Pulmonary artery denervation improves pulmonary arterial hypertension induced right ventricular dysfunction by modulating the local renin-angiotensin-aldosterone system

Downregulation of PDCD4 through STAT3/ATF6/autophagy mediates MIF-induced PASMCs proliferation/migration and vascular remodeling

To address the molecular mechanisms underlying macrophage migration inhibitory factor (MIF) induced pulmonary artery smooth muscle cells (PASMCs) proliferation, migration and vascular remodeling in pulmonary hypertension (PH), primary cultured rat PASMCs and monocrotaline (MCT)-induced rats with PH were applied in the present study. The results showed that MIF increased signal transducer and activator of transcription 3 (STAT3) phosphorylation, and then stimulated activating transcription factor 6 (ATF6) activation, subsequently triggered autophagy activation, which further led to programmed cell death factor 4 (PDCD4) lysosomal degradation, and eventually promoted PASMCs proliferation/migration. In lung tissues of MCT rats, MIF protein expression was elevated, phosphorylation of STAT3 and activation of ATF6 were increased, activation of autophagy was evident, and reduction of PDCD4 was observed. Intervention with MIF inhibitor 4-Iodo-6-phenylpyrimidine (4-IPP), ATF6 blocker melatonin or autophagy inhibitor chloroquine, confirmed the in vitro interaction among MIF, STAT3, ATF6, autophagy and PDCD4 in MCT induced rats with PH. Targeting MIF/STAT3/ATF6/autophagy/PDCD4 axis effectively prevented the development of PH by suppressing PASMCs proliferation and vascular remodeling. In conclusions, we demonstrate that MIF activates the STAT3/ATF6/autophagy cascade and then degrades PDCD4 leading to PASMCs proliferation/migration and pulmonary vascular remodeling, suggesting that intervention this axis might have potential value in management of PH.

Pulmonary Artery Denervation Inhibits Left Stellate Ganglion Stimulation-Induced Ventricular Arrhythmias Originating From the RVOT

BACKGROUND

Electrical stimulation of the left stellate ganglion (LSG) can evoke ventricular arrhythmias (VAs) that originate from the right ventricular outflow tract (RVOT). The involvement of pulmonary artery innervation is unclear.

OBJECTIVES

This study investigated the effects of selective pulmonary artery denervation (PADN) on blood pressure (BP), sympathetic activity, ventricular effective refractory period (ERP), and the incidence of VAs induced by LSG stimulation in canines.

METHODS

Radiofrequency ablation with basic anesthetic monitoring was used to induce PADN in canines. In Protocol 1 (n = 11), heart rate variability, serum norepinephrine and angiotensin-II levels, BP changes and ventricular ERP in response to LSG stimulation were measured before and after PADN. In Protocol 2 (n = 8), the incidence of VAs induced by LSG stimulation was calculated before and after PADN in a canine model of complete atrioventricular block. In addition, sympathetic nerves in the excised pulmonary arteries were immunohistochemically stained with tyrosine hydroxylase.

RESULTS

The low-frequency components of heart rate variability, serum norepinephrine and angiotensin-II levels were remarkably decreased post-PADN. Systolic BP elevation and RVOT ERP shortening induced by LSG stimulation were mitigated by PADN. The number of RVOT-premature ventricular contractions as well as RVOT tachycardia episodes and duration induced by LSG stimulation were significantly reduced after PADN. In addition, a large number of tyrosine hydroxylase-immunoreactive nerve fibers were located in the anterior wall of the pulmonary artery.

CONCLUSIONS

PADN ameliorated RVOT ERP shortening, and RVOT-VAs induced by LSG stimulation by inhibiting cardiac sympathetic nerve activity.

Loss of Amphiregulin drives inflammation and endothelial apoptosis in pulmonary hypertension

Pulmonary hypertension (PH) is a vascular disease characterized by elevated pulmonary arterial pressure, leading to right ventricular failure and death. Pathogenic features of PH include endothelial apoptosis and vascular inflammation, which drive vascular remodeling and increased pulmonary arterial pressure. Re-analysis of the whole transcriptome sequencing comparing human pulmonary arterial endothelial cells (PAECs) isolated from PH and control patients identified AREG, which encodes Amphiregulin, as a key endothelial survival factor. PAECs from PH patients and mice exhibited down-regulation of AREG and its receptor epidermal growth factor receptor (EGFR). Moreover, the deficiency of AREG and EGFR in ECs in vivo and in vitro heightened inflammatory leukocyte recruitment, cytokine production, and endothelial apoptosis, as well as diminished angiogenesis. Correspondingly, hypoxic mice lacking Egfr in ECs (cdh5 ^cre/+ Egfr ^fl/fl) displayed elevated RVSP and pulmonary remodeling. Computational analysis identified NCOA6, PHB2, and RRP1B as putative genes regulating AREG in endothelial cells. The master transcription factor of hypoxia HIF-1⍺ binds to the promoter regions of these genes and up-regulates their expression in hypoxia. Silencing of these genes in cultured PAECs decreased inflammation and apoptosis, and increased angiogenesis in hypoxic conditions. Our pathway analysis and gene silencing experiments revealed that BCL2-associated agonist of cell death (BAD) is a downstream mediator of AREG BAD silencing in ECs lacking AREG mitigated inflammation and apoptosis, and suppressed tube formation. In conclusion, loss of Amphiregulin and its receptor EGFR in PH is a crucial step in the pathogenesis of PH, promoting pulmonary endothelial cell death, influx of inflammatory myeloid cells, and vascular remodeling.

Monocrotaline-Induced Pulmonary Arterial Hypertension and Bosentan Treatment in Rats: Focus on Plasma and Erythrocyte Parameters

The objective of our study was to contribute to the characterization of monocrotaline-induced pulmonary arterial hypertension (PAH) in a rat model, with emphasis on the renin-angiotensin-aldosterone system, parameters of oxidative stress, the activity of matrix metalloproteinases, and erythrocyte parameters. Moreover, we aimed to analyze the effects of bosentan. Experiments were performed on 12-week-old male Wistar rats randomly assigned to 3 groups: control, monocrotaline-treated (60 mg/kg), and monocrotaline combined with bosentan (300 mg/kg/day). Our study confirmed the well-known effects of monocrotaline administration on lungs and the right ventricle, as well as pulmonary arterial pressure. In addition, we observed activation of the alternative pathway of the renin-angiotensin system, namely an increase in angiotensin (Ang) 1-7 and Ang 1-5 together with an increase in Ang I, but without any change in Ang II level, and downregulation of aldosterone 4 weeks after monocrotaline administration. For the first time, modifications of erythrocyte Na,K-ATPase enzyme kinetics were demonstrated as well. Our observations do not support data obtained in PAH patients showing an increase in Ang II levels, increase in oxidative stress, and deterioration in RBC deformability. Although bosentan primarily targets the vascular smooth muscle, our study confirmed its antioxidant effect. The obtained data suggest that besides the known action of bosentan, it decreases heart rate and increases erythrocyte deformability, and hence could have a beneficial hemodynamic effect in the PAH condition.

Current status of pulmonary artery denervation

Pulmonary hypertension is a progressive disease with a poor long-term prognosis and high mortality. Pulmonary artery denervation (PADN) is emerging as a potential novel therapy for this condition. The basis of pursuing a sympathetic denervation strategy has its origins in a body of experimental translation work that has demonstrated that denervation can reduce sympathetic nerve activity in various animal models. This reduction in pulmonary sympathetic nerve activity is associated with a reduction in pathological pulmonary hemodynamics in response to mechanical, pharmacological, and toxicologically induced pulmonary hypertension. The most common method of PADN is catheter-directed thermal ablation. Since 2014, there have been 12 reports on the role of PADN in 490 humans with pulmonary hypertension (311:179; treated: control). Of these, six are case series, three are randomized trials, and three are case reports. Ten studies used percutaneous PADN techniques, and two combined PADN with mitral and/or left atrial surgery. PADN treatment has low mortality and morbidity and is associated with an improved 6-minute walking distance, a reduction in both mean pulmonary artery pressure and pulmonary vascular resistance, and an improvement in cardiac output. These improved outcomes were seen over a median follow-up of 12 months (range 2–46 months). A recent meta-analysis of human trials also supports the effectiveness of PADN in carefully selected patients. Based on the current literature, PADN can be effective in select patients with pulmonary hypertension. Additional randomized clinical trials against best medical therapy are required.

A Meta-analysis of the efficacy of pulmonary artery denervation in the treatment of pulmonary hypertension

BACKGROUND

Pulmonary hypertension (pH) is a progressive and fatal disease with poor long-term prognosis and high mortality. Although great progress has been made in current treatment methods, the survival rate is still poor. Therefore, we need to find an effective treatment for pH.

OBJECTIVE

pH is a type of refractory, progressive, and fatal pulmonary vascular disease which involves a variety of clinical conditions and may complicate most cardiovascular and respiratory diseases. Pulmonary artery denervation (PADN) therapy for pH has become the current trend, but its clinical application still faces a series of problems, and its efficacy remains controversial. The purpose of the study is to evaluate the literature on the effects of PADN for pH.

METHOD

The PubMed, Embase, and Web of Science databases were searched by two researchers until April 9th, 2021. The literature was read and screened, and effective data(6-minute walking distance, cardiac output, mPAP, PVR,Left ventricular end-systolic diameter,Cardiac output,Readmission rate,Mortality,Cardiac function,and so on) was extracted, collated, and analyzed. The literature was managed by Endnote 9.3 software and evaluated by RevMan 5.3 software.

RESULTS

The meta-analysis included five controlled experiments with a total of 339 patients. The literature quality evaluations were all Level B. The meta-analysis results showed that compared with the control group, PADN treatment could improve the 6-minute walking distance of pH patients [WMD = 103.72, 95%CI (49.63, 157.82), P < 0.05], reduce mean pulmonary artery pressure (mPAP) [WMD = -7.26, 95%CI (-10.86, -3.66), P < 0.05], reduce pulmonary vascular resistance (PVR) [WMD = -4.53, 95%CI (-8.23, -0.83), P < 0.05], and improve cardiac output [WMD = 0.48, 95%CI (0.23, 0.73), P < 0.05]. There was no significant effect on the left ventricular end-systolic diameter [WMD = -0.13, 95%CI (-0.49, 0.24), P > 0.05], readmission rate [OR = 0.14, 95%CI (0.01, 1.87), P > 0.05], mortality rate [OR = 0.77, 95%CI (0.22, 2.69), P > 0.05], or cardiac function [OR = 0.32, 95%CI (0.05, 2.10), P > 0.05].

CONCLUSION

PADN is an effective method for the treatment of pH which is worthy of clinical promotion.

Mineralocorticoid receptors in pulmonary hypertension and right heart failure: From molecular biology to therapeutic targeting

Pulmonary hypertension (PH) is a devastating condition characterized by pulmonary vascular remodelling, leading to progressive increase in pulmonary artery pressure and subsequent right ventricular failure. Aldosterone and the mineralocorticoid receptor (MR), a nuclear transcription factor, are key drivers of cardiovascular disease and MR antagonists are well-established in heart failure. Now, a growing body of evidence points at a detrimental role of MR in PH. Pharmacological MR blockade attenuated PH and prevented RV failure in experimental models. Mouse models with cell selective MR deletion suggest that this effect is mediated by MR in endothelial cells. While the evidence from experimental studies appears convincing, the available clinical data on MR antagonist use in patients with PH is more controversial. Integrated analysis of clinical data together with MR-dependent molecular alterations may provide insights why some patients respond to MRA treatment while others do not. Potential ways to identify MRA 'responders' include the analysis of underlying PH causes, stage of disease, or sex, as well as new biomarkers.

Neurohormonal modulation in pulmonary arterial hypertension

Pulmonary hypertension is a fatal condition of elevated pulmonary pressures, complicated by right heart failure. Pulmonary hypertension appears in various forms; one of those is pulmonary arterial hypertension (PAH) and is particularly characterised by progressive remodelling and obstruction of the smaller pulmonary vessels. Neurohormonal imbalance in PAH patients is associated with worse prognosis and survival. In this back-to-basics article on neurohormonal modulation in PAH, we provide an overview of the pharmacological and nonpharmacological strategies that have been tested pre-clinically and clinically. The benefit of neurohormonal modulation strategies in PAH patients has been limited by lack of insight into how the neurohormonal system is changed throughout the disease and difficulties in translation from animal models to human trials. We propose that longitudinal and individual assessments of neurohormonal status are required to improve the timing and specificity of neurohormonal modulation strategies. Ongoing developments in imaging techniques such as positron emission tomography may become helpful to determine neurohormonal status in PAH patients in different disease stages and optimise individual treatment responses.

[Pulmonary artery denervation in pulmonary hypertension: physiological and clinical aspects]

This article is a review of the findings of experimental and clinical studies of a new method of treatment of pulmonary hypertension - pulmonary artery denervation with the help of radiofrequency ablation, cryodenervation and ultrasonic impact. Pulmonary artery denervation results in decreased neurogenic tonic sympathetic and, probably, increased parasympathetic effects on pulmonary vessels. On models of experimental monocrotaline-induced pulmonary hypertension in various-species animals, it was determined that pulmonary artery denervation is followed by decreased activity of local pulmonary renin-angiotensin system, slowed processes of remodeling of pulmonary vessels, hypertrophy and fibrosis of the right ventricle, with inhibition of progression of pulmonary hypertension by means of suppression of extracellular signal-regulated kinase 1/2 (ERK 1/2) which regulates differentiation, proliferation and migration of smooth muscle cells. However, the problem of the pattern of pulmonary microcirculation changes (pre- and postcapillary resistance, capillary filtration coefficient) after pulmonary artery denervation warrants further study. The findings of clinical studies in patients with pulmonary hypertension suggest that pulmonary artery denervation inducing a decrease of pressure therein, as well as pulmonary vessel resistance did not lead to normalization of pulmonary haemodynamics.The mentioned impact partially removes the neurogenic component of multicircuit and multifactorial regulation of pulmonary circulation. Therefore, along with pulmonary artery denervation, further search for pharmacological agents selectively influencing pulmonary vessels remains a problem of current importance.

Neurohormonal Modulation as a Therapeutic Target in Pulmonary Hypertension

The autonomic nervous system (ANS) and renin-angiotensin-aldosterone system (RAAS) are involved in many cardiovascular disorders, including pulmonary hypertension (PH). The current review focuses on the role of the ANS and RAAS activation in PH and updated evidence of potential therapies targeting both systems in this condition, particularly in Groups 1 and 2. State of the art knowledge in preclinical and clinical use of pharmacologic drugs (beta-blockers, beta-three adrenoceptor agonists, or renin-angiotensin-aldosterone signaling drugs) and invasive procedures, such as pulmonary artery denervation, is provided.

Pulmonary Artery Denervation as an Innovative Treatment for Pulmonary Hypertension With and Without Heart Failure

Pulmonary hypertension (PH) is categorized into 5 groups based on etiology. The 2 most prevalent forms are pulmonary arterial hypertension (PAH) and PH due to left heart disease (PH-LHD). Therapeutic options do exist for PAH to decrease symptoms and improve functional capacity; however, the mortality rate remains high and clinical improvements are limited. PH-LHD is the most common cause of PH; however, no treatment exists and the use of PAH-therapies is discouraged. Pulmonary artery denervation (PADN) is an innovative catheter-based ablation technique targeting the afferent and efferent fibers of a baroreceptor reflex in the main pulmonary artery (PA) trunk and its bifurcation. This reflex is involved in the elevation of the PA pressure seen in PH. Since 2013, both animal trials and human trials have shown the efficacy of PADN in improving PAH, including improved hemodynamic parameters, increased functional capacity, decreased PA remodeling, and much more. PADN has been shown to decrease the rate of rehospitalization, PH-related complications, and death, and is an overall safe procedure. PADN has also been shown to be effective for PH-LHD. Additional therapeutic mechanisms and benefits of PADN are discussed along with new PADN techniques. PADN has shown efficacy and safety as a potential treatment option for PH.

Transection of the cervical sympathetic trunk inhibits the progression of pulmonary arterial hypertension via ERK-1/2 Signalling

Background

Abnormal sympathetic hyperactivity has been shown to lead to pulmonary arterial hypertension (PAH) deterioration. The purpose of this study was to examine whether the transection of the cervical sympathetic trunk (TCST) can inhibit the progression of PAH in a monocrotaline (MCT)-induced PAH model and elucidate the underlying mechanisms.

Methods

Rats were randomly divided into four groups, including a control group, an MCT group, an MCT + sham group and an MCT + TCST group. After performing haemodynamic and echocardiographic measurements, the rats were sacrificed for the histological study, and the norepinephrine (NE) concentrations and protein expression level of tyrosine hydroxylase (TH) were evaluated. The protein expression levels of extracellular signal-regulated kinase (ERK)-1/2, proliferating cell nuclear antigen (PCNA), cyclin A2 and cyclin D1 in pulmonary artery vessels and pulmonary arterial smooth muscle cells (PASMCs) were determined.

Results

Compared with the MCT + sham group, TCST profoundly reduced the mean pulmonary arterial pressure (mPAP) (22.02 ± 4.03 mmHg vs. 31.71 ± 2.94 mmHg), right ventricular systolic pressure (RVSP) (35.21 ± 5.59 mmHg vs. 48.36 ± 5.44 mmHg), medial wall thickness (WT%) (22.48 ± 1.75% vs. 46.10 ± 3.16%), and right ventricular transverse diameter (RVTD) (3.78 ± 0.40 mm vs. 4.36 ± 0.29 mm) and increased the tricuspid annular plane systolic excursion (TAPSE) (2.00 ± 0.12 mm vs. 1.41 ± 0.24 mm) (all P < 0.05). The NE concentrations and protein expression levels of TH were increased in the PAH rats but significantly decreased after TCST. Furthermore, TCST reduced the increased protein expression of PCNA, cyclin A2 and cyclin D1 induced by MCT in vivo. We also found that NE promoted PASMC viability and activated the ERK-1/2 pathway. However, the abovementioned NE-induced changes could be suppressed by the specific ERK-1/2 inhibitor U0126.

Conclusion

TCST can suppress pulmonary artery remodelling and right heart failure in MCT-induced PAH. The main mechanism may be that TCST decreases the NE concentrations in lung tissues, thereby preventing NE from promoting PASMC proliferation mediated by the ERK-1/2 signalling pathway.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1090-2) contains supplementary material, which is available to authorized users.

Transthoracic Pulmonary Artery Denervation for Pulmonary Arterial Hypertension

Objective—

Pulmonary arterial hypertension is characterized by progressive pulmonary vascular remodeling and persistently elevated mean pulmonary artery pressures and pulmonary vascular resistance. We aimed to investigate whether transthoracic pulmonary artery denervation (TPADN) attenuated pulmonary artery (PA) remodeling, improved right ventricular (RV) function, and affected underlying mechanisms. We also explored the distributions of sympathetic nerves (SNs) around human PAs for clinical translation.

Approach and Results—

We identified numerous SNs in adipose and connective tissues around the main PA trunks and bifurcations in male Sprague Dawley rats, which were verified in samples from human heart transplant patients. Pulmonary arterial hypertensive rats were randomized into TPADN and sham groups. In the TPADN group, SNs around the PA trunk and bifurcation were completely and accurately removed under direct visualization. The sham group underwent thoracotomy. Hemodynamics, RV function, and pathological changes in PA and RV tissues were measured via right heart catheterization, cardiac magnetic resonance imaging, and pathological staining, respectively. Compared with the sham group, the TPADN group had lower mean pulmonary arterial pressures, less PA and RV remodeling, and improved RV function. Furthermore, TPADN inhibited neurohormonal overactivation of the sympathetic nervous system and renin-angiotensin-aldosterone system and regulated abnormal expressions and signaling of neurohormone receptors in local tissues.

Conclusions—

There are numerous SNs around the rat and human main PA trunks and bifurcations. TPADN completely and accurately removed the main SNs around PAs and attenuated pulmonary arterial hypertensive progression by inhibiting excessive activation of the sympathetic nervous system and renin-angiotensin-aldosterone system neurohormone-receptor axes.

Effects of Pulmonary Hypertension and Right Ventricular Function in Short and Long-Term Kidney Function

BACKGROUND

Pulmonary hypertension is not uncommon in patients with renal disease and vice versa; therefore, it influences treatments and outcomes. There is a large body of literature on pulmonary hypertension in patients with kidney disease, its prognostic implications, economic burden, and management strategies. However, the converse, namely the hemodynamic effects of pulmonary hypertension on kidney function (acute and chronic kidney injury) is less studied and described. There is also increasing interest in the effects of pulmonary hypertension on kidney transplant outcomes. The relationship is a complex phenomenon and multiple body systems and mechanisms are involved in its pathophysiology. Although the definition of pulmonary hypertension has evolved over time with the understanding of multiple interplays between the heart, lungs, kidneys, etc; there is limited evidence to provide a specific treatment strategy when kidneys and lungs are affected at the same time. Nevertheless, available evidence appears to support new therapeutics and highlights the importance of individualized approach. There is sufficient research showing that the morbidity and mortality from PH are driven by the influence of the pulmonary hemodynamic dysfunction on the kidneys.

CONCLUSION

This concise review focuses on the effects of pulmonary hypertension on the kidneys, including, the patho-physiological effects of pulmonary hypertension on acute kidney injury, progression of CKD, effects on kidney transplant outcomes, progression of kidney disease in situations such as post LVAD implantation and novel diagnostic indices. We believe a review of this nature will fill in an important gap in understanding the prognostic implication of pulmonary hypertension on renal disease, and help highlight this important component of the cardio-reno-pulmonary axis.

Minimally invasive transtracheal cardiac plexus block for sympathetic neuromodulation

BACKGROUND

Bilateral thoracoscopic stellectomy has antiarrhythmic effects, but the procedure is invasive with associated morbidity. Sympathetic nerves from both stellate ganglia form the deep cardiac plexus (CP) in the aortopulmonary window, anterior to the trachea.

OBJECTIVE

The purpose of this study was to demonstrate a novel and minimally invasive transtracheal approach to block the CP in porcine models.

METHODS

In 12 Yorkshire pigs, right (RSG) and left (LSG) stellate ganglia were electrically stimulated and sympathetic baseline response recorded (hemodynamic parameters and T-wave pattern). Aortopulmonary window was accessed transtracheally with endobronchial ultrasound guidance, and local stimulation of CP confirmed the location. Injection of 1% lidocaine (n = 10) or saline solution (n = 2) was performed, and RSG and LSG responses were re-evaluated and compared with baseline.

RESULTS

Transtracheal lidocaine injection into the CP successfully blocked bilateral sympathetic induced changes (%) in T-wave amplitude (282.8% ± 152.2% vs 20.1% ± 16.5%; P <.001 [LSG]; 338.9% ± 189.8% vs 28% ± 18.3%; P <.001 [RSG]), Tp-Te interval (87.9% ± 37.2% vs 6.9% ± 6.7%; P <.001 [LSG]; 32.6% ± 27.4% vs 6.9% ± 4.7%; P <.035 [RSG]), and left ventricular dP/dT_max (148.3% ± 108.5% vs 16.5% ± 13.4%; P <.001 [LSG]; 243.1% ± 105.2% vs 19.0% ± 12.4%; P <.001 [RSG]). RSG-induced elevations of systemic, left ventricular, and pulmonary arterial pressures were blocked by lidocaine injection into CP (P <.005 for all comparisons). Stellate ganglia response was not affected in sham studies. No complications were observed during the procedures.

CONCLUSION

Minimally invasive transtracheal injection of lidocaine into the CP blocked the sympathetic response of either RSG and LSG. Transtracheal assessment of CP may allow for minimally invasive and selective ablation of cardiac innervation, extending the cardiac sympathectomy denervation benefits to those not suitable for surgery.

Kidney dysfunction in patients with pulmonary arterial hypertension

Pulmonary arterial hypertension (PH) and chronic kidney disease (CKD) both profoundly impact patient outcomes, whether as primary disease states or as co-morbid conditions. PH is a common co-morbidity in CKD and vice versa. A growing body of literature describes the epidemiology of PH secondary to chronic kidney disease and end-stage renal disease (ESRD) (WHO group 5 PH). But, there are only limited data on the epidemiology of kidney disease in group 1 PH (pulmonary arterial hypertension [PAH]). The purpose of this review is to summarize the current data on epidemiology and discuss potential disease mechanisms and management implications of kidney dysfunction in PAH. Kidney dysfunction, determined by serum creatinine or estimated glomerular filtration rate, is a frequent co-morbidity in PAH and impaired kidney function is a strong and independent predictor of mortality. Potential mechanisms of PAH affecting the kidneys are increased venous congestion, decreased cardiac output, and neurohormonal activation. On a molecular level, increased TGF-β signaling and increased levels of circulating cytokines could have the potential to worsen kidney function. Nephrotoxicity does not seem to be a common side effect of PAH-targeted therapy. Treatment implications for kidney disease in PAH include glycemic control, lifestyle modification, and potentially Renin-Angiotensin-Aldosterone System (RAAS) blockade.