Effects of carvedilol on right ventricular function in chronic heart failure

Tricuspid Regurgitation Management for Heart Failure

There is growing evidence that severe tricuspid regurgitation (TR) impacts clinical outcomes in a variety of cardiovascular disease states. The late presentation of patients with advanced TR highlights the underappreciation of the disease, as well as the pitfalls of current guideline-directed medical management. Given the high in-hospital mortality associated with isolated tricuspid valve surgery, transcatheter options continue to be explored with the hope of improved survival and reduced heart failure hospitalizations. In this review, we explore the physiology of TR, discuss the etiologic classes of TR, and explore the transcatheter options for treatment and who might benefit from device therapy.

Exploring Sex Differences of Beta-Blockers in the Treatment of Hypertension: A Systematic Review and Meta-Analysis

AIMS

In the prevention of cardiovascular morbidity and mortality, early recognition and adequate treatment of hypertension are of leading importance. However, the efficacy of antihypertensives may be depending on sex disparities. Our objective was to evaluate and quantify the sex-diverse effects of beta-blockers (BB) on hypertension and cardiac function. We focussed on comparing hypertensive female versus male individuals.

METHODS AND RESULTS

A systematic search was performed for studies on BBs from inception to May 2020. A total of 66 studies were included that contained baseline and follow up measurements on blood pressure (BP), heart rate (HR), and cardiac function. Data also had to be stratified for sex. Mean differences were calculated using a random-effects model. In females as compared to males, BB treatment decreased systolic BP 11.1 mmHg (95% CI, -14.5; -7.8) vs. 11.1 mmHg (95% CI, -14.0; -8.2), diastolic BP 8.0 mmHg (95% CI, -10.6; -5.3) vs. 8.0 mmHg (95% CI, -10.1; -6.0), and HR 10.8 beats per minute (bpm) (95% CI, -17.4; -4.2) vs. 9.8 bpm (95% CI, -11.1; -8.4)), respectively, in both sexes' absolute and relative changes comparably. Left ventricular ejection fraction increased only in males (3.7% (95% CI, 0.6; 6.9)). Changes in left ventricular mass and cardiac output (CO) were only reported in males and changed -20.6 g (95% CI, -56.3; 15.1) and -0.1 L (95% CI, -0.5; 0.2), respectively.

CONCLUSIONS

BBs comparably lowered BP and HR in both sexes. The lack of change in CO in males suggests that the reduction in BP is primarily due to a decrease in vascular resistance. Furthermore, females were underrepresented compared to males. We recommend that future research should include more females and sex-stratified data when researching the treatment effects of antihypertensives.

Identifying risk factors for perioperative decline in right ventricular performance in cardiac surgery patients: a prospective observational study in a tertiary care hospital

OBJECTIVES

Impaired right ventricular (RV) function after cardiac surgery is associated with morbidity and long-term mortality. The purpose of this study was to identify factors that play a role in the development of RV dysfunction in the perioperative cardiac surgery setting.

DESIGN

We performed a prospective, observational, single centre study. Over a 2-year period, baseline and perioperative characteristics were recorded. For analysis, subjects were divided into three groups: patients with a ≥3% absolute increase in postoperative RV ejection fraction (RVEF) in comparison to baseline (RVEF+), patients with a ≥3% absolute decrease in RVEF (RVEF-) and patients with a <3% absolute change in RVEF (RVEF=).

SETTING

Tertiary care hospital in the Netherlands.

PARTICIPANTS

We included all cardiac surgery patients ≥18 years of age equipped with a pulmonary artery catheter and admitted to the ICU in 2015-2016. There were no exclusion criteria. A total number of 267 patients were included (65.5% men).

OUTCOME MEASURES

Risk factors for a perioperative decline in RV function.

RESULTS

A reduction in RVEF was observed in 40% of patients. In multivariate analysis, patients with RVEF- were compared with patients with RVEF= (first-mentioned OR) and RVEF+ (second-mentioned OR). Preoperative use of calcium channel blocker (CCB) (OR 3.06, 95% CI 1.24 to 7.54/OR 2.73, 95% CI 1.21 to 6.16 (both p=0.015)), intraoperative fluid balance (FB) (OR 1.45, 95% CI 1.02 to 2.06 (p=0.039)/OR 1.09, 95% CI 0.80 to 1.49 (p=0.575)) and baseline RVEF (OR 1.22; 95% CI 1.14 to 1.30/OR 1.27, 95% CI 1.19 to 1.35 (both p<0.001)) were identified as independent risk factors for a decline in RVEF during surgery.

CONCLUSION

Apart from the impact of the perioperative FB, preoperative use of a CCB as a risk factor for perioperative reduction in RVEF is the most prominent new finding of this study.

Epidemiology, Pathophysiology, and Management of Native Atrioventricular Valve Regurgitation in Heart Failure Patients

Atrioventricular regurgitation is frequent in the setting of heart failure. It is due to atrial and ventricular remodelling, as well as rhythmic disturbances and loss of synchrony. Once atrioventricular regurgitation develops, it can aggravate the underlying heart failure, and further participate and aggravate its own severity. Its presence is therefore concomitantly a surrogate of advance disease and a predictor of mortality. Heart failure management, including medical therapy, cardiac resynchronization therapy, and restoration of sinus rhythm, are the initial steps to reduce atrioventricular regurgitation. In the current review, we analyse the current data assessing the epidemiology, pathophysiology, and impact of non-valvular intervention on atrioventricular regurgitation including medical treatment, cardiac resynchronization and atrial fibrillation ablation.

Beta-blockers and inhibitors of the renin-angiotensin aldosterone system for chronic heart failure with preserved ejection fraction

BACKGROUND

Beta-blockers and inhibitors of the renin-angiotensin-aldosterone system improve survival and reduce morbidity in people with heart failure with reduced left ventricular ejection fraction (LVEF); a review of the evidence is required to determine whether these treatments are beneficial for people with heart failure with preserved ejection fraction (HFpEF).

OBJECTIVES

To assess the effects of beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, angiotensin receptor neprilysin inhibitors, and mineralocorticoid receptor antagonists in people with HFpEF.

SEARCH METHODS

We updated searches of CENTRAL, MEDLINE, Embase, and one clinical trial register on 14 May 2020 to identify eligible studies, with no language or date restrictions. We checked references from trial reports and review articles for additional studies.  SELECTION CRITERIA: We included randomised controlled trials with a parallel group design, enrolling adults with HFpEF, defined by LVEF greater than 40%.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 41 randomised controlled trials (231 reports), totalling 23,492 participants across all comparisons. The risk of bias was frequently unclear and only five studies had a low risk of bias in all domains. Beta-blockers (BBs) We included 10 studies (3087 participants) investigating BBs. Five studies used a placebo comparator and in five the comparator was usual care. The mean age of participants ranged from 30 years to 81 years. A possible reduction in cardiovascular mortality was observed (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.62 to 0.99; number needed to treat for an additional benefit (NNTB) 25; 1046 participants; three studies), however, the certainty of evidence was low. There may be little to no effect on all-cause mortality (RR 0.82, 95% CI 0.67 to 1.00; 1105 participants; four studies; low-certainty evidence). The effects on heart failure hospitalisation, hyperkalaemia, and quality of life remain uncertain. Mineralocorticoid receptor antagonists (MRAs) We included 13 studies (4459 participants) investigating MRA. Eight studies used a placebo comparator and in five the comparator was usual care. The mean age of participants ranged from 54.5 to 80 years. Pooled analysis indicated that MRA treatment probably reduces heart failure hospitalisation (RR 0.82, 95% CI 0.69 to 0.98; NNTB = 41; 3714 participants; three studies; moderate-certainty evidence). However, MRA treatment probably has little or no effect on all-cause mortality (RR 0.91, 95% CI 0.78 to 1.06; 4207 participants; five studies; moderate-certainty evidence) and cardiovascular mortality (RR 0.90, 95% CI 0.74 to 1.11; 4070 participants; three studies; moderate-certainty evidence). MRA treatment may have little or no effect on quality of life measures (mean difference (MD) 0.84, 95% CI -2.30 to 3.98; 511 participants; three studies; low-certainty evidence). MRA treatment was associated with a higher risk of hyperkalaemia (RR 2.11, 95% CI 1.77 to 2.51; number needed to treat for an additional harmful outcome (NNTH) = 11; 4291 participants; six studies; high-certainty evidence). Angiotensin-converting enzyme inhibitors (ACEIs) We included eight studies (2061 participants) investigating ACEIs. Three studies used a placebo comparator and in five the comparator was usual care. The mean age of participants ranged from 70 to 82 years. Pooled analyses with moderate-certainty evidence suggest that ACEI treatment likely has little or no effect on cardiovascular mortality (RR 0.93, 95% CI 0.61 to 1.42; 945 participants; two studies), all-cause mortality (RR 1.04, 95% CI 0.75 to 1.45; 1187 participants; five studies) and heart failure hospitalisation (RR 0.86, 95% CI 0.64 to 1.15; 1019 participants; three studies), and may result in little or no effect on the quality of life (MD -0.09, 95% CI -3.66 to 3.48; 154 participants; two studies; low-certainty evidence). The effects on hyperkalaemia remain uncertain. Angiotensin receptor blockers (ARBs) Eight studies (8755 participants) investigating ARBs were included. Five studies used a placebo comparator and in three the comparator was usual care. The mean age of participants ranged from 61 to 75 years. Pooled analyses with high certainty of evidence suggest that ARB treatment has little or no effect on cardiovascular mortality (RR 1.02, 95% 0.90 to 1.14; 7254 participants; three studies), all-cause mortality (RR 1.01, 95% CI 0.92 to 1.11; 7964 participants; four studies), heart failure hospitalisation (RR 0.92, 95% CI 0.83 to 1.02; 7254 participants; three studies), and quality of life (MD 0.41, 95% CI -0.86 to 1.67; 3117 participants; three studies). ARB was associated with a higher risk of hyperkalaemia (RR 1.88, 95% CI 1.07 to 3.33; 7148 participants; two studies; high-certainty evidence). Angiotensin receptor neprilysin inhibitors (ARNIs) Three studies (7702 participants) investigating ARNIs were included. Two studies used ARBs as the comparator and one used standardised medical therapy, based on participants' established treatments at enrolment. The mean age of participants ranged from 71 to 73 years. Results suggest that ARNIs may have little or no effect on cardiovascular mortality (RR 0.96, 95% CI 0.79 to 1.15; 4796 participants; one study; moderate-certainty evidence), all-cause mortality (RR 0.97, 95% CI 0.84 to 1.11; 7663 participants; three studies; high-certainty evidence), or quality of life (high-certainty evidence). However, ARNI treatment may result in a slight reduction in heart failure hospitalisation, compared to usual care (RR 0.89, 95% CI 0.80 to 1.00; 7362 participants; two studies; moderate-certainty evidence). ARNI treatment was associated with a reduced risk of hyperkalaemia compared with valsartan (RR 0.88, 95% CI 0.77 to 1.01; 5054 participants; two studies; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

There is evidence that MRA and ARNI treatment in HFpEF probably reduces heart failure hospitalisation but probably has little or no effect on cardiovascular mortality and quality of life. BB treatment may reduce the risk of cardiovascular mortality, however, further trials are needed. The current evidence for BBs, ACEIs, and ARBs is limited and does not support their use in HFpEF in the absence of an alternative indication. Although MRAs and ARNIs are probably effective at reducing the risk of heart failure hospitalisation, the treatment effect sizes are modest. There is a need for improved approaches to patient stratification to identify the subgroup of patients who are most likely to benefit from MRAs and ARNIs, as well as for an improved understanding of disease biology, and for new therapeutic approaches.

Local hyperactivation of L-type Ca2+ channels increases spontaneous Ca2+ release activity and cellular hypertrophy in right ventricular myocytes from heart failure rats

Right ventricle (RV) dysfunction is an independent predictor of patient survival in heart failure (HF). However, the mechanisms of RV progression towards failing are not well understood. We studied cellular mechanisms of RV remodelling in a rat model of left ventricle myocardial infarction (MI)-caused HF. RV myocytes from HF rats show significant cellular hypertrophy accompanied with a disruption of transverse-axial tubular network and surface flattening. Functionally these cells exhibit higher contractility with lower Ca²⁺ transients. The structural changes in HF RV myocytes correlate with more frequent spontaneous Ca²⁺ release activity than in control RV myocytes. This is accompanied by hyperactivated L-type Ca²⁺ channels (LTCCs) located specifically in the T-tubules of HF RV myocytes. The increased open probability of tubular LTCCs and Ca²⁺ sparks activation is linked to protein kinase A-mediated channel phosphorylation that occurs locally in T-tubules. Thus, our approach revealed that alterations in RV myocytes in heart failure are specifically localized in microdomains. Our findings may indicate the development of compensatory, though potentially arrhythmogenic, RV remodelling in the setting of LV failure. These data will foster better understanding of mechanisms of heart failure and it could promote an optimized treatment of patients.

Impact of β-blocker therapy on right ventricular function in heart failure patients with reduced ejection fraction. A prospective evaluation

BACKGROUND

Beta-blocker (β-blocker) therapy has been shown to improve mortality and reduce hospitalizations in patients with heart failure (HF) with reduced ejection fraction (HFrEF). Although the physiological action mechanisms of β-blockers are well described, their effects on right ventricular (RV) function have not been prospectively studied.

OBJECTIVE

This prospective study aimed to (a) evaluate whether β-blocker therapy impacts RV remodeling based on echo parameters and (b) determine the predictive echo factors of β-blocker therapy response.

METHODS

From September 2017 to September 2018, HF patients were prospectively enrolled using CIBIS criteria: Class II, III, or IV HF; left ventricular ejection fraction (LVEF) of ≤40%; hospitalized for HF within the previous 12 months. Echo evaluation was performed before initiating β-blocker therapy and 3 months after optimal dose adjustment. Based on previous studies, patients with (absolute) LVEF ≥ 5% improvement were considered significant β-blocker therapy responders.

RESULTS

Overall, 40 patients (pts) completed the study, characterized as follows by age: 70 ± 10 years; gender: 10 women; cardiomyopathy etiology: idiopathic in 24 and ischemic in 16; NYHA Class: II in 22 and III in 10; LVEF: 32 ± 5%; and NTProBNP: 2665 ± 2400 pg/mL. The final population comprised 32 pts (79%), with eight (21%) excluded: two because of β-blocker therapy intolerance, one lost to follow-up, and five withdrew from the study. Under β-blocker therapy, several echo parameters significantly improved: LVEF from 31.7 ± 9 to 40.5 ± 9 (P < .0001); LV end-diastolic volume (EDV) from 154 ± 54 to 143 ± 45 mL (P = .06); LV end-systolic volume (ESV) from 107 ± 49 to 88 ± 37 mL (P = .0006); LV ES from 46 ± 11 to 64 ± 13 mL (P = .008); LV end-diastolic diameter (EDD) from 57 ± 9 to 54 ± 6 mm (P = .04); LV end-systolic diameter (ESD) from 48 ± 10 to 44 ± 7 mm (P = .007); and right ventricular systolic pressure (RV SP) from 39 ± 10 to 32 ± 8 mm Hg (P = .0001). Significant modifications were observed in terms of RV echo parameters: right ventricular (RV) size decreased from 30 ± 4 to 27 ± 5 mm (P = .03), while RV systolic function significantly improved based on tricuspid annular plane systolic excursion (TAPSE) (16.5 ± 4 vs. 19 ± 4 mm; 0.0006); DTI-derived tricuspid lateral annular systolic velocity wave (S') (10 ± 2 vs. 11.3 ± 3 cm/s; P = .03); and RIMP (Tei index) (0.5 ± 0.1 vs 0.46 ± 0.1; P = .04). RV 2D fractional area change (%) did not significantly differ despite a clear improvement tendency (35 ± 6 vs. 37 ± 4%; P = .1). No significant modifications were observed concerning LV diastolic parameters. Overall, β-blocker echo responders (n = 23/32; 72%) exhibited the same left and right echo parameters. No echo variables predicted the β-blocker response.

CONCLUSIONS

In HFrEF pts, β-blocker therapy significantly improves LV and RV systolic remodeling. Accordingly, β-blocker therapy could be applied as soon as possible in HFrEF patients with right ventricular dysfunction so as to limit RV remodeling.

Left ventricular remodelling in chronic primary mitral regurgitation: implications for medical therapy

Surgical repair or replacement of the mitral valve is currently the only recommended therapy for severe primary mitral regurgitation. The chronic elevation of wall stress caused by the resulting volume overload leads to structural remodelling of the muscular, vascular and extracellular matrix components of the myocardium. These changes are initially compensatory but in the long term have detrimental effects, which ultimately result in heart failure. Understanding the changes that occur in the myocardium due to volume overload at the molecular and cellular level may lead to medical interventions, which potentially could delay or prevent the adverse left ventricular remodelling associated with primary mitral regurgitation. The pathophysiological changes involved in left ventricular remodelling in response to chronic primary mitral regurgitation and the evidence for potential medical therapy, in particular beta-adrenergic blockers, are the focus of this review.

Novel Insights and Treatment Strategies for Right Heart Failure

PURPOSE OF REVIEW

The function of the right ventricle (RV) is intimately linked to its preload (systemic volume status) and afterload (pulmonary vasculature). In this review, we explore current knowledge in RV physiology, RV function assessment, causes of right heart failure (RHF), and specific treatment strategies for RHF.

RECENT FINDINGS

We examine the evidence behind new pharmacological therapies available, such as macitentan and riociguat in the treatment of specific etiologies of RHF. We will also focus on RHF in the setting of heart failure with preserved ejection fraction (HFpEF) and in the presence of left ventricular assist devices (LVAD), looking at current treatment recommendations, including mechanical circulatory support. Lastly, we will look to the horizon for the latest research on RHF, including the molecular basis of RHF and potential novel treatment methods for this old yet poorly understood syndrome. Disturbances in this complex relationship result in the clinical syndrome of RHF. Despite advances in the management of left heart diseases, much work remains to be done to understand and manage RHF.

Beta-blockers and inhibitors of the renin-angiotensin aldosterone system for chronic heart failure with preserved ejection fraction

BACKGROUND

Beta-blockers and inhibitors of the renin-angiotensin aldosterone system improve survival and reduce morbidity in people with heart failure with reduced left ventricular ejection fraction. There is uncertainty whether these treatments are beneficial for people with heart failure with preserved ejection fraction and a comprehensive review of the evidence is required.

OBJECTIVES

To assess the effects of beta-blockers, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, angiotensin receptor neprilysin inhibitors, and mineralocorticoid receptor antagonists in people with heart failure with preserved ejection fraction.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and two clinical trial registries on 25 July 2017 to identify eligible studies. Reference lists from primary studies and review articles were checked for additional studies. There were no language or date restrictions.

SELECTION CRITERIA

We included randomised controlled trials with a parallel group design enrolling adult participants with heart failure with preserved ejection fraction, defined by a left ventricular ejection fraction of greater than 40 percent.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion and extracted data. The outcomes assessed included cardiovascular mortality, heart failure hospitalisation, hyperkalaemia, all-cause mortality and quality of life. Risk ratios (RR) and, where possible, hazard ratios (HR) were calculated for dichotomous outcomes. For continuous data, mean difference (MD) or standardised mean difference (SMD) were calculated. We contacted trialists where neccessary to obtain missing data.

MAIN RESULTS

37 randomised controlled trials (207 reports) were included across all comparisons with a total of 18,311 participants.Ten studies (3087 participants) investigating beta-blockers (BB) were included. A pooled analysis indicated a reduction in cardiovascular mortality (15% of participants in the intervention arm versus 19% in the control arm; RR 0.78; 95% confidence interval (CI) 0.62 to 0.99; number needed to treat to benefit (NNTB) 25; 1046 participants; 3 studies). However, the quality of evidence was low and no effect on cardiovascular mortality was observed when the analysis was limited to studies with a low risk of bias (RR 0.81; 95% CI 0.50 to 1.29; 643 participants; 1 study). There was no effect on all-cause mortality, heart failure hospitalisation or quality of life measures, however there is uncertainty about these effects given the limited evidence available.12 studies (4408 participants) investigating mineralocorticoid receptor antagonists (MRA) were included with the quality of evidence assessed as moderate. MRA treatment reduced heart failure hospitalisation (11% of participants in the intervention arm versus 14% in the control arm; RR 0.82; 95% CI 0.69 to 0.98; NNTB 41; 3714 participants; 3 studies; moderate-quality evidence) however, little or no effect on all-cause and cardiovascular mortality and quality of life measures was observed. MRA treatment was associated with a greater risk of hyperkalaemia (16% of participants in the intervention group versus 8% in the control group; RR 2.11; 95% CI 1.77 to 2.51; 4291 participants; 6 studies; high-quality evidence).Eight studies (2061 participants) investigating angiotensin converting enzyme inhibitors (ACEI) were included with the overall quality of evidence assessed as moderate. The evidence suggested that ACEI treatment likely has little or no effect on cardiovascular mortality, all-cause mortality, heart failure hospitalisation, or quality of life. Data for the effect of ACEI on hyperkalaemia were only available from one of the included studies.Eight studies (8755 participants) investigating angiotensin receptor blockers (ARB) were included with the overall quality of evidence assessed as high. The evidence suggested that treatment with ARB has little or no effect on cardiovascular mortality, all-cause mortality, heart failure hospitalisation, or quality of life. ARB was associated with an increased risk of hyperkalaemia (0.9% of participants in the intervention group versus 0.5% in the control group; RR 1.88; 95% CI 1.07 to 3.33; 7148 participants; 2 studies; high-quality evidence).We identified a single ongoing placebo-controlled study investigating the effect of angiotensin receptor neprilysin inhibitors (ARNI) in people with heart failure with preserved ejection fraction.

AUTHORS' CONCLUSIONS

There is evidence that MRA treatment reduces heart failure hospitalisation in heart failure with preserverd ejection fraction, however the effects on mortality related outcomes and quality of life remain unclear. The available evidence for beta-blockers, ACEI, ARB and ARNI is limited and it remains uncertain whether these treatments have a role in the treatment of HFpEF in the absence of an alternative indication for their use. This comprehensive review highlights a persistent gap in the evidence that is currently being addressed through several large ongoing clinical trials.

Evaluation and Management of Right-Sided Heart Failure: A Scientific Statement From the American Heart Association

Background and Purpose:

The diverse causes of right-sided heart failure (RHF) include, among others, primary cardiomyopathies with right ventricular (RV) involvement, RV ischemia and infarction, volume loading caused by cardiac lesions associated with congenital heart disease and valvular pathologies, and pressure loading resulting from pulmonic stenosis or pulmonary hypertension from a variety of causes, including left-sided heart disease. Progressive RV dysfunction in these disease states is associated with increased morbidity and mortality. The purpose of this scientific statement is to provide guidance on the assessment and management of RHF.

Methods:

The writing group used systematic literature reviews, published translational and clinical studies, clinical practice guidelines, and expert opinion/statements to summarize existing evidence and to identify areas of inadequacy requiring future research. The panel reviewed the most relevant adult medical literature excluding routine laboratory tests using MEDLINE, EMBASE, and Web of Science through September 2017. The document is organized and classified according to the American Heart Association to provide specific suggestions, considerations, or reference to contemporary clinical practice recommendations.

Results:

Chronic RHF is associated with decreased exercise tolerance, poor functional capacity, decreased cardiac output and progressive end-organ damage (caused by a combination of end-organ venous congestion and underperfusion), and cachexia resulting from poor absorption of nutrients, as well as a systemic proinflammatory state. It is the principal cause of death in patients with pulmonary arterial hypertension. Similarly, acute RHF is associated with hemodynamic instability and is the primary cause of death in patients presenting with massive pulmonary embolism, RV myocardial infarction, and postcardiotomy shock associated with cardiac surgery. Functional assessment of the right side of the heart can be hindered by its complex geometry. Multiple hemodynamic and biochemical markers are associated with worsening RHF and can serve to guide clinical assessment and therapeutic decision making. Pharmacological and mechanical interventions targeting isolated acute and chronic RHF have not been well investigated. Specific therapies promoting stabilization and recovery of RV function are lacking.

Conclusions:

RHF is a complex syndrome including diverse causes, pathways, and pathological processes. In this scientific statement, we review the causes and epidemiology of RV dysfunction and the pathophysiology of acute and chronic RHF and provide guidance for the management of the associated conditions leading to and caused by RHF.

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.

Right heart dysfunction and failure in heart failure with preserved ejection fraction: mechanisms and management. Position statement on behalf of the Heart Failure Association of the European Society of Cardiology

There is an unmet need for effective treatment strategies to reduce morbidity and mortality in patients with heart failure with preserved ejection fraction (HFpEF). Until recently, attention in patients with HFpEF was almost exclusively focused on the left side. However, it is now increasingly recognized that right heart dysfunction is common and contributes importantly to poor prognosis in HFpEF. More insights into the development of right heart dysfunction in HFpEF may aid to our knowledge about this complex disease and may eventually lead to better treatments to improve outcomes in these patients. In this position paper from the Heart Failure Association of the European Society of Cardiology, the Committee on Heart Failure with Preserved Ejection Fraction reviews the prevalence, diagnosis, and pathophysiology of right heart dysfunction and failure in patients with HFpEF. Finally, potential treatment strategies, important knowledge gaps and future directions regarding the right side in HFpEF are discussed.

2017 Comprehensive Update of the Canadian Cardiovascular Society Guidelines for the Management of Heart Failure

Since the inception of the Canadian Cardiovascular Society heart failure (HF) guidelines in 2006, much has changed in the care for patients with HF. Over the past decade, the HF Guidelines Committee has published regular updates. However, because of the major changes that have occurred, the Guidelines Committee believes that a comprehensive reassessment of the HF management recommendations is presently needed, with a view to producing a full and complete set of updated guidelines. The primary and secondary Canadian Cardiovascular Society HF panel members as well as external experts have reviewed clinically relevant literature to provide guidance for the practicing clinician. The 2017 HF guidelines provide updated guidance on the diagnosis and management (self-care, pharmacologic, nonpharmacologic, device, and referral) that should aid in day-to-day decisions for caring for patients with HF. Among specific issues covered are risk scores, the differences in management for HF with preserved vs reduced ejection fraction, exercise and rehabilitation, implantable devices, revascularization, right ventricular dysfunction, anemia, and iron deficiency, cardiorenal syndrome, sleep apnea, cardiomyopathies, HF in pregnancy, cardio-oncology, and myocarditis. We devoted attention to strategies and treatments to prevent HF, to the organization of HF care, comorbidity management, as well as practical issues around the timing of referral and follow-up care. Recognition and treatment of advanced HF is another important aspect of this update, including how to select advanced therapies as well as end of life considerations. Finally, we acknowledge the remaining gaps in evidence that need to be filled by future research.

Clinical utility of sympathetic blockade in cardiovascular disease management

INTRODUCTION

A dysregulated sympathetic nervous system is a major factor in the development and progression of cardiovascular disease; thus, understanding the mechanism and function of the sympathetic nervous system and appropriately regulating sympathetic activity to treat various cardiovascular diseases are crucial. Areas covered: This review focused on previous studies in managing hypertension, atrial fibrillation, coronary artery disease, heart failure, and perioperative management with sympathetic blockade. We reviewed both pharmacological and non-pharmacological management. Expert commentary: Chronic sympathetic nervous system activation is related to several cardiovascular diseases mediated by various pathways. Advancement in measuring sympathetic activity makes visualizing noninvasively and evaluating the activation level even in single fibers possible. Evidence suggests that sympathetic blockade still has a role in managing hypertension and controlling the heart rate in atrial fibrillation. For ischemic heart disease, beta-adrenergic receptor antagonists have been considered a milestone drug to control symptoms and prevent long-term adverse effects, although its clinical implication has become less potent in the era of successful revascularization. Owing to pathologic involvement of sympathetic nervous system activation in heart failure progression, sympathetic blockade has proved its value in improving the clinical course of patients with heart failure.

Hypoxia sensing through -adrenergic receptors

Life-sustaining responses to low oxygen, or hypoxia, depend on signal transduction by HIFs, but the underlying mechanisms by which cells sense hypoxia are not completely understood. Based on prior studies suggesting a link between the β-adrenergic receptor (β-AR) and hypoxia responses, we hypothesized that the β-AR mediates hypoxia sensing and is necessary for HIF-1α accumulation. Beta blocker treatment of mice suppressed hypoxia induction of renal HIF-1α accumulation, erythropoietin production, and erythropoiesis in vivo. Likewise, beta blocker treatment of primary human endothelial cells in vitro decreased hypoxia-mediated HIF-1α accumulation and binding to target genes and the downstream hypoxia-inducible gene expression. In mechanistic studies, cAMP-activated PKA and/or GPCR kinases (GRK), which both participate in β-AR signal transduction, were investigated. Direct activation of cAMP/PKA pathways did not induce HIF-1α accumulation, and inhibition of PKA did not blunt HIF-1α induction by hypoxia. In contrast, pharmacological inhibition of GRK, or expression of a GRK phosphorylation-deficient β-AR mutant in cells, blocked hypoxia-mediated HIF-1α accumulation. Mass spectrometry-based quantitative analyses revealed a hypoxia-mediated β-AR phosphorylation barcode that was different from the classical agonist phosphorylation barcode. These findings indicate that the β-AR is fundamental to the molecular and physiological responses to hypoxia.

Optimal Use of Beta-Blockers for Congestive Heart Failure

Beta-blockers are the cornerstone treatment for congestive heart failure (HF). Current HF guidelines commonly recommend β-blockers for the treatment of HF with reduced left ventricular ejection fraction (LVEF). The effect of β-blockers, however, is less clear for HF patients with preserved LVEF, unstable severe acute HF, or right ventricular failure. This review summarizes the effect of β-blockers in various clinical situations and suggests a strategy for optimal use. (Circ J 2016; 80: 565-571).

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.

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.

Implication of right ventricular dysfunction on long-term outcome in patients with ischemic cardiomyopathy undergoing coronary artery bypass grafting with or without surgical ventricular reconstruction

OBJECTIVE

Whether right ventricular dysfunction affects clinical outcome after coronary artery bypass grafting with or without surgical ventricular reconstruction is still unknown. The aim of the study was to assess the impact of right ventricular dysfunction on clinical outcome in patients with ischemic cardiomyopathy undergoing coronary artery bypass grafting with or without surgical ventricular reconstruction.

METHODS

Of 1000 patients in the Surgical Treatment for Ischemic Heart Failure with coronary artery disease, left ventricular ejection fraction 35% or less, and anterior dysfunction, who were randomized to undergo coronary artery bypass grafting or coronary artery bypass grafting + surgical ventricular reconstruction, baseline right ventricular function could be assessed by echocardiography in 866 patients. Patients were followed for a median of 48 months. All-cause mortality or cardiovascular hospitalization was the primary end point, and all-cause mortality alone was a secondary end point.

RESULTS

Right ventricular dysfunction was mild in 102 patients (12%) and moderate or severe in 78 patients (9%). Moderate to severe right ventricular dysfunction was associated with a larger left ventricle, lower ejection fraction, more severe mitral regurgitation, higher filling pressure, and higher pulmonary artery systolic pressure (all P < .0001) compared with normal or mildly reduced right ventricular function. A significant interaction between right ventricular dysfunction and treatment allocation was observed. Patients with moderate or severe right ventricular dysfunction who received coronary artery bypass grafting + surgical ventricular reconstruction had significantly worse outcomes compared with patients who received coronary artery bypass grafting alone on both the primary (hazard ratio, 1.86; confidence interval, 1.06-3.26; P = .028) and the secondary (hazard ratio, 3.37; confidence interval, 1.36-8.37; P = .005) end points. After adjusting for all other prognostic clinical factors, the interaction remained significant with respect to all-cause mortality (P = .022).

CONCLUSIONS

Adding surgical ventricular reconstruction to coronary artery bypass grafting may worsen long-term survival in patients with ischemic cardiomyopathy with moderate to severe right ventricular dysfunction, which reflects advanced left ventricular remodeling.

Beta-blockers Associated with a Mortality Benefit in Patients with Systolic Dysfunction and Elevated Serum Bilirubin

Background:

Hyperbilirubinemia is associated with increased mortality in heart failure (HF) patients. We evaluated the impact of evidence-based medical therapy, in particular beta-blocker on the survival of patients with HF and hyperbilirubinemia.

Methods and Results:

We reviewed the charts of all patients followed at our tertiary care heart failure clinic. Hyperbilirubinemia was defined as total bilirubin >30 µmol/L (1.5 times the upper limit of our laboratory value). The primary endpoint was all-cause mortality. The secondary endpoint was a composite of death, cardiac transplant or ventricular assistance device implantation (VAD). Of 1035 HF patients, 121 patients (11.7%) had hyperbilirubinemia. Median follow-up was 556 days. Hyperbilirubinemia was associated with an eight-fold increase in all-cause mortality, hazard ratio (HR): 8.78[95% Confidence Intervals (CI): 5.89-13.06]. Beta-blocker use was associated with approximately 60% reduction in all-cause mortality (HR: 0.38, 95% CI:0.15-0.94) and 70% reduction in the composite secondary endpoint (HR:0.31, 95% CI:0.13-0.71) in patients with hyperbilirubinemia.

Conclusion:

HF patients with hyperbilirubinemia have increased early mortality, need for cardiac transplantation or VAD. Beta-blocker use was associated with early survival benefit in these patients. Bilirubin levels should be monitored in patients with HF and early initiation of beta-blockers in patients with hyperbilirubinemia should be considered.

The right ventricle in pulmonary arterial hypertension: disorders of metabolism, angiogenesis and adrenergic signaling in right ventricular failure

The right ventricle (RV) is the major determinant of functional state and prognosis in pulmonary arterial hypertension. RV hypertrophy (RVH) triggered by pressure overload is initially compensatory but often leads to RV failure. Despite similar RV afterload and mass some patients develop adaptive RVH (concentric with retained RV function), while others develop maladaptive RVH, characterized by dilatation, fibrosis, and RV failure. The differentiation of adaptive versus maladaptive RVH is imprecise, but adaptive RVH is associated with better functional capacity and survival. At the molecular level, maladaptive RVH displays greater impairment of angiogenesis, adrenergic signaling, and metabolism than adaptive RVH, and these derangements often involve the left ventricle. Clinically, maladaptive RVH is characterized by increased N-terminal pro-brain natriuretic peptide levels, troponin release, elevated catecholamine levels, RV dilatation, and late gadolinium enhancement on MRI, increased (18)fluorodeoxyglucose uptake on positron emission tomography, and QTc prolongation on the ECG. In maladaptive RVH there is reduced inotrope responsiveness because of G-protein receptor kinase-mediated downregulation, desensitization, and uncoupling of β-adrenoreceptors. RV ischemia may result from capillary rarefaction or decreased right coronary artery perfusion pressure. Maladaptive RVH shares metabolic abnormalities with cancer including aerobic glycolysis (resulting from a forkhead box protein O1-mediated transcriptional upregulation of pyruvate dehydrogenase kinase), and glutaminolysis (reflecting ischemia-induced cMyc activation). Augmentation of glucose oxidation is beneficial in experimental RVH and can be achieved by inhibition of pyruvate dehydrogenase kinase, fatty acid oxidation, or glutaminolysis. Therapeutic targets in RV failure include chamber-specific abnormalities of metabolism, angiogenesis, adrenergic signaling, and phosphodiesterase-5 expression. The ability to restore RV function in experimental models challenges the dogma that RV failure is irreversible without regression of pulmonary vascular disease.

The right ventricle: biologic insights and response to disease: updated

Despite ample evidence that right ventricular function is a critical determinant of the clinical response to a spectrum of cardiovascular diseases, there has been only a limited analysis of the unique and distinguishing physiologic properties of the RV under normal circumstances and in response to pathologic insults. This knowledge deficit is increasingly acknowledged. This review highlights some of these features and underscores the fact that rational therapy in RV failure needs to acknowledge its unique physiology and ought to be chamber specific. That is proven therapies for LV dysfunction do not necessarily apply to the RV. The updated version of this review now acknowledges recent advances in the understanding of metabolic, inflammatory and gender-specific influences on the right ventricle.

Quantifying longitudinal right ventricular dysfunction in patients with old myocardial infarction by using speckle-tracking strain echocardiography

BACKGROUND

We investigated longitudinal right ventricular (RV) function assessed using speckle-tracking strain echocardiography in patient with myocardial infarction (MI), and identified the contributing factors for RV dysfunction.

METHODS

We retrospectively studied 71 patients with old MI (the OMI group) and 45 normal subjects (the Control group) who underwent a transthoracic echocardiography. Global and free wall RV peak systolic strains (PSSs) in the longitudinal direction were measured by using speckle-tracking strain echocardiography. Left ventricular (LV) PSSs were measured in the longitudinal, radial and circumferential directions. Cardiac hemodynamics including peak systolic pulmonary artery pressure was also assessed non-invasively. Plasma brain natriuretic peptide (BNP) levels were measured in all patients.

RESULTS

In the OMI group, 73% of the patients had a normal estimated peak systolic pulmonary artery pressure of less than 35 mmHg. Global and free wall RV PSS were impaired in the OMI group compared with the Control group, and these RV systolic indices were significantly associated with heart rate, logarithmic transformed plasma BNP, greater than 1 year after onset of MI, Doppler-derived estimated pulmonary vascular resistance, LV systolic indices, LV mass index, infarcted segments within a territory of the left circumflex artery and residual total occlusion in the culprit right coronary artery. Multivariable linear regression analysis indicated that reduced longitudinal LV PSS in the 4-chamber view and BNP levels ≥500 pg/ml were independently associated with reduced global and free wall RV PSS. Moreover, when patients were divided into 3 groups according to plasma BNP levels (BNP <100 pg/ml; n = 31, 100 ≤BNP <500 pg/ml; n = 24, and BNP ≥500 pg/ml; n = 16), only patients with BNP ≥500 pg/ml had a strong correlation between RV PSS and longitudinal LV PSS in the 4-chamber view (r = 0.78 for global RV PSS and r = 0.71 for free wall RV PSS, p <0.05).

CONCLUSION

Longitudinal RV systolic strain depends significantly on longitudinal LV systolic strain especially in patients with high plasma BNP levels, but not on estimated peak systolic pulmonary artery pressure. These results indicate that process of RV myocardial dysfunction following MI may be governed by neurohormonal activation which causing ventricular remodeling rather than increased RV afterload.

Right side of heart failure

The function of the right ventricle (RV) in heart failure (HF) has been mostly ignored until recently. A 2006 report of the National Heart, Lung, and Blood Institute identified a gap between RV research efforts and its clinical importance compared with that of the left ventricle. This recent shift in paradigm is fueled by the prognostic value ascribed to RV failure in HF and morbidity/mortality after myocardial infarction and surgery. In this review, we examine the significance of RV failure in the HF setting, its clinical presentation and pathophysiology, and ways to evaluate RV function using echocardiographic measurements. Furthermore, we discuss the medical management of RV failure including traditional therapies like beta-blockers and newer options like nitric oxide, phosphodiesterase inhibitors, and calcium sensitizers. Mechanical support is also examined. Finally, this review places an emphasis on RV failure in the setting of left ventricular assist devices and heart transplantation.

Right ventricular failure in congenital heart disease

Despite developments in surgical techniques and other interventions, right ventricular (RV) failure remains an important clinical problem in several congenital heart diseases (CHD). RV function is one of the most important predictors of mortality and morbidity in patients with CHD. RV failure is a progressive disorder that begins with myocardial injury or stress, neurohormonal activation, cytokine activation, altered gene expression, and ventricular remodeling. Pressure-overload RV failure caused by RV outflow tract obstruction after total correction of tetralogy of Fallot, pulmonary stenosis, atrial switch operation for transposition of the great arteries, congenitally corrected transposition of the great arteries, and systemic RV failure after the Fontan operation. Volume-overload RV failure may be caused by atrial septal defect, pulmonary regurgitation, or tricuspid regurgitation. Although the measurement of RV function is difficult because of many reasons, the right ventricle can be evaluated using both imaging and functional modalities. In clinical practice, echocardiography is the primary mode for the evaluation of RV structure and function. Cardiac magnetic resonance imaging is increasingly used for evaluating RV structure and function. A comprehensive evaluation of RV function may lead to early and optimal management of RV failure in patients with CHD.

The right ventricle: biologic insights and response to disease

Despite ample evidence that right ventricular function is a critical determinant of the clinical response to a spectrum of cardiovascular diseases, there has been only a limited analysis of the unique and distinguishing physiologic properties of the RV under normal circumstances and in response to pathologic insults. This review highlights some of these features and underscores the fact that rational therapy in RV failure should acknowledge this physiology and ought to be chamber specific.

Right ventricular dysfunction following acute myocardial infarction in the absence of pulmonary hypertension in the mouse

BACKGROUND

Cardiac remodelling after AMI is characterized by molecular and cellular mechanisms involving both the ischemic and non-ischemic myocardium. The extent of right ventricular (RV) dilatation and dysfunction and its relation to pulmonary hypertension (PH) following AMI are unknown. The aim of the current study was to evaluate changes in dimensions and function of the RV following acute myocardial infarction (AMI) involving the left ventricle (LV).

METHODS

We assessed changes in RV dimensions and function 1 week following experimental AMI involving the LV free wall in 10 mice and assessed for LV and RV dimensions and function and for the presence and degree of PH.

RESULTS

RV fractional area change and tricuspidal annular plane systolic excursion significantly declined by 33% (P = 0.021) and 28% (P = 0.001) respectively. Right ventricular systolic pressure measured invasively in the mouse was within the normal values and unchanged following AMI.

CONCLUSION

AMI involving the LV and sparing the RV induces a significant acute decline in RV systolic function in the absence of pulmonary hypertension in the mouse indicating that RV dysfunction developed independent of changes in RV afterload.

Relationship between left and right ventricular ejection fractions in chronic advanced systolic heart failure: insights from the BEST trial

AIMS

Abnormally low right ventricular ejection fraction (RVEF) is a predictor of poor outcomes in chronic heart failure (HF) patients with low left ventricular ejection fraction (LVEF). However, little is known about the relationship between LVEF and RVEF in these patients.

METHODS AND RESULTS

Of the 2707 Beta-blocker Evaluation of Survival Trial (BEST) participants with ambulatory chronic HF, New York Heart Association class III-IV symptoms, and LVEF ≤ 35%, 2008 patients had gated-equilibrium radionuclide angiographic data on baseline LVEF and RVEF. Patients were categorized into quartiles by LVEF ≥ 29% (n = 507), 23-28% (n = 513), 17-22% (n = 538), and < 17% (n = 450). Logistic regression models were used to determine the association of LVEF quartiles (reference, ≥ 29%) with abnormally low RVEF (<20%). The prevalence of RVEF < 20% for patients with LVEF quartiles ≥ 29, 23-28, 17-22, and < 17% were 3, 6, 15, and 32%, respectively. Unadjusted odds ratios [95% confidence intervals (CIs)] for RVEF < 20% (vs. ≥ 20%) associated with LVEF quartiles 23-28, 17-22, and < 17% (reference, ≥ 29%) were 2.18 (1.14-4.17; P = 0.018), 6.32 (3.54-11.30; P < 0.001), and 16.67 (9.46-29.39; P < 0.001), respectively. Respective multivariable-adjusted odds ratios (95% CIs) were 1.82 (0.94-3.54; P = 0.076), 4.55 (2.48-8.35; P < 0.001), and 10.53 (5.70-19.44; P< 0.001), respectively. Heart failure symptoms and signs had unadjusted associations with low RVEF, but lacked intrinsic associations.

CONCLUSION

In patients with advanced systolic HF, LVEF has a strong dose-dependent relationship with RVEF which is independent of other characteristics, and low LVEF is useful as a surrogate marker of abnormally low RVEF in these patients.

Medical and surgical treatment of acute right ventricular failure

Acute right ventricular (RV) failure is a frequent and serious clinical challenge in the intensive care unit. It is usually seen as a consequence of left ventricular failure, pulmonary embolism, pulmonary hypertension, sepsis, acute lung injury or after cardiothoracic surgery. The presence of acute RV failure not only carries substantial morbidity and mortality, but also complicates the use of commonly used treatment strategies in critically ill patients. In contrast to the left ventricle, the RV remains relatively understudied, and investigations of the treatment of isolated RV failure are rare and usually limited to nonrandomized observations. We searched PubMed for papers in the English language by using the search words right ventricle, right ventricular failure, pulmonary hypertension, sepsis, shock, acute lung injury, cardiothoracic surgery, mechanical ventilation, vasopressors, inotropes, and pulmonary vasodilators. These were used in various combinations. We read the abstracts of the relevant titles to confirm their relevance, and the full papers were then extracted. References from extracted papers were checked for any additional relevant papers. This review summarizes the general measures, ventilation strategies, vasoactive substances, and surgical as well as mechanical approaches that are currently used or actively investigated in the treatment of the acutely failing RV.

Do we have two hearts? New insights in right ventricular function supported by myocardial imaging echocardiography

RV performance is difficult to evaluate, given its geometry, interrelationship with the left ventricle, and sensitivity to alterations in pulmonary pressure. This article focuses on some of the challenges related to the assessment of RV function in the setting of the RV's unique anatomic, physiologic, conventional and newer echocardiographic aspects, and therapeutic implications. The majority of proposed methods of echocardiographic assessment of RV function are based on volumetric approximations of the RV. Such approaches have inherent limitations, first as volume-related measures such as EF are load dependent, second because of the complex geometry of the RV. The issue of RV geometry is usually overcome using geometry-independent parameters such as tricuspid annular excursion and the Tei index. The recent introduction of real-time three-dimensional echocardiography and myocardial imaging echocardiography (tissue Doppler imaging, 1D-strain and 2D-strain echocardiography) implied a great progress in echocardiography. Tissue Doppler imaging allows the quantitative assessment of RV systolic and diastolic function by means of measurement of myocardial velocities. Strain measurements have been shown to correlate well with sonomicrometry segment length measurements both in the inflow and outflow tract of the RV and under different loading conditions. Other findings have been reported in chronic and acute clinical settings. Standard and novel echocardiographic methods of assessment of RV size and performance can help clinicians in the treatment of acute and chronic RV failure and contribute to a better understanding of the peculiar chamber-related functional mechanisms in the context of ventricular interdependent independency.

Effects of right ventricular ejection fraction on outcomes in chronic systolic heart failure

BACKGROUND

Studies of the effect of right ventricular ejection fraction (RVEF) on outcomes in heart failure (HF) are limited by small sample size and short follow-up.

METHODS AND RESULTS

We examined the effect of baseline RVEF on outcomes in 2008 Beta-Blocker Evaluation of Survival Trial (BEST) participants with HF and left ventricular ejection fraction <or=35% during 24 months of mean follow-up. RVEF, estimated by gated-equilibrium radionuclide ventriculography, was used to categorize patients into 4 RVEF groups: >or=40% (n=733), 30% to 39% (n=531), 20% to 29% (n=473), and <20% (n=271). Unadjusted rates for all-cause mortality in patients with RVEF >or=40%, 30% to 39%, 20% to 29%, and <20% were 27%, 32%, 35%, and 47%, respectively. When compared with patients with RVEF >or=40%, unadjusted hazard ratios and 95% confidence intervals for all-cause mortality for those with RVEF 30% to 39%, 20% to 29%, and <20% were 1.19 (0.97 to 1.46; P=0.087), 1.45 (1.17 to 1.78; P=0.001), and 1.98 (1.59 to 2.47; P<0.0001), respectively. Respective multivariable-adjusted hazard ratios (95% confidence intervals) for all-cause mortality associated with RVEF 30% to 39%, 20% to 29%, and <20% were 1.07 (0.87 to 1.32; P=0.518), 1.12 (0.89 to 1.40; P=0.328), and 1.32 (1.02 to 1.71; P=0.034), respectively. Adjusted hazard ratios (95% confidence intervals) for other outcomes associated with RVEF <20% (compared with >or=40%) were as follows: cardiovascular mortality, 1.33 (1.01 to 1.76; P=0.041); HF mortality, 1.61 (1.03 to 2.52; P=0.037); sudden cardiac death, 1.29 (0.87 to 1.91; P=0.212); all-cause hospitalization, 1.21 (1.00 to 1.47; P=0.056); and HF hospitalization, 1.39 (1.10 to 1.77; P=0.007).

CONCLUSIONS

Baseline RVEF <20% is a significant independent predictor of mortality and HF hospitalization in systolic HF.

Carvedilol inhibits proliferation of cultured pulmonary artery smooth muscle cells of patients with idiopathic pulmonary arterial hypertension

Idiopathic pulmonary arterial hypertension (IPAH) is associated with proliferation of smooth muscle cells (SMCs) in small pulmonary arteries. Inhibition of proliferation of pulmonary artery smooth muscle cells (PASMCs) may be an effective treatment of patients with idiopathic pulmonary arterial hypertension. Recent studies have shown that carvedilol, an alpha- and beta-blocker with antioxidant and calcium channel blocking properties, inhibits the proliferation of cultured normal human pulmonary artery smooth muscle cells. In this study, we tested the hypothesis that carvedilol has antiproliferative effects on pulmonary artery smooth muscle cells of patients with idiopathic pulmonary arterial hypertension. Pulmonary artery smooth muscle cells from six idiopathic pulmonary arterial hypertension patients who had undergone lung transplantation were cultured. To determine cell proliferation, H-thymidine incorporation was measured. Platelet-derived growth factor-induced proliferation of IPAH-PASMCs was significantly greater than that of normal control pulmonary artery smooth muscle cells. Carvedilol (0.1 microM to 10 microM) inhibited the proliferation of idiopathic pulmonary arterial hypertension-pulmonary artery smooth muscle cells in a concentration-dependent manner. Prazosin (an alpha-blocker) and N-acetyl L cysteine (an antioxidant agent) (0.1 microM to 10 microM) did not inhibit their proliferation, but the high concentration of propranolol (a beta-blocker) and nifedipine (a calcium channel blocker) (10 microM) inhibited the proliferation. The combination of propranolol and nifedipine inhibited the proliferation but only at a high concentration (10 microM) combination. Cell cycle analysis revealed that carvedilol (10 microM) significantly decreased the number of cells in S and G2/M phases. These results indicate that carvedilol inhibits the exaggerated proliferation of pulmonary artery smooth muscle cells of patients with idiopathic pulmonary arterial hypertension partially via its beta-blocking [corrected] and calcium channel blocking effects in vitro.

Effect of bisoprolol on right ventricular function and brain natriuretic peptide in patients with heart failure

Beta-blocker use improves left ventricular ejection fraction (LVEF) in patients with heart failure. A similar effect of b blockers on right ventricular function has been proposed, although the effect of bisoprolol, a highly selective b-1 blocker, on right ventricular function has not been assessed. This study investigated the short-term effect of bisoprolol on right ventricular function in chronic heart failure patients. A cohort of 30 heart failure patients who were not taking b blockers at baseline was studied prospectively. Right ventricular ejection fraction (RVEF) and LVEF were measured at both baseline and 4 months by radionuclide angiography. Bisoprolol was up-titrated during four monthly visits by a preestablished protocol to a target dose of 10 mg/d. The dose of vasodilators was not changed. Quality of life and brain natriuretic peptide level were assessed. Mean age was 62.7+/-14.3 years. Baseline RVEF was 30.7%+/-6.3% and baseline LVEF was 21.7%+/-9.4%. Mean bisoprolol dose reached was 5.3+/-3.9 mg daily. At 4 months, RVEF significantly increased by 7.1% (95% confidence interval, 3.9-10.2; p=0.0001) and LVEF also increased significantly by 7.9% (95% confidence interval, 4.0%-11.9%; p=0.0003). Quality-of-life score improved from 42.8 to 30.8 (p=0.047). No correlation was found between brain natriuretic peptide levels and RVEF. Bisoprolol treatment for 4 months resulted in a significant improvement of RVEF, which paralleled the improvement of LVEF.

Low-dose carvedilol improves left ventricular function and reduces cardiovascular hospitalization in Japanese patients with chronic heart failure: the Multicenter Carvedilol Heart Failure Dose Assessment (MUCHA) trial

BACKGROUND

The efficacy and optimum dose of beta-blockers have not been established in Japanese patients with chronic heart failure (CHF). The efficacy and safety of two doses of carvedilol, a beta-blocker with vasodilator and antioxidant actions, were investigated in Japanese patients with CHF.

METHODS

After screening and a carvedilol challenge phase, 174 patients with mild to moderate CHF were randomly assigned (double-blinded) to placebo, 2.5 mg of carvedilol twice daily, or 10 mg of carvedilol twice daily. After a 2- to 4-week uptitration phase, maintenance treatment was continued for 24 to 48 weeks. The primary end point was improvement of the global assessment of CHF by the attending physician. Secondary end points were death or hospitalization for cardiovascular disease, cardiovascular hospitalization, hospitalization for heart failure, change of left ventricular ejection fraction, and change in New York Heart Association class.

RESULTS

Carvedilol therapy achieved dose-dependent improvement of all end points (P for linear trend, range.002 to <.001). Both carvedilol groups showed marked risk reduction (71% to 91%) for cardiovascular and CHF hospitalization and for death or cardiovascular hospitalization (P range,.024 to <.001 for pairwise comparisons with placebo). No significant differences were observed for noncardiovascular hospitalization or adverse events.

CONCLUSIONS

In Japanese patients with mild or moderate CHF, carvedilol achieved dose-related improvement of CHF and left ventricular ejection fraction; cardiovascular hospitalization was markedly reduced. At 5 mg/d, carvedilol conferred an important patient benefit, less than at 20 mg/d.

Myocardial gene expression in dilated cardiomyopathy treated with beta-blocking agents

BACKGROUND

Beta-blocker therapy may improve cardiac function in patients with idiopathic dilated cardiomyopathy. We tested the hypothesis that beta-blocker therapy produces favorable functional effects in dilated cardiomyopathy by altering the expression of myocardial genes that regulate contractility and pathologic hypertrophy.

METHODS

We randomly assigned 53 patients with idiopathic dilated cardiomyopathy to treatment with a beta-adrenergic-receptor blocking agent (metoprolol or carvedilol) or placebo. The amount of messenger RNA (mRNA) for contractility-regulating genes (those encoding beta1- and beta2-adrenergic receptors, calcium ATPase in the sarcoplasmic reticulum, and alpha- and beta-myosin heavy-chain isoforms) and of genes associated with pathologic hypertrophy (beta-myosin heavy chain and atrial natriuretic peptide) was measured with a quantitative reverse-transcription polymerase chain reaction in total RNA extracted from biopsy specimens of the right ventricular septal endomyocardium. Myocardial levels of beta-adrenergic receptors were also measured. Measurements were conducted at base line and after six months of treatment, and changes in gene expression were compared with changes in the left ventricular ejection fraction as measured by radionuclide ventriculography.

RESULTS

Twenty-six of 32 beta-blocker-treated patients (those with complete mRNA measurements) had an improvement in left ventricular ejection fraction of at least 5 ejection-fraction (EF) units (mean [+/-SE] increase, 18.8+/-1.8). As compared with the six beta-blocker-treated patients who did not have a response (mean change, a decrease of 2.5+/-1.8 EF units), those who did have a response had an increase in sarcoplasmic-reticulum calcium ATPase mRNA and alpha-myosin heavy chain mRNA and a decrease in beta-myosin heavy chain mRNA. The change in sarcoplasmic-reticulum calcium ATPase was not present in the patients in the placebo group who had a spontaneous response. There were no differences between those who had a response and those who did not in terms of the change in mRNA or protein expression of beta-adrenergic receptors.

CONCLUSIONS

In idiopathic dilated cardiomyopathy, functional improvement related to treatment with beta-blockers is associated with changes in myocardial gene expression.

Carvedilol in the failing heart

Patients with chronic heart failure due to left ventricular systolic dysfunction of ischemic or nonischemic etiology have shown improvement in morbidity and mortality with carvedilol therapy. In patients with symptomatic (New York Heart Association class II-IV) heart failure, carvedilol improves left ventricular ejection fraction and clinical status, and slows disease progression, reducing the combined risk of mortality and hospitalization. Despite the overwhelming evidence for their benefit, there continues to be a large treatment gap between those who would derive benefit and those who actually receive the drug. In this article, the pharmacology, clinical trial evidence, and the potential differences between carvedilol and other beta blockers are discussed. Carvedilol provides powerful therapy in the treatment of chronic heart failure caused by a variety of etiologies and in a wide array of clinical settings.

Right ventricular ischemia in patients with primary pulmonary hypertension

OBJECTIVES

The goal of this study was to determine whether right ventricular (RV) ischemia is a contributory factor in the development of RV dysfunction in patients with primary pulmonary hypertension (PPH).

BACKGROUND

Patients with advanced PPH develop RV dysfunction, characterized by a decreased cardiac output, increased right atrial pressure (RAP) and/or elevated RV end-diastolic pressure, which progresses to heart failure and death. The cause of this dysfunction is unknown. Right ventricular ischemia may play a role in its development.

METHODS

From 1992 to 1999, a prospective study involving 23 patients with PPH at the Instituto Nacional de Cardiologia "Ignacio Chavez" (Mexico City, Mexico) was undertaken. These patients were evaluated clinically and further studied by echocardiography, right heart catheterization and stress myocardial scintigraphy using technetium 99m sestamibi.

RESULTS

Nine patients of 23 were found to have scintigraphic images consistent with RV ischemia. Significant correlation was found between RV ischemia obtained through myocardial perfusion scintigraphy and elevation of RV end-diastolic pressure (p < 0.001), elevation of RAP (p < 0.037) and a decrease in mixed venous oxygen saturation (p < 0.0001). No other clinical or hemodynamic variables showed a significant correlation with RV ischemia.

CONCLUSIONS

A direct correlation exists between RV ischemia, as determined by myocardial scintigraphy, and hemodynamic alterations suggestive of RV dysfunction in patients with PPH.