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.

Diagnosis and Management of Pulmonary Hypertension and Right Ventricular Failure in the Cardiovascular Intensive Care Unit

Pulmonary hypertension (PH) encompasses a broad range of conditions, including pulmonary artery hypertension, left-sided heart disease, and pulmonary and thromboembolic disorders. Successful diagnosis and management rely on an integrated clinical assessment of the patient's physiology and right heart function. Right ventricular (RV) heart failure is often a result of PH, but may result from varying abnormalities in preload, afterload, and intrinsic myocardial dysfunction, which require distinct management strategies. Consideration of an individual's hemodynamic phenotype and physiologic circumstances is paramount in management of PH and RV failure, particularly when there is clinical instability in the intensive care setting.

Right ventricular assessment in pulmonary hypertension

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of assessment of right ventricular function in the context of pulmonary hypertension and pulmonary arterial hypertension (PAH). We will review unique features of right ventricular anatomy, delineation of cause of pulmonary hypertension through careful right ventricular assessment, echocardiographic and hemodynamic evaluation, and the importance of this assessment in prognosis.

RECENT FINDINGS

The importance of performance in prognosis and risk assessment in patients with pulmonary hypertension has been continually emphasized in ongoing research. Representative parameters of right ventricular function have been shown to be predictive of prognosis in patients with pulmonary hypertension. Further, the importance of serial right ventricular assessment in risk assessment and prognosis has remained an emerging theme.

SUMMARY

Careful evaluation of right ventricular function is paramount in assessing the cause of pulmonary hypertension and severity of disease. Further, it has prognostic significance, as many representative parameters of right ventricular function have been linked with mortality. In our opinion, right ventricular function should be assessed serially throughout the course of treatment in pulmonary hypertension, and baseline parameters in addition to dynamic changes should be incorporated into risk assessment. Achieving normal or near-normal right ventricular performance may serve as a principal goal in the treatment of pulmonary hypertension.

May-Thurner Anatomy in Patients With Chronic Thromboembolic Pulmonary Hypertension: An Important Clinical Association

OBJECTIVES

The aim of this study was to investigate the incidence of May-Thurner anatomy (MTA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and identify its predictors.

BACKGROUND

MTA is an anatomical variant characterized by compression of left common iliac vein by the overlying right iliac artery. Over time, this leads to venous intimal scarring, blood flow stasis, and the development of deep vein thrombosis (DVT). DVT is a known risk factor for the development of CTEPH. The prevalence of this anatomical variation in patients with CTEPH is unknown.

METHODS

A retrospective chart review was conducted in patients referred to Temple University Hospital's cardiac catheterization laboratory for the evaluation of CTEPH between January 2016 and June 2020. Among these patients, those who underwent invasive venography were evaluated for the presence of angiographic MTA. Multivariate regression was used to identify factors associated with presence of MTA.

RESULTS

A total of 193 patients with CTEPH were referred for pulmonary angiography, of whom 148 patients underwent invasive venography. MTA was identified in 44 patients (29.7%). Factors associated with the presence of MTA were lower extremity DVT (odds ratio: 3.5; 95% confidence interval: 1.58-7.8; P = 0.002), and left lower extremity post-thrombotic syndrome (odds ratio: 2.0; 95% confidence interval: 0.98-4.1; P = 0.05). Patients with MTA were more likely to undergo pulmonary thromboendarterectomy than patients without MTA (79.5% vs 58.7%; P = 0.015).

CONCLUSIONS

MTA is very common in patients with CTEPH. History of lower extremity DVT and or left lower extremity post-thrombotic syndrome was associated with the presence of MTA.

Improvement after bariatric surgery in chronic thromboembolic pulmonary hypertension: a novel treatment target

A 66-year-old man with a medical history significant for multiple pulmonary embolism and morbid obesity was evaluated for chronic thromboembolic pulmonary hypertension. Echocardiogram and right heart catheterisation were significant for severe pulmonary hypertension. Therefore, he was started on pulmonary hypertension medical therapy with riociguat and ambrisentan, in addition to anticoagulation. He experienced a dramatic clinical response to medical therapy. Despite haemodynamic improvement, the patient remained symptomatic with significant fatigue, exertional dyspnea and poor functional status as highlighted by a 6 min walk distance of only 128 m. Patient was referred for bariatric surgery with a gastric sleeve, after which he successfully lost 95 lbs in 6 months. Postoperative right heart catheterisation demonstrated normal pulmonary  vascular resistance and cardiac output. His echocardiogram revealed normal right ventricular size and function. His 6 min walk distance also nearly quadrupled from 128 to 512 m, consistent with WHO Functional Class I.