Wilcox, Jennifer

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.

Background: Normative changes in right ventricular (RV) structure and function have not been characterized in the context of treatment-associated functional recovery (RV functional recovery [RVFnRec]). The aim of this study is to assess the clinical relevance of a proposed RVFnRec definition. Methods: We evaluated 63 incident patients with pulmonary arterial hypertension by right heart catheterization and cardiac magnetic resonance imaging at diagnosis and cardiac magnetic resonance imaging and invasive cardiopulmonary exercise testing following treatment (≈11 months). Sex, age, ethnicity matched healthy control subjects (n=62) with 1-time cardiac magnetic resonance imaging and noninvasive cardiopulmonary exercise testing were recruited from the PVDOMICS (Redefining Pulmonary Hypertension through Pulmonary Vascular Disease Phenomics) project. We examined therapeutic cardiac magnetic resonance imaging changes relative to the evidence-based peak oxygen consumption (VO 2peak )>15 mL/(kg·min) to define RVFnRec by receiver operating curve analysis. Afterload was measured as mean pulmonary artery pressure, resistance, compliance, and elastance. Results: A drop in RV end-diastolic volume of −15 mL best defined RVFnRec (area under the curve, 0.87; P =0.0001) and neared upper 95% CI RV end-diastolic volume of controls. This cutoff was met by 22 out of 63 (35%) patients which was reinforced by freedom from clinical worsening, RVFnRec 1 out of 21 (5%) versus no RVFnRec 17 out of 42, 40% (log-rank P =0.006). A therapy-associated increase of 0.8 mL/mm Hg in compliance had the best predictive value of RVFnRec (area under the curve, 0.76; [95% CI, 0.64–0.88]; P =0.001). RVFnRec patients had greater increases in stroke volume, and cardiac output at exercise. Conclusions: RVFnRec defined by RV end-diastolic volume therapeutic decrease of −15 mL predicts exercise capacity, freedom from clinical worsening, and nears normalization. A therapeutic improvement of compliance is superior to other measures of afterload in predicting RVFnRec. RVFnRec is also associated with increased RV output reserve at exercise.

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 > 0.208 for all), but defining iron deficiency as transferrin saturation (TSAT) <21% did. Compared to those with TSAT ≥21%, patients with TSAT <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 < 0.001). Patients with a TSAT <21% had more right ventricular remodeling on cardiac magnetic resonance but similar pulmonary vascular resistance on catheterization. Transferrin saturation <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 <21% identifies patients with lower exercise capacity, worse functional status, right heart remodeling, and adverse clinical outcomes.

Background: Invasive hemodynamic evaluation through right heart catheterization plays an essential role in the diagnosis, categorization, and risk stratification of patients with pulmonary hypertension. Methods: Subjects enrolled in the PVDOMICS (Redefining Pulmonary Hypertension through Pulmonary Vascular Disease Phenomics) program undergo an extensive invasive hemodynamic evaluation that includes repeated measurements at rest and during several provocative physiological challenges. It is a National Institutes of Health/National Heart, Lung, and Blood Institute initiative to reclassify pulmonary hypertension groups based on clustered phenotypic and phenomic characteristics. At a subset of centers, participants also undergo an invasive cardiopulmonary exercise test to assess changes in hemodynamics and gas exchange during exercise. Conclusions: When coupled with other physiological testing and blood -omic analyses involved in the PVDOMICS study, the comprehensive right heart catheterization protocol described here holds promise to clarify the diagnosis and clustering of pulmonary hypertension patients into cohorts beyond the traditional 5 World Symposium on Pulmonary Hypertension groups. This article will describe the methods applied for invasive hemodynamic characterization in the PVDOMICS program. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02980887.