Exercise Pulmonary Hypertension Predicts Clinical Outcomes in Patients With Dyspnea on Effort

The prognostic relevance of exercise pulmonary hypertension in cardiac and pulmonary diseases

PURPOSE OF REVIEW

In this review, we provide an overview of the prognostic implications of exPH in patients with various common cardiac and pulmonary diseases.

RECENT FINDINGS

Exercise pulmonary hypertension (exPH) has been recently re-introduced in the current European Society of Cardiology/European Respiratory Society pulmonary hypertension guidelines. Accordingly, exPH is defined as a mean pulmonary arterial pressure (mPAP)/cardiac output ( CO ) slope greater than 3 mmHg/l/min. Key considerations for this re-introduction included increasing understanding on normal pulmonary hemodynamics during exercise and the broadly available evidence on the association of an abnormal mPAP/ CO slope with poor survival in the general population and in different disease entities.

SUMMARY

Exercise (patho-)physiology has opened a new field for clinical research facilitating recognition of cardiovascular and pulmonary vascular diseases in an early stage. Such early recognition with significant prognostic and possibly therapeutic relevance, but being undetectable at rest, makes exercise pulmonary hemodynamics particularly interesting for common diseases, such as valvular heart disease, left heart disease, and chronic pulmonary disease.

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.

The Management of Mild Pulmonary Hypertension in Clinical Practice

The definition of pulmonary hypertension (PH) has been revised recently, with the mean pulmonary artery pressure (mPAP) threshold (assessed by right heart catheterization) reduced from ⩾25 mm Hg to >20 mm Hg. This change reflects the mPAP upper limit of normal and a lower limit that is independently associated with adverse outcomes. To improve the specificity of diagnosing pathogenic increases in mPAP, however, a diagnosis of precapillary PH now also includes pulmonary vascular resistance >2.0 Wood units (WU) (lowered from >3.0 WU). These changes are positioned to capture approximately 55% more patients with PH. Because all clinical trials showing a benefit of pulmonary vasodilator therapy in precapillary PH used the classical hemodynamic definition, the approach to the diagnosis and management of patients with mild PH (i.e., mPAP 21-24 mm Hg and pulmonary vascular resistance 2-3 WU) requires particular consideration. Here, we use a question/answer format to discuss key areas in the management of mild PH, including practical information tailored to clinicians without training in PH.

Non-arterial line cardiac output calculation misclassifies exercise pulmonary hypertension and increases risk of data loss particularly in black, scleroderma and Raynaud's patients during invasive exercise testing

BACKGROUND

The direct Fick principle is the standard for calculating cardiac output (CO) to detect CO-dependent conditions like exercise pulmonary hypertension (ePH). Fick COarterial incorporates arterial haemoglobin (Hba) and oxygen saturation (S aO2 ) with oxygen consumption from exercise testing, while Fick COnon-arterial substitutes mixed venous haemoglobin (Hbmv) and peripheral oxygen saturation (S pO2 ) in the absence of an arterial line. The decision to employ an arterial catheter for exercise testing varies, and discrepancies in oxygen saturation and haemoglobin between arterial and non-arterial methods may lead to differences in Fick CO, potentially affecting ePH classification.

METHODS

We performed a retrospective analysis of 296 consecutive invasive cardiopulmonary exercise testing (iCPET) studies comparing oxygen saturation from pulse oximetry (S pO2 ) and radial arterial (S aO2 ), Hba and Hbmv, and CO calculated with arterial (COarterial) and non-arterial (COnon-arterial) values. We assessed the risk of misclassification of pre- and post-capillary ePH and data loss due to inaccurate S pO2 .

RESULTS

When considering all stages from rest to peak exercise, Hba and Hbmv demonstrated high correlation, while S pO2 and S aO2 as well as COarterial and COnon-arterial demonstrated low correlation. Data loss was significantly higher across all stages of exercise for S pO2 (n=346/1926 (18%)) compared to S aO2 (n=17/1923 (0.88%)). We found that pre- and post-capillary ePH were misclassified as COnon-arterial data (n=7/41 (17.1%) and n=2/23 (8.7%), respectively). Patients with scleroderma and/or Raynaud's (n=11/33 (33.3%)) and black patients (n=6/19 (31.6%)) had more S pO2 data loss.

CONCLUSION

Reliance upon S pO2 during invasive exercise testing results in the misclassification of pre- and post-capillary ePH, and unmeasurable S pO2 for black, scleroderma and Raynaud's patients can preclude accurate exercise calculations, thus limiting the diagnostic and prognostic value of invasive exercise testing without an arterial line.

Uncovering Unrecognized Heart Failure With Preserved Ejection Fraction Among Individuals With Obesity and Dyspnea

BACKGROUND

Although heart failure with preserved ejection fraction (HFpEF) has become the predominant heart failure subtype, it remains clinically under-recognized. HFpEF diagnosis is particularly challenging in the setting of obesity given the limitations of natriuretic peptides and resting echocardiography. We examined invasive and noninvasive HFpEF diagnostic criteria among individuals with obesity and dyspnea without known cardiovascular disease to determine the prevalence of hemodynamic HFpEF in the community.

METHODS

Research volunteers with dyspnea and obesity underwent resting echocardiography; participants with possible pulmonary hypertension qualified for invasive cardiopulmonary exercise testing. HFpEF was defined using rest or exercise pulmonary capillary wedge pressure criteria (≥15 mm Hg or Δpulmonary capillary wedge pressure/Δcardiac output slope, >2.0 mm Hg·L-1·min-1).

RESULTS

Among n=78 participants (age, 53±13 years; 65% women; body mass index, 37.3±6.8 kg/m2), 40 (51%) met echocardiographic criteria to undergo invasive cardiopulmonary exercise testing. In total, 24 participants (60% among the cardiopulmonary exercise testing group, 31% among the total sample) were diagnosed with HFpEF by rest or exercise pulmonary capillary wedge pressure (n=12) or exercise criteria (n=12). There were no differences in NT-proBNP (N-terminal pro-B-type natriuretic peptide; 79 [62-104] versus 73 [57-121] pg/mL) or resting echocardiography (mitral E/e' ratio, 9.1±3.1 versus 8.0±2.7) among those with versus without HFpEF (P>0.05 for all). Distributions of HFpEF diagnostic scores were similar, with the majority classified as intermediate risk (100% versus 93.75% [H2FPEF] and 87.5% versus 68.75% [HFA-PEFF (Heart Failure Association Pretest assessment, echocardiography and natriuretic peptide, functional testing, and final etiology)] in those with versus without HFpEF).

CONCLUSIONS

Among adults with obesity and dyspnea without known cardiovascular disease, at least a third had clinically unrecognized HFpEF uncovered on invasive cardiopulmonary exercise testing. Clinical, biomarker, resting echocardiography, and diagnostic scores were similar among those with and without HFpEF. These results suggest clinical underdiagnosis of HFpEF among individuals with obesity and dyspnea and highlight limitations of noninvasive testing in the identification of HFpEF.

mPAP/CO Slope and Oxygen Uptake Add Prognostic Value in Aortic Stenosis

BACKGROUND

Recent guidelines redefined exercise pulmonary hypertension as a mean pulmonary artery pressure/cardiac output (mPAP/CO) slope >3 mm Hg·L-1·min-1. A peak systolic pulmonary artery pressure >60 mm Hg during exercise has been associated with an increased risk of cardiovascular death, heart failure rehospitalization, and aortic valve replacement in aortic valve stenosis. The prognostic value of the mPAP/CO slope in aortic valve stenosis remains unknown.

METHODS

In this prospective cohort study, consecutive patients (n=143; age, 73±11 years) with an aortic valve area ≤1.5 cm2 underwent cardiopulmonary exercise testing with echocardiography. They were subsequently evaluated for the occurrence of cardiovascular events (ie, cardiovascular death, heart failure hospitalization, new-onset atrial fibrillation, and aortic valve replacement) during a follow-up period of 1 year. Findings were externally validated (validation cohort, n=141).

RESULTS

One cardiovascular death, 32 aortic valve replacements, 9 new-onset atrial fibrillation episodes, and 4 heart failure hospitalizations occurred in the derivation cohort, whereas 5 cardiovascular deaths, 32 aortic valve replacements, 1 new-onset atrial fibrillation episode, and 10 heart failure hospitalizations were observed in the validation cohort. Peak aortic velocity (odds ratio [OR] per SD, 1.48; P=0.036), indexed left atrial volume (OR per SD, 2.15; P=0.001), E/e' at rest (OR per SD, 1.61; P=0.012), mPAP/CO slope (OR per SD, 2.01; P=0.002), and age-, sex-, and height-based predicted peak exercise oxygen uptake (OR per SD, 0.59; P=0.007) were independently associated with cardiovascular events at 1 year, whereas peak systolic pulmonary artery pressure was not (OR per SD, 1.28; P=0.219). Peak Vo2 (percent) and mPAP/CO slope provided incremental prognostic value in addition to indexed left atrial volume and aortic valve area (P<0.001). These results were confirmed in the validation cohort.

CONCLUSIONS

In moderate and severe aortic valve stenosis, mPAP/CO slope and percent-predicted peak Vo2 were independent predictors of cardiovascular events, whereas peak systolic pulmonary artery pressure was not. In addition to aortic valve area and indexed left atrial volume, percent-predicted peak Vo2 and mPAP/CO slope cumulatively improved risk stratification.

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.

Exercise pulmonary hypertension by the mPAP/CO slope in primary mitral regurgitation

AIMS

Exercise-induced pulmonary hypertension (PH), defined by a mean pulmonary arterial pressure over cardiac output (mPAP/CO) slope >3 mmHg/L/min, has important diagnostic and prognostic implications. The aim of this study is to investigate the value of the mPAP/CO slope in patients with more than moderate primary mitral regurgitation (MR) with preserved ejection fraction and no or discordant symptoms.

METHODS AND RESULTS

A total of 128 consecutive patients were evaluated with exercise echocardiography and cardiopulmonary testing. Clinical outcome was defined as the composite of mitral valve intervention, new-onset atrial fibrillation, cardiovascular hospitalization, and all-cause mortality. The mean age was 63 years, 61% were male, and the mean LVEF was 66 ± 6%. The mPAP/CO slope correlated with peak VO2 (r = -0.52, P < 0.001), while the peak systolic pulmonary artery pressure (sPAP) did not (r = -0.06, P = 0.584). Forty-six per cent (n = 59) had peak exercise sPAP ≥60 mmHg, and 37% (n = 47) had mPAP/CO slope >3 mmHg/L/min. Event-free survival was 55% at 1 year and 46% at 2 years, with reduced survival in patients with mPAP/CO slope >3 mmHg/L/min (hazard ratio, 4.9; 95% confidence interval, 2.9-8.2; P < 0.001). In 53 cases (41%), mPAP/CO slope and peak sPAP were discordant: patients with slope >3 mmHg/L/mmHg and sPAP <60 mmHg (n = 21) had worse outcome vs. peak sPAP ≥60 mmHg and normal slope (n = 32, log-rank P = 0.003). The mPAP/CO slope improved predictive models for outcome, incremental to resting and exercise sPAP, and peak VO2.

CONCLUSION

Exercise PH defined by the mPAP/CO slope >3 mmHg/L/min is associated with decreased exercise capacity and a higher risk of adverse events in significant primary MR and no or discordant symptoms. The slope provides a greater prognostic value than single sPAP measures and peak VO2.

Simultaneous Cardiopulmonary Exercise Testing and Echocardiography for Investigation of Cardiopulmonary Dysfunction in Outpatients: Protocol for a Scoping Review

BACKGROUND

Cardiopulmonary dysfunction is a complex process with a broad range of etiologies. Investigations performed either at rest or those that only assess the function of a single organ (heart or lungs) are often insufficient. A simultaneous cardiopulmonary exercise test with stress echocardiography is a new approach to assessing cardiopulmonary dysfunction as it provides anatomical and functional imaging simultaneously while under increasing stress. To date, the application of cardiopulmonary exercise test-stress echocardiography (CPET-SE) has been broad and without structure, and its effect on patient outcomes is unclear.

OBJECTIVE

The objective of this scoping review is to explore and analyze the evidence regarding the role of simultaneous CPET-SE in investigating cardiopulmonary dysfunction in outpatients. It will include any published study in which adult (older than or equal to 18 years of age) patients have completed a CPET-SE for the investigation of cardiopulmonary dysfunction.

METHODS

This review will follow the Arksey and O'Malley framework, supported by the Joanna Briggs Institute methodology for scoping reviews. It will use the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) checklist. Data sources will include MEDLINE, Scopus, Embase, and Cochrane (including reviews, trials, and protocols) electronic databases, with no date range defined. The search will be limited to the English language with no restrictions regarding pathology. Secondary references of the included sources will also be assessed by a hand search for suitability. A 2-person title-abstract screen and data charting process will be used. Independent experts will be used for consultation including an academic librarian and clinicians. The Covidence software will be used for article screening.

RESULTS

This scoping review will provide a unified and detailed description of the applications of CPET-SE in investigating cardiopulmonary dysfunction. This will provide a platform for future research harnessing this investigatory method. The results will be presented in both tabular and graphical formats to ensure clarity. The results of this scoping review will be submitted to a relevant peer-reviewed academic journal for publication.

CONCLUSIONS

The CPET-SE is a powerful tool for investigating cardiopulmonary dysfunction but remains in its infancy with a patchwork approach to indications, data reporting, and interpretation. This scoping review will unify the literature and provide a platform for future researchers and the development of a comprehensive application guideline.

TRIAL REGISTRATION

Open Science Framework; https://osf.io/98r3e.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/52076.

Exercise Testing in Patients with Pulmonary Hypertension

Pulmonary hypertension (PH), defined by a mean pulmonary artery pressure of >20 mm Hg, often presents with non-specific symptoms such as dyspnea and exercise intolerance, making it difficult to diagnose early before the onset of right heart dysfunction. Therefore, exercise testing can be of great utility for clinicians who are evaluating patients with an unclear etiology of exercise intolerance by helping identify the underlying mechanisms of their disease. The presence of PH is associated with adverse clinical outcomes, with distinct differences and patterns in the cardiovascular and ventilatory responses to exercise across various PH phenotypes. We discuss the role of exercise-invasive hemodynamic testing, cardiopulmonary exercise testing, and exercise stress echocardiography modalities across the spectrum of PH.

Right Ventricular-Vascular Uncoupling Predicts Pulmonary Hypertension in Clinically Diagnosed Heart Failure With Preserved Ejection Fraction

BACKGROUND

Pulmonary hypertension (PH) is highly prevalent in patients with heart failure with preserved ejection fraction (HFpEF), and it is a strong predictor of adverse outcomes. We aimed to determine possible echocardiographic parameters to predict the presence of PH in patients with HFpEF.

METHODS AND RESULTS

A total of 113 patients with HFpEF were prospectively enrolled from November 2017 to July 2022. The patients underwent invasive cardiac catheterization and simultaneous echocardiography at rest and during exercise. The parameters indicating right ventricle-pulmonary artery uncoupling, including tricuspid annular plane systolic excursion (TAPSE)/pulmonary artery systolic pressure (PASP) and tricuspid annular systolic velocity (TAS')/PASP were calculated. Receiver operating characteristic curve analysis was used to determine the optimal cut-off points of TAPSE/PASP and TAS'/PASP to differentiate patients with HFpEF with PH from those without PH. Sixty-eight patients with HFpEF with PH and 45 without PH were included. Those with PH had lower TAPSE/PASP and TAS'/PASP at rest and during exercise compared with those without PH. Both resting/stress TAPSE/PASP and TAS'/PASP were correlated with rest/exercise pulmonary capillary wedge pressure and mean pulmonary artery pressure. In multivariable regression analysis, TAPSE/PASP remained a significant predictor of exercise pulmonary capillary wedge pressure and mean pulmonary artery pressure. In receiver operating characteristic curve analysis, the optimal cut-off points of TAPSE/PASP and TAS'/PASP to differentiate patients with HFpEF with PH from those without PH were ≤0.62 and ≤0.47, respectively.

CONCLUSIONS

Right ventricle-pulmonary artery uncoupling is closely correlated with abnormal rest/exercise hemodynamics (pulmonary capillary wedge pressure and mean pulmonary artery pressure) in patients with HFpEF. TAPSE/PASP and TAS'/PASP can be useful parameters to detect PH in patients with HFpEF.

Systemic Arterial Oxygen Levels Differentiate Pre- and Post-capillary Predominant Hemodynamic Abnormalities During Exercise in Undifferentiated Dyspnea on Exertion

BACKGROUND

Whether systemic oxygen levels (SaO2) during exercise can provide a window into invasively derived exercise hemodynamic profiles in patients with undifferentiated dyspnea on exertion is unknown.

METHODS

We performed cardiopulmonary exercise testing with invasive hemodynamic monitoring and arterial blood gas sampling in individuals referred for dyspnea on exertion. Receiver operator analysis was performed to distinguish heart failure with preserved ejection fraction from pulmonary arterial hypertension.

RESULTS

Among 253 patients (mean ± SD, age 63 ± 14 years, 55% female, arterial O2 [PaO2] 87 ± 14 mmHg, SaO2 96% ± 4%, resting pulmonary capillary wedge pressure [PCWP] 18 ± 4mmHg, and pulmonary vascular resistance [PVR] 2.7 ± 1.2 Wood units), there was no exercise PCWP threshold, measured up to 49 mmHg, above which hypoxemia was consistently observed. Exercise PaO2 was not correlated with exercise PCWP (rho = 0.04; P = 0.51) but did relate to exercise PVR (rho = -0.46; P < 0.001). Exercise PaO2 and SaO2 levels distinguished left-heart-predominant dysfunction from pulmonary-vascular-predominant dysfunction with an area under the curve of 0.89 and 0.89, respectively.

CONCLUSION

Systemic O2 levels during exercise distinguish relative pre- and post-capillary pulmonary hemodynamic abnormalities in patients with undifferentiated dyspnea. Hypoxemia during upright exercise should not be attributed to isolated elevation in left heart filling pressures and should prompt consideration of pulmonary vascular dysfunction.

Interatrial Shunt Devices

Elevated left atrial pressure during exercise is a hallmark of heart failure (HF) and is associated with adverse left atrial remodeling and poor outcomes. To decompress the pressure-overloaded left atrium in patients with HF, several device-based approaches have been developed to create a permanent, pressure-dependent, left-to-right interatrial shunt. Such approaches are currently in various stages of investigations in both HF with reduced ejection fraction (EF) and HF with preserved EF. This review discusses the evolution of the concept of left atrial decompression and summarizes the current landscape of device-based approaches used for left atrial decompression.

Updated Hemodynamic Definition and Classification of Pulmonary Hypertension

Pulmonary hypertension (PH) is a pathophysiological manifestation of a heterogeneous group of diseases characterized by abnormally elevated pulmonary arterial pressures diagnosed on right heart catheterization. The 2022 European Society of Cardiology (ESC) and European Respiratory Society (ERS) Guidelines for the diagnosis and treatment of PH provides a new hemodynamic definition to define PH by lowering the threshold of the mean pulmonary artery pressure (mPAP) to 20 mm Hg. Precapillary PH is thus now defined as a mPAP >20 mm Hg together with a normal pulmonary artery wedge pressure (<15 mm Hg) and an increased pulmonary vascular resistance (>2 Wood Units). The ESC/ERS 2022 Guidelines also introduce a revised clinical classification of PH while retaining its previous distinction between the five groups according to the underlying pathophysiology.

Proteomics and Precise Exercise Phenotypes in Heart Failure With Preserved Ejection Fraction: A Pilot Study

BACKGROUND

While exercise impairments are central to symptoms and diagnosis of heart failure with preserved ejection fraction (HFpEF), prior studies of HFpEF biomarkers have mostly focused on resting phenotypes. We combined precise exercise phenotypes with cardiovascular proteomics to identify protein signatures of HFpEF exercise responses and new potential therapeutic targets.

METHODS AND RESULTS

We analyzed 277 proteins (Olink) in 151 individuals (N=103 HFpEF, 48 controls; 62±11 years; 56% women) with cardiopulmonary exercise testing with invasive monitoring. Using ridge regression adjusted for age/sex, we defined proteomic signatures of 5 physiological variables involved in HFpEF: peak oxygen uptake, peak cardiac output, pulmonary capillary wedge pressure/cardiac output slope, peak pulmonary vascular resistance, and peak peripheral O2 extraction. Multiprotein signatures of each of the exercise phenotypes captured a significant proportion of variance in respective exercise phenotypes. Interrogating the importance (ridge coefficient magnitude) of specific proteins in each signature highlighted proteins with putative links to HFpEF pathophysiology (eg, inflammatory, profibrotic proteins), and novel proteins linked to distinct physiologies (eg, proteins involved in multiorgan [kidney, liver, muscle, adipose] health) were implicated in impaired O2 extraction. In a separate sample (N=522, 261 HF events), proteomic signatures of peak oxygen uptake and pulmonary capillary wedge pressure/cardiac output slope were associated with incident HFpEF (odds ratios, 0.67 [95% CI, 0.50-0.90] and 1.43 [95% CI, 1.11-1.85], respectively) with adjustment for clinical factors and B-type natriuretic peptides.

CONCLUSIONS

The cardiovascular proteome is associated with precision exercise phenotypes in HFpEF, suggesting novel mechanistic targets and potential methods for risk stratification to prevent HFpEF early in its pathogenesis.

[New definition and classification of pulmonary hypertension]

In the recent ESC/ERS guidelines on the diagnosis and management of pulmonary hypertension (PH) several important changes have been made in respect of the definition and classification of PH.The mPAP cut-off for defining PH was lowered. PH is now defined by an mPAP > 20 mmHg assessed by right heart catheterization. Moreover, the PVR threshold for defining precapillary PH was lowered. Precapillary PH is now defined by a PVR > 2 WU and a pulmonary arterial wedge pressure (PAWP) ≤ 15 mmHg. Furthermore, the increasing evidence for the clinical relevance of pulmonary exercise hemodynamics led to the reintroduction of exercise pulmonary hypertension (EPH) 1. EPH is characterized by a mPAP/CO-slope > 3 mmHg/L/min during exercise testing. In the classification of PH five groups are distinguished: Pulmonary arterial hypertension (group 1), PH associated with left heart disease (group 2), PH associated with lung diseases and/or hypoxia (Group 3), PH associated with pulmonary artery obstructions (group 4) and PH with unclear and/or multi-factorial mechanisms (group 5).In the following guideline-translation we focus on novel aspects regarding the definition and classification of PH and to provide additional background information.

[Pulmonary hypertension associated with left heart disease (group 2)]

Pulmonary hypertension associated with left heart disease (PH-LHD) corresponds to group two of pulmonary hypertension according to clinical classification. Haemodynamically, this group includes isolated post-capillary pulmonary hypertension (IpcPH) and combined post- and pre-capillary pulmonary hypertension (CpcPH). PH-LHD is defined by an mPAP > 20 mmHg and a PAWP > 15 mmHg, pulmonary vascular resistance (PVR) with a cut-off value of 2 Wood Units (WU) is used to differentiate between IpcPH and CpcPH. A PVR greater than 5 WU indicates a dominant precapillary component. PH-LHD is the most common form of pulmonary hypertension, the leading cause being left heart failure with preserved (HFpEF) or reduced ejection fraction (HFmrEF, HFrEF), valvular heart disease and, less commonly, congenital heart disease. The presence of pulmonary hypertension is associated with increased symptom burden and poorer outcome across the spectrum of left heart disease. Differentiating between group 1 pulmonary hypertension with cardiac comorbidities and PH-LHD, especially due to HFpEF, is a particular challenge. Therapeutically, no general recommendation for the use of PDE5 inhibitors in HFpEF-associated CpcPH can be made at this time. There is currently no reliable rationale for the use of PAH drugs in IpcPH, nor is therapy with endothelin receptor antagonists or prostacyclin analogues recommended for all forms of PH-LHD.

iCPET Calculator: A Web-Based Application to Standardize the Calculation of Alpha Distensibility in Patients With Pulmonary Arterial Hypertension

Background Pulmonary vascular distensibility associates with right ventricular function and clinical outcomes in patients with unexplained dyspnea and pulmonary hypertension. Alpha distensibility coefficient is determined from a nonlinear fit to multipoint pressure-flow plots. Study aims were to (1) create and test a user-friendly tool to standardize analysis of exercise hemodynamics including distensibility, and (2) investigate changes in distensibility following treatment in patients with pulmonary arterial hypertension. Methods and Results Participants with an exercise right heart catherization were retrospectively identified from the University of Arizona Pulmonary Hypertension (UA PH) registry and split into a pulmonary arterial hypertension group, a comparator group, and a control group. Right ventricular function was quantified using the coupling ratio and diastolic stiffness. Prototypes of the invasive cardiopulmonary exercise testing (iCPET) calculator were developed using Matlab, Python, and RShiny to analyze exercise hemodynamics and alpha distensibility coefficient, α (%/mm Hg) from multipoint pressure flow plots. Interclass correlation coefficients were calculated for interplatform and interobserver variability in alpha. No significant bias in the intraplatform (Matlab versus RShiny; intraclass correlation coefficient: 0.996) or interobserver (intraclass correlation coefficient: 0.982) comparison of alpha values. Afterload significantly decreased (P<0.05) with no change in alpha distensibility in the pulmonary arterial hypertension group at follow-up. The comparator group had no change in pressure, resistance or alpha distensibility. There were no significant changes in RV diastolic stiffness at follow-up. Conclusions The interactive user interface in the iCPET calculator allows exploration of alpha distensibility using standardized methods. No significant change in alpha distensibility at follow-up suggests that alpha may be less modifiable in patients with long-standing pulmonary arterial hypertension.

Diastolic exercise stress testing in heart failure with preserved ejection fraction: The DEST-HF study

AIMS

Pulmonary capillary wedge pressure (PAWP) ≥25 mmHg during bicycle ergometry is recommended to uncover occult heart failure with preserved ejection fraction. We hypothesized that PAWP increase would differ in available diastolic stress tests and that the margin of PAWP ≥25 mmHg would only be reliably achieved through ergometry.

METHODS AND RESULTS

We conducted a prospective, single-arm study in patients with an intermediate risk for heart failure with preserved ejection fraction according to the ESC HFA-PEFF score. A total of 19 patients underwent four stress test modalities in randomized order: leg raise, fluid challenge, handgrip, and bicycle ergometry. The primary outcome was the difference (Δ) between resting and exercise PAWP in each modality. Secondary outcomes were differences (Δ) in mean pulmonary artery pressure (mPAP), cardiac output (CO), as well as the ratios between mPAP and PAWP to CO. Compared to resting values, passive leg raise (Δ7.7 ± 8.0 mmHg, p = 0.030), fluid challenge (Δ9.2 ± 6.4 mmHg, p = 0.003), dynamic handgrip (Δ9.6 ± 7.5 mmHg, p = 0.002), and bicycle ergometry (Δ22.3 ± 5.0 mmHg, p < 0.001) uncovered increased PAWP during exercise. Amongst these, bicycle ergometry also demonstrated the highest ΔmPAP (27.2 ± 7.1 mmHg, p < 0.001), ΔCO (3.3 ± 2.6 L/min, p < 0.001), ΔmPAP/CO ratio (2.3 ± 2.0 mmHg/L/min, p < 0.001), and ΔPAWP/CO ratio (2.2 ± 1.4 mmHg/L/min, p < 0.001) compared to other modalities. PAWP ≥25 mmHg was only reliably achieved in bicycle ergometry (31.1 ± 3.9 mmHg). In all other modalities only 10.5% of patients achieved PAWP ≥25 mmHg (handgrip 18.4 ± 6.6 mmHg, fluid 18.1 ± 5.6 mmHg, leg raise 16.5 ± 7.0 mmHg).

CONCLUSIONS

We demonstrate that bicycle ergometry exhibits a distinct haemodynamic response with higher increase of PAWP compared to other modalities. This finding needs to be considered for valid detection of exercise PAWP ≥25 mmHg when non-bicycle tests remain inconclusive.

Pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a rare and progressive disease characterised by remodelling of the pulmonary arteries and progressive narrowing of the pulmonary vasculature. This leads to a progressive increase in pulmonary vascular resistance and pulmonary arterial pressure and, if left untreated, to right ventricular failure and death. A correct diagnosis requires a complete work-up including right heart catheterisation performed in a specialised centre. Although our knowledge of the epidemiology, pathology and pathophysiology of the disease, as well as the development of innovative therapies, has progressed in recent decades, PAH remains a serious clinical condition. Current treatments for the disease target the three specific pathways of endothelial dysfunction that characterise PAH: the endothelin, nitric oxide and prostacyclin pathways. The current treatment algorithm is based on the assessment of severity using a multiparametric risk stratification approach at the time of diagnosis (baseline) and at regular follow-up visits. It recommends the initiation of combination therapy in PAH patients without cardiopulmonary comorbidities. The choice of therapy (dual or triple) depends on the initial severity of the condition. The main treatment goal is to achieve low-risk status. Further escalation of treatment is required if low-risk status is not achieved at subsequent follow-up assessments. In the most severe patients, who are already on maximal medical therapy, lung transplantation may be indicated. Recent advances in understanding the pathophysiology of the disease have led to the development of promising emerging therapies targeting dysfunctional pathways beyond endothelial dysfunction, including the TGF-β and PDGF pathways.

The role of invasive cardiopulmonary exercise testing in patients with unexplained dyspnea: a systemic review

BACKGROUND

Dyspnoea is a common complaint that often remains unexplained with no diagnosis and poor management despite extensive, repetitive and costly testing. Invasive cardiopulmonary testing has been used in the evaluation of dyspnoea, however, its role is not yet well defined. We sought to perform a systematic review of the literature looking at the role of invasive cardiopulmonary testing in the evaluation of chronic dyspnoea and/or exercise intolerance.

METHODS AND RESULTS

We performed a literature review in accordance with PRISMA, analysing articles published in peer-reviewed journals between January 1st 1985 and January 31st 2020, available in 3 databases. The aim was to identify randomised and non-randomised clinical studies that focussed on the utility of invasive cardiopulmonary exercise test in the evaluation of dyspnoea. Emphasis was placed on studies that noted the use of exercise stress testing with the concomitant use of right heart catheterisation to evaluate hemodynamics as part of the work up for dyspnoea. We identified 6 retrospective studies that assessed the use of exercise hemodynamics to identify the aetiology of dyspnoea.

CONCLUSION

Invasive cardiopulmonary exercise test is a useful tool for identifying the cause of unexplained dyspnoea. It can be helpful in early recognition and prognostication of patients with heart failure with preserved ejection fraction and pulmonary hypertension. It has also shown to be beneficial for constructing a multidisciplinary approach to chronic dyspnoea.

Pulmonary Hypertension: A Contemporary Review

Major advances in pulmonary arterial hypertension, pulmonary hypertension (PH) associated with lung disease, and chronic thromboembolic PH cast new light on the pathogenetic mechanisms, epidemiology, diagnostic approach, and therapeutic armamentarium for pulmonary vascular disease. Here, we summarize key basic, translational, and clinical PH reports, emphasizing findings that build on current state-of-the-art research. This review includes cutting-edge progress in translational pulmonary vascular biology, with a guide to the diagnosis of patients in clinical practice, incorporating recent PH definition revisions that continue emphasis on early detection of disease. PH management is reviewed including an overview of the evolving considerations for the approach to treatment of PH in patients with cardiopulmonary comorbidities, as well as a discussion of the groundbreaking sotatercept data for the treatment of pulmonary arterial hypertension.

Exercise Testing in the Risk Assessment of Pulmonary Hypertension

TOPIC IMPORTANCE

Right ventricular dysfunction in pulmonary hypertension (PH) contributes to reduced exercise capacity, morbidity, and mortality. Exercise can unmask right ventricular dysfunction not apparent at rest, with negative implications for prognosis.

REVIEW FINDINGS

Among patients with pulmonary vascular disease, right ventricular afterload may increase during exercise out of proportion to increases observed among healthy individuals. Right ventricular contractility must increase to match the demands of increased afterload to maintain ventricular-arterial coupling (the relationship between contractility and afterload) and ultimately cardiac output. Impaired right ventricular contractile reserve leads to ventricular-arterial uncoupling, preventing cardiac output from increasing during exercise and limiting exercise capacity. Abnormal pulmonary vascular response to exercise can signify early pulmonary vascular disease and is associated with increased mortality. Impaired right ventricular contractile reserve similarly predicts poor outcomes, including reduced exercise capacity and death. Exercise provocation can be used to assess pulmonary vascular response to exercise and right ventricular contractile reserve. Noninvasive techniques (including cardiopulmonary exercise testing, transthoracic echocardiography, and cardiac MRI) as well as invasive techniques (including right heart catheterization and pressure-volume analysis) may be applied selectively to the screening, diagnosis, and risk stratification of patients with suspected or established PH. Further research is required to determine the role of exercise stress testing in the management of pulmonary vascular disease.

SUMMARY

This review describes the current understanding of clinical applications of exercise testing in the risk assessment of patients with suspected or established PH.

Risk Stratification in Pulmonary Arterial Hypertension, Update and Perspectives

Risk stratification in pulmonary arterial hypertension (PAH) is crucial in assessing patient prognosis. It serves a prominent role in everyday patient care and can be determined using several validated risk assessment scores worldwide. The recently published 2022 European Society of Cardiology (ESC)/European Respiratory Society (ERS) guidelines underline the importance of risk stratification not only at baseline but also during follow-up. Achieving a low-risk status has now become the therapeutic goal, emphasising the importance of personalised therapy. The application of these guidelines is also important in determining the timing for lung transplantation referral. In this review, we summarise the most relevant prognostic factors of PAH as well as the parameters used in PAH risk scores and their evolution in the guidelines over the last decade. Finally, we describe the central role that risk stratification plays in the current guidelines not only in European countries but also in Asian countries.

Role of Exercise Stress Echocardiography in Pulmonary Hypertension

Resting and exercise right heart catheterisation is the gold standard method to diagnose and differentiate types of pulmonary hypertension (PH). As it carries technical challenges, the question arises if non-invasive exercise stress echocardiography may be used as an alternative. Exercise echocardiography can unmask exercise PH, detect the early stages of left ventricular diastolic dysfunction, and, therefore, differentiate between pre- and post-capillary PH. Regardless of the underlying aetiology, a developed PH is associated with increased mortality. Parameters of overt right ventricle (RV) dysfunction, including RV dilation, reduced RV ejection fraction, and elevated right-sided filling pressures, are detectable with resting echocardiography and are associated with worse outcome. However, these measures all fail to identify occult RV dysfunction. Echocardiographic measures of RV contractile reserve during exercise echocardiography are very promising and provide incremental prognostic information on clinical outcome. In this paper, we review pulmonary haemodynamic response to exercise, briefly describe the modalities for assessing pulmonary haemodynamics, and discuss in depth the contemporary key clinical application of exercise stress echocardiography in patients with PH.

Heart Failure With Preserved Ejection Fraction: JACC Scientific Statement

The incidence and prevalence of heart failure with preserved ejection fraction (HFpEF) continue to rise in tandem with the increasing age and burdens of obesity, sedentariness, and cardiometabolic disorders. Despite recent advances in the understanding of its pathophysiological effects on the heart, lungs, and extracardiac tissues, and introduction of new, easily implemented approaches to diagnosis, HFpEF remains under-recognized in everyday practice. This under-recognition presents an even greater concern given the recent identification of highly effective pharmacologic-based and lifestyle-based treatments that can improve clinical status and reduce morbidity and mortality. HFpEF is a heterogenous syndrome and recent studies have suggested an important role for careful, pathophysiological-based phenotyping to improve patient characterization and to better individualize treatment. In this JACC Scientific Statement, we provide an in-depth and updated examination of the epidemiology, pathophysiology, diagnosis, and treatment of HFpEF.

The role and mechanism of FTO in pulmonary vessels

Pulmonary vascular remodeling (PVR) is the main factor of pulmonary hypertension (PH). The pathological characteristics of PVR are vascular smooth muscle hyperplasia, hypertrophy, and extensive damage. In vivo experiments, the expression of FTO in PH rat lung tissues of different rat models of hypoxia PH was observed by immunohistochemical method. mRNA microarray analysis was used to analyze the differential expressed genes in rat lung tissues. In vitro experiments, we developed models of overexpression and knockdown of FTO to study the effect of FTO protein expression on cell apoptotic, cell cycle, and the abundance of m⁶A. The expression of FTO was increased in PH rats. FTO knockdown can inhibit the proliferation of PASMCs, thereby regulating the cell cycle and reducing the expression of Cyclin D1 and the abundance of m⁶A, while overexpression of FTO leads to increased expression of Cyclin D1 and the abundance of m⁶A. FTO destroys the stability of Cyclin D1 by regulating the abundance of Cyclin D1 m⁶A, causing cell cycle arrest and inducing cell proliferation, thus inducing the occurrence and development of PVR in PH.

Cardiopulmonary exercise testing applied to respiratory medicine: Myths and facts

Cardiopulmonary exercise testing (CPET) remains poorly understood and, consequently, largely underused in respiratory medicine. In addition to a widespread lack of knowledge of integrative physiology, several tenets of CPET interpretation have relevant controversies and limitations which should be appropriately recognized. With the intent to provide a roadmap for the pulmonologist to realistically calibrate their expectations towards CPET, a collection of deeply entrenched beliefs is critically discussed. They include a) the actual role of CPET in uncovering the cause(s) of dyspnoea of unknown origin, b) peak O₂ uptake as the key metric of cardiorespiratory capacity, c) the value of low lactate ("anaerobic") threshold to differentiate cardiocirculatory from respiratory causes of exercise limitation, d) the challenges of interpreting heart rate-based indexes of cardiovascular performance, e) the meaning of peak breathing reserve in dyspnoeic patients, f) the merits and drawbacks of measuring operating lung volumes during exercise, g) how best interpret the metrics of gas exchange inefficiency such as the ventilation-CO₂ output relationship, h) when (and why) measurements of arterial blood gases are required, and i) the advantages of recording submaximal dyspnoea "quantity" and "quality". Based on a conceptual framework that links exertional dyspnoea to "excessive" and/or "restrained" breathing, I outline the approaches to CPET performance and interpretation that proved clinically more helpful in each of these scenarios. CPET to answer clinically relevant questions in pulmonology is a largely uncharted research field: I, therefore, finalize by highlighting some lines of inquiry to improve its diagnostic and prognostic yield.

Role of cardiopulmonary exercise test in early diagnosis of pulmonary hypertension in scleroderma patients

INTRODUCTION

Pulmonary arterial hypertension (PAH) is a severe, high mortality and progressive disease. Early diagnosis and treatment improves the prognosis. Patients with scleroderma disease presents high risk of developing PAH. Established screening strategies - echocardiogram and DETECT algorithm - recognize the disease when it is already advanced. Cardiopulmonary exercise testing (CPET) detects pulmonary vascular injury in earlier stages.

METHODS

Prospective study of 52 consecutive patients diagnosed of scleroderma in our health area, during 2 years (2018 and 2019). All of them undergo CPET, in addition to the annual systematic screening. Sensitivity of current PAH screening is compared to CPET. To confirm the presence of PAH, right heart catheterization (RHC) is performed. In case of suspected PAH in CPET, but non-confirmatory right heart catheterization at rest, patients carried out exercise RHC.

RESULTS

Fifty-two CPET were performed, of which 16 suggested PAH. Resting RHC confirmed PAH in 5 patients and exercise RHC in 7 (diagnostic sensitivity of CPET together with rest and exercise catheterization of 100%). Of these 16 patients, DETECT had identified 10, of whom resting RHC confirmed PAH in 3 and exercise RHC in 2 (guideline-based diagnostic algorithm sensitivity 70%).

CONCLUSIONS

CPET and exercise RHC could detect PAH earlier than established screening in patients with scleroderma disease, allowing early diagnosis.

A comparative study on the diagnostic efficacy of different diagnostic criteria for exercise pulmonary hypertension

BACKGROUND

Exercise pulmonary hypertension (ePH) has three common diagnostic criteria: the mean pulmonary artery pressure (mPAP) > 30 mmHg and total pulmonary resistance (TPR) at peak exercise >3 Wood units ("Joint criteria"), the mPAP/cardiac output (CO) slope of the two-point measurement (ΔmPAP/ΔCO) > 3 mmHg/L/min ("Two-point criteria"), and the mPAP/CO slope of the multi-point data >3 mmHg/L/min ("Multi-point criteria"). We compared the diagnostic efficacy of these criteria, which remain controversial.

METHODS

Following resting right heart catheterization (RHC), all patients underwent exercise RHC (eRHC). The patients were divided into different ePH and non-exercise pulmonary hypertension (nPH) groups according to the above criteria. Joint criteria were used as the reference to compare the other two, namely diagnostic concordance, sensitivity and specificity. We conducted further analysis to determine the correlation between different diagnostic criteria grouping and the clinical severity of PH.

RESULTS

Thirty-three patients with mPAP_rest ≤ 20 mmHg were enrolled. a) Diagnostic concordance, sensitivity and specificity: compared with Joint criteria, the diagnostic concordances of Two-point criteria and Multi-point criteria were 78.8% (κ = 0.570, P < 0.01) and 90.9% (κ = 0.818, P < 0.01), respectively; the sensitivity of Two-point criteria was high (100%), but the specificity was poor (56.3%); however, Multi-point criteria exhibited higher sensitivity (94.1%) and specificity (87.5%). b) Clinically relevant analysis: a significant difference was observed in several clinical severity indicators between ePH and nPH patients according to Multi-point criteria grouping(all P < 0.05).

CONCLUSION

Multi-point criteria are more clinically relevant and provide better diagnostic efficiency.

Disproportionate exercise-induced pulmonary hypertension in relation to cardiac output in heart failure with preserved ejection fraction: a non-invasive echocardiographic study

AIMS

Pulmonary hypertension (PH) and pulmonary vascular remodelling are common in patients with heart failure with preserved ejection fraction (HFpEF). Many patients with HFpEF demonstrate an abnormal pulmonary haemodynamic response to exercise that is not identifiable at rest. This can be estimated non-invasively by the mean pulmonary artery pressure-cardiac output relationship (mPAP/CO slope). We sought to characterize the pathophysiology of disproportionate exercise-induced PH in relation to CO (DEi-PH) and its prognostic impact in patients with HFpEF.

METHODS AND RESULTS

A total of 345 patients (166 HFpEF and 179 controls) underwent ergometry exercise stress echocardiography with simultaneous expired gas analysis. DEi-PH was defined as the mPAP/CO slope >5.2 mmHg/L/min (median value). At rest, there were no differences in right ventricular (RV) function and severity of PH between HFpEF patients with and without DEi-PH. Compared with controls (n = 179) and HFpEF without DEi-PH (n = 83), HFpEF with DEi-PH (n = 83) demonstrated worse exercise capacity (lower peak oxygen consumption), depressed RV systolic function, impaired RV-pulmonary artery coupling, limitation in CO augmentation, more right-sided congestion, and worse ventilatory efficiency (higher minute ventilation vs. carbon dioxide volume) during peak exercise. Kaplan-Meier analyses showed that HFpEF patients with DEi-PH had higher rates of composite outcomes of all-cause mortality or heart failure events than those without (log-rank p = 0.0002).

CONCLUSION

Patients with HFpEF and DEi-PH demonstrated distinct pathophysiologic features that become apparent only during exercise. These data suggest that DEi-PH is a pathophysiologic phenotype of HFpEF and reinforce the importance of exercise stress echocardiography for detailed characterization of HFpEF.

The controversial role of beta-blockers in heart failure with preserved ejection fraction

Beta-blocker (BB) therapy is a main pillar in treating patients with heart failure and reduced ejection fraction and has shown a prognostic benefit. However, evidence for application of BB in heart failure with preserved ejection fraction (HFpEF), especially in the absence of coronary artery disease, atrial fibrillation or arterial hypertension, is scarce. HFpEF is characterized by elevations in left atrial pressure and reduced compliance of the left ventricle leading to a hampered increase of cardiac output (CO) during exercise, which results in exertional dyspnea. This may be due to either a limited increase in stroke volume or reduced chronotropy during physical activity. We critically discuss the pathophysiological background of HFpEF, current data on BB in heart failure therapy, as well as the potential benefits and harms of BB therapy in HFpEF. Furthermore, we argue that non-cardio selective BB with peripheral activity to reduce afterload may be more suitable in this population than cardio-selective BB. Although preliminary data on BB in HFpEF are available, multicenter prospective trials to assess a reduction of cardiovascular morbidity are warranted. Future trials need to focus on phenotyping HFpEF patients and assess who may benefit most from tailored BB therapy.

Central haemodynamic abnormalities and outcome in patients with unexplained dyspnoea

AIMS

Little data are available regarding prognostic implications of invasive exercise testing in heart failure with preserved ejection fraction (HFpEF). The present study aimed to investigate whether rest and exercise central haemodynamic abnormalities are associated with adverse clinical outcomes in patients with dyspnea.

METHODS AND RESULTS

Patients with exertional dyspnoea and ejection fraction ≥50% (n = 764) underwent invasive exercise testing and follow-up for heart failure hospitalization or death. There were 117 patients with events over a median follow-up of 2.7 (interquartile range 0.5-4.6) years. Among patients with normal resting pulmonary artery wedge pressure (PAWP) (<15 mmHg, n = 380 [50%]), increased exercise PAWP (≥25 mmHg) was present in 187 (24% of cohort) and was associated with 2.4-fold higher risk of events compared to those with normal exercise PAWP (<25 mmHg, n = 193 [25%]) (hazard ratio [HR] 2.44; 95% confidence interval [CI] 1.11-5.36; p = 0.03), while patients with elevated resting PAWP (≥15 mmHg, n = 384 [50%]) displayed even higher risk compared to HFpEF with normal resting PAWP (HR 2.24; 95% CI 1.38-3.65; p = 0.001). Similar findings were observed for rest/exercise right atrial pressure, and rest/exercise pulmonary artery pressures. Higher peak oxygen consumption was associated with decreased risk of events, and this relationship was solely explained by exercise cardiac output. In a multivariable-adjusted Cox model, each 1 standard deviation (SD) increase in exercise PAWP was associated with a 41% greater hazard of events (HR 1.41; 95% CI 1.13-1.76; p = 0.002), while each 1 SD decrease in exercise cardiac output was associated with a 37% increased risk (HR 0.63; 95% CI 0.47-0.83; p = 0.001).

CONCLUSIONS

Haemodynamic abnormalities currently used for diagnosis of HFpEF are associated with increased risk for adverse events. Treatments that reduce central pressures while improving cardiac output reserve may offer greatest benefit to improve outcomes in HFpEF.

Role of Echocardiography in Diabetic Cardiomyopathy: From Mechanisms to Clinical Practice

It has been well established that diabetes mellitus (DM) is considered as a core risk factor for the development of cardiovascular diseases. However, what is less appreciated is the fact that DM may affect cardiac function irrespective of cardiac pathologies to which it contributes, such as coronary artery disease and hypertension. Although echocardiography provides accurate and reproducible diagnostic and prognostic data in patients with DM, its use in these patients is still underappreciated, resulting in progression of DM-related heart failure in many patients. Hence, in the present review, we aimed to discuss the role of echocardiography in the contemporary management of diabetic cardiomyopathy (DCM), as well as the role of emerging echocardiographic techniques, which may contribute to earlier diagnosis and more appropriate management of this complication of DM. In order to improve outcomes, focus must be placed on early diagnosis of this condition using a combination of echocardiography and emerging biomarkers, but perhaps the more important thing is to change perspective when it comes to the clinical importance of DCM.

Pulmonary hypertension during exercise underlies unexplained exertional dyspnoea in patients with Type 2 diabetes

AIMS

To compare the cardiac function and pulmonary vascular function during exercise between dyspnoeic and non-dyspnoeic patients with Type 2 diabetes mellitus (T2DM).

METHODS AND RESULTS

Forty-seven T2DM patients with unexplained dyspnoea and 50 asymptomatic T2DM patients underwent exercise echocardiography combined with ergospirometry. Left ventricular (LV) function [stroke volume, cardiac output (CO), LV ejection fraction, systolic annular velocity (s')], estimated LV filling pressures (E/e'), mean pulmonary arterial pressures (mPAPs) and mPAP/COslope were assessed at rest, low- and high-intensity exercise with colloid contrast. Groups had similar patient characteristics, glycemic control, stroke volume, CO, LV ejection fraction, and E/e' (P > 0.05). The dyspnoeic group had significantly lower systolic LV reserve at peak exercise (s') (P = 0.021) with a significant interaction effect (P < 0.001). The dyspnoeic group also had significantly higher mPAP and mPAP/CO at rest and exercise (P < 0.001) with significant interaction for mPAP (P < 0.009) and insignificant for mPAP/CO (P = 0.385). There was no significant difference in mPAP/COslope between groups (P = 0.706). However, about 61% of dyspnoeic vs. 30% of non-dyspnoeic group had mPAP/COslope > 3 (P = 0.009). The mPAP/COslope negatively predicted V̇O2peak in dyspneic group (β = -1.86, 95% CI: -2.75, -0.98; multivariate model R2:0.54).

CONCLUSION

Pulmonary hypertension and less LV systolic reserve detected by exercise echocardiography with colloid contrast underlie unexplained exertional dyspnoea and reduced exercise capacity in T2DM.

Betablockers reduce oxygen pulse increase and performance in heart failure patients with preserved ejection fraction

BACKGROUND

Beta blockers (BB) reduce chronotropic response and exercise capacity in heart failure with preserved ejection fraction (HFpEF). To analyze the influence of BB on exercise performance and O 2 pulse increase as a surrogate for stroke volume in HFpEF.

METHODS

We retrospectively analyzed the influence of BB intake (yes: n = 48/no: n = 51) on peak oxygen uptake (VO 2peak), oxygen uptake efficiency slope (OUES), and increase of O 2 pulse in HFpEF patients undergoing cardiopulmonary exercise testing (CPET). Associations of outcome variables and risk category of the algorithm of the Heart Failure Association of the European Society of Cardiology (HFA-PEFF score) were calculated.

RESULTS

Patients on BB showed lower VO 2peak (p = .003) and OUES (p = .002), with a dominant effect in the high-risk (p = .020; 0.002), but not in the low risk-group (p = .434; p = .499). In the intermediate group BB showed a trend towards lower VO 2peak (p = .078) and lower values for OUES (p = .020). Patients on BB also demonstrated a lower increase of O 2 pulse during exercise (p = .002), without differences between HFA-PEFF risk groups (low: p = .322, intermediate: p = .269, high: p = .313).

CONCLUSIONS

BB reduce exercise capacity and O 2 pulse increase in HFpEF patients. Direct quantification of O 2 pulse increase may help to improve the discrimination of HFpEF patients.

Alterations of pulmonary vascular afterload in exercise-induced pre- and post-capillary pulmonary hypertension

Exercise imposes increased pulmonary vascular afterload based on rises in pulmonary artery (PA) wedge pressure, declines in PA compliance, and resistance-compliance time. In health, afterload stress stabilizes during steady-state exercise. Our objective was to examine alterations of these exercise-associated stresses in states of pre- and post-capillary pulmonary hypertension (PH). PA hemodynamics were evaluated at rest, 2 and 7 min of steady-state exercise at moderate intensity in patients who exhibited Pre-capillary (n = 22) and post-capillary PH (n = 22). Patients with normal exercise hemodynamics (NOR-HD) (n = 32) were also studied. During exercise in all groups, PA wedge pressure increased at 2 min, with no further change at 7 min. In post-capillary PH and NOR-HD, increases in PA diastolic pressure and diastolic pressure gradient remained stable at 2 and 7 min of exercise, while in pre-capillary PH, both continued to increase at 7 min. The behavior of the diastolic pressure gradient was linearly related to the duration of resistance-compliance time at rest (r²  = 0.843) and exercise (r²  = 0.760). Exercise resistance-compliance time was longer in pre-capillary PH associated with larger increases in diastolic pressure gradient. Conversely, resistance-compliance time was shortest in post-capillary PH compared to pre-capillary PH and NOR-HD and associated with limited increases in exercise diastolic pressure gradient. During steady-state, modest-intensity exercise-specific patterns of pulmonary vascular afterload responses were observed in pre- and post-capillary PH relative to NOR-HD. Longer resistance-compliance time related to greater increases in PA diastolic pressure and diastolic pressure gradients in pre-capillary PH, while shorter resistance-compliance time appeared to limit these increases in post-capillary PH.

Impact of Exercise-Induced Pulmonary Hypertension on Right Ventricular Function and on Worsening of Cardiovascular Risk in HIV Patients

Background and Aim: Exercise-induced pulmonary hypertension (ExPH) predicts clinical outcomes, such as all-cause mortality and cardiovascular (CV) hospitalizations, in patients with dyspnea on effort. We investigated its prognostic significance in human immunodeficiency virus (HIV)-affected patients. Methods: In 52 consecutive HIV patients with either low (n = 47) or intermediate probability (n = 5) of PH at rest, we evaluated—at time 0 and after 2 years—the prognostic determinants of CV risk, according to the 2015 European Society of Cardiology (ESC)/European Respiratory Society (ERS) Guidelines. Patients were classified with or without ExPH at stress echocardiography (ESE) and cardiopulmonary exercise test (CPET). We then related ExPH at time 0 with clinical worsening (CV risk score increase >20% after 2 years). Results: Right ventricle (RV) systolic function was significantly reduced in patients with ExPH compared to those without ExPH at CPET. This also occurred in patients with intermediate/high probability compared to those with low probability of ExPH at ESE. The former exhibited worse values of TAPSE and FAC (p < 0.001 and p = 0.01, respectively). A significantly higher proportion of patients with ExPH (CPET) or with intermediate/high probability of ExPH (ESE) had higher sPAP (p < 0.001), mPAP (p = 0.004) and higher TRV (p = 0.006), as well as higher right atrial area (p < 0.001) and indexed right atrial volume (p = 0.004). Total pulmonary vascular resistance (expressed by the ratio between TRV and the velocity-time integral at the level of the right ventricular outflow tract) was higher both in patients with ExPH and in those with intermediate/high probability of ExPH (p < 0.001). Patients with intermediate/high probability of ExPH at ESE showed a trend (p = 0.137) towards clinical worsening compared to those with low probability of ExPH. No patients with low probability of ExPH had a >20% increased CV risk score after 2 years. We found an association between higher NT-proBNP and the presence or intermediate/high probability of ExPH after 2 years (p = 0.048 at CPET, p = 0.033 at ESE). Conclusions: The assessment of ExPH may predict a trend of increasing CV risk score over time. If confirmed at a longer follow-up, ExPH could contribute to better risk stratification in HIV patients.

Updated definition of exercise pulmonary hypertension

In the recently published European Society of Cardiology/European Respiratory Society guidelines on the diagnosis and treatment of pulmonary hypertension (PH) the haemodynamic definitions of PH were updated and a new definition for exercise PH was introduced. Accordingly, exercise PH is characterised by a mean pulmonary arterial pressure/cardiac output (CO) slope >3 Wood units (WU) from rest to exercise. This threshold is supported by several studies demonstrating prognostic and diagnostic relevance of exercise haemodynamics in various patient cohorts. From a differential diagnostic point of view, an elevated pulmonary arterial wedge pressure/CO slope >2 WU may be suitable to identify post-capillary causes of exercise PH. Right heart catheterisation remains the gold standard to assess pulmonary haemodynamics both at rest and exercise. In this review, we discuss the evidence that led to the reintroduction of exercise PH in the PH definitions.

Hemodynamic Assessment in Heart Failure with Preserved Ejection Fraction

Heart failure (HF) with preserved ejection fraction (HFpEF) is characterized by an inability of the heart to perfuse the body without pathologic increases in filling pressure at rest or during exertion. Right heart catheterization provides direct assessment for HF, providing the most robust and direct method to evaluate the central hemodynamic abnormalities, and serves as the gold standard to confirm or refute the presence of HFpEF. This article reviews current understanding of the best practices in the performance and interpretation of hemodynamic assessment, relates important pathophysiologic concepts to clinical care, and discusses current and evidence-based applications of hemodynamics in HFpEF.