Existing drugs and agents under investigation for pulmonary arterial hypertension

Impact of pulmonary hypertension on arteriovenous fistula failure of hemodialysis patients: A 10 years follow-up cohort study

BACKGROUND

Pulmonary hypertension (PH) is common in patients with end-stage renal disease (ESRD). Arteriovenous fistulas (AVF) creation may involve in the pathogenesis of PH. The aim of this study was to explore the impact of PH after AVF creation on the AVF failure rate in maintenance hemodialysis (MHD) patients.

METHODS

From January 1, 2009, to January 1, 2019, we retrospectively collected data of 578 MHD patients in Guangdong Provincial People's Hospital Blood Purification Center, China. Patients were followed-up until AVF failure or death or May 25, 2020. According to the systolic pulmonary artery pressure (SPAP) within 1 year after the establishment of AVF, the MHD patients were divided into three groups: SPAP ⩽ 35 mmHg, 35 < SPAP < 45 mmHg, SPAP ⩾ 45 mmHg. The primary outcome was AVF failure defined as AVF cannot complete hemodialysis. The secondary outcomes were all-cause mortality.

RESULTS

A total of 578 patients were analyzed. The average age was 60.66 ± 15.34 years (58.1% men). Of these, 26.1% of patients were reported PH. The SPAP exhibited a left-skewed nonparametric distribution and the overall SPAP after the creation of AVF was 39.00 (29.00-52.00) mmHg. The median follow-up was 5.8 (5.5-6.3) years. Overall, 12.8% (74/578) patients were reported AVF failure events. There was no significant difference in AVF failure rate among three groups (p = 0.070). A total of 111 (19.2%) died during the follow-up period. Compared with the SPAP ⩽35 mmHg group, only the all-cause death rate significantly increased in MHD patients with PH (p < 0.001).

CONCLUSIONS

The secondary pulmonary hypertension after AVF creation did not increase the risk of AVF failure in MHD patients, but significantly increased the risk of mortality for this portion of the patients. Future larger sample sizes, multi-center, and prospective trials are needed to make sure which type of access will benefit on their survival for MHD patients with SPAP ⩾35 mmHg.

[Pulmonary arterial hypertension and renal impairment in patients from the National Institute of Cardiology Dr. Ignacio Chávez, Mexico]

Objective

The objective of the study was to describe the clinical characteristics and the evolution of the severity of pulmonary arterial hypertension (PAH) and the degree of renal failure.

Material and methods

A retrospective observational study was carried out in which the physical and electronic medical records of 60 patients older than 18 years with a diagnosis of pulmonary arterial hypertension were analyzed.

Results

In our study, 11.4% of the severe PAH group worsened renal function at six months, and 13.6% of the participants worsened it at one year. In contrast, in the group with moderate PAH, 18.8% worsened at six months, and 12.5% worsened at one year. Also, the GFR at one year was 54.15 mL/min/1.73 m2 in the moderate PAH group and in the severe PAH group was 73.55 mL/min/1.73 m2.

Conclusion

The results of this research suggest that the deterioration of kidney function is related to the severity of pulmonary arterial hypertension.

Efficacy and safety of statin therapy in pulmonary hypertension: a systematic review and meta-analysis

Background

Pulmonary hypertension (PH) is a multi-causal disease and no satisfactory therapeutic strategies for it. Statins have been suggested as potential drugs in PH, whose effects in different clinic types of PH have not been conclusive. In this study, we included randomized controlled clinical trials (RCTs) evaluating the efficacy and safety of statins therapy in PH.

Methods

We searched databases including Medline, Embase, Cochrane, PubMed and Web of science, with time up to January 1, 2019. With 95% confidence interval (CI), weighted mean difference (WMD) or standardized mean difference (SMD) was pooled and calculated in a random or fixed effect model according to I2 statistic.

Results

A total of nine RCTs with 657 patients were included. Four types of statins (atorvastatin, pravastatin, rosuvastatin and simvastatin) were used at different doses (10-80 mg daily) for up to 6 months. In the pooled-data analysis, compared with placebo, there were significant improvements in pulmonary arterial pressure (PAP), in addition to low-density lipoprotein (LDL) in patients treated with statins, but not in 6-minute walking distance (6MWD), cardiac index (CDI). No more adverse events and all-cause mortality were revealed. Subgroup analysis indicated that statins could decrease PAP in the subtype of PH due to chronic obstructive pulmonary disease (COPD), but not pulmonary arterial hypertension (PAH).

Conclusions

This study indicates that statins can efficiently and safely reduce PAP in PH, especially in the subtype due to COPD. Further RCTs are needed to focus on the efficacy and safety of statin therapy in different subtypes of PH.

Epidemiology and risk factors in CKD patients with pulmonary hypertension: a retrospective study

BACKGROUND

Pulmonary hypertension (PH) is a rare disease often associated with high mortality and is recently recognized as a common complication secondary to chronic kidney disease (CKD). Epidemiological data for this disorder across the spectrum of CKD is poorly understood.

METHODS

We retrospectively analyzed 705 CKD patients with complete clinical records from July 2013 to September 2015. All the patients were estimated by echocardiography and PH was defined as pulmonary artery systolic pressure (PASP) > 35 mmHg. The prevalence of PH in CKD patients was investigated, and their association was evaluated with a logistic regression model.

RESULTS

The overall prevalence of PH was 47.38%, in which mild, moderate and severe PH accounted for 22.13, 15.04 and 10.21%, respectively. The prevalence of PH in CKD stage 1-5 was 14.29, 33.33, 38.89, 40.91 and 64.47%. The prevalence of total PH was 57.63% in PD patients and 58.82% in HD patients. Compared with the non-dialysis patients, the prevalence of PH was much higher in patients receiving dialysis. Body mass index (BMI), hemoglobin, triglyceride (TG), proteinuria, parathyroid hormone (PTH) and estimated glomerular filtration rate (eGFR) were independent risk factors of PH in CKD patients.

CONCLUSIONS

The prevalence of PH is increased with the deterioration of renal function, however, which has no direct relation to the severity of PH. PH occurs more frequently in dialysis patients. Higher BMI and TG, more sever anemia, proteinuria and secondary hyperparathyroidism, poor renal dysfunction predict predict the more prevalence of PH in CKD patients.

Upregulation of Klotho potentially inhibits pulmonary vascular remodeling by blocking the activation of the Wnt signaling pathway in rats with PM2.5-induced pulmonary arterial hypertension

We evaluated the effects of Klotho on pulmonary vascular remodeling and cell proliferation and apoptosis in rat models with PM2.5-induced pulmonary arterial hypertension (PAH) via the Wnt signaling pathway. After establishing rat models of PM2.5-induced PAH, these Sprague-Dawley male rats were randomized into control and model groups. Cells extracted from the model rats were sub-categorized into different groups. Activation of Wnt/β-catenin signaling transcription factor was detected by a TOPFlash/FOPFlash assay. A serial of experiment was conducted to identify the mechanism of Klotho on PHA via the Wnt signaling pathway. VEGF levels and PaCO₂ content were higher in the model group, while PaO_2, NO₂^- /NO₃^- content and Klotho level was lower compared to the control group. In comparison to the control group, the model group had decreased Klotho and Bax levels, and elevated Wnt-1, β-catenin, bcl-2, survivin, and PCNA expression, VEGF, IL-6, TNF-α, TNF-β1, and bFGF levels, as well as the percentage of pulmonary artery ring contraction. The Klotho vector, DKK-1 and DKK-1 + Klotho vector groups exhibited reduced cell proliferation, luciferase activity, and the expression of Wnt-1, β-catenin, bcl-2, survivin, and PCNA, as well as shortened S phase compared with the blank and NC groups. Compared with the Klotho vector and DKK-1 groups, the DKK-1 + Klotho vector groups had reduced cell proliferation, luciferase activity, and the expression of Wnt-1, β-catenin, bcl-2, survivin, and PCNA, as well as a shortened S phase. Conclusively, Klotho inhibits pulmonary vascular remodeling by inactivation of Wnt signaling pathway.

Corneal Endothelial Cell Integrity in Precut Human Donor Corneas Enhanced by Autocrine Vasoactive Intestinal Peptide

PURPOSE

To demonstrate that vasoactive intestinal peptide (VIP), a corneal endothelial (CE) cell autocrine factor, maintains the integrity of corneal endothelium in human donor corneoscleral explants precut for endothelial keratoplasty.

METHODS

Twelve paired human donor corneoscleral explants used as control versus VIP-treated explants (10 nM, 30 minutes, 37°C) were shipped (4°C) to the Lions Eye Institute for Transplantation and Research for precutting (Moria CBM-ALTK Keratome), shipped back to the laboratory, and cultured in ciliary neurotrophic factor (CNTF, 0.83 nM, 37°C, 24 hours). Trephined endothelial discs (8-8.5 mm) were analyzed for differentiation markers (N-cadherin, CNTF receptor α subunit [CNTFRα], and connexin 43) by Western blot after a quarter of the discs from 4 paired explants were cut away and stained with alizarin red S for microscopic damage analysis. Two additional paired explants (6 days in culture) were stained for panoramic view of central CE damage.

RESULTS

VIP treatment increased N-cadherin and CNTFRα levels (mean ± SEM) to 1.38 ± 0.11-fold (P = 0.003) and 1.46 ± 0.22-fold (P = 0.03) of paired controls, respectively, whereas CE cell CNTF responsiveness in upregulation of connexin 43 increased to 2.02 ± 0.5 (mean ± SEM)-fold of the controls (P = 0.04). CE damage decreased from (mean ± SEM) 10.0% ± 1.2% to 1.6% ± 0.3% (P < 0.0001) and 9.1% ± 1.1% to 2.4% ± 1.0% (P = 0.0006). After 6 days in culture, the damage in whole CE discs decreased from 20.0% (control) to 5.5% (VIP treated).

CONCLUSIONS

VIP treatment before precut enhanced the preservation of corneal endothelium.

Advanced Therapy in Eisenmenger Syndrome: A Systematic Review

Treatment options for patients with the Eisenmenger syndrome have until recently been scarce, but new knowledge in the field of pulmonary arterial hypertension has expanded the therapeutic possibilities for these patients. Advanced therapy with pulmonary vasodilators has become part of the standard treatment, offering long-term benefits on exercise capacity, clinical symptoms, and possibly survival. However, there are currently only few studies to guide the use of advanced therapies in this population, and important questions such as indications for initiation or escalation of advanced therapy and valid effect parameters and treatment goals remain unanswered. This review covers the pharmacology, therapeutic options, risk stratification, and treatment strategy of pulmonary arterial hypertension-specific drugs in patients with Eisenmenger syndrome.

Efficacy of Statin Therapy in Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis

Since the evidence regarding statin therapy in PAH has not been conclusive, we assessed the impact of statin therapy in PAH through a systematic review and meta-analysis of available studies. We searched selected databases up to August 1, 2015 to identify the studies investigating the effect of statin administration on PAH. Meta-analysis was performed using either a fixed-effects or random-effect model according to I(2) statistic. Meta-analysis of 8 studies with 665 patients did not suggest any significant improvement in 6-min walking distance (6MWD) by statin therapy (weighed mean difference [WMD]: -6.08 m, 95% confidence interval [CI]: -25.66, 13.50, p = 0.543; Q = 8.41, I(2) = 28.64%). Likewise, none of the other indices including pulmonary arterial pressure (WMD: -0.97 mmHg, 95%CI: -4.39, 2.44, p = 0.577; Q = 14.64, I(2) = 79.51%), right atrial pressure (WMD: 1.01 mmHg, 95%CI: -0.93, 2.96, p = 0.307; Q = 44.88, I(2) = 95.54%), cardiac index (WMD: 0.05 L/min/m(2), 95%CI: -0.05, 0.15, p = 0.323; Q = 3.82, I(2) = 21.42%), and pulmonary vascular resistance (WMD: -1.42 dyn*s/cm(5), 95%CI: -72.11, 69.27, p = 0.969; Q = 0.69, I(2) = 0%) was significantly altered by statin therapy. In conclusion, the results of the meta-analysis did not show a statistically significant effect of statin therapy in the improvement of 6MWD, pulmonary arterial pressure, right atrial pressure, cardiac index and pulmonary vascular resistance.

HIV-associated pulmonary arterial hypertension: from bedside to the future

Pulmonary arterial hypertension (PAH) is a life-threatening complication of HIV infection. The prevalence of HIV-associated PAH (HIV-PAH) seems not to be changed over time, regardless of the introduction of highly active antiretroviral therapy (HAART). In comparison with the incidence of idiopathic PAH in the general population (1-2 per million), HIV-infected patients have a 2500-fold increased risk of developing PAH. HIV-PAH treatment is similar to that for all PAH conditions and includes lifestyle changes, general treatments and specific treatments.