Limitations of right ventricular annular parameters in the early postoperative period following pulmonary endarterectomy: an observational study

Riociguat and the right ventricle in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension

Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are progressive diseases that can lead to right heart failure and death. Right ventricular dysfunction, hypertrophy and maladaptive remodelling are consequences of increased right ventricular (RV) afterload in PAH and CTEPH and are indicative of long-term outcomes. Because RV failure is the main cause of morbidity and mortality in PAH and CTEPH, successful treatments should lead to improvements in RV parameters. Riociguat is a soluble guanylate cyclase stimulator approved for the treatment of PAH and inoperable or persistent/recurrent CTEPH after pulmonary endarterectomy. This review examines the current evidence showing the effect of riociguat on the right ventricle, with particular focus on remodelling, function and structural parameters in preclinical models and patients with PAH or CTEPH.

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

While chronic thromboembolic pulmonary hypertension (CTEPH) results from macroscopic and microscopic obstruction of the pulmonary vascular bed, the function of the right ventricle (RV) and increased RV afterload are the main determinants of its symptoms and prognosis. In this review, we assess RV function in patients diagnosed with CTEPH with a focus on the contributions of RV afterload and dysfunction to the pathogenesis of this disease. We will also discuss changes in RV function and geometry in response to treatment, including medical therapy, pulmonary endarterectomy, and balloon pulmonary angioplasty.

Pulmonary Endarterectomy for Chronic Thromboembolic Pulmonary Hypertension: A Systematic Review of the Most Updated Literature

Pulmonary endarterectomy (PEA) is the treatment of choice in case of chronic thromboembolic pulmonary hypertension (CTEPH). PEA is performed by an increasing number of surgeons; however, the reported outcomes are limited to a few registries or to individual centers' experiences. This systematic review focuses on pre-operative evaluation, intra-operative procedure and post-operative results in patients submitted to PEA for CTEPH. The literature included was searched using a formal strategy, combining the terms "pulmonary endarterectomy" AND "chronic pulmonary hypertension" and focusing on studies published in the last 5 years (2017-2022) to give a comprehensive overview on the most updated literature. The selection of the adequate surgical candidate is a crucial point, and the decision should always be performed by expert multidisciplinary teams composed of surgeons, pulmonologists and radiologists. In all the included studies, the surgical procedure was performed through a median sternotomy with intermittent deep hypothermic circulatory arrest under cardiopulmonary bypass. In case of residual pulmonary hypertension, alternative combined treatments should be considered (balloon angioplasty and/or medical therapy until lung transplantation in highly selected cases). Short- and long-term outcomes, although not homogenous across the different studies, are acceptable in highly experienced CTEPH centers.

Non-invasive follow-up strategy after pulmonary endarterectomy for CTEPH

Background

The success of pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) is usually evaluated by performing a right heart catheterisation (RHC). Here, we investigate whether residual pulmonary hypertension (PH) can be sufficiently excluded without the need for a RHC, by making use of early post-operative haemodynamics, or N-terminal pro-brain natriuretic peptide (NT-proBNP), cardiopulmonary exercise testing (CPET) and transthoracic echocardiography (TTE) 6 months after PEA.

Methods

In an observational analysis, residual PH after PEA measured by RHC was related to haemodynamic data from the post-operative intensive care unit time and data from a 6-month follow-up assessment including NT-proBNP, TTE and CPET. After dichotomisation and univariate analysis, sensitivity, specificity, positive predictive value, negative predictive value (NPV) and likelihood ratios were calculated.

Results

Thirty-six out of 92 included patients had residual PH 6 months after PEA (39%). Correlation between early post-operative and 6-month follow-up mean pulmonary artery pressure was moderate (Spearman rho 0.465, p<0.001). Early haemodynamics did not predict late success. NT-proBNP >300 ng·L⁻¹ had insufficient NPV (0.71) to exclude residual PH. Probability for PH on TTE had a moderate NPV (0.74) for residual PH. Peak oxygen consumption (V′_O2) <80% predicted had the highest sensitivity (0.85) and NPV (0.84) for residual PH.

Conclusions

CPET 6 months after PEA, and to a lesser extent TTE, can be used to exclude residual CTEPH, thereby safely reducing the number of patients needing to undergo re-RHC after PEA.

In approximately one-third to one-half of CTEPH patients, residual pulmonary hypertension after pulmonary endarterectomy can be excluded based on cardiopulmonary exercise testing or echocardiography, without the need for right heart catheterisationhttps://bit.ly/3pbj2Ge