Pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension

Current surgical management of chronic thromboembolic pulmonary disease

Chronic thromboembolic pulmonary disease (CTEPD) with or without pulmonary hypertension (PH) is an important potential consequence of venous thromboembolic disease. Untreated CTEPD with pulmonary hypertension (CTEPH) is associated with high rates of morbidity and mortality. Several treatment options are now available for patients with CTEPD and CTEPH, including pulmonary endarterectomy (PEA), balloon pulmonary angioplasty, medical therapy or a combination of therapies. Choice of treatment depends on the location of the thromboembolic disease burden, presence and severity of PH and patient factors, including frailty, parenchymal lung disease and other comorbidities. PEA is a complex surgery that can result in excellent outcomes and resolution of disease, but also comes with the risk of serious perioperative complications. This manuscript examines the history of PEA and its place in Australasia, and reports on outcomes from the main Australasian CTEPH expert centre. It provides a summary of up-to-date guidance on how PEA should be utilised in the overall management of these patients and describes opportunities and challenges for the future diagnosis and management of this disease, particularly in the Australasian setting.

Balloon pulmonary angioplasty for proximal chronic thromboembolic pulmonary hypertension in patients ineligible for pulmonary endarterectomy

Balloon pulmonary angioplasty (BPA) to treat chronic thromboembolic pulmonary hypertension (CTEPH) is generally reserved for distal obstruction precluding pulmonary endarterectomy (PEA) but can be used in patients with proximal disease who are at high surgical risk or refuse surgery. This single-center retrospective study compared BPA efficacy in patients with proximal versus distal CTEPH. Of the 478 patients, 36 had proximal disease, follow-up was 11.6 months and mean number of BPA 6. After BPA, PVR, and mean pulmonary artery pressure decreased significantly in the proximal and distal groups (from 6.5 to 4.0 WU and 39 to 31 mmHg and from 7.6 to 3.8 WU and 44 to 31 mmHg, respectively, p < 0.001 for all comparisons). NYHA class also improved significantly in both groups, from 3 to 2, whereas the 6-min walk distance, cardiac output, and serum NT pro-BNP showed significant improvements only in the distal group. Thus, when PEA for CTEPH is technically feasible but not performed due to severe comorbidities or patient refusal, BPA can produce significant hemodynamic improvements, albeit less marked than in patients with distal disease. Better patient selection to BPA might improve outcomes in patients with proximal disease who are ineligible for PEA.

Chronic thromboembolic pulmonary hypertension treatment and sex: Systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Chronic thromboembolic pulmonary hypertension (CTEPH) is a complication of pulmonary embolism and a major cause of chronic pulmonary hypertension leading to right heart failure and death. While pulmonary endarterectomy is the treatment of choice, some patients might benefit from medical therapy or balloon pulmonary angioplasty. Sex differences in outcomes of these therapies are not well characterized.

MATERIAL AND METHODS

We conducted a systematic review and meta-analysis to investigate sex differences in outcomes of various therapies for CTEPH. We searched MEDLINE, PubMed, Embase, CINAHL and the Cochrane Library databases between January 1, 2010 and April 30, 2021, published in English. We pooled incidence estimates using random-effects meta-analyses. We evaluated heterogeneity using the I2 statistic. We assessed publication bias using Begg's and Egger's tests. This study is registered in PROSPERO, CRD42021268504.

RESULTS

A total of 19 studies met the eligibility criteria, but only 3 trials provided separate outcomes for women and men. Two studies evaluated the efficacy of BPA, and one study evaluated the efficacy of riociguat (129 patients). Overall, 57.3% of patients were women and 62.6% were in functional class III. Mean time of follow-up was 55.5 (SD 26.1) weeks. Women showed a significantly better response in cardiac index (mean difference [MD], 0.10L/min/m2; 95% confidence interval [CI], 0.04-0.16; I2=0%; P=0.001). Alternatively, the reduction of pulmonary vascular resistances was significantly higher for men than for women (MD, 161.17dynscm-5; 95% CI, 67.99-254.35; I2=0%; P=0.0007).

CONCLUSIONS

Women and men might show different hemodynamic responses to riociguat or BPA for CTEPH.

[Chronic thromboembolic pulmonary hypertension]

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease, but an important late sequela after acute pulmonary embolism. Therefore, follow-up after at least three months of sufficient anticoagulation is recommended. Patients with suspected CTEPH should be referred to specialized CTEPH centers for further evaluation and treatment.Three treatment modalities are available: pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA) and pulmonary hypertension-targeted drugs. The indication for surgery depends mainly on the localization of the pulmonary arterial obstructions. Severe comorbidities as well as advanced age need individual evaluation, but do not present strict exclusion criteria. Multimodal treatments are common practice in inoperable CTEPH. However, treatment decision making in an experienced multidisciplinary team is mandatory.

[Chronic thromboembolic pulmonary hypertension]

Chronic thromboembolic pulmonary disease (CTEPD) is an important late complication of acute pulmonary embolism, in which the thrombi transform into fibrous tissue, become integrated into the vessel wall, and lead to chronic obstructions. CTEPD is differentiated into cases without pulmonary hypertension (PH), characterized by a mean pulmonary arterial pressure up to 20 mmHg and a form with PH. Then, it is still referred to as chronic thromboembolic pulmonary hypertension (CTEPH).When there is suspicion of CTEPH, initial diagnostic tests should include echocardiography and ventilation/perfusion scan to detect perfusion defects. Subsequently, referral to a CTEPH center is recommended, where further imaging diagnostics and right heart catheterization are performed to determine the appropriate treatment.Currently, three treatment modalities are available. The treatment of choice is pulmonary endarterectomy (PEA). For non-operable patients or patients with residual PH after PEA, PH-targeted medical therapy, and the interventional procedure of balloon pulmonary angioplasty (BPA) are available. Increasingly, PEA, BPA, and pharmacological therapy are combined in multimodal concepts.Patients require post-treatment follow-up, preferably at (CTE)PH centers. These centers are required to perform a minimum number of PEA surgeries (50/year) and BPA interventions (100/year).

Chronic thromboembolic pulmonary hypertension-medical, interventional, and surgical therapy

Chronic thromboembolic pulmonary hypertension (CTEPH) is an important late sequela of pulmonary embolism and a common form of pulmonary hypertension. Currently, three specific treatment modalities are available: pulmonary endarterectomy, balloon pulmonary angioplasty, and targeted medical therapy. The treatment decision depends mainly on the exact localization of the underlying pulmonary arterial obstructions. Pulmonary endarterectomy is the gold standard treatment of CTEPH. For inoperable patients, riociguat and treprostinil are approved. In addition, interventional therapy is recommended if appropriate target lesions are proven. Evaluation and treatment of patients with CTEPH in experienced centers are mandatory.

Surgical Treatment of Another Sequalae of COVID-19: Post-COVID CTEPH

BACKGROUND

Coronavirus disease 2019 (COVID-19) is still an ongoing entity and every day we face new sequalae of the disease. We hereby present surgical results of patients who are treated for post-COVID chronic thromboembolic pulmonary hypertension.

METHODS

Data were collected among patients who underwent pulmonary endarterectomy and had a diagnosis of post-COVID chronic thromboembolic pulmonary hypertension. All data were retrospectively reviewed from a prospectively conducted database. Operative mortality was described as death in hospital or within 30 days of surgery.

RESULTS

Eleven patients (seven males, four females; median age, 52 [22-63] years) were identified. Pulmonary vascular resistance improved significantly from 572 dyn/s/cm-5 (240-1,192) to 240 (195-377) dyn/s/cm-5 (p < 0.005). Significant difference was also detected in median mPAP, as it decreased from 40 mm Hg (24-54) to 24 mm Hg (15-36) following surgery (p < 0.005). Mortality was observed in one patient due to sepsis on the fifth postoperative day. Median time from COVID-19 disease to surgery was 12 months (6-24). Median length of hospital stay of the survivors was 10 days (8-14).

CONCLUSION

In the new era of chronic thromboembolic pulmonary hypertension, hybrid approach including surgery, balloon pulmonary angioplasty, and medical treatment has been recommended. pulmonary endarterectomy is still the only curative treatment when the disease is surgically accessible. We hereby report the first publication of post-COVID chronic thromboembolic pulmonary hypertension patients who were surgically treated. As we see a lot of long-term symptoms and clinical manifestations in patients who had COVID-19, we should always remember chronic thromboembolic pulmonary hypertension in the differential diagnosis.

Evaluation of diagnostic accuracy of dual-energy computed tomography in patients with chronic thromboembolic pulmonary hypertension compared to V/Q-SPECT and pulmonary angiogram

Purpose

The relevance of dual-energy computed tomography (DECT) for the detection of chronic thromboembolic pulmonary hypertension (CTEPH) still lies behind V/Q-SPECT in current clinical guidelines. Therefore, our study aimed to assess the diagnostic accuracy of DECT compared to V/Q-SPECT with invasive pulmonary angiogram (PA) serving as the reference standard.

Methods

A total of 28 patients (mean age 62.1 years ± 10.6SD; 18 women) with clinically suspected CTEPH were retrospectively included. All patients received DECT with the calculation of iodine maps, V/Q-SPECT, and PA. Results of DECT and V/Q-SPECT were compared, and the percent of agreement, concordance (utilizing Cohen's kappa), and accuracy (kappa²) to PA were calculated. Furthermore, radiation doses were analyzed and compared.

Results

In total, 18 patients were diagnosed with CTEPH (mean age 62.4 years ± 11.0SD; 10 women) and 10 patients had other diseases. Compared to PA, accuracy and concordance for DECT were superior to V/Q-SPECT in all patients (88.9% vs. 81.3%; k = 0.764 vs. k = 0.607) and in CTEPH patients (82.4% vs. 70.1%; k = 0.694 vs. k = 0.560). Furthermore, the mean radiation dose was significantly lower for DECT vs. V/Q-SPECT (p = 0.0081).

Conclusion

In our patient cohort, DECT is at least equivalent to V/Q-SPECT in diagnosing CTEPH and has the added advantage of significantly lower radiation doses in combination with simultaneous assessment of lung and heart morphology. Hence, DECT should be the subject of ongoing research, and if our results are further confirmed, it should be implemented in future diagnostic PH algorithms at least on par with V/Q-SPECT.

Pathophysiology and Treatment of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a condition in which an organic thrombus remains in the pulmonary artery (PA) even after receiving anticoagulation therapy for more than 3 months and is complicated by pulmonary hypertension (PH), leading to right-sided heart failure and death. CTEPH is a progressive pulmonary vascular disease with a poor prognosis if left untreated. The standard treatment for CTEPH is pulmonary endarterectomy (PEA), which is usually performed only in specialized centers. In recent years, balloon pulmonary angioplasty (BPA) and drug therapy for CTEPH have also shown good results. This review discusses the complex pathogenesis of CTEPH and presents the standard of care, PEA, as well as a new device called BPA, which is showing remarkable progress in efficacy and safety. Additionally, several drugs are now demonstrating established evidence of efficacy in treating CTEPH.

Therapie der chronisch thromboembolischen pulmonalen Hypertonie

Die chronisch thromboembolische pulmonale Hypertonie (CTEPH) ist eine wichtige und oft gut behandelbare Form der pulmonalen Hypertonie. Es stehen aktuell 3 Therapiemodalitäten zur Verfügung: die pulmonale Endarteriektomie, die pulmonale Ballonangioplastie und die gezielte medikamentöse Behandlung. Das therapeutische Konzept hängt maßgeblich von der Lokalisation der zugrunde liegenden pulmonalarteriellen fibrösen Obstruktionen ab. Die pulmonale Endarteriektomie ist der Goldstandard in der Behandlung der CTEPH. Für inoperable Patienten stehen mittlerweile 2 zugelassene Substanzen (Riociguat und Treprostinil) zur Verfügung. Daneben wird bei Vorhandensein entsprechender Zielgebiete die interventionelle Therapie empfohlen. Evaluation und Behandlung von CTEPH-Patienten sollte in entsprechend erfahrenen Zentren erfolgen.

The Evolving Management and Treatment Options for Patients with Pulmonary Hypertension: Current Evidence and Challenges

Pulmonary hypertension may develop as a disease process specific to pulmonary arteries with no identifiable cause or may occur in relation to other cardiopulmonary and systemic illnesses. The World Health Organization (WHO) classifies pulmonary hypertensive diseases on the basis of primary mechanisms causing increased pulmonary vascular resistance. Effective management of pulmonary hypertension begins with accurately diagnosing and classifying the disease in order to determine appropriate treatment. Pulmonary arterial hypertension (PAH) is a particularly challenging form of pulmonary hypertension as it involves a progressive, hyperproliferative arterial process that leads to right heart failure and death if untreated. Over the last two decades, our understanding of the pathobiology and genetics behind PAH has evolved and led to the development of several targeted disease modifiers that ameliorate hemodynamics and quality of life. Effective risk management strategies and more aggressive treatment protocols have also allowed better outcomes for patients with PAH. For those patients who experience progressive PAH with medical therapy, lung transplantation remains a life-saving option. More recent work has been directed at developing effective treatment strategies for other forms of pulmonary hypertension, such as chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary hypertension due to other lung or heart diseases. The discovery of new disease pathways and modifiers affecting the pulmonary circulation is an ongoing area of intense investigation.

Direct oral anticoagulants in patients with chronic thromboembolic pulmonary hypertension and the presence of recent thrombus during pulmonary endarterectomy

Patients with chronic thromboembolic pulmonary hypertension (CTEPH) require lifelong anticoagulant therapy. The safety and efficacy of direct oral anticoagulant (DOAC) in the chronic and transitional management of CTEPH has not been investigated. We performed a retrospective analysis of 405 consecutive pulmonary endarterectomy (PEA) cases at the University of California, San Diego, from July 2015 through July 2017. PEA specimen was reviewed for the presence of acute or subacute thrombotic material distinct from the expected chronic disease removed at the time of PEA by two investigators blinded to the patient information. Of 405 PEA cases, 166 patients (41.0%) were anticoagulated with one of three available DOACs; 239 (59.0%) presented on either oral vitamin-K antagonist or chronic injectable therapy. There were no significant differences in baseline characteristics between DOAC and non-DOAC groups. Evidence of recent thrombus was observed in 22 (13.3%) in the DOAC group versus 16 (6.7%) within the non-DOAC group. The odds ratio of DOACs usage and evidence of recent thrombus was 2.34 (95% confidence interval: 1.1-5.0, p = 0.03) after adjusting for age, gender, race, body mass index, and history of antiphospholipid antibody syndrome. CTEPH patients referred for PEA while on DOAC therapy were twice as likely to have associated acute or subacute thrombi present at the time of surgery compared with those on more traditional, non-DOAC anticoagulant therapies. This raises questions of the safety and efficacy of DOACs in the chronic management of CTEPH.

Pulmonary endarterectomy: technique and pitfalls

Chronic thromboembolic pulmonary hypertension (CTEPH) remains a rare and underdiagnosed disease. After one or several episodes of acute pulmonary embolism, around 3% of patients develop CTEPH and two-thirds of these patients are potential surgical candidates. Besides surgery, additional treatment modalities are pulmonary arterial hypertension medication and balloon pulmonary angioplasty. Patients should be evaluated in CTEPH expert centers to ensure the most appropriate therapy. Pulmonary endarterectomy (PEA) is a complex, but standardized surgical procedure aiming to clear the obstructed pulmonary arteries completely. For optimal visualization, deep hypothermic circulatory arrest is a prerequisite. This article will give an overview of the evaluation, indication and surgical management of patients with CTEPH.

Pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension: a systematic review

BACKGROUND

Pulmonary thromboendarterectomy (PTE) is the gold standard treatment for patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, the results are poorly quantified outside a few registry reports and several individual centers.

METHODS

A systematic review was performed searching five electronic databases assessing the outcomes for adult patients undergoing PTE for CTEPH. All articles that reported mortality data were included. Primary outcome measures were early/inpatient mortality; secondary outcomes were survival, pulmonary haemodynamics, morbidity and functional status following PTE for CTEPH. Results were pooled via a meta-analysis of proportions and meta-regression.

RESULTS

A total of 5,717 studies were identified, yielding sixty-one relevant papers. Thirty-day mortality ranged from 0.8% to 24.4%, and on meta-analysis was 8.4% [95% confidence interval (CI): 7.2-9.6%]. Mortality was noted to decrease with increasing center volume of PTE cases (P<0.01). Residual pulmonary hypertension was reported in 8.2% to 44.5% of patients.

CONCLUSIONS

CTEPH is associated with acceptable short-term mortality and an improvement in pulmonary hemodynamics. With increasing volume of experience and ongoing developments over time peri-operative mortality continues to decrease.

Carbon Monoxide Diffusion Capacity as a Severity Marker in Pulmonary Hypertension

Carbon monoxide diffusion capacity (DLCO) is negatively associated with patient survival in idiopathic pulmonary hypertension (PH), but is not included in the risk stratification score proposed by the 2015 European guidelines. Since 2015, several new stratification scores based on a 3- or 4-severity scale have been explored. This retrospective cohort single-center study sought to investigate the association between DLCO and PH severity and survival. We included 85 treatment-naive patients with precapillary PH and DLCO measurement at diagnosis. DLCO status, based on lower and upper quartiles ranges, was added to a 3- and a 4-strata modified-risk assessment. DLCO was strongly associated with transplant-free survival (HR 0.939, 95% CI: 0.908–0.971, p < 0.001). In the intermediate and high-risk categories, DLCO was associated with transplant-free survival, irrespective of the risk category (HR 0.934, 95% CI: 0.880–0.980, p = 0.005). The correlation between modified-risk category and transplant-free survival was significant (HR 4.60, 95% CI: 1.294–16.352, p = 0.018). Based on the Akaike information criterion (AIC) levels, the 3- and 4-strata modified-risk stratification fits our results better than the conventional stratification. Low DLCO is associated with patient transplant-free survival, independently of the risk category. Inclusion of DLCO into a PH risk stratification score seems promising and needs further investigation.

Current strategies for managing chronic thromboembolic pulmonary hypertension: results of the worldwide prospective CTEPH Registry

Background

Pulmonary endarterectomy (PEA), pulmonary arterial hypertension (PAH) therapy and balloon pulmonary angioplasty (BPA) are currently accepted therapies for chronic thromboembolic pulmonary hypertension (CTEPH). This international CTEPH Registry identifies clinical characteristics of patients, diagnostic algorithms and treatment decisions in a global context.

Methods

1010 newly diagnosed consecutive patients were included in the registry between February 2015 and September 2016. Diagnosis was confirmed by right heart catheterisation, ventilation–perfusion lung scan, computerised pulmonary angiography and/or invasive pulmonary angiography after at least 3 months on anticoagulation.

Results

Overall, 649 patients (64.3%) were considered for PEA, 193 (19.1%) for BPA, 20 (2.0%) for both PEA and BPA, and 148 (14.7%) for PAH therapy only. Reasons for PEA inoperability were technical inaccessibility (n=235), comorbidities (n=63) and patient refusal (n=44). In Europe and America and other countries (AAO), 72% of patients were deemed suitable for PEA, whereas in Japan, 70% of patients were offered BPA as first choice. Sex was evenly balanced, except in Japan where 75% of patients were female. A history of acute pulmonary embolism was reported for 65.6% of patients. At least one PAH therapy was initiated in 35.8% of patients (26.2% of PEA candidates, 54.5% of BPA candidates and 54.1% of those not eligible for either PEA or BPA). At the time of analysis, 39 patients (3.9%) had died of pulmonary hypertension-related causes (3.5% after PEA and 1.8% after BPA).

Conclusions

The registry revealed noticeable differences in patient characteristics (rates of pulmonary embolism and sex) and therapeutic approaches in Japan compared with Europe and AAO.

There are distinct regional differences in the management of CTEPH patients but globally, the proportion of patients managed by PEA remains stable, independently of the new established treatment options of PAH therapies and BPAhttps://bit.ly/3zEXxkv

Time trends of pulmonary endarterectomy in patients with chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension is considered as a rare but severe complication after acute pulmonary embolism and is potentially curable by pulmonary endarterectomy. We aimed to evaluate, over an 11-year period, time trends of in-hospital outcomes of pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension patients and to investigate predictors of the in-hospital course. We analyzed data on the characteristics, comorbidities, treatments, and in-hospital outcomes for all chronic thromboembolic pulmonary hypertension patients treated with pulmonary endarterectomy in the German nationwide inpatient sample between 2006 and 2016. Overall, 1398 inpatients were included. Annual number of pulmonary endarterectomy increased from 67 in 2006 to 194 in 2016 (P < 0.001), in parallel with a significant decrease of in-hospital mortality (10.9% in 2008 to 1.5% in 2016; P < 0.001). Patients' characteristics shifted slightly toward older age and higher prevalence of chronic renal insufficiency and obesity over time, whereas duration of hospital stay decreased over time. Independent predictors of in-hospital mortality were age (OR 1.03 (95%CI: 1.01-1.05); P = 0.001), right heart failure (2.55 (1.37-4.76); P = 0.003), in-hospital complications such as ischemic stroke (6.87 (1.06-44.70); P = 0.044) and bleeding events like hemopneumothorax (24.93 (6.18-100.57); P < 0.001). Annual pulmonary endarterectomy volumes per center below 10 annual procedures were associated with higher rates of adverse in-hospital outcomes. Annual numbers of chronic thromboembolic pulmonary hypertension patients treated with pulmonary endarterectomy increased markedly in Germany between 2006 and 2016, in parallel with a decrease of in-hospital mortality. Our findings suggest that perioperative management of pulmonary endarterectomy, institutional experience, and patient selection is crucial and has improved over time.

Pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension: state-of-the-art 2020

Pulmonary endarterectomy is the treatment of choice for patients with operable chronic thromboembolic pulmonary hypertension (CTEPH) as it is potentially curative. In expert centers that conduct > 50 pulmonary endarterectomy procedures per year, peri- and post-surgical mortality rates are very low and long-term outcomes are excellent, with three-year post-operative survival of > 80%. Therapeutic decisions in CTEPH are based largely on the location of the arterial obstruction, with pulmonary endarterectomy for obstructions in main, lobar, and segmental vessels, and balloon pulmonary angioplasty and medical therapy for small-vessel disease. Medical therapy is also an option for patients with persistent/recurrent pulmonary hypertension after pulmonary endarterectomy or balloon pulmonary angioplasty. With increasing surgical experience and improvements in instruments and procedures, an increasing number of patients are now considered operable who would previously have been inoperable, including some patients with subsegmental disease. At our University (University of California San Diego), around 200 pulmonary endarterectomy procedures are performed every year and several advances have been developed, including resection of more distal disease, availability of pulmonary endarterectomy to patients previously considered to be at too high risk for surgery, improved management of post-pulmonary endarterectomy complications, and minimally invasive pulmonary endarterectomy. Pulmonary endarterectomy can be combined with other treatment modalities, including balloon pulmonary angioplasty, medical therapy for persistent/recurrent pulmonary hypertension after pulmonary endarterectomy, and medical therapy or balloon pulmonary angioplasty as bridging therapy before surgery. Data on these combinations are, however, limited. Combination treatment should therefore be considered on an individual patient basis. In the future, however, multimodal therapy with pulmonary endarterectomy, balloon pulmonary angioplasty, and/or medical therapy is likely to be an important treatment option for many patients.

Platelet count trends and response to fondaparinux in a cohort of heparin-induced thrombocytopenia suspected patients after pulmonary endarterectomy

A definitive diagnosis of heparin-induced thrombocytopenia (HIT) is difficult to make, especially in patients undergoing cardiac surgery. In this retrospective cohort study, we assessed the platelet count trends and the response to fondaparinux in a population of patients of suspected HIT after pulmonary endarterectomy (PEA). Patients enrolled in this study were over the age of 18 years, and survived longer than 7 days after PEA between January 1, 2011 and December 31, 2015. HIT likelihood was assessed by the 4 T's score and interpreted by our institutional algorithm. 54 patients were operated, and 49 patients met the inclusion criteria. Six patients met the criteria for suspected HIT and were treated with fondaparinux until the platelet recovered. No significant difference was observed of clinical characteristics between intermediate to high HIT likelihood patients (HIT SUSPECTED) and low HIT likelihood patients (NO HIT SUSPECTED). HIT SUSPECTED patients reached platelet count lowest later (about 5.5 days after PEA), while NO HIT SUSPECTED patients is about 4.0 days after PEA. Percentage of platelet counts decrease (> 50%) was larger than NO HIT SUSPECTED patients (< 50%). There was no difference in mortality or residual pulmonary hypertension between HIT SUSPECTED and NO HIT SUSPECTED patients. Two HIT SUSPECTED patients who used heparin after PEA died, the other four survived by replacing heparin or low molecular weight heparin with fondaparinux. Suspected HIT patients should be surveilled carefully. Platelet counts trends may have some hints in the prevention of HIT. Fondaparinux may be effective for patients with suspected HIT.

Supervised Exercise Training in Patients with Chronic Thromboembolic Pulmonary Hypertension as Early Follow-Up Treatment after Pulmonary Endarterectomy: A Prospective Cohort Study

BACKGROUND

Data on exercise training in chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary endarterectomy (PEA) as well as data on clinical and haemodynamic changes shortly after PEA are lacking.

OBJECTIVE

The objective of this prospective study was to analyse the safety, feasibility, and the effectiveness of combined supervised inpatient rehabilitation in patients with CTEPH directly after PEA.

METHODS

CTEPH patients started a 19-week rehabilitation program (3 weeks as inpatients and continued at home for another 16 weeks) with supervised exercise training as follow-up treatment shortly after PEA. Haemodynamics were assessed by right heart catheterisation before PEA and 22 weeks after PEA. Non-invasive assessments as transthoracic echocardiography and 6-min walking distance (6MWD) were performed before PEA and after 3 (that is, beginning of rehabilitation), 6, and 22 weeks following PEA. Adverse events were recorded throughout the study.

RESULTS

Forty-five CTEPH patients were included (49% female, 57.6 ± 12.4 years old, 60% WHO functional class III). Rehabilitation was started 3.3 ± 0.9 weeks after PEA. Exercise training was well tolerated in all patients without severe side effects. Haemodynamics measured by right heart catheterisation significantly improved from pre-PEA to 22 weeks post-PEA in cardiac output (+1.2 ± 1.5 L/min, 33.4%, p = 0.001) and mean pulmonary arterial pressure (-19 ± 13 mm Hg, -39.6%, p < 0.0001). Right heart size measured by echocardiography, 6MWD, quality of life, and oxygen saturation significantly improved not only within the first 3 weeks after PEA but also during the following 19 weeks of exercise training.

CONCLUSIONS

Supervised exercise training was feasible as early follow-up treatment after PEA. Further controlled studies are needed to discriminate the effects of PEA and early follow-up rehabilitation.

TRIAL REGISTRATION

The study was registered at clinicaltrials.gov (NCT01393327) on July 13, 2011. The study start date was January 2010, and completion date was December 2013.

Risk factors for chronic thromboembolic pulmonary hypertension - Importance of thyroid disease and function

INTRODUCTION

Although a number of risk factors for chronic thromboembolic pulmonary hypertension (CTEPH) have been reported, the exact prevalence is controversial and varies between published cohorts. The aim of the present study was to investigate the prevalence of risk factors in operable CTEPH patients with special emphasis on thyroid disease and function.

MATERIAL AND METHODS

Overall, 228 CTEPH patients (47.7% female; median age 63 [IQR 52-72] years) scheduled for pulmonary endarterectomy between 01/2014 and 12/2015 were studied. Prevalence of risk factors was assessed, and patients were classified according to their thyroid function based on laboratory measurements.

RESULTS

As many as 86.0% of patients reported a history of pulmonary embolism (PE; of those, 24.5% were diagnosed with "acute" PE less than six months before the diagnosis of CTEPH), 80.7% of patients had a blood group non-0 and 24.1% of patients had known thyroid disease (of those, 78.2% hypothyroidism). Laboratory measurements revealed thyroid dysfunction in 10.5% of patients (of those, 54.8% had no known thyroid disease). Patients with hypothyroid function had higher WHO functional classes, NT-proBNP levels and a lower cardiac index compared to patients with euthyroid function.

CONCLUSIONS

The prevalence of a history of PE and blood group non-0 was higher than previously reported. However, a relevant proportion of patients might have suffered from pre-existing CTEPH rather than acute PE. Thyroid disease and dysfunction were frequent and hypothyroid function associated with more severe disease.

Non-Invasive Approach for Evaluation of Pulmonary Hypertension Using Extracellular Vesicle-Associated Small Non-Coding RNA

Extracellular vesicles are released by numerous cell types of the human body under physiological but also under pathophysiological conditions. They are important for cell–cell communication and carry specific signatures of peptides and RNAs. In this study, we aimed to determine whether extracellular vesicles isolated from patients with pulmonary hypertension show a disease specific signature of small non-coding RNAs and thus have the potential to serve as diagnostic and prognostic biomarkers. Extracellular vesicles were isolated from the serum of 23 patients with chronic thromboembolic pulmonary hypertension (CTEPH) and 23 controls using two individual methods: a column-based method or by precipitation. Extracellular vesicle- associated RNAs were analyzed by next-generation sequencing applying molecular barcoding, and differentially expressed small non-coding RNAs were validated by quantitative real-time polymerase chain reaction (qRT-PCR). We identified 18 microRNAs and 21 P-element induced wimpy testis (PIWI)-interacting RNAs (piRNAs) or piRNA clusters that were differentially expressed in CTEPH patients compared with controls. Bioinformatic analysis predicted a contribution of these piRNAs to the progression of cardiac and vascular remodeling. Expression levels of DQ593039 correlated with clinically meaningful parameters such as mean pulmonary arterial pressure, pulmonary vascular resistance, right ventricular systolic pressure, and levels of N-terminal pro-brain natriuretic peptide. Thus, we identified the extracellular vesicle- derived piRNA, DQ593039, as a potential biomarker for pulmonary hypertension and right heart disease.

2018 TSOC guideline focused update on diagnosis and treatment of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterized as a progressive and sustained increase in pulmonary vascular resistance, which may induce right ventricular failure. In 2014, the Working Group on Pulmonary Hypertension of the Taiwan Society of Cardiology (TSOC) conducted a review of data and developed a guideline for the management of PAH.⁴ In recent years, several advancements in diagnosis and treatment of PAH has occurred. Therefore, the Working Group on Pulmonary Hypertension of TSOC decided to come up with a focused update that addresses clinically important advances in PAH diagnosis and treatment. This 2018 focused update deals with: (1) the role of echocardiography in PAH; (2) new diagnostic algorithm for the evaluation of PAH; (3) comprehensive prognostic evaluation and risk assessment; (4) treatment goals and follow-up strategy; (5) updated PAH targeted therapy; (6) combination therapy and goal-orientated therapy; (7) updated treatment for PAH associated with congenital heart disease; (8) updated treatment for PAH associated with connective tissue disease; and (9) updated treatment for chronic thromboembolic pulmonary hypertension.

Exercise right heart catheterisation before and after pulmonary endarterectomy in patients with chronic thromboembolic disease

Symptomatic patients with chronic thromboembolic disease (CTED) without pulmonary hypertension often show an excessive increase in mean pulmonary arterial pressure (MPAP) during exercise.

We report on the impact of pulmonary endarterectomy (PEA) on pulmonary haemodynamics in a prospective series of 32 consecutive CTED patients who underwent PEA. All patients had a comprehensive diagnostic work-up including right heart catheterisation at baseline and 12 months after PEA. Furthermore, in 12 patients exercise right heart catheterisation was performed before and after PEA.

After PEA, MPAP was lower at rest (20±3 versus 17±3 mmHg; p=0.008) and during maximal exercise (39±8 versus 31±6 mmHg; p=0.016). The mean total pulmonary resistance (TPR) decreased from 3.6±0.8 Wood Units (WU) pre-operatively to 2.7±0.7 WU 1 year after PEA (p=0.004) and the mean slope of the MPAP/cardiac output (CO) relationship decreased from 3.6±1.0 to 2.3±0.8 WU (p=0.002). Peak oxygen uptake increased from 1.2±0.4 to 1.5±0.3 L·min−1 (p=0.014) and ventilatory equivalents of carbon dioxide decreased from 39±2 to 30±2 (p=0.002). There was a significant improvement in quality of life assessed by the Cambridge Pulmonary Hypertension Outcome Review questionnaire.

In CTED patients, PEA resulted in haemodynamic and clinical improvements. The means of TPR and MPAP/CO slopes decreased to <3.0 WU.