A Comprehensive Assessment of Right Ventricular Function in Chronic Thromboembolic Pulmonary Hypertension

Assessment of right ventricle-to-pulmonary artery coupling by three-dimensional echocardiography in pre-capillary pulmonary hypertension: comparison with tricuspid annular plane systolic excursion /systolic pulmonary artery pressure ratio

BACKGROUND

The tricuspid annular plane systolic excursion/systolic pulmonary artery pressure ratio (TAPSE/sPAP) has limitations in evaluating right ventricle-to-pulmonary artery (RV-PA) coupling, particularly when pulmonary artery pressure cannot be accurately estimated by tricuspid regurgitation or when TAPSE cannot accurately reflect right ventricular systolic function in certain scenarios. Therefore, this study aimed to explore the value of three-dimensional echocardiography (3DE) coupling parameters in assessing RV-PA coupling in patients with pre-capillary pulmonary hypertension (PH).

METHODS

Fifty-nine patients with pre-capillary PH were retrospectively recruited. The surrogate "gold standard" of RV-PA coupling was derived from right heart catheterization (RHC) and cardiac magnetic resonance imaging (CMR). The relationships between echocardiographic RV-PA coupling parameters and RHC-CMR coupling standard were analyzed by Pearson's test and Bland‒Altman test. Additionally, 24 chronic thromboembolic pulmonary hypertension (CTEPH) patients were enrolled to explore the changes in echocardiographic RV-PA coupling parameters before and after PEA. Multivariate ordinal regression analysis was performed to identify echocardiographic parameters associated with prognostic risk stratification in pre-capillary PH patients.

RESULTS

3DE coupling parameters demonstrated strong correlation and good agreement with the RHC-CMR coupling standard. In contrast, TAPSE/sPAP was moderately correlated to the RHC-CMR coupling standard, but showed poor consistency, with a significant bias of 0.44 (95% CI: 0.374, 0.511). Before and after PEA, stroke volume/end-systolic volume (SV/ESV) derived by 3DE remained moderately correlated with pulmonary vascular resistance (PVR) and mean pulmonary artery pressure (mPAP) (r =-0.614, -0.655, P < 0.001), whereas TAPSE/sPAP was only associated with PVR and mPAP in CTEPH patients before PEA (r=-0.605, -0.758, P < 0.001). Multivariate regression analysis revealed TAPSE/sPAP as the strongest predictor of prognostic risk.

CONCLUSIONS

3DE-derived coupling parameters offer a noninvasive and reliable approach for assessing RV-PA coupling in patients with pre-capillary PH, especially for patients who cannot accurately estimate pulmonary artery pressure or have undergone cardiac surgery. 3DE SV/ESV is superior to TAPSE/sPAP for assessing postoperative RV-PA coupling in CTEPH patients, TAPSE/sPAP remains a valuable parameter for prognostic risk stratification in pre-capillary PH patients. Echocardiography can provide valuable information for assessing RV-PA coupling and prognosis in patients with pre-capillary PH. However, the application of echocardiographic coupling parameters should be determined based on the specific clinical context.

Diagnosis and Treatment Patterns of Chronic Thromboembolic Pulmonary Hypertension in Russia, Kazakhstan, Turkey, Lebanon, and Saudi Arabia: A Registry Study

BACKGROUND

Patients with chronic thromboembolic pulmonary hypertension (CTEPH) in countries with limited resources have, to date, been poorly represented in registries.

OBJECTIVE

This work assesses the epidemiology, diagnosis, hemodynamic and functional parameters, and treatment of CTEPH in Russia, Kazakhstan, Turkey, Lebanon, and Saudi Arabia.

METHODS

A prospective, cohort, phase IV, observational registry with 3-year follow-up (n = 212) in patients aged ≥ 18 years diagnosed with CTEPH was created. Clinical, hemodynamic, and functional parameters were obtained at an initial visit, follow-up visits, and a final visit at the end of 3 years' observation or end of follow-up. Data were recorded on electronic case report forms. Parameters evaluated included 6-minute walking distance (6MWD), use of pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA), pulmonary hypertension (PH)-targeted therapy, and survival. All statistical analyses were exploratory and descriptive, and were performed in the overall population.

RESULTS

The most common symptoms were typical of those expected for CTEPH. Almost 90% of patients underwent right heart catheterization at diagnosis or initial study visit. In total, 66 patients (31%) underwent PEA before the initial visit; 95 patients (45%) were considered operable, 115 (54%) were inoperable, and two (1%) had no operability data. Only 26 patients (12%) had been assessed for BPA at their initial visit. PH-targeted therapy was documented at diagnosis for 77 patients (36%), most commonly a phosphodiesterase type 5 inhibitor (23%). Use of PH-targeted therapy increased to 142 patients (67%) at the initial visit, remaining similar after 3 years. Use of riociguat increased from 6% of patients at diagnosis to 38% at 3 years. Between baseline and end of observation, results for patients with paired data showed an increase in 6MWD. Survival at the end of observation was 88%.

CONCLUSIONS

These data highlight the current diagnosis and management of CTEPH in the participating countries. They show that early CTEPH diagnosis remains challenging, and use of off-label PH-targeted therapy is common.

CLINICALTRIALS

gov: NCT02637050; registered December 2015.

Clinical-radiological-pathological correlation in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare and potentially life-threatening complication of acute pulmonary embolism. It is characterised by persistent fibro-thrombotic pulmonary vascular obstructions and elevated pulmonary artery pressure leading to right heart failure. The diagnosis is based on two steps, as follows: 1) suspicion based on symptoms, echocardiography and ventilation/perfusion scan and 2) confirmation with right heart catheterisation, computed tomography pulmonary angiography and, in most cases, digital subtraction angiography. The management of CTEPH requires a multimodal approach, involving medical therapy, interventional procedures and surgical intervention. This clinical-radiological-pathological correlation paper illustrates the diagnostic and therapeutic management of two patients. The first had chronic thromboembolic pulmonary disease without pulmonary hypertension at rest but with significant physical limitation and was successfully treated with pulmonary endarterectomy. The second patient had CTEPH associated with splenectomy and was considered unsuitable for surgery because of exclusive subsegmental lesions combined with severe pulmonary hypertension. The patient benefited from multimodal treatment involving medical therapy followed by multiple sessions of balloon pulmonary angioplasty. Both patients had normalised functional capacity and pulmonary haemodynamics 3-6 months after the interventional treatment. These two examples show that chronic thromboembolic pulmonary diseases are curable if diagnosed promptly and referred to CTEPH centres for specialist treatment.

Monographic Issue on Pulmonary Hypertension: Medical and Interventional Treatment for Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism. The reasons why clots do not resorb are incompletely understood, but the result is partial or complete fibrothrombotic obstruction of pulmonary arteries. A secondary microvasculopathy aggravates the pulmonary hypertension (PH) as a consequence of high flow and shear stress in the nonoccluded arteries. The treatment of CTEPH has long been purely surgical, but many patients were inoperable because of inaccessible lesions or severe comorbidities. Alternatives were developed, including medical therapy and more recently balloon pulmonary angioplasty (BPA). Depending on the generation of the obstructed vessels, the treatment will be surgical, up to the (sub)segmental level, or by BPA for more distal vessels. PH drugs are used to treat the microvasculopathy. The current paper describes the therapeutic management of inoperable patients: the medical approach with PH drugs used in mono- or combination therapy; the proper use of anticoagulants in CTEPH; the technique, indications, and results at short- and long-term of BPA; the multimodal approach for inoperable patients combining PH drugs and BPA; and the effects of rehabilitation. It shows the importance of a multidisciplinary approach to the disease.

Impact of Balloon Pulmonary Angioplasty on Right Ventricular Function in Patients With Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) can develop in some patients after an acute pulmonary embolism. The disease is characterized by the conversion of emboli into fibrotic thrombi that chronically impede normal circulation through the pulmonary arteries and increase pulmonary vascular resistance. Over time, this increases right ventricular (RV) afterload and strains the RV. The RV compensates by undergoing cardiomyocyte hypertrophy and RV dilation that can maintain stroke volume. However, these adaptations eventually decrease cardiac output and lead to right heart failure. Balloon pulmonary angioplasty has been developed as a treatment option for CTEPH by systematically disrupting thrombosed vessels and improving blood flow throughout the pulmonary circulation. This ultimately reverses the structural maladaptation's seen in CTEPH and improves RV function.