. Patients with G2 and G2–3 were more anaemic, with poorer kidney function, more cardiac dysfunction, and higher N-terminal pro-B-type natriuretic peptide than G3. Lung diffusion was more impaired in G3 and G2–3, but commonly abnormal even in G2. Exercise capacity was severely and similarly impaired across all groups, with no differences in 6-min walk distance or peak oxygen consumption, and pulmonary vasoreactivity to nitric oxide did not differ. In a multivariable Cox regression model, patients with G2 had lower risk of death or transplant compared with G3 (hazard ratio [HR] 0.51, 95% confidence interval [CI] 0.30–0.86), and patients with G2–3 also displayed lower risk compared with G3 (HR 0.57, 95% CI 0.38–0.86). Conclusions Overlap is common in patients with a pulmonary or cardiac basis for PH. While lung structure/function is clearly more impaired in G3 and G2–3 than G2, pulmonary abnormalities are common in G2, even when clinically judged as isolated LHD. Further study is required to identify optimal systematic evaluations to guide therapeutic innovation for PH associated with combined heart and lung disease. Clinical Trial Registration: ClinicalTrials.gov NCT02980887.

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.

Abstract Aims Iron deficiency is common in pulmonary hypertension, but its clinical significance and optimal definition remain unclear. Methods and results Phenotypic data for 1028 patients enrolled in the Redefining Pulmonary Hypertension through Pulmonary Vascular Disease Phenomics study were analyzed. Iron deficiency was defined using the conventional heart failure definition and also based upon optimal cut-points associated with impaired peak oxygen consumption (peakVO2), 6-min walk test distance, and 36-Item Short Form Survey (SF-36) scores. The relationships between iron deficiency and cardiac and pulmonary vascular function and structure and outcomes were assessed. The heart failure definition of iron deficiency endorsed by pulmonary hypertension guidelines did not identify patients with reduced peakVO2, 6-min walk test, and SF-36 (P &gt; 0.208 for all), but defining iron deficiency as transferrin saturation (TSAT) &lt;21% did. Compared to those with TSAT ≥21%, patients with TSAT &lt;21% demonstrated lower peakVO2 [absolute difference: −1.89 (−2.73 to −1.04) mL/kg/min], 6-min walk test distance [absolute difference: −34 (−51 to −17) m], and SF-36 physical component score [absolute difference: −2.5 (−1.3 to −3.8)] after adjusting for age, sex, and hemoglobin (all P &lt; 0.001). Patients with a TSAT &lt;21% had more right ventricular remodeling on cardiac magnetic resonance but similar pulmonary vascular resistance on catheterization. Transferrin saturation &lt;21% was also associated with increased mortality risk (hazard ratio 1.63, 95% confidence interval 1.13–2.34; P = 0.009) after adjusting for sex, age, hemoglobin, and N-terminal pro-B-type natriuretic peptide. Conclusion The definition of iron deficiency in the 2022 European Society of Cardiology (ESC)/European Respiratory Society (ERS) pulmonary hypertension guidelines does not identify patients with lower exercise capacity or functional status, while a definition of TSAT &lt;21% identifies patients with lower exercise capacity, worse functional status, right heart remodeling, and adverse clinical outcomes.