Management Strategies for Acute Pulmonary Embolism in the Intensive Care Unit.

TOPIC IMPORTANCE: Acute pulmonary embolism (PE) is a common disease encountered by pulmonologists, cardiologists, and critical care physicians throughout the world. For patients with high risk (defined by systemic hypotension) and intermediate high-risk (defined by the absence of systemic hypotension but the presence of numerous other concerning clinical and imaging features) acute PE, intensive care is often necessary. Initial management strategies should focus on optimization of right ventricular (RV) function while decisions about advanced interventions are being considered. REVIEW FINDINGS: Here we review the existing literature of various vasoactive agents, intravenous fluids and diuretics, and pulmonary vasodilators in both animal models and human trials of acute PE. We also review the potential complications of endotracheal intubation and positive pressure ventilation in acute PE. Finally, we review the data of veno-arterial extracorporeal membrane oxygen use in acute PE. The above interventions are discussed in the context of the underlying pathophysiology of acute RV failure in acute PE with corresponding illustrations. SUMMARY: Norepinephrine is a reasonable first choice for hemodynamic support with vasopressin as an adjunct. Intravenous loop diuretics may be useful if there is evidence of RV dysfunction or volume overload. Fluids should only be given if there is concern for hypovolemia and absence of RV dilatation. Supplemental oxygen administration should be considered even without hypoxemia. Positive pressure ventilation should be avoided if possible. VA-ECMO cannulation should be implemented early if ongoing deterioration occurs despite these interventions.

NT-pro-BNP is predictive of morbidity and mortality after pulmonary thromboendarterectomy and is independent of preoperative hemodynamics.

Current predictors of clinical outcomes after pulmonary thromboendarterectomy (PTE) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) are largely limited to preoperative clinical characteristics. N-terminal-pro-brain natriuretic peptide (NT-pro-BNP), a biomarker of right ventricular dysfunction, has not yet been well described as one such predictor. From 2017 to 2021, 816 patients with CTEPH referred to the University of California, San Diego for PTE were reviewed for differences in NT-pro-BNP to predict preoperative characteristics and postoperative outcomes up to 30 days post-PTE. For analysis, NT-pro-BNP was dichotomized to less than/equal to or greater than 1000 pg/mL based on the mean of the study population. Mean NT-pro-BNP was 1095.9 ±1783.4 pg/mL and median was 402.5 pg/mL (interquartile range: 119.5-1410.8). Of the 816 patients included, 250 had NT-pro-BNP > 1000 pg/mL. Those with NT-pro-BNP > 1000 pg/mL were significantly more likely to have worse preoperative functional class (III-IV) and worse preoperative hemodynamics. Patients with NT-pro-BNP > 1000 pg/mL also tended to have more postoperative complications including reperfusion pulmonary edema (22% vs. 5.1%, p < 0.001), airway hemorrhage (8.4% vs. 4.9%, p = 0.075), residual pulmonary hypertension (11.9% vs. 3.1%, p < 0.001), and 30-day mortality (4.8% vs. 1.1%, p = 0.001). Even after adjusting for confounders, patients with NT-pro-BNP > 1000 pg/mL had a 2.48 times higher odds (95% confidence interval: 1.45-4.00) of reaching a combined endpoint that included the above complications. Preoperative NT-pro-BNP > 1000 pg/mL is a strong predictor of more severe preoperative hemodynamics and identifies patients at higher risk for postoperative complications.

Consistent seasonal flexibility of the gut and its regions across wild populations of a winter-quiescent fish.

Seasonality in north-temperate environments imposes drastic temperature and resource variations that shape the seasonal ecophysiology of resident organisms. A better understanding of an organism's capacity to flexibly respond to this drastic seasonal variation may reveal important mechanisms for tolerating or responding to environmental variation introduced by global change. In fishes, the digestive system is both the interface between resource and energy acquisition and one of the most expensive organ systems to maintain. However, little evidence describing the capacity for seasonal flexibility in the digestive tract of wild northern fishes exists. Here, we investigated phenotypic flexibility in the size of the gastrointestinal (GI) tract across three northern populations of a winter-dormant warm-water fish, pumpkinseed sunfish (Lepomis gibbosus). In all populations, pumpkinseed exhibited pronounced structural flexibility in the GI tract, aligned with winter and the timing of reproduction. The dry mass of the GI increased by 1.3- to nearly 2.5-fold in the early spring. The pyloric caeca demonstrated the greatest capacity for flexibility, increasing by up to 3.7-fold prior to reproduction. In all populations, minimum dry GI mass was consistently achieved during winter and mid-summer. This capacity for gut flexibility may represent a novel mechanism for facilitating rapid adaptive responses (e.g. metabolic plasticity) to future environmental change.

Cardiopulmonary exercise test to detect cardiac dysfunction from pulmonary vascular disease.

BACKGROUND: Cardiac dysfunction from pulmonary vascular disease causes characteristic findings on cardiopulmonary exercise testing (CPET). We tested the accuracy of CPET for detecting inadequate stroke volume (SV) augmentation during exercise, a pivotal manifestation of cardiac limitation in patients with pulmonary vascular disease. METHODS: We reviewed patients with suspected pulmonary vascular disease in whom CPET and right heart catheterization (RHC) measurements were taken at rest and at anaerobic threshold (AT). We correlated CPET-determined O2·pulseAT/O2·pulserest with RHC-determined SVAT/SVrest. We evaluated the sensitivity and specificity of O2·pulseAT/O2·pulserest to detect SVAT/SVrest below the lower limit of normal (LLN). For comparison, we performed similar analyses comparing echocardiographically-measured peak tricuspid regurgitant velocity (TRVpeak) with SVAT/SVrest. RESULTS: From July 2018 through February 2023, 83 simultaneous RHC and CPET were performed. Thirty-six studies measured O2·pulse and SV at rest and at AT. O2·pulseAT/O2·pulserest correlated highly with SVAT/SVrest (r = 0.72, 95% CI 0.52, 0.85; p < 0.0001), whereas TRVpeak did not (r = -0.09, 95% CI -0.47, 0.33; p = 0.69). The AUROC to detect SVAT/SVrest below the LLN was significantly higher for O2·pulseAT/O2·pulserest (0.92, SE 0.04; p = 0.0002) than for TRVpeak (0.69, SE 0.10; p = 0.12). O2·pulseAT/O2·pulserest of less than 2.6 was 92.6% sensitive (95% CI 76.6%, 98.7%) and 66.7% specific (95% CI 35.2%, 87.9%) for deficient SVAT/SVrest. CONCLUSIONS: CPET detected deficient SV augmentation more accurately than echocardiography. CPET-determined O2·pulseAT/O2·pulserest may have a prominent role for noninvasive screening of patients at risk for pulmonary vascular disease, such as patients with persistent dyspnea after pulmonary embolism.

Shared and Distinct Genomics of Chronic Thromboembolic Pulmonary Hypertension and Pulmonary Embolism.

RATIONALE: Chronic Thromboembolic Pulmonary Hypertension involves formation and non-resolution of thrombus, dysregulated inflammation, angiogenesis and the development of a small vessel vasculopathy. OBJECTIVES: We aimed to establish the genetic basis of chronic thromboembolic pulmonary hypertension to gain insight into its pathophysiological contributors. METHODS: We conducted a genome-wide association study on 1907 European cases and 10363 European controls. We co-analysed our results with existing results from genome-wide association studies on deep vein thrombosis, pulmonary embolism and idiopathic pulmonary arterial hypertension. MEASUREMENTS AND MAIN RESULTS: Our primary association study revealed genetic associations at the ABO, FGG, F11, MYH7B, and HLA-DRA loci. Through our co-analysis we demonstrate further associations with chronic thromboembolic pulmonary hypertension at the F2, TSPAN15, SLC44A2 and F5 loci but find no statistically significant associations shared with idiopathic pulmonary arterial hypertension. CONCLUSIONS: Chronic thromboembolic pulmonary hypertension is a partially heritable polygenic disease, with related though distinct genetic associations to pulmonary embolism and to deep vein thrombosis.

Observational cohort study to validate SEARCH, a novel hierarchical algorithm to define long-term outcomes after pulmonary embolism.

BACKGROUND: Chronic dyspnoea and exercise impairment are common after acute pulmonary embolism (PE) but are not defined and quantified sufficiently to serve as outcomes in clinical trials. The planned project will clinically validate a novel method to determine discrete, clinically meaningful diagnoses after acute PE. The method uses an algorithm entitled SEARCH, for symptom screen, exercise testing, arterial perfusion, resting echocardiography, confirmatory imaging and haemodynamic measurements. SEARCH is a stepwise algorithm that sorts patients by a hierarchical series of dichotomous tests into discreet categories of long-term outcomes after PE: asymptomatic, post-PE deconditioning, symptoms from other causes, chronic thromboembolism with ventilatory inefficiency, chronic thromboembolism with small stroke volume augmentation, chronic thromboembolic disease and chronic thromboembolic pulmonary hypertension. METHODS: The project will test the inter-rater reliability of the SEARCH algorithm by determining whether it will yield concordant post-PE diagnoses when six independent reviewers review the same diagnostic data on 150 patients evaluated at two time points after PE. The project will also determine whether the post-PE diagnoses are stable, according to the SEARCH algorithm, between the first evaluation and the subsequent one 6 months later. IMPLICATIONS: Validation of the SEARCH algorithm would offer clinicians a straightforward method to diagnose post-PE conditions that are rarely distinguished clinically. Their categorisation and definition will allow post-PE conditions to be used as endpoints in clinical trials of acute PE treatment. TRIAL REGISTRATION NUMBER: NCT05568927.

Updates in the diagnosis and management of chronic thromboembolic disease.

PURPOSE OF REVIEW: Chronic thromboembolic disease (CTED) is distinct from chronic thromboembolic pulmonary hypertension (CTEPH) and is defined by dyspnea on exertion after acute pulmonary embolism with the presence of residual perfusion defects and absence of resting pulmonary hypertension. Here, we review clinical features and diagnostic criteria for CTED and summarize treatment options. RECENT FINDINGS: The optimal management for CTED is unclear as the long-term outcomes of conservative vs. invasive treatment for this disease have not been reported. There are a few studies evaluating outcomes of pulmonary thromboendarterectomy and balloon pulmonary angioplasty (BPA) in CTED, concluding that these procedures are safe and effective in select patients. However, these trials are small nonrandomized observational studies, reporting outcomes only up to 1 year after the intervention. Conservative management of CTED with observation, pulmonary hypertension-targeted therapy, or cardiopulmonary rehabilitation has not been studied. It is unknown whether these treatments are as effective or superior to pulmonary thromboendarterectomy or BPA in CTED. SUMMARY: The management of CTED is individualized and based on symptoms and exercise limitations. Early referral of patients with CTED to a specialized CTEPH center is recommended to determine if watchful waiting, BPA, or pulmonary thromboendarterectomy is most beneficial.

Applied winter biology: threats, conservation and management of biological resources during winter in cold climate regions.

Winter at high latitudes is characterized by low temperatures, dampened light levels and short photoperiods which shape ecological and evolutionary outcomes from cells to populations to ecosystems. Advances in our understanding of winter biological processes (spanning physiology, behaviour and ecology) highlight that biodiversity threats (e.g. climate change driven shifts in reproductive windows) may interact with winter conditions, leading to greater ecological impacts. As such, conservation and management strategies that consider winter processes and their consequences on biological mechanisms may lead to greater resilience of high altitude and latitude ecosystems. Here, we use well-established threat and action taxonomies produced by the International Union of Conservation of Nature-Conservation Measures Partnership (IUCN-CMP) to synthesize current threats to biota that emerge during, or as the result of, winter processes then discuss targeted management approaches for winter-based conservation. We demonstrate the importance of considering winter when identifying threats to biodiversity and deciding on appropriate management strategies across species and ecosystems. We confirm our expectation that threats are prevalent during the winter and are especially important considering the physiologically challenging conditions that winter presents. Moreover, our findings emphasize that climate change and winter-related constraints on organisms will intersect with other stressors to potentially magnify threats and further complicate management. Though conservation and management practices are less commonly considered during the winter season, we identified several potential or already realized applications relevant to winter that could be beneficial. Many of the examples are quite recent, suggesting a potential turning point for applied winter biology. This growing body of literature is promising but we submit that more research is needed to identify and address threats to wintering biota for targeted and proactive conservation. We suggest that management decisions consider the importance of winter and incorporate winter specific strategies for holistic and mechanistic conservation and resource management.

Repeat pulmonary thromboendarterectomy outcomes: A 15-year single-center retrospective review.

OBJECTIVE: Chronic thromboembolic pulmonary hypertension is potentially curable via pulmonary thromboendarterectomy. A minority of patients experience recurrence of their symptoms and are eligible for repeat pulmonary thromboendarterectomy. However, little data exist regarding risk factors and outcomes for this patient population. METHODS: We performed a retrospective review of the University of California San Diego chronic thromboembolic pulmonary hypertension quality improvement database, including all patients who underwent pulmonary thromboendarterectomy from December 2005 to December 2020. Of the 2019 cases performed during this period, 46 were repeat pulmonary thromboendarterectomy procedures. Demographics, preoperative and postoperative hemodynamics, and surgical complications were compared between the repeat pulmonary thromboendarterectomy group and 1008 first pulmonary thromboendarterectomy group. RESULTS: Repeat pulmonary thromboendarterectomy recipients were more likely to be younger, to have an identified hypercoagulable state, and to have higher preoperative right atrial pressure. Etiologies of recurrent disease include incomplete initial endarterectomy, discontinuation of anticoagulation (noncompliance or for medical reasons), and anticoagulation treatment failure. Patients who received repeat pulmonary thromboendarterectomy had significant hemodynamic improvement, but less pronounced compared with patients who received first pulmonary thromboendarterectomy. Repeat pulmonary thromboendarterectomy was associated with an increased risk of postoperative bleeding, reperfusion lung injury, residual pulmonary hypertension, and increased ventilator, intensive care unit, and hospital days. However, hospital mortality was similar between the groups (2.2% vs 1.9%). CONCLUSIONS: This is the largest reported series of repeat pulmonary thromboendarterectomy surgery. Despite an increase in postoperative complications, this study demonstrates that repeat pulmonary thromboendarterectomy surgery can result in significant hemodynamic improvement with acceptable surgical mortality in an experienced center.

Distal vessel pulmonary thromboendarterectomy: Results from a single institution.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is primarily managed by pulmonary thromboendarterectomy (PTE). As advanced surgical techniques permit resection at the segmental and subsegmental level, PTE can now be curative for CTEPH mostly involving the distal pulmonary arteries. METHODS: Between January 2017 and June 2021, consecutive patients undergoing PTE were categorized according to the most proximal level of chronic thrombus resection: Level I (main pulmonary artery), Level II (lobar), Level III (segmental) and Level IV (subsegmental). Proximal disease patients (any Level I or II) were compared to distal disease (Level III or IV bilaterally) patients. Demographics, medical history, preoperative pulmonary hemodynamics, and immediate postoperative outcomes were obtained for each group. RESULTS: During the study period, 794 patients underwent PTE, 563 with proximal disease and 231 with distal disease. Patients with distal disease more frequently had a history of an indwelling intravenous device, splenectomy, upper extremity thrombosis or use thyroid replacement and less often had prior lower extremity thrombosis or hypercoagulable state. Despite more use of PAH-targeted medications in the distal disease group (63.2% vs 50.1%, p < 0.001), preoperative hemodynamics were similar. Both patient groups exhibited significant improvements in pulmonary hemodynamics postoperatively with comparable in-hospital mortality rates. Compared to proximal disease, a lower percentage of patients with distal disease showed residual pulmonary hypertension (3.1% vs 6.9%, p = 0.039) and airway hemorrhage (3.0% vs 6.6%, p = 0.047) postoperatively. CONCLUSIONS: Thromboendarterectomy for distal (segmental and subsegmental) CTEPH is technically feasible and may result in favorable pulmonary hemodynamic outcomes, without increased mortality or morbidity.

Multidisciplinary Approach to Chronic Thromboembolic Pulmonary Hypertension: Role of Radiologists.

Management of chronic thromboembolic pulmonary hypertension (CTEPH) should be determined by a multidisciplinary team, ideally at a specialized CTEPH referral center. Radiologists contribute to this multidisciplinary process by helping to confirm the diagnosis of CTEPH and delineating the extent of disease, both of which help determine a treatment decision. Preoperative assessment of CTEPH usually employs multiple imaging modalities, including ventilation-perfusion (V/Q) scanning, echocardiography, CT pulmonary angiography (CTPA), and right heart catheterization with pulmonary angiography. Accurate diagnosis or exclusion of CTEPH at imaging is imperative, as this remains the only form of pulmonary hypertension that is curative with surgery. Unfortunately, CTEPH is often misdiagnosed at CTPA, which can be due to technical factors, patient-related factors, radiologist-related factors, as well as a host of disease mimics including acute pulmonary embolism, in situ thrombus, vasculitis, pulmonary artery sarcoma, and fibrosing mediastinitis. Although V/Q scanning is thought to be substantially more sensitive for CTEPH compared with CTPA, this is likely due to lack of recognition of CTEPH findings rather than a modality limitation. Preoperative evaluation for pulmonary thromboendarterectomy (PTE) includes assessment of technical operability and surgical risk stratification. While the definitive therapy for CTEPH is PTE, other minimally invasive or noninvasive therapies also lead to clinical improvements including greater survival. Complications of PTE that can be identified at postoperative imaging include infection, reperfusion edema or injury, pulmonary hemorrhage, pericardial effusion or hemopericardium, and rethrombosis. ©RSNA, 2022 Online supplemental material is available for this article.

Airway Hemorrhage Complicating Pulmonary Thromboendarterectomy: Risk Factors and Outcomes.

BACKGROUND: Airway hemorrhage is a known complication of pulmonary thromboendarterectomy (PTE) in patients with chronic thromboembolic pulmonary hypertension. Predisposing factors for postoperative airway hemorrhage have not been well described. The aims of this study were to determine the incidence and outcomes of airway hemorrhage after PTE and to identify potential risk factors. METHODS: This was a retrospective chart review of subjects undergoing PTE between 2015 and 2019. Postoperative airway hemorrhage was defined as significant endobronchial bleeding requiring withholding anticoagulation, bronchial blocker placement, and/or extracorporeal membrane oxygenation (ECMO). RESULTS: Of 877 subjects who underwent PTE, 58 subjects (6.6%) developed postoperative airway hemorrhage. Subjects with hemorrhage were more likely to be women (60% vs 45%, P = .03), to be older (57.8 vs 54.0 years, P = .04), and to have a higher incidence of preoperative hemoptysis (19.0% vs 7.6%, P = .006) compared with control subjects (subjects without airway hemorrhage). Those with hemorrhage had significantly higher preoperative right atrial pressure (P = .002) and pulmonary vascular resistance (P < .001) and a higher incidence of residual pulmonary hypertension (P = .005). Airway hemorrhage management included ECMO with bronchial blocker (n = 2), bronchial blocker without ECMO (n = 26), or withholding anticoagulation alone until bleeding subsided (n = 30). Mortality was significantly higher in those with airway hemorrhage compared with control subjects (13.8% vs 1.2%, P < .001). CONCLUSIONS: The incidence of postoperative airway hemorrhage is low but associated with significant mortality. Older age, female sex, preoperative hemoptysis, and worse preoperative pulmonary hypertension were associated with an increased risk of developing postoperative airway hemorrhage.

Evaluation of Dyspnea and Exercise Intolerance After Acute Pulmonary Embolism.

Long-term dyspnea and exercise intolerance are common clinical problems after acute pulmonary embolism. Unfortunately, no single test can distinguish among the range of potential pathologic outcomes after pulmonary embolism. We illustrate a stepwise approach to post-pulmonary embolism evaluation that uses a hierarchic series of clinically validated diagnostic tests. The algorithm is represented by the acronym SEARCH, which stands for Symptom screening, Exercise testing, Arterial perfusion, Resting echocardiography, Confirmatory chest imaging, and Hemodynamics measured by right heart catheterization. We illustrate the algorithm with a patient whom we saw in our pulmonary embolism follow-up clinic. Patients are asked at least 6 months after pulmonary embolism whether they have returned to their baseline level of respiratory comfort and exercise tolerance. Patients with dyspnea and exercise intolerance undergo noninvasive cardiopulmonary exercise testing to identify elevated ventilatory dead space ratios, decreased stroke volume augmentation with exercise, and other physiologic abnormalities during exertion. Ventilation-perfusion scanning is performed on those patients with exercise-related physiologic findings to confirm the presence of residual pulmonary arterial obstruction or to suggest alternative diagnoses. Resting echocardiography may provide evidence of pulmonary hypertension; confirmatory imaging with pulmonary angiography or CT angiography may disclose findings characteristic of chronic pulmonary artery obstruction. Finally, right heart catheterization is performed to confirm chronic thromboembolic pulmonary hypertension; if resting pulmonary hemodynamics are normal, then invasive cardiopulmonary exercise testing may disclose exercise-induced defects.

Etiology of pulmonary hypertension in multiple myeloma: A case series and literature review.

BACKGROUND: Multiple myeloma is often complicated by pulmonary hypertension through a variety of mechanisms. These mechanisms include pulmonary hypertension (PH) due to concomitant cardiac amyloid, high output heart failure due to anemia or lytic bone lesions, chronic thromboembolic pulmonary hypertension (CTEPH), toxicity from medications to treat multiple myeloma, and congestive heart failure. This case series highlights the various mechanisms through which multiple myeloma patients develop pulmonary hypertension. OBJECTIVES: To identify the etiologies of pulmonary hypertension and their management among multiple myeloma patients treated at University of California San Diego. METHODS: A retrospective chart review was performed to identify patients with multiple myeloma and pulmonary hypertension who were evaluated at the University of California San Diego between July 2013 and July 2021. Patients also required a right heart catheterization to be included. Demographics, comorbidities, clinical course, and etiology of pulmonary hypertension were obtained from chart review. RESULTS: There were 11 patients included. Of the 11 patients described, two had PH due to cardiac amyloid, one had PH due to high output heart failure, one had PH due to CTEPH, two had pulmonary arterial hypertension due to medications (carfilzomib), and five had PH due to congestive heart failure. The right heart catheterization and echocardiogram findings of the various mechanisms of PH in multiple myeloma are described. CONCLUSIONS: Pulmonary hypertension in multiple myeloma is a common finding that necessitates further evaluation. The initial evaluation should include an echocardiogram and thorough medication review. Further diagnostic testing should be guided by the patient's history and can include right heart catheterization, cardiac biopsy, ventilation-perfusion scan, and bone scan.

Metabolomic Profiles Differentiate Scleroderma-PAH From Idiopathic PAH and Correspond With Worsened Functional Capacity.

BACKGROUND: The prognosis and therapeutic responses are worse for pulmonary arterial hypertension associated with systemic sclerosis (SSc-PAH) compared with idiopathic pulmonary arterial hypertension (IPAH). This discrepancy could be driven by divergence in underlying metabolic determinants of disease. RESEARCH QUESTION: Are circulating bioactive metabolites differentially altered in SSc-PAH vs IPAH, and can this alteration explain clinical disparity between these PAH subgroups? STUDY DESIGN AND METHODS: Plasma biosamples from 400 patients with SSc-PAH and 1,082 patients with IPAH were included in the study. Another cohort of 100 patients with scleroderma with no PH and 44 patients with scleroderma with PH was included for external validation. More than 700 bioactive lipid metabolites, representing a range of vasoactive and immune-inflammatory pathways, were assayed in plasma samples from independent discovery and validation cohorts using liquid chromatography/high-resolution mass spectrometry-based approaches. Regression analyses were used to identify metabolites that exhibited differential levels between SSc-PAH and IPAH and associated with disease severity. RESULTS: From hundreds of circulating bioactive lipid molecules, five metabolites were found to distinguish between SSc-PAH and IPAH, as well as associate with markers of disease severity. Relative to IPAH, patients with SSc-PAH carried increased levels of fatty acid metabolites, including lignoceric acid and nervonic acid, as well as eicosanoids/oxylipins and sex hormone metabolites. INTERPRETATION: Patients with SSc-PAH are characterized by an unfavorable bioactive metabolic profile that may explain the poor and limited response to therapy. These data provide important metabolic insights into the molecular heterogeneity underlying differences between subgroups of PAH.

Patient selection for balloon pulmonary angioplasty: Six-year results from a high volume PTE surgical center.

Chronic thromboembolic pulmonary hypertension (CTEPH) is the result of incompletely resolved pulmonary emboli (PE) that lead to chronic right heart failure. The two mechanical treatment options are pulmonary thromboendarterectomy (PTE) and balloon pulmonary angioplasty (BPA). There are no formal criteria for BPA patient selection and treatment decisions vary according to a center's experience with BPA and PTE. We performed a retrospective review of consecutive patients treated with PTE and BPA at UCSD from March 2015 to 2021. Clinical and hemodynamic data were collected. Patients were categorized according to the rationale for BPA. One hundred fifty three patients underwent 643 BPA sessions, and 1104 patients underwent PTE. Patients selected for PTE had worse baseline hemodynamics with mean pulmonary artery pressure 41.1 ± 11.7 versus 34.6 ± 11.2 mmHg, p < 0.001. 59% of patients selected for BPA had surgically inaccessible disease, 21% had residual CTEPH after PTE, 10% had a discordance between disease burden and symptoms/hemodynamics, 7% had comorbidities that prevented PTE and 3% refused PTE surgery. 28% of patients who underwent PTE had exclusively level III or IV disease based on surgical specimen. There were no BPA procedure-related mortalities and minor pulmonary vascular complication rates during BPA were 9.2%. The most common reason for BPA selection was surgically inaccessible disease followed by residual CTEPH after PTE. Almost one third of patients who underwent PTE had exclusively distal disease by surgical criteria and might have been directed to BPA at a less experienced surgical center.

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.

Drug-Drug Interactions in the Management of Patients With Pulmonary Arterial Hypertension.

The management of pulmonary arterial hypertension (PAH) has become more complex in recent years because of increased pharmacotherapy options and longer patient survival with increasing numbers of comorbidities. As such, more opportunities exist for drug-drug interactions between PAH-targeted medications and medications potentially used to treat comorbid conditions. In this review, we provide an overview of pharmaceutical metabolism by cytochrome P450 and discuss important drug-drug interactions for the 14 Food and Drug Administration-approved medications for PAH in the nitric oxide (NO), endothelin, and prostacyclin pathways. Among the targets in the NO pathway (sildenafil, tadalafil, and riociguat), important interactions with nitrates, protease inhibitors, and other phosphodiesterase inhibitors can cause profound hypotension. In the endothelin pathway, bosentan is associated with more drug interactions via CYP3A4 inhibition; macitentan and ambrisentan have fewer interactions of note. Although the parenteral therapies in the prostacyclin pathway bypass significant liver metabolism and avoid drug interactions, selexipag and oral treprostinil may exhibit interactions with CYP2C8 inhibitors such as gemfibrozil and clopidogrel, which can raise drug levels. Finally, we provide a framework for identifying potential drug-drug interactions and avoiding errors.

Iron deficiency and pulmonary arterial hypertension.

The purpose of this review article is to provide a comprehensive review of iron deficiency in the setting of pulmonary arterial hypertension (PAH) and to evaluate the utility of iron supplementation in PAH. Iron deficiency is present in 33%-46% of patients with PAH and has been associated with reduced exercise capacity, compromised oxygen handling, deterioration of right ventricular function, and even mortality. Iron homeostasis and the pathophysiology of PAH are highly intertwined, which has inspired the use of iron supplementation in patients with iron deficiency and PAH. A literature search was performed to identify all available evidence on iron supplementation for PAH. Limited evidence has suggested poor oral bioavailability of oral iron dosed three times a day, but newer formulations such as ferrous maltol may provide better absorption and clinical benefit, especially when dosed less frequently, such as every other day. Intravenous (IV) iron has been shown in observational studies to improve outcomes, but the single randomized control trial in patients without anemia has failed to show benefits in any measure of exercise tolerance. Larger randomized control studies on oral iron with good bioavailability or IV iron in patients with anemia are warranted to explore the potential utility of iron supplementation in patients with PAH.