Pulmonary hypertension: a contraindication to the use of -adrenoceptor blocking agents

Cardiac Arrhythmias in Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension: Mechanistic Insights, Pathophysiology, and Outcomes

Arrhythmias are increasingly recognized as severe complications of precapillary pulmonary hypertension, encompassing pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). Despite their significant contribution to symptoms, morbidity, in-hospital mortality, and potentially sudden death in PAH/CTEPH, there remains a lack of comprehensive data on epidemiology, pathophysiology, and outcomes to inform the management of these patients. This review provides an overview of the latest evidence on this subject, spanning from the molecular mechanisms underlying arrhythmias in the hypertrophied or failing right heart to the clinical aspects of epidemiology, diagnosis, and treatment.

Medical Emergencies in Pulmonary Hypertension

The management of acute medical emergencies in patients with pulmonary hypertension (PH) can be challenging. Patients with preexisting PH can rapidly deteriorate due to right ventricular decompensation when faced with acute physiological challenges that would usually be considered low-risk scenarios. This review considers the assessment and management of acute medical emergencies in patients with PH, encompassing both pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH), acknowledging these comprise the more severe groups of PH. Management protocols are described in a systems-based approach. Respiratory emergencies include pulmonary embolism, airways disease, and pneumonia; cardiac emergencies including arrhythmia and chest pain with acute myocardial infarction are discussed, alongside PH-specific emergencies such as pulmonary artery dissection and extrinsic coronary artery compression by a dilated proximal pulmonary artery. Other emergencies including sepsis, severe gastroenteritis with dehydration, syncope, and liver failure are also considered. We propose management recommendations for medical emergencies based on available evidence, international guidelines, and expert consensus. We aim to provide advice to the specialist alongside the generalist, and emergency doctors, nurses, and acute physicians in nonspecialist centers. A multidisciplinary team approach is essential in the management of patients with PH, and communication with local and specialist PH centers is paramount. Close hemodynamic monitoring during medical emergencies in patients with preexisting PH is vital, with early referral to critical care recommended given the frequent deterioration and high mortality in this setting.

Portopulmonary Hypertension

PoPH is a well-recognized complication of portal hypertension with or without cirrhosis and is classified as a subset of PAH. Identification of PoPH is crucial as it has a major impact on prognosis and liver transplant candidacy. Echocardiogram is the initial screening tool of choice and the patient should proceed to RHC for confirmation. PAH-directed therapy is the treatment of choice, allowing the patient to achieve a hemodynamic threshold to undergo a liver transplant safely.

Atrial Fibrillation and Ventricular Tachyarrhythmias: Advancements for Better Outcomes

Cardiac arrhythmias are associated with several cardiac diseases and are prevalent in people with or without structural and valvular abnormalities. Ventricular arrhythmias (VA) can be life threating and their onset require immediate medical attention. Similarly, atrial fibrillation and flutter lead to stroke, heart failure and even death. Optimal treatment of VA is variable and depends on the medical condition associated with the rhythm disorder (which includes reversible causes such as myocardial ischemia or pro-arrhythmic drugs). While an implanted cardioverter defibrillator is often indicated in secondary prevention of VA. This review highlights the newest advancements in these techniques and management of ventricular and atrial tachyarrhythmias, along with pharmacological therapy.

Perioperative Management of Pulmonary Hypertension. a Review

Pulmonary hypertension is a rare and progressive pathology defined by abnormally high pulmonary artery pressure mediated by a diverse range of aetiologies. It affects up to twenty-six individuals per one million patients currently living in the United Kingdom (UK), with a median life expectancy of 2.8 years in idiopathic pulmonary hypertension. The diagnosis of pulmonary hypertension is often delayed due to the presentation of non-specific symptoms, leading to a delay in referral to specialists services. The complexity of treatment necessitates a multidisciplinary approach, underpinned by a diverse disease aetiology from managing the underlying disease process to novel specialist treatments. This has led to the formation of dedicated specialist treatment centres within centralised UK cities. The article aimed to provide a concise overview of pulmonary hypertension's clinical perioperative management, including key definitions, epidemiology, pathophysiology, and risk stratification.

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 for pulmonary arterial hypertension

Pulmonary arterial hypertension remains a progressive, life-limiting disease despite optimal medical therapy. Pulmonary artery denervation has arisen as a novel intervention in the treatment of pulmonary arterial hypertension, and other forms of pulmonary hypertension, with the aim of reducing the sympathetic activity of the pulmonary circulation. Pre-clinical studies and initial clinical trials have demonstrated that the technique can be performed safely with some positive effects on clinical, haemodynamic and echocardiographic markers of disease. The scope of the technique in current practice remains limited given the absence of well-designed, large-scale, international randomised controlled clinical trials. This review provides an overview of this exciting new treatment modality, including pathophysiology, technical innovations and recent trial results.

Right heart failure in pulmonary hypertension: Diagnosis and new perspectives on vascular and direct right ventricular treatment

Adaptation of right ventricular (RV) function to increased afterload-known as RV-arterial coupling-is a key determinant of prognosis in pulmonary hypertension. However, measurement of RV-arterial coupling is a complex, invasive process involving analysis of the RV pressure-volume relationship during preload reduction over multiple cardiac cycles. Simplified methods have therefore been proposed, including echocardiographic and cardiac MRI approaches. This review describes the available methods for assessment of RV function and RV-arterial coupling and the effects of pharmacotherapy on these variables. Overall, pharmacotherapies for pulmonary hypertension have shown beneficial effects on various measures of RV function, but it is often unclear if these are direct RV effects or indirect results of afterload reduction. Studies of the effects of pharmacotherapies on RV-arterial coupling are limited and mostly restricted to experimental models. Simplified methods to assess RV-arterial coupling should be validated and incorporated into routine clinical follow-up and future clinical trials. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.1/issuetoc.

Pathophysiology, incidence, management, and consequences of cardiac arrhythmia in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension

Arrhythmias are increasingly recognized as serious, end-stage complications of pre-capillary pulmonary hypertension, including pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). Although arrhythmias contribute to symptoms, morbidity, in-hospital mortality, and possibly sudden death in PAH/CTEPH, there remains a paucity of epidemiologic, pathophysiologic, and outcome data to guide management of these patients. This review summarizes the most current evidence on the topic: from the molecular mechanisms driving arrhythmia in the hypertrophied or failing right heart, to the clinical aspects of epidemiology, diagnosis, and management.

Endothelial Phenotype Evoked by Low Dose Carvedilol in Pulmonary Hypertension

Background: The therapeutic benefits of β-blockers are well established in left heart failure. The Pulmonary Arterial Hypertension Treatment with Carvedilol for Heart Failure [PAHTCH] study showed safety and possible benefit of carvedilol in pulmonary arterial hypertension (PAH) associated right heart failure over 6 months. This study aims at evaluating the short-term cardiovascular effects and early mechanistic biomarkers of carvedilol therapy.

Methods: Thirty patients with pulmonary hypertension (PH) received low dose carvedilol (3.125 mg twice daily) for 1 week prior to randomization to placebo, low-dose, or dose-escalating carvedilol therapy. Echocardiography was performed at baseline and 1 week. Exercise capacity was assessed by 6 min walk distance (6MWD). The L-arginine/nitric oxide pathway and other biological markers of endothelial function were measured.

Results: All participants tolerated 1 week of carvedilol without adverse effects. After 1 week of carvedilol, 6MWD and heart rate at peak exercise did not vary (both p > 0.1). Heart rate at rest and 1 min post walk dropped significantly (both p < 0.05) with a trend for increase in heart rate recovery (p = 0.08). Right ventricular systolic pressure (RVSP) decreased by an average of 13 mmHg (p = 0.002). Patients who had a decrease in RVSP of more than 10 mm Hg were defined as responders (n = 17), and those with a lesser drop as non-responders (n = 13). Responders had a significant drop in pulmonary vascular resistance (PVR) after 1 week of carvedilol (p = 0.004). In addition, responders had a greater decrease in heart rate at rest and 1 min post walk compared to non-responders (both p < 0.05). Responders had higher plasma arginine and global bioavailability of arginine at baseline compared to non-responders (p = 0.03 and p = 0.05, respectively). After 1 week of carvedilol, responders had greater increase in urinary nitrate (p = 0.04). Responders treated with carvedilol had a sustained drop in RVSP and PVR after 6 months of carvedilol with no change in cardiac output.

Conclusions: Low-dose carvedilol for 1 week can potentially identify a PH responder phenotype that may benefit from β-blockers that is associated with less endothelial dysfunction.

Clinical Trial Registration:http://www.clinicaltrials.gov. identifier: NCT01586156.

Neurohormonal modulation as therapeutic avenue for right ventricular dysfunction in pulmonary artery hypertension: till the dawn, waiting

Neuro-hormonal activation may lead to or be associated with pulmonary arterial hypertension (PAH) and right ventricular dysfunction. Notwithstanding whether it is the cause or the consequence of PAH-related right ventricle (RV) dysfunction neurohormonal activation contributes to significant morbidity and mortality in patients with PAH and the progression of RV dysfunction. Experimental data regarding the use of beta adrenergic blockade and renin-angiotensin aldosterone system modulation are encouraging. However, clinical studies have largely been negative or neutral; and, neuro-hormonal modulation is discouraged in patients with PAH related RV dysfunction for fear of systemic hypotension. Herein, we summarize the pathophysiological background that supports the potential role of neuro-hormonal modulation in the management of PAH related RV dysfunction; also present current clinical experience; and, discuss the need for controlled studies to move forward. Lastly, we review potential non- pharmacological modalities for neuro-hormonal modulations in PAH patients with RV dysfunction.

Beta1-adrenoceptor antagonist, metoprolol attenuates cardiac myocyte Ca2+ handling dysfunction in rats with pulmonary artery hypertension

Right heart failure is the major cause of death in Pulmonary Artery Hypertension (PAH) patients but is not a current, specific therapeutic target. Pre-clinical studies have shown that adrenoceptor blockade can improve cardiac function but the mechanisms of action within right ventricular (RV) myocytes are unknown. We tested whether the β1-adrenoceptor blocker metoprolol could improve RV myocyte function in an animal model of PAH, by attenuating adverse excitation-contraction coupling remodeling. PAH with RV failure was induced in rats by monocrotaline injection. When PAH was established, animals were given 10 mg/kg/day metoprolol (MCT + BB) or vehicle (MCT). The median time to the onset of heart failure signs was delayed from 23 days (MCT), to 31 days (MCT + BB). At 23 ± 1 days post-injection, MCT + BB showed improved in vivo cardiac function, measured by echocardiography. RV hypertrophy was reduced despite persistent elevated afterload. RV myocyte contractility during field stimulation was improved at higher pacing frequencies in MCT + BB. Preserved t-tubule structure, more uniform evoked Ca2+ release, increased SERCA2a expression and faster ventricular repolarization (measured in vivo by telemetry) may account for the improved contractile function. Sarcoplasmic reticulum Ca2+ overload was prevented in MCT + BB myocytes resulting in fewer spontaneous Ca2+ waves, with a lower pro-arrhythmic potential. Our novel finding of attenuation of defects in excitation contraction coupling by β1-adrenoceptor blockade with delays in the onset of HF, identifies the RV as a promising therapeutic target in PAH. Moreover, our data suggest existing therapies for left ventricular failure may also be beneficial in PAH induced RV failure.

Mechanisms of right heart disease in pulmonary hypertension (2017 Grover Conference Series)

Current dogma is that pathological hypertrophy of the right ventricle is a direct consequence of pulmonary vascular remodeling. However, progression of right ventricle dysfunction is not always lung-dependent. Increased afterload caused by pulmonary vascular remodeling initiates the right ventricle hypertrophy, but determinants leading to adaptive or maladaptive hypertrophy and failure remain unknown. Ischemia in a hypertrophic right ventricle may directly contribute to right heart failure. Rapidly enlarging cardiomyocytes switch from aerobic to anaerobic energy generation resulting in cell growth under relatively hypoxic conditions. Cardiac muscle reacts to an increased afterload by over-activation of the sympathetic system and uncoupling and downregulation of β-adrenergic receptors. Recent studies suggest that β blocker therapy in PH is safe, well tolerated, and preserves right ventricle function and cardiac output by reducing right ventricular glycolysis. Fibrosis, an evolutionary conserved process in host defense and wound healing, is dysregulated in maladaptive cardiac tissue contributing directly to right ventricle failure. Despite several mechanisms having been suggested in right heart disease, the causes of maladaptive cardiac remodeling remain unknown and require further research.

Autonomic nervous system involvement in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a chronic pulmonary vascular disease characterized by increased pulmonary vascular resistance (PVR) leading to right ventricular (RV) failure. Autonomic nervous system involvement in the pathogenesis of PAH has been demonstrated several years ago, however the extent of this involvement is not fully understood. PAH is associated with increased sympathetic nervous system (SNS) activation, decreased heart rate variability, and presence of cardiac arrhythmias. There is also evidence for increased renin-angiotensin-aldosterone system (RAAS) activation in PAH patients associated with clinical worsening. Reduction of neurohormonal activation could be an effective therapeutic strategy for PAH. Although therapies targeting adrenergic receptors or RAAS signaling pathways have been shown to reverse cardiac remodeling and improve outcomes in experimental pulmonary hypertension (PH)-models, the effectiveness and safety of such treatments in clinical settings have been uncertain. Recently, novel direct methods such as cervical ganglion block, pulmonary artery denervation (PADN), and renal denervation have been employed to attenuate SNS activation in PAH. In this review, we intend to summarize the multiple aspects of autonomic nervous system involvement in PAH and overview the different pharmacological and invasive strategies used to target autonomic nervous system for the treatment of PAH.

Pulmonary arterial hypertension treatment with carvedilol for heart failure: a randomized controlled trial

BACKGROUND

Right-sided heart failure is the leading cause of death in pulmonary arterial hypertension (PAH). Similar to left heart failure, sympathetic overactivation and β-adrenoreceptor (βAR) abnormalities are found in PAH. Based on successful therapy of left heart failure with β-blockade, the safety and benefits of the nonselective β-blocker/vasodilator carvedilol were evaluated in PAH.

METHODS

PAH Treatment with Carvedilol for Heart Failure (PAHTCH) is a single-center, double-blind, randomized, controlled trial. Following 1-week run-in, 30 participants were randomized to 1 of 3 arms for 24 weeks: placebo, low-fixed-dose, or dose-escalating carvedilol. Outcomes included clinical measures and mechanistic biomarkers.

RESULTS

Decreases in heart rate and blood pressure with carvedilol were well tolerated; heart rate correlated with carvedilol dose. Carvedilol-treated groups had no decrease in exercise capacity measured by 6-minute walk, but had lower heart rates at peak and after exercise, and faster heart rate recovery. Dose-escalating carvedilol was associated with reduction in right ventricular (RV) glycolytic rate and increase in βAR levels. There was no evidence of RV functional deterioration; rather, cardiac output was maintained.

CONCLUSIONS

Carvedilol is likely safe in PAH over 6 months of therapy and has clinical and mechanistic benefits associated with improved outcomes. The data provide support for longer and larger studies to establish guidelines for use of β-blockers in PAH.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01586156FUNDING. This project was supported by NIH R01HL115008 and R01HL60917 and in part by the National Center for Advancing Translational Sciences, UL1TR000439.

Use of β-Blockers in Pulmonary Hypertension

Contrasting with the major attention that left heart failure has received, right heart failure remains understudied both at the preclinical and clinical levels. However, right ventricle failure is a major predictor of outcomes in patients with precapillary pulmonary hypertension because of pulmonary arterial hypertension, and in patients with postcapillary pulmonary hypertension because of left heart disease. In pulmonary hypertension, the status of the right ventricle is one of the most important predictors of both morbidity and mortality. Paradoxically, there are currently no approved therapies targeting the right ventricle in pulmonary hypertension. By analogy with the key role of β-blockers in the management of left heart failure, some authors have proposed to use these agents to support the right ventricle function in pulmonary hypertension. In this review, we summarize the current knowledge on the use of β-blockers in pulmonary hypertension.

Bisoprolol in idiopathic pulmonary arterial hypertension: an explorative study

While beta-blockers are considered contraindicated in pulmonary arterial hypertension (PAH), the prognostic significance of sympathetic nervous system over-activity suggests a potential benefit of beta-blocker therapy. The aim of this randomised, placebo-controlled, crossover, single centre study was to determine the effects of bisoprolol on right ventricular ejection fraction (RVEF) in idiopathic PAH (iPAH) patients. Additional efficacy and safety parameters were explored.Patients with optimally treated, stable iPAH (New York Heart Association functional class II/III) were randomised to placebo or bisoprolol. Imaging and functional measurements were performed at baseline, crossover and end of study.18 iPAH patients were included, because inclusion faltered before enrolment of the targeted 25 patients. 17 patients completed 6 months of bisoprolol, 15 tolerated bisoprolol, one patient required intravenous diuretics. Bisoprolol was associated with a lower heart rate (17 beats per minute, p=0.0001) but RVEF remained unchanged. A drop in cardiac index (0.5 L·min(-1)·m(-2), p=0.015) was observed, along with a trend towards a decreased 6-min walking distance (6MWD).Although careful up-titration of bisoprolol was tolerated by most patients and resulted in a decreased heart rate, no benefit of bisoprolol in iPAH was demonstrated. Decreases in cardiac index and 6MWD suggest a deteriorated cardiac function. The results do not favour the use of bisoprolol in iPAH patients.

The adrenergic system in pulmonary arterial hypertension: bench to bedside (2013 Grover Conference series)

In heart failure with reduced left ventricular ejection fraction (HFrEF), adrenergic activation is a key compensatory mechanism that is a major contributor to progressive ventricular remodeling and worsening of heart failure. Targeting the increased adrenergic activation with β-adrenergic receptor blocking agents has led to the development of arguably the single most effective drug therapy for HFrEF. The pressure-overloaded and ultimately remodeled/failing right ventricle (RV) in pulmonary arterial hypertension (PAH) is also adrenergically activated, which raises the issue of whether an antiadrenergic strategy could be effectively employed in this setting. Anecdotal experience suggests that it will be challenging to administer an antiadrenergic treatment such as a β-blocking agent to patients with established moderate-severe PAH. However, the same types of data and commentary were prevalent early in the development of β-blockade for HFrEF treatment. In addition, in HFrEF approaches have been developed for delivering β-blocker therapy to patients who have extremely advanced heart failure, and these general principles could be applied to RV failure in PAH. This review examines the role played by adrenergic activation in the RV faced with PAH, contrasts PAH-RV remodeling with left ventricle remodeling in settings of sustained increases in afterload, and suggests a possible approach for safely delivering an antiadrenergic treatment to patients with RV dysfunction due to moderate-severe PAH.

Outcomes of β-blocker use in pulmonary arterial hypertension: a propensity-matched analysis

The utility and safety of β-blockers in pulmonary hypertension is controversial. Anecdotal reports suggest that β-blockers may be harmful in these patients. The aim of our study was to evaluate outcomes of β-blocker use in pulmonary hypertension.We reviewed patients from our pulmonary hypertension registry between 2000 and 2011. Patients who continued to use β-blockers were compared to those who never used β-blockers for all-cause mortality, time to clinical worsening events, defined as death, lung transplantation and hospitalisation due to pulmonary hypertension. We also evaluated the effect of β-blockers on 6-min walking distance and New York Heart Association (NYHA) functional class.133 patients used β-blockers and 375 patients never used β-blockers. Mean±sd age was 57±16 years and the median follow-up period was 78 months. Propensity-matched analysis showed that the adjusted odds ratio (95% CI) for mortality with β-blocker use was 1.13 (0.69-1.82) and for clinical worsening events was 0.96 (0.55-1.68). No significant difference was noted in probability of survival and time to clinical worsening events. Patients on β-blockers walked a shorter distance on follow-up 6 min walk test; follow-up NYHA class was similar between groups.Pulmonary hypertension patients receiving β-blockers had a similar survival and time to clinical worsening events compared to patients not receiving them. Functional outcomes were similar, although β-blocker use was associated with a tendency towards shorter walking distance.

Sympathetic nervous system activation and β-adrenoceptor blockade in right heart failure

Right heart failure may develop from pulmonary arterial hypertension or various forms of congenital heart disease. Right ventricular adaptation to the increased afterload is the most important prognostic factor in pulmonary hypertension and congenital heart disease, which share important pathophysiological mechanisms, despite having different aetiologies. There is substantial evidence of increased sympathetic nervous system activation in right heart failure related to both pulmonary hypertension and congenital heart disease. It is unknown to which degree this activation is an adaptive response, a maladaptive response, or if it mainly reflects disease progression. Several experimental studies and clinical trials have been conducted to answer these questions. Here, we review the existing knowledge on sympathetic nervous system activation and the effects of β-adrenoceptor blockade in experimental and clinical right heart failure. This review identifies important gaps in our understanding of the right ventricle and discusses the potential of β-blockers in the treatment of right heart failure.

β-Blocker Therapy Is Not Associated With Adverse Outcomes in Patients With Pulmonary Arterial Hypertension

Background—

The safety of β-blockers in patients with isolated right ventricular failure because of pulmonary arterial hypertension (PAH) is unclear.

Methods and Results—

We studied 564 PAH patients (total cohort) referred to our center from 1982 to 2013. Propensity score-matching was used to match pairs of PAH patients with and without β-blocker use (matched cohort). We compared all-cause mortality between the groups in the total cohort and the matched cohort using bootstrap validation, Kaplan–Meier, and Cox proportional hazard analyses. Seventy-one of the 564 patients in the total cohort were on β-blockers. They were older, had higher prevalence of comorbidities, and were more often on diuretics, digoxin, and angiotensin converting enzyme inhibitors. The severity of PAH and right ventricular failure was similar between those with and without β-blocker use. After propensity matching, 63 patients with β-blocker use were compared with 51 patients without β-blocker use. During a median follow-up time of 4.8 years, there were 339 (60%) deaths in the total cohort and 70 deaths (61%) in the matched cohort. There was no difference in absolute mortality between those with and without β-blockers ( P =0.71). β-Blocker use was not associated with increased all-cause mortality in the total cohort after adjusting for propensity score (adjusted hazard ratio, 1.0; 95% confidence interval, 0.7–1.5) and in the matched cohort (hazard ratio, 1.2; 95% confidence interval, 0.8–2.0).

Conclusions—

There was no statistically significant difference in long-term mortality between propensity score-matched pairs of PAH patients with and without β-blocker use. These findings need further validation in prospective clinical trials.

Novel therapeutic approaches to preserve the right ventricle

The right ventricle (RV) is increasingly recognized for its role in heart disease. In fact, RV function is a strong predictor of outcome in patients with cardiovascular disease. Although the focus in heart failure has been on the left ventricle (LV), recently the spotlight has been shifting to include the RV. The RV and LV have different embryological origins and respond differently to stressors and to therapies. Newer therapies targeting the RV have been investigated in an attempt to improve right-ventricular adaptation to cardiovascular diseases. In this review, we summarize the differences between the RV and LV and focus on novel therapies that target the RV.

A low resting heart rate at diagnosis predicts favourable long-term outcome in pulmonary arterial and chronic thromboembolic pulmonary hypertension. A prospective observational study

Background

A low resting heart rate (HR) is prognostically favourable in healthy individuals and in patients with left heart disease. In this study we investigated the impact of HR at diagnosis on long-term outcome in patients with differently classified precapillary pulmonary hypertension (pPH).

Methods

pPH patients diagnosed as pulmonary arterial (PAH) or inoperable chronic thromboembolic pulmonary hypertension (CTEPH) were registered and regularly followed at our centre Baseline characteristics and events defined as either death or lung transplantation were noted. The prognostic value of HR was analysed using Kaplan Meier estimates, live tables and Cox regression.

Results

206 patients with PAH (148) and inoperable CTEPH (58) were included. The median HR was 82 bpm. pPH with a HR below 82 bpm had a significantly longer overall event-free survival (2409 vs.1332 days, p = .000). This advantage was similarly found if PAH and CTEPH were analysed separately. Although a lower HR was associated with a better hemodynamic and functional class, HR was a strong and independent prognostic marker for transplant free survival even if corrected for age, sex, hemodynamics and functional status.

Conclusion

We show that resting HR at diagnosis is a strong and independent long-term prognostic marker in PAH and CTEPH. Whether reducing HR by pharmacological agents would improve outcome in pPH has to be assessed by future trials with high attention to safety.

Acute and short-term hemodynamic effects of metoprolol in Eisenmenger syndrome: a preliminary observational study

BACKGROUND

Progressive heart failure and sudden cardiac death are the common causes of death in Eisenmenger syndrome. β-Bockers may be useful in Eisenmenger syndrome, but the safety and efficacy are not proven. The objective of the study was to evaluate the hemodynamic effects and safety of metoprolol in Eisenmenger syndrome.

METHODS

Fifteen patients of Eisenmenger syndrome with a mean age of 22.6 (±8.9) years were studied. Hemodynamic parameters were measured at baseline, after 15 mg of intravenous metoprolol and 6 weeks after oral metoprolol (25 mg/d for 2 weeks and 50 mg/d for 4 weeks).

RESULTS

Intravenous metoprolol was well tolerated, although there was a significant decrease in pulmonary and systemic blood flows. The calculated pulmonary vascular resistance index (23.3 ± 8.6 to 27.4 ± 10.6 Wood U, P = .005) and systemic vascular resistance index (34.9 ± 9.9 to 41.9 ± 13.5 Wood U, P = .005) increased significantly. After 6 weeks of oral metoprolol, the pulmonary artery mean pressure declined significantly (79.9 ± 12.9 to 73.4 ± 14.0 mm Hg, P = .04), which was associated with a slight decrease in mean aortic pressures as compared with baseline. The 6-minutes walk distance increased (401.2 ± 99.9 to 462.5 ± 81.7 m, P = .005).

CONCLUSIONS

Preliminary observations suggest that metoprolol is safe and well tolerated in selected patients with Eisenmenger syndrome. Acute hemodynamic worsening recovers in the short term, and the exercise capacity improves in most patients. Larger studies are warranted.