Right Heart Adaptation to Exercise in Pulmonary Hypertension: An Invasive Hemodynamic Study

Right ventricular reserve in cardiopulmonary disease: A simultaneous hemodynamic and three-dimensional echocardiographic study

BACKGROUND

Right ventricular (RV) reserve has been linked to exercise capacity and prognosis in cardiopulmonary diseases. However, evidence in this setting is limited, due to the complex shape and load dependency of the RV. We sought to study RV adaptation to exercise by simultaneous three-dimensional echocardiography (3DE) and right heart catheterization (RHC).

METHODS

Patients with heart failure with preserved ejection fraction (HFpEF) or pulmonary vascular disease (PVD) underwent simultaneous supine rest/exercise RHC-3DE. They were subdivided based on RV ejection fraction (EF) changes: (1) exhausted RV reserve, RVEF-; (2) preserved RV reserve, RVEF+.

RESULTS

Sixty percent of patients were RVEF-. Distribution of HFpEF/PVD, as well as RV volumes and RVEF at rest were similar in the 2 groups. Hemodynamic metrics of RV afterload, as well as their exercise-induced changes, were similar in the 2 groups. During exercise, RV end-diastolic volume increased more in RVEF- than in RVEF+ (29±29 vs 7±25 ml, p<0.05). RV end-systolic volume increased by 21[12;31] ml in RVEF- and decreased by 8[-15;1] ml in RVEF+ (p<0.001). RV-pulmonary artery coupling was lower in RVEF- at peak exercise (p<0.05). Peak RVEF was associated with left ventricular preload (R2=0.14, p=0.011). Cardiac output increased less in RVEF- than in RVEF+ (+2.3±2.0 vs +4.0±2.4 liter/min, p<0.05). Peak RVEF was associated with oxygen consumption (p<0.01).

CONCLUSIONS

Exhausted RV reserve, as evaluated by 3DE, was frequent in HFpEF and PVD, was relatively independent from classical afterload parameters, was associated with RV-pulmonary artery decoupling, RV dilation, enhanced ventricular interdependence, and cardiac limitation to exercise. Intrinsic RV dysfunction may contribute to exhausted RV reserve.

Invasive haemodynamic assessment in heart failure with preserved ejection fraction

Despite the increasing prevalence and substantial burden of heart failure with preserved ejection fraction (HFpEF), which constitutes up to 50% of all heart failure cases, significant challenges persist in its diagnostic and therapeutic strategies. These difficulties arise primarily from the heterogeneous nature of the condition, the presence of various comorbidities and a wide range of phenotypic variations. Considering these challenges, current international guidelines endorse the utilization of invasive haemodynamic assessments, including resting and exercise haemodynamics, as the gold standard for enhancing diagnostic accuracy in cases where traditional diagnostic methods yield inconclusive results. These assessments are crucial not only for confirming the diagnosis but also for delineating the complex underlying pathophysiology, enabling the development of personalized treatment strategies, and facilitating the precise classification of HFpEF phenotypes. In this review, we summarize the haemodynamic changes observed in patients with HFpEF, comparing resting and exercise-induced parameters to those of normal subjects. Additionally, we discuss the current role of invasive haemodynamics in HFpEF assessment and highlight its utility beyond diagnosis, such as identifying HFpEF comorbidities, guiding phenotype-based personalized therapies and characterizing prognostication. Finally, we address the challenges associated with utilizing invasive haemodynamics and propose future directions, focusing on integrating these assessments into routine HFpEF care.

Left atrial shunting devices: why, what, how, and… when?

Left atrial (LA) hypertension is central in the pathophysiology of heart failure (HF) in general and of HF with preserved ejection fraction (HFpEF) in particular. Despite approved treatments, a number of HF patients continue experiencing disabling symptoms due to LA hypertension, causing pulmonary congestion, pulmonary hypertension, and right heart dysfunction, at rest and/or during exercise. LA decompression therapies, i.e., left atrial shunting through a specifically designed device (either implant-based or implant-free), are being studied in various forms of HF to alleviate LA hypertension and patients' symptoms. Despite a solid background and favorable signals from initial non-randomized clinical trials, the quest for the optimal HF candidate for interatrial shunt devices is still an area of active research that at the same time is helping to better elucidate the intricate pathophysiology of HF(pEF).

Cardiopulmonary Exercise Testing in Research

Cardiopulmonary exercise testing is an active research area in patients with unexplained dyspnea, heart failure, and pulmonary hypertension. Focus has centered on the use of novel hemodynamic parameters to further characterize these disease states, influence therapeutics, and determine prognosis. Translational research focuses on the underlying cardiopulmonary physiology to more precisely quantify the effect of pulmonary vascular disease on the right ventricle and pulmonary function/hemodynamics. In addition, phenotyping unexplained dyspnea is of critical importance, given the significant heterogeneity of this patient population with implications for therapies and clinical trial design.

Cardiac power output associated with hospitalization and mortality in coronary artery disease patients at stage B heart failure

Background

Cardiac power output (CPO) predicts outcomes in advanced heart failure (HF) and cardiogenic shock, but its role in early HF stages is unclear. This study assessed the prognostic value of CPO in coronary artery disease patients with asymptomatic left ventricular systolic dysfunction (ALVSD) at stage B HF.

Methods

We conducted a retrospective analysis of coronary artery disease patients who underwent coronary and pulmonary artery catheterization between 2006 and 2016. Stage B HF with ALVSD was defined as left ventricular ejection fraction < 50 %, without HF symptoms, signs, or prior HF hospitalization. CPO was derived from invasive hemodynamic parameters. Endpoints included HF hospitalization, cardiovascular mortality, and all-cause mortality over a 5-year follow-up.

Results

A total of 783 coronary artery disease patients with ALVSD at stage B HF were enrolled. Incidence rates (per 1000 person-years) were 13.9 for HF hospitalization, 14.5 for cardiovascular mortality, and 23.7 for all-cause mortality.Multivariate analysis adjusting for covariates demonstrated that CPO was independent associated with all endpoints. Patients with a low CPO (<0.97 Watts) were at significantly higher risk for HF hospitalization (adjusted hazard ratio [HR]: 4.04; 95 % CI: 1.53 - 10.6; p = 0.005), cardiovascular mortality (adjusted HR: 2.73; 95 % CI: 1.19 - 6.27; p = 0.018), and all-cause mortality (adjusted HR: 1.86; 95 % CI: 1.05 - 3.30; p = 0.035) compared to those with higher CPO, regardless of subgroup classification.

Conclusion

Resting CPO in patients with ALVSD is significantly associated with adverse events, including HF hospitalization and mortality, highlighting its value in early-stage HF management.

Pulmonary hypertension associated with left heart disease

Left heart disease (LHD) is the most common cause of pulmonary hypertension (PH), which may be classified further as isolated post-capillary (ipcPH) or combined post- and pre-capillary PH (cpcPH). The 7th World Symposium on Pulmonary Hypertension PH-LHD task force reviewed newly reported randomised clinical trials and contemplated novel opportunities for improving outcome. Results from major randomised clinical trials reinforced prior recommendations against the use of pulmonary arterial hypertension therapy in PH-LHD outside of clinical trials, and suggested possible harm. Greater focus on phenotyping was viewed as one general strategy by which to ultimately improve clinical outcomes. This is potentially achievable by individualising ipcPH versus cpcPH diagnosis for patients with pulmonary arterial wedge pressure within a diagnostic grey zone (12-18 mmHg), and through a newly developed PH-LHD staging system. In this model, PH accompanies LHD across four stages (A=at risk, B=structural heart disease, C=symptomatic heart disease, D=advanced), with each stage characterised by progression in clinical characteristics, haemodynamics and potential therapeutic strategies. Along these lines, the task force proposed disaggregating PH-LHD to emphasise specific subtypes for which PH prevalence, pathophysiology and treatment are unique. This includes re-interpreting mitral and aortic valve stenosis through a contemporary lens, and focusing on PH within the hypertrophic cardiomyopathy and amyloid cardiomyopathy clinical spectra. Furthermore, appreciating LHD in the profile of PH patients with chronic lung disease and chronic thromboembolic pulmonary disease is essential. However, engaging LHD patients in clinical research more broadly is likely to require novel methodologies such as pragmatic trials and may benefit from next-generation analytics to interpret results.

Hemodynamic markers independent of pulmonary capillary wedge pressure can discriminate between pre and postcapillary exercise-induced pulmonary hypertension

The discrimination between pre and postcapillary exercise-induced pulmonary hypertension relies on accurate measurement of pulmonary capillary wedge pressure, which can be unreliable. We found that exercise pulmonary artery compliance and right atrial pressure (AUC 0.88, 0.89, respectively) can differentiate subtypes of exercise-induced pulmonary hypertension in the absence of wedge pressure.

Left Atrial Hemodynamics and Clinical Utility in Heart Failure

Comprehensive knowledge of the left atrium (LA) and its pathophysiology has emerged as an important clinical and research focus in the heart failure (HF) arena. Although studies on HF focusing on investigating left ventricular remodeling are numerous, those on atrial structural and functional changes have received comparatively less attention. Studies on LA remodeling have recently received increasing attention, and LA pressure (LAP) has become a novel target for advanced monitoring and is a potential therapeutic approach for treating HF. Various devices specifically designed for the direct measurement of LAP have been developed to optimize HF treatment by reducing LAP. This review focuses on LA hemodynamic monitoring and effective LAP decompression.

A roadmap for therapeutic discovery in pulmonary hypertension associated with left heart failure. A scientific statement of the Heart Failure Association (HFA) of the ESC and the ESC Working Group on Pulmonary Circulation & Right Ventricular Function

Pulmonary hypertension (PH) associated with left heart failure (LHF) (PH-LHF) is one of the most common causes of PH. It directly contributes to symptoms and reduced functional capacity and negatively affects right heart function, ultimately leading to a poor prognosis. There are no specific treatments for PH-LHF, despite the high number of drugs tested so far. This scientific document addresses the main knowledge gaps in PH-LHF with emphasis on pathophysiology and clinical trials. Key identified issues include better understanding of the role of pulmonary venous versus arteriolar remodelling, multidimensional phenotyping to recognize patient subgroups positioned to respond to different therapies, and conduct of rigorous pre-clinical studies combining small and large animal models. Advancements in these areas are expected to better inform the design of clinical trials and extend treatment options beyond those effective in pulmonary arterial hypertension. Enrichment strategies, endpoint assessments, and thorough haemodynamic studies, both at rest and during exercise, are proposed to play primary roles to optimize early-stage development of candidate therapies for PH-LHF.