Elevated Anti-Xa in the Setting of Prophylactic Unfractionated Subcutaneous Heparin Administration.

Venous thromboembolism prophylaxis with subcutaneous unfractionated heparin or low molecular weight heparin is a common practice in hospitalized patients. Typically, prophylactic doses of these medications have poor bioavailability and thus do not reach therapeutic serum concentrations. However, in certain circumstances, heparin binding proteins may become saturated. Here we report a case series of 5 patients who had elevated anti-Xa levels while receiving prophylactic dosing of subcutaneous unfractionated heparin.

Long-term impact of add-on sequential triple combination therapy in pulmonary arterial hypertension: real world experience.

BACKGROUND: Sequential triple combination therapy is recommended for pulmonary arterial hypertension (PAH) patients who are not at therapeutic goal on dual therapy, but long-term data on efficacy and safety is scarce. OBJECTIVE: To assess the long-term impact of sequential triple combination therapy in patients with PAH who are not at goal on dual combination therapy. STUDY DESIGN AND METHODS: We performed a retrospective observational study in a racially/ethnically diverse cohort of consecutive PAH patients on a stable dual therapy regimen who remained in intermediate- or high-risk category and were subsequently initiated on sequential triple combination therapy. We studied interval change in functional, echocardiographic, and hemodynamic parameters, REVEAL 2.0 risk category and ERS/ESC 2022 simplified four-strata risk category. Multivariate logistic regression analysis was performed to identify independent predictors of successful risk reduction (achievement or maintenance of REVEAL 2.0 low-risk category). Kaplan-Meier survival curves were created to assess the effect of risk reduction on survival. RESULTS: Out of 414 PAH patients seen in our program, 55 patients received add-on sequential triple combination regimen and had follow-up hemodynamic data. The mean age was 57 years, with 85% women. The most common etiology of PAH was idiopathic/heritable (41.8%). Most patients were WHO functional class III (76.4%), and 34.5% of patients were in high-risk category (REVEAL 2.0). On a median follow-up of 68 weeks, there was a significant improvement in WHO Functional Class (p < 0.001), six-minute walk distance (35 m) with 61.8% of patients achieving low-risk status by REVEAL 2.0, and a 28% of patients' improvement in pulmonary vascular resistance. Female gender was identified as a strong predictor of successful risk reduction, whereas Hispanic ethnicity estimated right atrial pressure on echocardiogram and pericardial effusion predicted lower probability of risk reduction. Patients who achieved or maintained low-risk status had significantly improved survival. CONCLUSION: Add-on sequential triple combination therapy significantly increased functional, echocardiographic, and hemodynamic parameters with improvement in risk category and survival.

Role of small airway dysfunction in unexplained exertional dyspnoea.

Background: Isolated small airway abnormalities may be demonstrable at rest in patients with normal spirometry; however, the relationship of these abnormalities to exertional symptoms remains uncertain. This study uses an augmented cardiopulmonary exercise test (CPET) to include evaluation of small airway function during and following exercise to unmask abnormalities not evident with standard testing in individuals with dyspnoea and normal spirometry. Methods: Three groups of subjects were studied: 1) World Trade Center (WTC) dust exposure (n=20); 2) Clinical Referral (n=15); and Control (n=13). Baseline evaluation included respiratory oscillometry. Airway function during an incremental workload CPET was assessed by: 1) tidal flow versus volume curves during exercise to assess for dynamic hyperinflation and expiratory flow limitation; and 2) post-exercise spirometry and oscillometry to evaluate for airway hyperreactivity. Results: All subjects demonstrated normal baseline forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC). Dyspnoea was reproduced during CPET in WTC and Clinical Referral groups versus Control without abnormality in respiratory pattern and minute ventilation. Tidal flow-volume curves uncovered expiratory flow limitation and/or dynamic hyperinflation with increased prevalence in WTC and Clinical Referral versus Control (55%, 87% versus 15%; p<0.001). Post-exercise oscillometry uncovered small airway hyperreactivity with increased prevalence in WTC and Clinical Referral versus Control (40%, 47% versus 0%, p<0.05). Conclusions: We uncovered mechanisms for exertional dyspnoea in subject with normal spirometry that was attributable to either small airway dysfunction during exercise and/or small airway hyperreactivity following exercise. The similarity of findings in WTC environmentally exposed and clinically referred cohorts suggests broad relevance for these evaluations.

Advances in the management of pulmonary arterial hypertension.

The management of pulmonary arterial hypertension (PAH) has significantly evolved over the last decades in the wake of more sensitive diagnostics and specialized clinical programs that can provide focused medical care. In the current era of PAH care, 1-year survival rates have increased to 86%-90% from 65% in the 1980s, and average long-term survival has increased to 6 years from 2.8 years. The heterogeneity in the etiology and disease course has opened doors to focusing research in phenotyping the disease and understanding the pathophysiology at a cellular and genetic level. This may eventually lead to precision medicine and the development of medications that may prevent or reverse pulmonary vascular remodeling. With more insight, clinical trial designs and primary end-points may change to identify the true survival benefit of pharmacotherapy. Identifying responders from non-responders to therapy may help provide individualized patient-centered care rather than an algorithm-based approach. The purpose of this review is to highlight the latest advances in screening, diagnosis, and management of PAH.

Advanced management of intermediate-high risk pulmonary embolism.

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2021. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2021 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from https://link.springer.com/bookseries/8901 .