Reddy, Yogesh N.V.

AbstractPulmonary hypertension (PH) associated with chronic kidney disease (CKD) (PH‐CKD) affects approximately 20%–40% of CKD patients and is associated with increased morbidity and mortality. PH and CKD are both pathophysiologically associated with nitric oxide (NO) deficiency. The NO pathway, an important therapeutic domain in pulmonary arterial hypertension (PAH), is an intriguing but unexplored target in PH‐CKD. We sought to improve understanding of the clinical significance of the NO pathway in patients with PH‐CKD by assessing the hemodynamic response to inhaled NO (iNO) during right heart catheterization (RHC). In this retrospective cohort study, patients with diagnosis codes of PH and stage IV/V CKD or end‐stage renal disease and estimated glomerular filtration rate < 60 mL/min/body surface area who underwent RHC and hemodynamic drug study between July 2011 and June 2021 were eligible. Patients with mean pulmonary artery pressure (mPAP) > 20 mmHg and pulmonary vascular resistance (PVR) > 3 Wood units were included. The final cohort included 37 patients (45.9% female, mean age 72.5 ± 9.7 years). A total of 56.7% of the cohort (21/37) had precapillary PH, while 43.2% (16/37) had combined precapillary postcapillary PH (Cpc‐PH). Median survival was 3.1 years after RHC. iNO was associated with a significant decrease in both mPAP and PVR. Hemodynamic changes in mPAP and PVR were similar in precapillary and Cpc‐PH groups. Among a small subset (n = 14) who were subsequently treated with PAH‐targeted therapy, treatment response was mixed and did not reveal significant benefit. Further studies are warranted to better define the potential role of PAH therapy in PH‐CKD.

AbstractChronic lung disease (CLD) is the second leading cause of pulmonary hypertension (PH) and is associated with significant morbidity and mortality. Although PH associated with CLD (PH‐CLD) leads to impaired health‐related quality of life (HRQOL), there are no validated tools to assess HRQOL in PH‐CLD. The Pulmonary Arterial Hypertension–Symptoms and Impact Questionnaire (PAH‐SYMPACT) is an HRQOL instrument aimed at assessing the symptoms and impact of PH on overall function and well‐being. We performed a single‐center prospective cohort study using PAH‐SYMPACT scores to compare symptoms, exercise capacity and HRQOL in patients with PAH and PH‐CLD. One hundred and twenty‐five patients (99 patients with idiopathic/heritable PAH and 26 with PH‐CLD) completed the PAH‐SYMPACT questionnaire which consists of 22 questions that assess HRQOL across four domains: cardiopulmonary (CP) symptoms, cardiovascular (CV) symptoms, physical impact (PI), and cognitive/emotional (CE) impact. Higher scores indicate worse HRQOL. We compared patients with PAH and PH‐CLD using a Wilcoxon rank sum or chi‐squared test as appropriate. Multivariate linear regression analysis was used to assess the relationship between PH classification and SYMPACT scores. Compared to PAH, patients with PH‐CLD were older, more likely to use oxygen and had worse functional class and exercise capacity. While there was no significant difference between the two groups in CP, CV, or CE domain scores, patients with PH‐CLD had significantly worse PI scores by univariate (1.79 vs. 1.13, p < 0.001) and multivariate analysis (1.61 vs. 1.17, p = 0.02) and overall worse SYMPACT scores (1.19 vs. 0.91, p = 0.03). In conclusion, patients with PH‐CLD have worse HRQOL as assessed by the PAH‐SYMPACT questionnaire versus patients with PAH. Although PAH‐SYMPACT has not been validated in PH‐CLD, the results of this study can guide clinicians in understanding the symptoms and impact of PH‐CLD relative to PAH.

Abstract Aims We aimed to clarify the extent to which cardiac and peripheral impairments to oxygen delivery and utilization contribute to exercise intolerance and risk for adverse events, and how this relates to diversity and multiplicity in pathophysiologic traits. Methods and results Individuals with heart failure with preserved ejection fraction (HFpEF) and non-cardiac dyspnoea (controls) underwent invasive cardiopulmonary exercise testing and clinical follow-up. Haemodynamics and oxygen transport responses were compared. HFpEF patients were then categorized a priori into previously-proposed, non-exclusive descriptive clinical trait phenogroups, including cardiometabolic, pulmonary vascular disease, left atrial myopathy, and vascular stiffening phenogroups based on clinical and haemodynamic profiles to contrast pathophysiology and clinical risk. Overall, patients with HFpEF (n = 643) had impaired cardiac output reserve with exercise (2.3 vs. 2.8 L/min, p = 0.025) and greater reliance on peripheral oxygen extraction augmentation (4.5 vs. 3.8 ml/dl, p &lt; 0.001) compared to dyspnoeic controls (n = 219). Most (94%) patients with HFpEF met criteria for at least one clinical phenogroup, and 67% fulfilled criteria for multiple overlapping phenogroups. There was greater impairment in peripheral limitations in the cardiometabolic group and greater cardiac output limitations and higher pulmonary vascular resistance during exertion in the other phenogroups. Increasing trait multiplicity within a given patient was associated with worse exercise haemodynamics, poorer exercise capacity, lower cardiac output reserve, and greater risk for heart failure hospitalization or death (hazard ratio 1.74, 95% confidence interval 1.08–2.79 for 0–1 vs. ≥2 phenogroup traits present). Conclusions Though cardiac output response to exercise is limited in patients with HFpEF compared to those with non-cardiac dyspnoea, the relative contributions of cardiac and peripheral limitations vary with differing numbers and types of clinical phenotypic traits present. Patients fulfilling criteria for greater multiplicity and diversity of HFpEF phenogroup traits have poorer exercise capacity, worsening haemodynamic perturbations, and greater risk for adverse outcome.

Introduction: Isolated functional tricuspid regurgitation (FTR) in the absence of structural heart disease may develop secondary to elevation in left heart pressures caused by left ventricular diastolic dysfunction (DD), as in heart failure with preserved ejection fraction (HFpEF). FTR may also herald the presence of occult DD or indicate greater risk for new-onset DD. However, prevalence and incidence of diastolic dysfunction (DD) in isolated FTR have not been studied. Aims: Investigate the prevalence and incidence of DD across the different severities of FTR of unclear cause. Methods: Adults with normal EF and without structural heart disease undergoing echocardiography at a tertiary medical center with a repeat study ≥6 months from baseline were identified. Severe DD was defined by ≥3/4 abnormal DD parameters (medial e’, medial E/e’, tricuspid regurgitation velocity, left atrial volume index) and moderate DD by ≥2. Results: Among 30,428 patients (median age 60; 50% women), FTR was absent in 73%, mild in 22%, moderate in 4%, and severe in 0.4%. Severe DD was present in 2%, 5%, 11%, and 13% patients, respectively, (p<.001) and moderate DD in 9%, 19%, 31%, and 48%, respectively (p<.001). The association of DD with increasing FTR was independent of all clinical characteristics. Over median 3.0 (IQR 1.5-5.4) years, incident severe and moderate DD developed more frequently with increasing FTR severity ( Figure) . Findings were confirmed in a propensity-matched subset where patients were matched for age, sex, BMI, atrial fibrillation, and comorbidities and in patients without lung disease or ≥moderate right ventricular enlargement. Conclusions: Patients with FTR of undefined etiology commonly have DD suggesting the presence of underlying left heart disease. Patients without apparent DD or HF at baseline who have FTR remain at significantly increased risk of developing DD over follow-up and may be a target population for therapies to prevent progression to clinical HFpEF.

ABSTRACT Aim Left atrial (LA) myopathy is increasingly recognized as an important phenotypic trait in heart failure (HF) with preserved ejection fraction (HFpEF). Right atrial (RA) remodelling and dysfunction also develop in HFpEF, but little data are available regarding the clinical characteristics and pathophysiology among patients with isolated LA, RA, or biatrial myopathy. Methods and results Patients with HFpEF underwent invasive haemodynamic exercise testing, comprehensive imaging including speckle tracking strain echocardiography, and clinical follow-up at Mayo Clinic between 2006 and 2018. LA myopathy was defined as LA volume index &gt;34 ml/m2 and/or LA reservoir strain ≤24% and RA myopathy by RA volume index &gt;39 ml/m2 in men and &gt;33 ml/m2 in women and/or RA reservoir strain ≤19.8%. Of 476 consecutively evaluated patients with HFpEF defined by invasive exercise testing with evaluable atrial structure/function, 125 (26%) had no atrial myopathy, 147 (31%) had isolated LA myopathy, 184 (39%) had biatrial myopathy, and 20 (4%) had isolated RA myopathy. Patients with HFpEF and biatrial myopathy had more atrial fibrillation, poorer left ventricular systolic and diastolic function, more severe pulmonary vascular disease, tricuspid regurgitation, ventricular interdependence and right ventricular dysfunction, and poorer cardiac output reserve with exercise. There were 94 patients with events over a median follow-up of 2.9 (interquartile range 1.4–4.6) years. Individuals with biatrial myopathy had an 84% higher risk of HF hospitalization or death as compared to those with isolated LA myopathy (hazard ratio 1.84; 95% confidence interval 1.16–2.92, p = 0.01). Conclusions Biatrial myopathy identifies patients with more advanced HFpEF characterized by more severe pulmonary vascular disease, right HF, poorer cardiac reserve, and a greater risk for adverse outcomes. Further study is required to define optimal strategies to treat and prevent biatrial myopathy in HFpEF.

Abstract Background Pulmonary veno-occlusive disease (PVOD) is a rare cause of pulmonary hypertension that primarily results in intimal fibrosis of the pulmonary venules and veins, the venous lesions are often associated with changes in interlobular septa, lung parenchyma, and pulmonary arterioles and arteries. Purpose We sought to study the clinical characteristics of patients with confirmed PVOD at a single large referral center. Methods We retrospectively reviewed data from a total of 675 patients with pulmonary hypertension (identified by ICD codes or search of text) from 2017 and 2022 from a database obtained from electronic medical records at our institution. Patients with group 2 pulmonary hypertension were excluded. Only 29 cases were confirmed by histology or genetic testing. Results Out of the 29 patients confirmed with PVOD, 28 (96.5%) had a characteristic histology (lung biopsy (55.1%), explanted lung for transplant (27.5%) and autopsy (13.7%)) and 1 (3.4%) had a positive genetic test for EIF2AK4 biallelic mutation. The age at diagnosis was 53±16 years, 14 (48.2%) were men, 2 (6.8%) had systemic scleroderma, 2 (6.8%) had psoriasis, 2 (6.8%) were exposed to cytotoxic agents, 16 (55.1%) were smokers and 2 (6.8%) had a family history of pulmonary hypertension. All patients had computed tomography of the chest but only 12 (41.3%) had all 3 typical features found in PVOD (ground glass opacities, interlobular septal thickening, and lymphadenopathy). The most common feature was interlobular septal thickening in 26 (89.6%), followed by ground glass opacities present in 25 (86.2%) and lymphadenopathy in 12 (41.3%) of the patients. At diagnosis, mean pulmonary artery pressure was 45±15 mmHg and pulmonary vascular resistance was 9±6 WU. The median DLCO was 41 (34-58) %. On echocardiogram, 14 (48.2%) had severely enlarged right ventricle (RV), RV function was ≥moderately reduced in 17 (58.6%), RV systolic pressure was 63±20 mmHg and 6 (20.6%) had pericardial effusion. Out of 21 (72.4%) patients who received pulmonary vasodilators, 4 (13.7%) received single agent. 10 (34.4%) received 2 agents, 6 (20.6%) 3 agents, and 1 (3.4%) received 4 agents. 35.7% of these treated patients reported an improvement or initial worsening of symptoms with subsequent improvement afterwards. 18 (62%) patients with PVOD died, 12 (41.3%) had a lung transplant and 6 (20.6%) were still alive without the transplant until the day data was collected. Mean duration from diagnosis to death and lung transplantation was 446 ± 405 days and 274±479 days respectively. Conclusion PVOD is a rare and lethal cause of pulmonary hypertension. When suspected, a trial of medical therapy should be initiated carefully. The evaluation for lung transplant should be considered early given its high mortality.

Abstract Background Pulmonary abnormalities are common in patients with prevalent heart failure (HF). Arterial hypoxemia is considered rare in HF, but this has not been rigorously evaluated in patients with HF and preserved EF (HFpEF). Methods Results Patients with HFpEF (n=539) and no clinically-relevant lung disease underwent invasive cardiopulmonary exercise testing with simultaneous blood and expired gas analysis. Exertional hypoxemia was defined by oxyhaeemoglobin saturation &lt;94%. As compared to those without hypoxemia (n=403), patients with hypoxemia (n=136, 25%) were slightly older, heavier, and had higher NT-proBNP levels. They had higher cardiac filling pressures, higher pulmonary vascular pressures, greater alveolar-arterial O2 difference compared to those without hypoxemia. These differences were replicated in a sensitivity analysis where patients with any spirometric abnormalities were excluded. Regression analyses revealed that increases in pulmonary arterial and capillary pressures were related to lower PaO2. The presence of exertional hypoxemia was associated with two-fold increased risk for death over 2.8 (IQR 0.7-5.5) years of follow up, (Adjusted:HR 2.00 (95%CI: 1.01−3.96), p=0.046). Conclusion One quarter of HFpEF patients displayed arterial desaturation during exercise. Patients with hypoxemia display more severely abnormal hemodynamics and increased mortality. Further study is required to better understand the mechanisms in patients with HFpEF.Hemodynamic changes at rest/exerciseRisk of death in HFpEF with hypoxemia

Abstract Background Right ventricular (RV) dysfunction is common in heart failure with preserved ejection fraction (HFpEF), portends worse prognosis, and is believed to be caused by contractile impairment and remodeling due to afterload mismatch from pulmonary hypertension (PH). The goal of this study was to examine the right heart in patients with HFpEF and resting mean pulmonary arterial (PA) pressure (MPAP)≤20 mmHg. Methods and results Among 621 patients with HFpEF undergoing comprehensive echocardiography and invasive cardiopulmonary exercise testing, 159 (26%) had resting MPAP≤20 mmHg (HFpEFMPAP≤20mmHg). In comparison to 73 controls, they were more obese, had more coronary disease and atrial fibrillation. After adjusting for BMI, there were no differences in plasma volume but NTproBNP was higher and peak oxygen consumption lower in HFpEFMPAP≤20mmHg than in controls (p = 0.002, &lt;0.001, respectively). While RV dimension was similar, tricuspid annular plane systolic excursion and RVs’ were lower in HFpEFMPAP≤20mmHg (18±5 vs. 22±4 mm, p = 0.005; 10±2 vs. 12±2 cm/s, p = 0.047, respectively). HFpEFMPAP≤20mmHg and controls displayed similar pulmonary vascular resistance, MPAP and right atrial pressure at rest, but during exercise, MPAP and right atrial pressure were higher in patients with HFpEFMPAP≤20mmHg (41±10 vs. 33±10 mmHg; 18±7 vs. 12±4 mmHg, p&lt;0.001, respectively). PA compliance was lower at both rest and exercise (rest 4.1±2.1 vs. 5.0±1.8; exercise 2.9±1.4 vs. 3.2±1.4 ml/mmHg, p&lt;0.001, for both). Conclusion Right heart dysfunction is present in patients with HFpEF even in the absence of frank PH. These patients display greater pulsatile RV loading by PA compliance even as resistance is not markedly elevated. These data support further study into novel therapies targeting pulsatile RV afterload in HFpEF.

Heart failure with preserved ejection fraction (HFpEF) is now the most common cause of pulmonary hypertension (PH), and the diagnosis of HFpEF should be considered in any patient with a preserved left ventricular systolic function being evaluated for PH. Accurately diagnosing HFpEF as compared with pulmonary arterial hypertension has critical treatment implications, given the vastly different treatment options available, and can be accurately guided using exercise right heart catheterization. In this review, the diagnostic approach and treatment implications of PH in patients at risk for HFpEF will be discussed.

Abstract Aims To study the impact of heart failure with preserved ejection fraction (HFpEF) vs. aortic stenosis (AS) lesion severity on left ventricular (LV) hypertrophy, diastolic dysfunction, left atrial (LA) dysfunction, haemodynamics, and exercise capacity. Methods and results Patients (n = 206) with at least moderate AS (aortic valve area ≤0.85 cm/m2) and discordant symptoms underwent cardiopulmonary exercise testing with simultaneous echocardiography. The population was stratified according to the probability of underlying HFpEF by the heavy, hypertension, atrial fibrillation, pulmonary hypertension, elder, filling pressure (H2FPEF) score [0–5 (AS/HFpEF−) vs. 6–9 points (AS/HFpEF+)] and AS severity (Moderate vs. Severe). Mean age was 73 ± 10 years with 40% women. Twenty-eight patients had Severe AS/HFpEF+ (14%), 111 Severe AS/HFpEF− (54%), 13 Moderate AS/HFpEF+ (6%), and 54 Moderate AS/HFpEF− (26%). AS/HFpEF+ vs. AS/HFpEF− patients, irrespective of AS severity, had a lower LV global longitudinal strain, impaired diastolic function, reduced LV compliance, and more pronounced LA dysfunction. The pulmonary arterial pressure–cardiac output slope was significantly higher in AS/HFpEF+ vs. AS/HFpEF− (5.4 ± 3.1 vs. 3.9 ± 2.2 mmHg/L/min, respectively; P = 0.003), mainly driven by impaired cardiac output and chronotropic reserve, with signs of right ventricular pulmonary arterial uncoupling. AS/HFpEF+ vs. AS/HFpEF− was associated with a lower peak aerobic capacity (11.5 ± 3.7 vs. 15.9 ± 5.9 mL/min/kg, respectively; P &lt; 0.0001) but did not differ between Moderate and Severe AS (14.7 ± 5.5 vs. 15.2 ± 5.9 mL/min/kg, respectively; P = 0.6). Conclusion A high H2FPEF score is associated with a reduced exercise capacity and adverse haemodynamics in patients with moderate to severe AS. Both exercise performance and haemodynamics correspond better with intrinsic cardiac dysfunction than AS severity.