Updated definition of exercise pulmonary hypertension

An overview of balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension

INTRODUCTION

Chronic thromboembolic pulmonary hypertension (CTEPH) is a severe and progressive condition caused by unresolved pulmonary arterial obstructions, leading to secondary microvasculopathy and poor hemodynamics. Pulmonary endarterectomy (PEA) is the first-line treatment for operable patients. Balloon pulmonary angioplasty (BPA) has emerged as a promising treatment option for patients considered inoperable due to distal lesions, comorbidities, or residual pulmonary hypertension (PH) after PEA. Following the development of the BPA in safety and efficacy, it has been widely adopted and utilized across the globe.

AREAS COVERED

This review covers the historical development of BPA, its clinical role, and technical methodologies. Medical therapies as an adjunctive role in CTEPH management are also discussed. Finally, we present recent BPA experiences from our institution, highlighting hemodynamic outcomes and survival rates.

EXPERT OPINION

BPA is a transformative treatment for patients with CTEPH, particularly those ineligible for PEA. Procedural refinements have significantly improved safety and efficacy. However, challenges remain, including the standardization of decision-making processes for management and the establishment of optimal treatment goals. Ongoing research continues to refine the role of BPA to improve outcomes and enhance the quality of life for patients with CTEPH. [Figure: see text].

Pulmonary gas exchange in relation to exercise pulmonary hypertension in patients with heart failure with preserved ejection fraction

BACKGROUND

Exercise pulmonary hypertension, defined as a mean pulmonary arterial pressure (mPAP)/cardiac output (Q̇c) slope >3 WU during exercise, is common in patients with heart failure with preserved ejection fraction (HFpEF). However, the pulmonary gas exchange-related effects of an exaggerated exercise pulmonary hypertension (EePH) response are not well defined, especially in relation to dyspnoea on exertion and exercise intolerance.

METHODS

48 HFpEF patients underwent invasive (pulmonary and radial artery catheters) constant-load (20 W) and maximal incremental cycle testing. Haemodynamic measurements (mPAP and Q̇c), arterial blood and expired gases, and ratings of perceived breathlessness (Borg 0-10 scale) were obtained. The mPAP/Q̇c slope was calculated from rest to 20 W. Those with a mPAP/Q̇c slope ≥4.2 (median) were classified as HFpEF+EePH (n=24) and those with a mPAP/Q̇c slope <4.2 were classified as HFpEF (without EePH) (n=24). The alveolar-arterial oxygen tension difference, dead space to tidal volume ratio (Bohr equation) and the minute ventilation to carbon dioxide production slope (from rest to 20 W) were calculated.

RESULTS

Arterial oxygen tension was lower (p=0.03) and dead space to tidal volume ratio was higher (p=0.03) at peak exercise in HFpEF+EePH than in HFpEF. The alveolar-arterial oxygen tension difference was similar at peak exercise between groups (p=0.14); however, patients with HFpEF+EePH achieved the peak alveolar-arterial oxygen tension difference at a lower peak work rate (p<0.01). The minute ventilation to carbon dioxide production slope was higher in HFpEF+EePH than in HFpEF (p=0.01). Perceived breathlessness was ≥1 unit higher at 20 W and peak oxygen uptake was lower (p<0.01) in HFpEF+EePH than in HFpEF.

CONCLUSIONS

These data suggest that EePH contributes to pulmonary gas exchange impairments during exercise by causing a ventilation/perfusion mismatch that provokes both ventilatory inefficiency and hypoxaemia, both of which seem to contribute to dyspnoea on exertion and exercise intolerance in patients with HFpEF.

Exercise Pulmonary Hypertension and Beyond: Insights in Exercise Pathophysiology in Pulmonary Arterial Hypertension (PAH) from Invasive Cardiopulmonary Exercise Testing

Pulmonary arterial hypertension (PAH) is a rare, progressive disease of the pulmonary vasculature that is associated with pulmonary vascular remodeling and right heart failure. While there have been recent advances both in understanding pathobiology and in diagnosis and therapeutic options, PAH remains a disease with significant delays in diagnosis and high morbidity and mortality. Information from invasive cardiopulmonary exercise testing (iCPET) presents an important opportunity to evaluate the dynamic interactions within and between the right heart circulatory system and the skeletal muscle during different loading conditions to enhance early diagnosis, phenotype disease subtypes, and personalize treatment in PAH given the shortcomings of contemporary diagnostic and therapeutic approaches. The purpose of this review is to present the current applications of iCPET in PAH and to discuss future applications of the testing methodology.

Exercise-induced pulmonary hypertension: rationale for correcting pressures for flow and guide to non-invasive diagnosis

Exercise-induced pulmonary hypertension (exPHT) is a haemodynamic condition linked to increased morbidity and mortality across various cardiopulmonary diseases. Traditional definitions of exPHT rely on absolute cut-offs, such as mean pulmonary artery pressure (mPAP) above 30 mmHg during exercise. However, recent research suggests that these cut-offs may not accurately reflect pathophysiological changes, leading to false positives and false negatives. Instead, the mPAP over cardiac output (CO) slope, which incorporates both pressure and flow measurements, has emerged as a more reliable indicator. A slope exceeding 3 mmHg/L/min is now considered diagnostic for exPHT and strongly correlates with adverse outcomes. Stress echocardiography serves as a viable alternative to invasive assessment, enabling broader implementation. This review discusses the physiological basis of pulmonary haemodynamics during exercise, the advantages of the mPAP/CO slope over absolute pressure measurements, the evidence supporting its inclusion in clinical guidelines, and provides a practical guide for non-invasive determining the mPAP/CO slope in clinical practice.

Exercise pulmonary hypertension in chronic thromboembolic pulmonary disease: A right heart catheterization study

Many patients with chronic thromboembolic pulmonary disease (CTEPD) suffer from exertional dyspnea. It is unclear if CTEPD is associated with exercise pulmonary hypertension (ePH). This cross-sectional study aimed to determine the occurrence of ePH in patients with CTEPD and to identify the haemodynamic changes during exercise. We recruited 36 patients with persistent dyspnoea and residual perfusion defects by ventilation/perfusion scintigraphy from a large cohort of patients with previous pulmonary embolism. All patients underwent exercise right heart catheterization before being classified into the following groups: (1) CTEPD without ePH; comprising patients with normal mean pulmonary artery pressure (mPAP) of ≤20 mmHg, but with mPAP/cardiac output (CO) slope of ≤3 mmHg/L/min, (2) CTEPD with ePH (CTEPD-ePH); those with CTEPD with an mPAP/CO slope of >3 mmHg/L/min, (3) chronic thromboembolic pulmonary hypertension (CTEPH); those with mPAP >20 mmHg, pulmonary arterial wedge pressure (PAWP) ≤ 15 mmHg and pulmonary vascular resistance >2 WU. The postcapillary contribution during exercise was considered present if the PAWP/CO slope of >2 mmHg/L/min. CTEPD without resting pulmonary hypertension (PH) was present in 29 (81%) of the 36 patients, of whom six (21%) had ePH, while five (14%) had CTEPH. Two patients had unclassified PH. Two (33%) of the six patients with CTEPD-ePH had a PAWP/CO slope of >2 mmHg/L/min, compared with two (40%) of the five of those with CTEPH. In conclusion, about 20% of patients with CTEPD and exertional dyspnoea had ePH. Exercise right heart catheterization revealed a notable proportion of patients with postcapillary contribution.