Partially hydrolyzed guar gum suppresses the progression of pulmonary arterial hypertension in a SU5416/hypoxia rat model.

This study investigated the effects of partially hydrolyzed guar gum (PHGG) on the development of pulmonary arterial hypertension using a SU5416/hypoxia rat model. Our results demonstrated that PHGG treatment suppressed the development of pulmonary hypertension and vascular remodeling with an altered gut microbiota composition.

Impact of residual pulmonary hypertension on long-term outcomes after pulmonary endarterectomy in the modern era.

Residual pulmonary hypertension (PH) negatively impacts long-term results following pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH). We sought to reveal whether modern PH therapy with PH-targeted medicine and balloon pulmonary angioplasty (BPA) improved long-term results of residual PH after PEA. Long-term findings of 80 patients who survived PEA between 2011 and 2019 were retrospectively investigated. One month after PEA, 30 patients developed residual PH defined as mean pulmonary artery pressure (mPAP) ≥25 mmHg, of whom 23 were treated by PH-targeted medicine and 9 by BPA. Patients with residual PH acquired considerably better functional status and exercise capacity after PEA, however, exhibited significantly worse survival rates than those without. Eleven patients died during follow-up: 8 patients with residual PH and 3 controls. Among patients with residual PH, the deceased had a significantly lower %decrease in mPAP from 1 month to 1 year following PEA (7.4 [-32.6 to 8.0] % vs. 10.4 [3.7-27.8] %, p = 0.03) and higher mPAP at 1 year following PEA (39.5 [33.25-42.5] vs. 27 [26-34] mmHg, p < 0.01) despite PH-targeted medicine than the survived. No patients passed away from right heart failure, and there was no difference between the groups in CTEPH-related mortality. Modern PH therapy was used to address the majority of residual PH. Long-term survival after PEA was negatively impacted by residual PH, but it appeared that long-term mortality was also correlated with unrelieved residual PH despite PH-targeted medicine. Modern PH therapy may have enhanced functional status and excercise capacity, and averted fatal right heart failure.

The extent of enlarged bronchial arteries is not correlated with the development of reperfusion pulmonary edema after pulmonary endarterectomy in patients with chronic thromboembolic pulmonary hypertension.

This study investigated whether dilated bronchial arteries are associated with reperfusion pulmonary edema in patients with chronic thromboembolic pulmonary hypertension. Results showed that the extent of enlarged bronchial arteries was not associated with the development of reperfusion pulmonary edema, whereas the residual pulmonary hypertension had a significant association.

Gut microbiota modification suppresses the development of pulmonary arterial hypertension in an SU5416/hypoxia rat model.

The pathogenesis of pulmonary arterial hypertension is closely associated with dysregulated inflammation. Recently, abnormal alterations in gut microbiome composition and function were reported in a pulmonary arterial hypertension experimental animal model. However, it remains unclear whether these alterations are a result or the cause of pulmonary arterial hypertension. The purpose of this study was to investigate whether alterations in the gut microbiome affected the hemodynamics in SU5416/hypoxia rats. We used the SU5416/hypoxia rat model in our study. SU5416/hypoxia rats were treated with a single SU5416 injection (30 mg/kg) and a three-week hypoxia exposure (10% O2). Three SU5416/hypoxia rats were treated with a combination of four antibiotics (SU5416/hypoxia + ABx group) for four weeks. Another group was exposed to hypoxia (10% O2) without the SU5416 treatment, and control rats received no treatment. Fecal samples were collected from each animal, and the gut microbiota composition was analyzed by 16S rRNA sequencing. The antibiotic treatment significantly suppressed the vascular remodeling, right ventricular hypertrophy, and increase in the right ventricular systolic pressure in SU5416/hypoxia rats. 16S rRNA sequencing analysis revealed gut microbiota modification in SU5416/hypoxia + ABx group. The Firmicutes-to-Bacteroidetes ratio in SU5416/hypoxia rats was significantly higher than that in control and hypoxia rats. Compared with the control microbiota, 14 bacterial genera, including Bacteroides and Akkermansia, increased, whereas seven bacteria, including Rothia and Prevotellaceae, decreased in abundance in SU5416/hypoxia rats. Antibiotic-induced modification of the gut microbiota suppresses the development of pulmonary arterial hypertension. Dysbiosis may play a causal role in the development and progression of pulmonary arterial hypertension.