Positive Vasoreactivity Testing in Pulmonary Arterial Hypertension: Therapeutic Consequences, Treatment Patterns, and Outcomes in the Modern Management Era.

BACKGROUND: Among patients with pulmonary arterial hypertension (PAH), acute vasoreactivity testing during right heart catheterization may identify acute vasoresponders, for whom treatment with high-dose calcium channel blockers (CCBs) is recommended. However, long-term outcomes in the current era remain largely unknown. We sought to evaluate the implications of acute vasoreactivity response for long-term response to CCBs and other outcomes. METHODS: Patients diagnosed with PAH between January 1999 and December 2018 at 15 pulmonary hypertension centers were included and analyzed retrospectively. In accordance with current guidelines, acute vasoreactivity response was defined by a decrease of mean pulmonary artery pressure by ≥10 mm Hg to reach <40 mm Hg, without a decrease in cardiac output. Long-term response to CCBs was defined as alive with unchanged initial CCB therapy with or without other initial PAH therapy and World Health Organization functional class I/II and/or low European Society of Cardiology/European Respiratory Society risk status at 12 months after initiation of CCBs. Patients were followed for up to 5 years; clinical measures, outcome, and subsequent treatment patterns were captured. RESULTS: Of 3702 patients undergoing right heart catheterization for PAH diagnosis, 2051 had idiopathic, heritable, or drug-induced PAH, of whom 1904 (92.8%) underwent acute vasoreactivity testing. A total of 162 patients fulfilled acute vasoreactivity response criteria and received an initial CCB alone (n=123) or in combination with another PAH therapy (n=39). The median follow-up time was 60.0 months (interquartile range, 30.8-60.0), during which overall survival was 86.7%. At 12 months, 53.2% remained on CCB monotherapy, 14.7% on initial CCB plus another initial PAH therapy, and the remaining patients had the CCB withdrawn and/or PAH therapy added. CCB long-term response was found in 54.3% of patients. Five-year survival was 98.5% in long-term responders versus 73.0% in nonresponders. In addition to established vasodilator responder criteria, pulmonary artery compliance at acute vasoreactivity testing, low risk status and NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels at early follow-up correlated with long-term response and predicted survival. CONCLUSIONS: Our data display heterogeneity within the group of vasoresponders, with a large subset failing to show a sustained satisfactory clinical response to CCBs. This highlights the necessity for comprehensive reassessment during early follow-up. The use of pulmonary artery compliance in addition to current measures may better identify those likely to have a good long-term response.

Early discharge and home treatment of patients with low-risk pulmonary embolism with the oral factor Xa inhibitor rivaroxaban: an international multicentre single-arm clinical trial.

AIMS: To investigate the efficacy and safety of early transition from hospital to ambulatory treatment in low-risk acute PE, using the oral factor Xa inhibitor rivaroxaban. METHODS AND RESULTS: We conducted a prospective multicentre single-arm investigator initiated and academically sponsored management trial in patients with acute low-risk PE (EudraCT Identifier 2013-001657-28). Eligibility criteria included absence of (i) haemodynamic instability, (ii) right ventricular dysfunction or intracardiac thrombi, and (iii) serious comorbidities. Up to two nights of hospital stay were permitted. Rivaroxaban was given at the approved dose for PE for ≥3 months. The primary outcome was symptomatic recurrent venous thromboembolism (VTE) or PE-related death within 3 months of enrolment. An interim analysis was planned after the first 525 patients, with prespecified early termination of the study if the null hypothesis could be rejected at the level of α = 0.004 (<6 primary outcome events). From May 2014 through June 2018, consecutive patients were enrolled in seven countries. Of the 525 patients included in the interim analysis, three (0.6%; one-sided upper 99.6% confidence interval 2.1%) suffered symptomatic non-fatal VTE recurrence, a number sufficiently low to fulfil the condition for early termination of the trial. Major bleeding occurred in 6 (1.2%) of the 519 patients comprising the safety population. There were two cancer-related deaths (0.4%). CONCLUSION: Early discharge and home treatment with rivaroxaban is effective and safe in carefully selected patients with acute low-risk PE. The results of the present trial support the selection of appropriate patients for ambulatory treatment of PE.

Home treatment of patients with low-risk pulmonary embolism with the oral factor Xa inhibitor rivaroxaban. Rationale and design of the HoT-PE Trial.

Pulmonary embolism (PE) is a potentially life-threatening acute cardiovascular syndrome. However, more than 95 % of patients are haemodynamically stable at presentation, and among them are patients at truly low risk who may qualify for immediate or early discharge. The Home Treatment of Pulmonary Embolism (HoT-PE) study is a prospective international multicentre single-arm phase 4 management (cohort) trial aiming to determine whether home treatment of acute low-risk PE with the oral factor Xa inhibitor rivaroxaban is feasible, effective, and safe. Patients with confirmed PE, who have no right ventricular dysfunction or free floating thrombi in the right atrium or ventricle, are eligible if they meet none of the exclusion criteria indicating haemodynamic instability, serious comorbidity or any condition mandating hospitalisation, or a familial/social environment unable to support home treatment. The first dose of rivaroxaban is given in hospital, and patients are discharged within 48 hours of presentation. Rivaroxaban is taken for at least three months. The primary outcome is symptomatic recurrent venous thromboembolism or PE-related death within three months of enrolment. Secondary outcomes include quality of life and patient satisfaction, and health care resource utilisation compared to existing data on standard-duration hospital treatment. HoT-PE is planned to analyse 1,050 enrolled patients, providing 80 % power to reject the null hypothesis that the recurrence rate of venous thromboembolism is >3 % with α≤0.05. If the hypothesis of HoT-PE is confirmed, early discharge and out-of-hospital treatment may become an attractive, potentially cost-saving option for a significant proportion of patients with acute PE.

Nitrogen supply affects arbuscular mycorrhizal colonization of Artemisia vulgaris in a phosphate-polluted field site.

Root colonization by arbuscular mycorrhizal fungi (AMF) was investigated in industrially polluted grassland characterized by exceptionally high phosphorus levels (up to 120 g kg(-1) soil). Along a pollution-induced nitrogen gradient, soil and tissue element concentrations of Artemisia vulgaris plants and their mycorrhizal status were determined. Additionally, we compared mycorrhization rates and above-ground biomass of A. vulgaris at N-fertilized and control plots in the N-poor area. Despite high soil and tissue P concentrations, plants from N-deficient plots, which were characterized by low tissue N concentrations and N : P ratios, were strongly colonized by AMF, whereas at a plot with comparable P levels, but higher soil and plant N concentrations and N : P ratios, mycorrhization rates were significantly lower. Correlation analyses revealed a negative relationship between percentage root colonization of A. vulgaris by AMF and both tissue N concentration and N : P ratio. Accordingly, in the fertilization experiment, control plants had higher mycorrhization rates than N-fertilized plants, whereas the species attained higher biomass at N-fertilized plots. The results suggest that N deficiency stimulates root colonization by AMF in this extraordinarily P-rich field site.