Chronic thromboembolic pulmonary hypertension in Australia and New Zealand: An analysis of the PHSANZ registry

Long-Term Safety and Efficacy of Macitentan in Inoperable Chronic Thromboembolic Pulmonary Hypertension: Results from MERIT and its Open-Label Extension

INTRODUCTION

Evidence for use of pulmonary arterial hypertension targeted-therapies in patients with chronic thromboembolic pulmonary hypertension (CTEPH) is limited. In MERIT-1, the endothelin receptor antagonist macitentan improved hemodynamic and functional parameters versus placebo in patients with inoperable CTEPH over a 24-week double-blind (DB) period. Its open-label (OL) extension study (MERIT-2) provides long-term safety/efficacy data.

METHODS

MERIT-2 (NCT02060721) was a multicenter, single-arm, OL, phase 2 extension study of MERIT-1. Patients completing MERIT-1 were eligible to receive 10 mg macitentan once-daily in MERIT-2. Safety and efficacy (6-min walk distance [6MWD] and change in World Health Organization functional class [WHO FC]) were assessed in all patients in MERIT-2 regardless of treatment received in DB (All patients MERIT-2 OL macitentan 10 mg group) and the subgroup of patients receiving DB macitentan in MERIT-1 (Long-term [DB/OL] macitentan 10 mg subgroup).

RESULTS

Of the 80 patients randomized in MERIT-1, 76 entered MERIT-2 (All patients MERIT-2 OL macitentan 10 mg group): 40 who received DB macitentan (DB-macitentan patients) and 36 DB placebo (DB-placebo patients). Median (interquartile range) macitentan exposure in the All patients MERIT-2 OL macitentan 10 mg group was 45.5 (26.0, 66.1) months. During the OL period, treatment-emergent adverse events (AE) were reported in 72 (94.7%) patients; most frequent were worsening of pulmonary hypertension (19.7%), decreased hemoglobin (18.4%) and upper respiratory tract infection (15.8%). Fourteen (18.4%) patients died; none were assessed as macitentan-related. At Month 6 post-OL baseline, mean (standard deviation) change in 6MWD was - 0.4 m (43.62) for DB-macitentan patients and 10.7 m (45.63) for DB-placebo patients; the majority had unchanged (83.3%) or improved (12.5%) WHO FC. Safety/efficacy analyses were consistent in the Long-term (DB/OL) macitentan 10 mg subgroup.

CONCLUSION

These analyses provide long-term safety/efficacy data in patients with inoperable CTEPH treated with macitentan. No unexpected safety findings occurred; reported AEs were consistent with the known safety profile of macitentan. At 6 months post-OL baseline, DB-placebo patients modestly improved 6MWD; DB-macitentan patients maintained improvements observed in MERIT-1. WHO FC was largely unchanged.

TRIAL REGISTRATION

ClinicalTrials.gov Identifiers: NCT02021292; NCT02060721.

Performance-based outcome measures for assessing physical capacity in patients with pulmonary embolism: A scoping review

INTRODUCTION

Up to 50 % of patients surviving a pulmonary embolism (PE) report persisting shortness of breath, reduced physical capacity and psychological distress. As the PE population is heterogeneous compared to other cardiovascular patient groups, outcome measures for assessing physical capacity traditionally used in cardiac populations may not be reliable for the PE population as a whole. This scoping review aims to 1) map performance-based outcome measures (PBOMs) used for assessing physical capacity in PE research, and 2) to report the psychometric properties of the identified PBOMs in a PE population.

METHODS

The review was conducted according to the Joanna Briggs Institute framework for scoping reviews and reported according to the PRISMA-Extension for Scoping Reviews guideline.

RESULTS

The systematic search of five databases identified 4585 studies, of which 243 studies met the inclusion criteria. Of these, 185 studies focused on a subgroup of patients with chronic thromboembolic pulmonary hypertension. Ten different PBOMs were identified in the included studies. The 6-minute walk test (6MWT) and cardiopulmonary exercise test (CPET) were the most commonly used, followed by the (Modified) Bruce protocol and Incremental Shuttle Walk test. No studies reported psychometric properties of any of the identified PBOMs in a PE population.

CONCLUSIONS

Publication of studies measuring physical capacity within PE populations has increased significantly over the past 5-10 years. Still, not one study was identified, reporting the validity, reliability, or responsiveness for any of the identified PBOMs in a PE population. This should be a priority for future research in the field.

Surgical and Device Interventions in the Treatment of Chronic Thromboembolic Disease

Chronic thromboembolic pulmonary disease (CTEPD) is characterized by unresolved clot burden in large pulmonary arteries, obstructive disease in smaller arteries, and increased downstream clot burden. This occurs in the setting of abnormal fibrinolysis or hematological disorders. Up to 50% of patients in some studies are unaware of a self-history of a deep venous thrombosis or pulmonary embolism. Ultimately, they present with symptoms of pulmonary hypertension (PH), which can result in right heart failure (RHF). Pulmonary endarterectomy (PEA) is curative, though many patients have prohibitive surgical risk or surgically inaccessible disease, warranting other interventions such as balloon pulmonary angioplasty (BPA) and medical therapy. Rarely, other treatment options may be implemented. We focus this review on PEA and BPA, with an overview of the history of CTEPD and the evolution of these procedures. We will briefly discuss other treatment modalities.

Can regional cerebral oxygen saturation monitoring during circulatory arrest time predict postoperative neurological dysfunction in patients undergoing surgical pulmonary thromboendarterectomy? Useful index for short- and long-term outcomes

A hypothermic circulatory arrest is usually used to correct thoracic aorta pathologies. The emergency treatment of acute type A aortic dissection and elective repair of aortic arch pathologies are the most common indications for using hypothermic circulatory arrest. A hypothermic circulatory arrest can also be used for surgical pulmonary thromboendarterectomy in patients with chronic thromboembolic pulmonary hypertension. Intervals with total circulatory arrest offer a clear surgical field for thrombus and emboli removal from the pulmonary artery branches. The price to pay for intermittent circulatory arrest during pulmonary thromboendarterectomy is postoperative neurological dysfunction due to brain hypothermia and hypoperfusion. A noninvasive method for cerebral monitoring during cardiac surgery is real-time regional cerebral oxygen saturation (rSO2 ). Liu et al. report that continuous monitoring of rSO2 during surgical pulmonary thromboendarterectomy may reduce the long cerebral hypoperfusion time and prevent postoperative neurological dysfunction.