Comparing the Efficacy of Tadalafil Versus Placebo on Pulmonary Artery Systolic Pressure and Right Ventricular Function in Patients with Beta-Thalassaemia Intermedia

Macitentan Administration for Pulmonary Hypertension Due to β-thalassemia with Multiple Organ Failure

A 51-year-old Thai woman diagnosed with β-thalassemia underwent regular blood transfusion and iron-chelating therapy. However, after voluntarily discontinuing treatment, the patient developed progressive dyspnea and was diagnosed with pulmonary hypertension following right heart catheterization. Despite resuming blood transfusions, her condition did not improve. Because the patient had a history of multiple organ failure, curative treatment for β-thalassemia was not feasible, and macitentan was administered. Despite experiencing hypotension as an adverse event, her condition remained stable during macitentan treatment. Thus, macitentan may be well tolerated in patients with pulmonary hypertension caused by β-thalassemia with multiple organ dysfunction.

The accuracy and influencing factors of Doppler echocardiography in estimating pulmonary artery systolic pressure: comparison with right heart catheterization: a retrospective cross-sectional study

Background

Noninvasive assessment of pulmonary artery systolic pressure by Doppler echocardiography (sPAP_ECHO) has been widely adopted to screen for pulmonary hypertension (PH), but there is still a high proportion of overestimation or underestimation of sPAP_ECHO. We therefore aimed to explore the accuracy and influencing factors of sPAP_ECHO with right heart catheterization (RHC) as a reference.

Methods

A total of 218 highly suspected PH patients who underwent RHC and echocardiography within 7 days were included. The correlation and consistency between tricuspid regurgitation (TR)-related methods and RHC results were tested by Pearson and Bland–Altman methods. TR-related methods included peak velocity of TR (TR Vmax), TR pressure gradient (TR-PG), TR mean pressure gradient (TR-mPG), estimated mean pulmonary artery pressure (mPAP_ECHO), and sPAP_ECHO. With mPAP ≥ 25 mm Hg measured by RHC as the standard diagnostic criterion of PH, the ROC curve was used to compare the diagnostic efficacy of sPAP_ECHO with other TR-derived parameters. The ratio (sPAP_ECHO–sPAP_RHC)/sPAP_RHC was calculated and divided into three groups as follows: patients with an estimation error between − 10% and + 10% were defined as the accurate group; patients with an estimated difference greater than + 10% were classified as the overestimated group; and patients with an estimation error greater than − 10% were classified as the underestimated group. The influencing factors of sPAP_ECHO were analyzed by ordinal regression analysis.

Results

sPAP_ECHO had the highest correlation coefficient (r = 0.781, P < 0.001), best diagnostic efficiency (AUC = 0.98), and lowest bias (mean bias = 0.07 mm Hg; 95% limits of agreement, − 32.08 to + 32.22 mm Hg) compared with other TR-related methods. Ordinal regression analysis showed that TR signal quality, sPAP_RHC level, and pulmonary artery wedge pressure (PAWP) affected the accuracy of sPAP_ECHO (P < 0.05). Relative to the good signal quality, the OR values of medium and poor signal quality were 0.26 (95% CI: 0.14, 0.48) and 0.23 (95% CI: 0.07, 0.73), respectively. Compared with high sPAP_RHC level, the OR values of low and medium sPAP_RHC levels were 21.56 (95% CI: 9.57, 48.55) and 5.13 (95% CI: 2.55, 10.32), respectively. The OR value of PAWP was 0.94 (95% CI: 0.89, 0.99). TR severity and right ventricular systolic function had no significant effect on the accuracy of sPAP_ECHO.

Conclusions

In this study, we found that all TR-related methods, including sPAP_ECHO, had comparable and good efficiency in PH screening. To make the assessment of sPAP_ECHO more accurate, attention should be paid to TR signal quality, sPAP_RHC level, and PAWP.

The wide spectrum of β-thalassaemia intermedia-induced pulmonary hypertension: two case reports on the possible role of specific pulmonary arterial hypertension therapy

Pulmonary hypertension (PH) development remains a significant cardiovascular complication of haemoglobinopathies, severely affecting the morbidity and mortality of such patients. According to the 5th World Symposium on PH, PH related with chronic haemolytic anaemias is classified in group 5, mainly due to the multifactorial pathophysiology of PH in this patient population. There are no clear guidelines regarding the management of PH in patients with haemoglobinopathies; the use of specific pulmonary arterial hypertension (PAH) therapy in patients with β-thalassaemia and PH is based on data derived from other forms of PH, expert opinion and small series or case reports. The existing knowledge on the use of specific-PAH therapy in β-thalassaemia patients with PH is limited, and in most cases the diagnosis of PH is based on echocardiographic findings only. We herein report two patients with β-thalassaemia intermedia (TI) and PH, who got same initial approach but different outcome, to highlight the wide spectrum of TI-induced PH, the importance of optimal disease-directed therapy and the possible role of specific-PAH therapy. We also emphasize the central role of right heart catheterization in the diagnosis and follow-up of PH, since this information does facilitate the suitable use or withdrawal of specific PAH drugs in these patients.

Challenges and Special Aspects of Pulmonary Hypertension in Middle- to Low-Income Regions: JACC State-of-the-Art Review

Challenges and special aspects related to the management and prognosis of pulmonary hypertension (PH) in middle- to low-income regions (MLIRs) range from late presentation to comorbidities, lack of resources and expertise, cost, and rare options of lung transplantation. Expert consensus recommendations addressing the specific challenges for prevention and therapy of PH in MLIRs with limited resources have been lacking. To date, 6 MLIR-PH registries containing mostly adult patients with PH exist. Importantly, the global prevalence of PH is much higher in MLIRs compared with high-income regions: group 2 PH (left heart disease), pulmonary arterial hypertension associated with unrepaired congenital heart disease, human immunodeficiency virus, or schistosomiasis are highly prevalent. This consensus statement provides selective, tailored modifications to the current PH guidelines to address the specific challenges faced in MLIRs, resulting in the first pragmatic and cost-effective consensus recommendations for PH care providers, patients, and their families.

Clinical efficacy of tadalafil compared to sildenafil in treatment of moderate to severe canine pulmonary hypertension: a pilot study

INTRODUCTION

Canine pulmonary hypertension (PH) is associated with high morbidity and mortality. Tadalafil, a phosphodiesterase-5 inhibitor used commonly in humans with PH, has not been evaluated in a clinical trial in dogs with naturally occurring PH. Our objectives were to compare the efficacy of tadalafil and sildenafil on PH assessed by peak tricuspid regurgitant flow velocity, estimated systolic pulmonary arterial pressure gradient, voluntary activity, quality of life, and safety profiles in dogs with moderate to severe PH.

ANIMALS

Twenty-three dogs with echocardiographic evidence of moderate to severe PH were enrolled.

METHODS

A prospective short-term, randomized, double-blinded pilot study was carried out. Dogs with PH were randomly allocated to receive sildenafil or tadalafil for 2 weeks and assessed via echocardiography, activity monitors, and owner-reported outcomes.

RESULTS

Collectively, phosphodiesterase-5 inhibition significantly decreased (improved) quality of life scores (p = 0.003) and visual analog score (p = 0.024) without significant between-treatment difference of these variables. Phosphodiesterase-5 inhibition did not significantly affect peak tricuspid regurgitant flow velocity (p = 0.056) or voluntary activity (p = 0.27). A total of 33% (7/21) of dogs experienced at least one adverse event during the study (tadalafil, n = 5; sildenafil, n = 2) with no significant difference between treatment type and incidence of adverse events (p = 0.36).

DISCUSSION

In this pilot study, phosphodiesterase-5 inhibition led to apparent improvement in quality of life scores without documenting superiority of tadalafil over sildenafil.

CONCLUSION

Tadalafil at a dose of 2 mg/kg once daily appears to be a viable alternative to sildenafil in dogs with moderate to severe PH.

Phosphodiesterase 5 inhibitors for pulmonary hypertension

BACKGROUND

Pulmonary hypertension (PH) comprises a group of complex and heterogenous conditions, characterised by elevated pulmonary artery pressure, and which left untreated leads to right-heart failure and death. PH includes World Health Organisation (WHO) Group 1 pulmonary arterial hypertension (PAH); Group 2 consists of PH due to left-heart disease (PH-LHD); Group 3 comprises PH as a result of lung diseases or hypoxia, or both; Group 4 includes PH due to chronic thromboembolic occlusion of pulmonary vasculature (CTEPH), and Group 5 consists of cases of PH due to unclear and/or multifactorial mechanisms including haematological, systemic, or metabolic disorders. Phosphodiesterase type 5 (PDE5) inhibitors increase vasodilation and inhibit proliferation.

OBJECTIVES

To determine the efficacy of PDE5 inhibitors for pulmonary hypertension in adults and children.

SEARCH METHODS

We performed searches of CENTRAL, MEDLINE, Embase, CINAHL, and Web of Science up to 26 September 2018. We handsearched review articles, clinical trial registries, and reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised controlled trials that compared any PDE5 inhibitor versus placebo, or any other PAH disease-specific therapies, for at least 12 weeks. We include separate analyses for each PH group.

DATA COLLECTION AND ANALYSIS

We imported studies identified by the search into a reference manager database. We retrieved the full-text versions of relevant studies, and two review authors independently extracted data. Primary outcomes were: change in WHO functional class, six-minute walk distance (6MWD), and mortality. Secondary outcomes were haemodynamic parameters, quality of life/health status, dyspnoea, clinical worsening (hospitalisation/intervention), and adverse events. When appropriate, we performed meta-analyses and subgroup analyses by severity of lung function, connective tissue disease diagnosis, and radiological pattern of fibrosis. We assessed the evidence using the GRADE approach and created 'Summary of findings' tables.

MAIN RESULTS

We included 36 studies with 2999 participants (with pulmonary hypertension from all causes) in the final review. Trials were conducted for 14 weeks on average, with some as long as 12 months. Two trials specifically included children.Nineteen trials included group 1 PAH participants. PAH participants treated with PDE5 inhibitors were more likely to improve their WHO functional class (odds ratio (OR) 8.59, 95% confidence interval (CI) 3.95 to 18.72; 4 trials, 282 participants), to walk 48 metres further in 6MWD (95% CI 40 to 56; 8 trials, 880 participants), and were 22% less likely to die over a mean duration of 14 weeks (95% CI 0.07 to 0.68; 8 trials, 1119 participants) compared to placebo (high-certainty evidence). The number needed to treat to prevent one additional death was 32 participants. There was an increased risk of adverse events with PDE5 inhibitors, especially headache (OR 1.97, 95% CI 1.33 to 2.92; 5 trials, 848 participants), gastrointestinal upset (OR 1.63, 95% CI 1.07 to 2.48; 5 trials, 848 participants), flushing (OR 4.12, 95% CI 1.83 to 9.26; 3 trials, 748 participants), and muscle aches and joint pains (OR 2.52, 95% CI 1.59 to 3.99; 4 trials, 792 participants).Data comparing PDE5 inhibitors to placebo whilst on other PAH-specific therapy were limited by the small number of included trials. Those PAH participants on PDE5 inhibitors plus combination therapy walked 19.66 metres further in six minutes (95% CI 9 to 30; 4 trials, 509 participants) compared to placebo (moderate-certainty evidence). There were limited trials comparing PDE5 inhibitors directly with other PAH-specific therapy (endothelin receptor antagonists (ERAs)). Those on PDE5 inhibitors walked 49 metres further than on ERAs (95% CI 4 to 95; 2 trials, 36 participants) (low-certainty evidence). There was no evidence of a difference in WHO functional class or mortality across both treatments.Five trials compared PDE5 inhibitors to placebo in PH secondary to left-heart disease (PH-LHD). The quality of data were low due to imprecision and inconsistency across trials. In those with PH-LHD there were reduced odds of an improvement in WHO functional class using PDE5 inhibitors compared to placebo (OR 0.53, 95% CI 0.32 to 0.87; 3 trials, 285 participants), and those using PDE5 inhibitors walked 34 metres further compared to placebo (95% CI 23 to 46; 3 trials, 284 participants). There was no evidence of a difference in mortality. Five trials compared PDE5 inhibitors to placebo in PH secondary to lung disease/hypoxia, mostly in COPD. Data were of low quality due to imprecision of effect and inconsistency across trials. There was a small improvement of 27 metres in 6MWD using PDE5 inhibitors compared to placebo in those with PH due to lung disease. There was no evidence of worsening hypoxia using PDE5 inhibitors, although data were limited. Three studies compared PDE5 inhibitors to placebo or other PAH-specific therapy in chronic thromboembolic disease. There was no significant difference in any outcomes. Data quality was low due to imprecision of effect and heterogeneity across trials.

AUTHORS' CONCLUSIONS

PDE5 inhibitors appear to have clear beneficial effects in group 1 PAH. Sildenafil, tadalafil and vardenafil are all efficacious in this clinical setting, and clinicians should consider the side-effect profile for each individual when choosing which PDE5 inhibitor to prescribe.While there appears to be some benefit for the use of PDE5 inhibitors in PH-left-heart disease, it is not clear based on the mostly small, short-term studies, which type of left-heart disease stands to benefit. These data suggest possible harm in valvular heart disease. There is no clear benefit for PDE5 inhibitors in pulmonary hypertension secondary to lung disease or chronic thromboembolic disease. Further research is required into the mechanisms of pulmonary hypertension secondary to left-heart disease, and cautious consideration of which subset of these patients may benefit from PDE5 inhibitors. Future trials in PH-LHD should be sufficiently powered, with long-term follow-up, and should include invasive haemodynamic data, WHO functional class, six-minute walk distance, and clinical worsening.