Five year risk assessment and treatment patterns in patients with chronic thromboembolic pulmonary hypertension.

AIMS: Repeated risk assessments and treatment patterns over long time are sparsely studied in chronic thromboembolic pulmonary hypertension (CTEPH); thus, we aimed to investigate changes in risk status and treatment patterns in incident patients with CTEPH over a 5 year period. METHODS AND RESULTS: Descriptive and explorative study including 311 patients diagnosed with CTEPH 2008-2019 from the Swedish pulmonary hypertension registry, stratified by pulmonary endarterectomy surgery (PEA). Risk and PH-specific treatment were assessed in surgically treated (PEA) and medically treated (non-PEA) patients at diagnosis and up to 5 years follow-up. Data are presented as median (Q1-Q3), count or per cent. Prior to surgery, 63% in the PEA-group [n = 98, age 64 (51-71) years, 37% female] used PH-specific treatment and 20, 69, and 10% were assessed as low, intermediate or high risk, respectively. After 1 year post-surgery, 34% had no PH-specific treatment or follow-up visit registered despite being alive at 5 years. Of patients with a 5 year visit (n = 23), 46% were at low and 54% at intermediate risk, while 91% used PH-specific treatment. In the non-PEA group [n = 213, age 72 (65-77) years, 56% female], 28% were assessed as low, 61% as intermediate and 11% as high risk. All patients at high risk versus 50% at low risk used PH-specific treatment. The 1 year mortality was 6%, while the risk was unchanged in 57% of the patients; 14% improved from intermediate to low risk, and 1% from high to low risk. At 5 years, 27% had a registered visit and 28% had died. Of patients with a 5 year visit (n = 58), 38% were at low, 59% at intermediate and 1% at high risk, and 86% used PH-specific treatment. CONCLUSIONS: Risk status assessed pre-surgery did not foresee long-term post-PEA risk and pre-surgery PH-specific treatment did not foresee long-term post-PEA treatment. Medically treated CTEPH patients tend to remain at the same risk over time, suggesting a need for improved treatment strategies in this group.

Risk stratification in chronic thromboembolic pulmonary hypertension predicts survival.

OBJECTIVES: To investigate if the pulmonary arterial hypertension (PAH) risk assessment tool presented in the 2015 ESC/ERS guidelines is valid for patients with chronic thromboembolic pulmonary hypertension (CTEPH) when taking pulmonary endarterectomy (PEA) into account. Design. Incident CTEPH patients registered in the Swedish PAH Registry (SPAHR) between 2008 and 2016 were included. Risk stratification performed at baseline and follow-up classified the patients as low-, intermediate-, or high-risk using the proposed ESC/ERS risk algorithm. Results. There were 250 CTEPH patients with median age (interquartile range) 70 (14) years, and 53% were male. Thirty-two percent underwent PEA within 5 (6) months. In a multivariable model adjusting for age, sex, and pharmacological treatment, patients with intermediate-risk or high-risk profiles at baseline displayed an increased mortality risk (Hazard Ratio [95% confidence interval]: 1.64 [0.69-3.90] and 5.39 [2.13-13.59], respectively) compared to those with a low-risk profile, whereas PEA was associated with better survival (0.38 [0.18-0.82]). Similar impact of risk profile and PEA was seen at follow-up. Conclusion. The ESC/ERS risk assessment tool identifies CTEPH patients with reduced survival. Furthermore, PEA improves survival markedly independently of risk group and age. Take home message: The ESC/ERS risk stratification for PAH predicts survival also in CTEPH patients, even when taking PEA into account.

Adherence to disease-specific drug treatment among patients with pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) require lifelong treatment. The aim of the present study was to investigate adherence to disease-specific treatment in patients with PAH or CTEPH. METHODS: The study comprised an adult population diagnosed with PAH (n=384) or CTEPH (n=187) alive in 2016-2017. The study utilised three registries: the Swedish PAH registry, the National Board of Health and Welfare, and Statistics Sweden. Withdrawals from pharmacies of disease-specific oral treatments were studied. Adherence was assessed as: 1) Number of days covered defined as the difference between the total number of daily dosages dispensed and the total number of days covered; and 2) Manual assessment by two persons that independently reviewed each patient's prescription fill history to detect anomalies or patterns of deteriorating or improving adherence over time. RESULTS: The mean age was 61±16 years, 61% were female and mean time since diagnosis was 4.6 years. Adherence was 62% using the Number of days covered method and 66% by the Manual assessment method. Drug-specific adherence varied from 91% for riociguat to 60% for sildenafil. Good adherence was associated with shorter time since diagnosis in patients with PAH and with lower number of concomitant other chronic treatments in patients with CTEPH. Age, sex, socioeconomic status or number of pulmonary hypertension (PH) treatments were not associated with adherence. CONCLUSION: Adherence to oral disease-specific treatment was 60-66% and associated with time since diagnosis and number of concomitant chronic treatments. Sex, age or socioeconomic factors did not affect adherence.

Alterations in plasma L-arginine and methylarginines in heart failure and after heart transplantation.

OBJECTIVE: Endothelial function, including the nitric oxide (NO)-pathway, has previously been extensively investigated in heart failure (HF). In contrast, studies are lacking on the NO pathway after heart transplantation (HT). We therefore investigated substances in the NO pathway prior to and after HT in relation to hemodynamic parameters. DESIGN: 12 patients (median age 50.0 yrs, 2 females), heart transplanted between June 2012 and February 2014, evaluated at our hemodynamic lab, at rest, prior to HT, as well as four weeks and six months after HT were included. All patients had normal left ventricular function post-operatively and none had post-operative pulmonary hypertension or acute cellular rejection requiring therapy at the evaluations. Plasma concentrations of ADMA, SDMA, L-Arginine, L-Ornithine and L-Citrulline were analyzed at each evaluation. RESULTS: In comparison to controls, the plasma L-Arginine concentration was low and ADMA high in HF patients, resulting in low L-Arginine/ADMA-ratio pre-HT. Already four weeks after HT L-Arginine was normalized whereas ADMA remained high. Consequently the L-Arginine/ADMA-ratio improved, but did not normalize. The biomarkers remained unchanged at the six-month evaluation and the L-Arginine/ADMA-ratio correlated inversely to pulmonary vascular resistance (PVR) six months post-HT. CONCLUSIONS: Plasma L-Arginine concentrations normalize after HT. However, as ADMA is unchanged, the L-Arginine/ADMA-ratio remained low and correlated inversely to PVR. Together these findings suggest that (i) the L-Arginine/ADMA-ratio may be an indicator of pulmonary vascular tone after HT, and that (ii) NO-dependent endothelial function is partly restored after HT. Considering the good postoperative outcome, the biomarker levels may be considered "normal" after HT.

Plasma L-arginine levels distinguish pulmonary arterial hypertension from left ventricular systolic dysfunction.

Pulmonary arterial hypertension (PAH) is a life-threatening condition, characterized by an imbalance of vasoactive substances and remodeling of pulmonary vasculature. Nitric oxide, formed from L-arginine, is essential for homeostasis and smooth muscle cell relaxation in PAH. Our aim was to compare plasma concentrations of L-arginine, asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) in PAH compared to left ventricular systolic dysfunction (LVSD) and healthy subjects. This was an observational, multicenter study comparing 21 patients with PAH to 14 patients with LVSD and 27 healthy subjects. Physical examinations were obtained and blood samples were collected. Plasma levels of ADMA, SDMA, L-arginine, L-ornithine, and L-citrulline were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Plasma levels of ADMA and SDMA were higher, whereas L-arginine and L-arginine/ADMA ratio were lower in PAH patients compared to healthy subjects (p < 0.001). Patients with PAH also had lower levels of L-arginine than patients with LVSD (p < 0.05). L-Arginine correlated to 6 min walking distance (6MWD) (r s = 0.58, p = 0.006) and L-arginine/ADMA correlated to WHO functional class (r s = -0.46, p = 0.043) in PAH. In conclusion, L-arginine levels were significantly lower in treatment naïve PAH patients compared to patients with LVSD. Furthermore, L-arginine correlated with 6MWD in PAH. L-arginine may provide useful information in differentiating PAH from LVSD.

Acute vasodilator response to vardenafil and clinical outcome in patients with pulmonary hypertension.

PURPOSE: Acute vasodilator testing is recommended in patients with pulmonary arterial hypertension to identify individuals who may benefit from long-term treatment with oral calcium channel blockers. The aim of this study was to investigate the use of vardenafil in acute vasoreactivity testing compared to adenosine. METHODS: A total of 20 patients eligible for right heart catheterisation were enrolled. Acute vasoreactivity testing was carried out with intravenous (iv) adenosine (n = 18) followed by oral vardenafil (n = 20). Haemodynamic responses were recorded at baseline and after 60 min (vardenafil). Responders were defined according to consensus guideline criteria. RESULTS: Both vardenafil and adenosine significantly decreased mean pulmonary arterial pressure (mPAP, p < 0.001 and p = 0.026, respectively) and pulmonary vascular resistance (p < 0.001 and p > 0.001, respectively), and significantly increased cardiac output (p = 0.001 and p = 0.005, respectively). Vardenafil reduced mPAP more than adenosine (p = 0.044), while adenosine resulted in higher responses of cardiac index (p = 0.009) and pulmonary arterial oxygen saturation (p = 0.042). Acute adverse reactions were common with adenosine, while no side effects were observed after a single oral dose vardenafil. Vardenafil identified five responders (out of 20), while adenosine identified three responders (out of 18). During a 7-year follow-up, vardenafil responders had significantly lower NT-proBNP levels compared to non-responders. CONCLUSIONS: Vardenafil may be safely used for acute vasoreactivity testing in patients with PH. A single oral dose of vardenafil is better tolerated than iv adenosine and may identify additional responders who could benefit from long-term vasodilator treatment.

Changes in plasma levels of asymmetric dimethylarginine, symmetric dimethylarginine, and arginine after a single dose of vardenafil in patients with pulmonary hypertension.

OBJECTIVE: We investigated whether vardenafil, a phosphodiesterase-5 inhibitor, alters plasma levels of asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and arginine. PATIENTS AND METHODS: ADMA, SDMA, and arginine were measured (0-540 min) in 12 patients with pulmonary hypertension after a single oral dose of vardenafil. Invasive hemodynamic data were collected at baseline and after 60 min. RESULTS: A reduction in ADMA was observed at 30 and 45 min with a median change of -11.1% (P=0.021) and -12.5% (P=0.002). SDMA decreased with a median -5.3% change (P=0.032) at 45 min. An increase in arginine, median 40.3% (P=0.002), 45.0% (P=0.010), and 77.1% (P=0.008) was observed at 120, 300, and 540 min respectively. An increase in the arginine/ADMA ratio, median 11.7% (P=0.012), 32.5% (P=0.003), 26.5% (P=0.021), 33% (P=0.007), 48.5% (P=0.007), and 63.1% (P=0.008) was observed at 15, 45, 60, 120, 300, and 540 min respectively. There was a positive correlation between vardenafil exposure and the percent change in the arginine/ADMA ratio from baseline to 540 min (r=0.80; P=0.01). A correlation between baseline mean right atrial pressure (mRAP) and baseline ADMA (r=0.65; P=0.023), and baseline SDMA (r=0.61; P=0.035) was observed. A correlation between the baseline arginine/ADMA ratio and baseline cardiac output (CO) (r=0.59; P=0.045) and baseline cardiac index (CI) (r=0.61; P=0.036) was observed. Baseline arginine/ADMA ratio correlated with baseline mRAP (r=-0.79; P=0.002). A correlation between change (0-60 min) in CI and change in arginine (r=0.77; P=0.003) as well as change in the arginine/ADMA ratio (r=0.61; P=0.037) was observed. CONCLUSIONS: Vardenafil induced changes in ADMA, SDMA, arginine, and the arginine/ADMA ratio in patients with PH. An increase in arginine and the arginine/ADMA ratio was associated with improvement in CI.

Acute haemodynamic response in relation to plasma vardenafil concentrations in patients with pulmonary hypertension.

AIMS: To evaluate the acute haemodynamic effects of a single oral dose of vardenafil and to study the drug concentration in relation to haemodynamic effects in patients with pulmonary hypertension (PH). METHODS: Sixteen patients with PH (aged 29-85\ years), received one single oral dose of vardenafil (5, 10 or 20 mg). The haemodynamic effect was assessed over a 60 min period. Vardenafil plasma concentrations were measured after 15, 30, 45 and 60 min using liquid chromatography-tandem mass spectrometry. RESULTS: At 60 min a reduction in mPAP with a median % decrease of -20.3% (range -48.3 to 3.0; P < 0.001) and an increase in cardiac output and the cardiac index with a median % change of 10.6% (range -25.0 to 88.1; P = 0.015) and 12.1% (range -24.0 to 94.4; P = 0.01) respectively was observed. The pulmonary vascular resistance (PVR) was reduced with a median % decrease of -28.9% (range -61.5 to -5.9; P < 0.001), and pulmonary selectivity was reflected by a median percent reduction of -16.9% (range -49.0 to 16.5; P = 0.002; n = 14) in the PVR/systemic vascular resistance ratio. There was a correlation between the plasma concentrations of vardenafil and change in mPAP (r = -0.579, P = 0.019) and between vardenafil concentrations and change in PVR (r = -0.662, P = 0.005). CONCLUSIONS: Vardenafil causes rapid changes in cardiopulmonary haemodynamics and there is a correlation between plasma vardenafil drug concentration and the acute changes in mPAP as well as PVR in patients with PH.

Cyclosporin A stimulates apical Na+/H+ exchange in LLC-PK1/PKE20 proximal tubular cells.

Cyclosporin A (CyA) causes renal Na(+) retention which may lead to arterial hypertension. The apical Na(+)/H(+) exchanger (NHE3) is responsible for bulk proximal tubular Na(+) reabsorption. The aim of this study was to investigate the effects of CyA on the NHE3 of polarized proximal tubular cells to evaluate cellular mechanisms of CyA-associated arterial hypertension. The change of the intracellular pH (Delta-[pH](i)/min) was determined as a measure of the activity of the NHE in LLC-PK(1)/PKE(20) cells using 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF). The NHE activity was identified as the apical NHE3 since it could be inhibited by the inhibitor S3226, but not by inhibitors of the basolateral isoform (NHE1) amiloride or HOE 694. CyA stimulated the NHE3 activity dose dependently. The mean increase stimulated by relevant CyA concentrations was 61+/-11%. A 24-h application of CyA also stimulated an increase of NHE3 activity which did not seem to be mediated by an increase of NHE3 RNA expression. The less immunosuppressive derivatives cyclosporin H and cyclosporin G caused NHE3 activation as well. Carbachol and ATP, which both induce a Ca(2+) release from internal Ca(2+) stores, also increased the NHE3 activity. The Ca(2+) chelator 1,2-bis-(2-aminophenoxy)-ethane-N,N,-N',N'-tetraacetic acid tetraacetoxymethyl ester (BAPTA-AM) abolished the CyA-associated NHE3 stimulation, whereas low extracellular Ca(2+) had no effect. CyA-associated effects did not seem to be mediated via inhibition of protein kinase C (PKC). CyA had no additive effects on the angiotensin II-associated NHE3 stimulation. Concurrent application of losartan did not impair the CyA-induced NHE3 stimulation. In conclusion CyA stimulates the apical NHE3 in proximal tubular cells. This is mediated by Ca(2+) release from intracellular stores but is independent of the action of angiotensin II or PKC.