Effect of medical treatment on heart failure incidence in patients with a systemic right ventricle

Propensity Score Analysis of Possible Medication Effects on Outcomes in Patients With Systemic Right Ventricles

Background

Patients with systemic right ventricle (SRV), either d-transposition of the great arteries following an atrial switch procedure or congenitally corrected transposition of the great arteries, develop severe right ventricular dysfunction, prompting appropriate medical therapy. However, the efficacy of beta-blockers and angiotensin receptor blockers or angiotensin-converting enzyme inhibitors (ACEI) in SRV patients is unproven.

Objectives

The objective of this study was to determine the effects of ACEI/ARB and beta-blockers on outcomes in SRV patients after accounting for likely cofounders affecting their use.

Methods

From a retrospective, multicenter study on heart failure-related outcome in individuals with SRV, those who were taking an ACEI/ARB, beta-blocker, or both of these medication were identified. We performed a propensity analysis to match them to those not using these medications at their initial visit. Matching was based on a propensity score, which captured co-morbidities, demographics, and baseline echocardiographic parameters. Primary outcome of death, transplant, or mechanical circulatory support, and secondary outcomes of heart failure hospitalizations/atrial arrhythmias were analyzed respectively.

Results

We identified 393 patients taking ACEI/ARB or beta-blocker, or taking both a beta-blocker and ACEI/ARB (62.1% male, median age 31.3 years) and 484 patients (56.4% male, median age of 26.0 years) who were neither on a beta-blocker nor on ACEI/ARB at the time of initial clinic visit. Median follow-up was ∼8 years. After propensity matching, medication use was not associated with decreased mortality, heart failure hospitalizations, or arrhythmias. Hazard ratios remained positive for beta blockers, implying potential harm rather than benefit.

Conclusions

In this large multicenter propensity-matched observational study, patients with SRV taking beta-blockers or ACEI/ARB did not have a benefit in survival or reduced hospitalization. The likelihood of demonstrating favorable effects in larger studies appears remote.

Sacubitril/Valsartan and Dapagliflozin in Patients with a Failing Systemic Right Ventricle: Effects on the Arrhythmic Burden

Background/Objectives: Angiotensin receptor neprilysin inhibitor (ARNI) and sodium-glucose co-transporter 2 inhibitors (SGLT2i) are essential medications in heart failure (HF) therapy, and their potential antiarrhythmic effects have been reported. Recently, ARNI and SGLT2i use for HF in adult congenital heart disease (ACHD) has been studied. However, whether any beneficial effects may be achieved on the arrhythmic burden in the complex population of ACHD with a systemic right ventricle (sRV) is still to be determined. Methods: We retrospectively collected all significant arrhythmic events from a cohort of patients with a failing sRV attending our tertiary care center on optimal guideline-directed medical therapy (GDMT) with ARNI and/or SGLT2i. Results: A total of 46 patients (mean age 38.2 ± 10.7 years, 58% male) on sacubitril/valsartan were included. Twenty-three (50%) patients were also started on dapagliflozin. After a median follow-up of 36 [Q1-Q3: 34-38] months, arrhythmic events occurred globally in 13 (28%) patients. Survival analysis showed significant reduction of clinically relevant atrial and ventricular arrhythmia at follow-up (p = 0.027). Conclusions: Our findings suggest that GDMT including sacubitril/valsartan and dapagliflozin may also offer an antiarrhythmic effect in ACHD patients with a failing sRV, by reducing the incidence of arrhythmic events at follow-up.

Unlocking the Potential: Angiotensin Receptor Neprilysin and Sodium Glucose Co-Transporter 2 Inhibitors for Right Ventricle Dysfunction in Heart Failure

This review article examines the mechanism of action of Angiotensin Receptor-Neprilysin Inhibitors (ARNIs) and Sodium-Glucose Co-Transporter 2 Inhibitors (SGLT2is) in managing chronic right ventricular (RV) dysfunction. Despite advancements in heart failure (HF) treatment, RV dysfunction remains a significant contributor to morbidity and mortality. This article explores the The article explores the impact of ARNIs and SGLT2is on RV function based on clinical and preclinical evidence, and the potential benefits of combined therapy. It highlights the need for further research to optimize patient outcomes and suggests that RV function should be considered in future clinical trials as part of risk stratification for HF therapies. This review underscores the importance of the early initiation of ARNIs and SGLT2is as per guideline-directed medical therapy for eligible HFrEF and HFpEF patients to improve co-existing RV dysfunction.

External Validation of a Risk Score Model for Predicting Major Clinical Events in Adults After Atrial Switch

BACKGROUND

A risk model has been proposed to provide a patient individualized estimation of risk for major clinical events (heart failure events, ventricular arrhythmia, all-cause mortality) in patients with transposition of the great arteries and atrial switch surgery. We aimed to externally validate the model.

METHODS AND RESULTS

A retrospective, multicentric, longitudinal cohort of 417 patients with transposition of the great arteries (median age, 24 years at baseline [interquartile range, 18-30]; 63% men) independent of the model development and internal validation cohort was studied. The performance of the prediction model in predicting risk at 5 years was assessed, and additional predictors of major clinical events were evaluated separately in our cohort. Twenty-five patients (5.9%) met the major clinical events end point within 5 years. Model validation showed good discrimination between high and low 5-year risk patients (Harrell C index of 0.73 [95% CI, 0.65-0.81]) but tended to overestimate this risk (calibration slope of 0.20 [95% CI, 0.03-0.36]). In our population, the strongest independent predictors of major clinical events were a history of heart failure and at least mild impairment of the subpulmonary left ventricle function.

CONCLUSIONS

We reported the first external validation of a major clinical events risk model in a large cohort of adults with transposition of the great arteries. The model allows for distinguishing patients at low risk from those at intermediate to high risk. Previous episode of heart failure and subpulmonary left ventricle dysfunction appear to be key markers in the prognosis of patients. Further optimizing risk models are needed to individualize risk predictions in patients with transposition of the great arteries.

Novel Approaches to the Failing Congenital Heart

PURPOSE OF REVIEW

Heart failure is the leading cause of morbidity and mortality in adults with congenital heart disease and is characterized by a variety of underlying mechanisms. Here, we aim to elaborate on the medical and technological advancements in the management of heart failure in adult patients with congenital heart disease and highlight the use of imaging modalities to guide therapy.

RECENT FINDINGS

There have been several advances over the past decade with angiotensin receptor neprilysin and sodium-glucose cotransporter-2 inhibitors, atrioventricular valve clips, transcatheter pulmonary valves, catheter ablation, and cardiac resynchronization therapy, as well as the introduction of lymphatic interventions. Expanded use of echocardiography, cardiac magnetic resonance imaging, and cardiac computed tomography has guided many of these therapies. Significant innovations in the management of heart failure in adults with congenital heart disease have evolved with advancements in imaging modalities playing a critical role in guiding treatment therapies.

LCZ696 (sacubitril/valsartan) inhibits pulmonary hypertension induced right ventricular remodeling by targeting pyruvate dehydrogenase kinase 4

BACKGROUND

Right ventricular (RV) function is a major prognostic factor in patients with cardiopulmonary disease. Effective medical therapies are available for left heart failure, but they are usually less effective or even ineffective in right heart failure. Here, we tested the hypothesis that LCZ696 (sacubitril/valsartan) can attenuate pressure overload-induced RV remodeling by inhibiting pyruvate dehydrogenase kinase 4 (PDK4).

METHODS

Adult male C57 mice were subjected to transverse aortic constriction (TAC), pulmonary artery constriction (PAC), or sham surgery. Bioinformatics analysis was used to screen for common differentially expressed genes (DEGs) between TAC and PAC. Chemical compounds targeting DEGs were predicted by molecular docking analysis. Effects of LCZ696 on PAC-induced RV remodeling and the associated PDK4-related mechanisms were investigated.

RESULTS

We found 60 common DEGs between PAC and TAC, and Pdk4 was one of the downregulated DEGs. From 47 chemical compounds with potential cardiovascular activity and PDK4 protein binding ability, we selected LCZ696 to treat PAC-induced RV remodeling because of its high docking score for binding PDK4. Compared with vehicle-treated PAC mice, LCZ696-treated mice had significantly smaller RV wall thickness and RV diameters, less myocardial fibrosis, lower expression of PDK4 protein, and less phosphorylation of glycogen synthase kinase-3β (p-GSK3β). In PAC mice, overexpression of Pdk4 blocked the inhibitory effect of LCZ696 on RV remodeling, whereas conditional knockout of Pdk4 attenuated PAC-induced RV remodeling.

CONCLUSIONS

Pdk4 is a common therapeutic target for pressure overload-induced left ventricular and RV remodeling, and LCZ696 attenuates RV remodeling by downregulating Pdk4 and inhibiting PDK4/p-GSK3β signal.

Cardiac Drugs in ACHD Cardiovascular Medicine

Adult congenital heart disease (ACHD) is a growing population that requires life-long care due to advances in pediatric care and surgical or catheter procedures. Despite this, drug therapy in ACHD remains largely empiric due to the lack of clinical data, and formalized guidelines on drug therapy are currently lacking. The aging ACHD population has led to an increase in late cardiovascular complications such as heart failure, arrhythmias, and pulmonary hypertension. Pharmacotherapy, with few exceptions, in ACHD is largely supportive, whereas significant structural abnormalities usually require interventional, surgical, or percutaneous treatment. Recent advances in ACHD have prolonged survival for these patients, but further research is needed to determine the most effective treatment options for these patients. A better understanding of the use of cardiac drugs in ACHD patients could lead to improved treatment outcomes and a better quality of life for these patients. This review aims to provide an overview of the current status of cardiac drugs in ACHD cardiovascular medicine, including the rationale, limited current evidence, and knowledge gaps in this growing area.

The association between myocardial ischemia and myocardial dysfunction in adult patients with systemic right ventricle - A single centre multimodality study

BACKGROUND

The exact interaction of factors leading to myocardial dysfunction and fibrosis of the systemic right ventricle (SRV) is not completely understood. Myocardial ischemia and injury associated with a supply-demand mismatch of the pressure overloaded SRV are thought to play an important role, however studies confirming this are lacking.

METHODS

Adult SRV patients were included in this single centre cohort study. All patients underwent a comprehensive diagnostic and imaging workup. A two-day stress-rest SPECT was performed to assess myocardial perfusion. SRV ischemia was defined as decreased segmental tracer uptake during exercise with significant improvement at rest. Contrast enhanced cardiac magnetic resonance imaging (CMR) was also performed in a subgroup of patients without contraindication, to assess focal myocardial fibrosis. Differences between patients with and without SRV ischemia were assessed.

RESULTS

Twenty-three SRV patients (15 with transposition of the great arteries after atrial switch procedure and 8 with congenitally corrected transposition of the great arteries; 5 (22%) females; mean age 38 ± 11 years) were included. Seven (30%) patients had SRV ischemia on SPECT. Late gadolinium enhancement on CMR was more common in patients with SRV ischemia (p = 0.002). However, there was no association between SRV ischemia and different echocardiographic or CMR parameters of SRV systolic function, laboratory markers (high-sensitivity troponin I and NT-proBNP) and exercise capacity.

CONCLUSIONS

Our multimodality study showed that SRV ischemia in adult SRV patients was associated with more focal myocardial fibrosis, but not with functional or imaging markers of SRV function.

Echo-Doppler and strain assessment of filling pressures in adults with congenitally corrected transposition and systemic right ventricles

AIMS

Systolic dysfunction of the systemic right ventricle (sRV) is common in adults with transposition of the great arteries and sRV. In acquired disease, diastology analysis for assessment of filling pressures (FP) is paramount in patient care.

METHODS AND RESULTS

Retrospective analysis of 47 adults with sRV without prior systemic tricuspid valve surgery undergoing catheterization and echocardiography within 7 days (median -2 [-1, -3]) from January 2000 to February 2021 at our institution. Median age was 48 (31, 55) years, and 16 (34.0%) patients were female. FPs were normal in 21 patients (44.7%). Left atrial size was enlarged in most patients (83.0%) with mean indexed value 58.3 ± 23.4 mL/m2. Tissue Doppler e' was not significantly different between those with high FPs vs. normal (medial 0.07 ± 0.03 vs. 0.08 ± 0.03 m/s, P = 0.63; lateral 0.08 ± 0.04 vs. 0.08 ± 0.04 m/s, P = 0.88). E velocity and subpulmonic mitral regurgitant velocity were higher in those with high FPs (0.9 ± 0.3 vs. 0.6 ± 0.2 m/s, P = 0.005; 3.8 ± 1.1 vs. 2.8 ± 0.9 m/s, P = 0.004). Left atrial reservoir strain, sRV global longitudinal strain, and subpulmonic left ventricular strain were worse in those with high FP (18.0 ± 7.6 vs. 27.9 ± 10.2%, P = 0.0009; -13.0 ± 4.4 vs. -17.9 ± 5.0%, P = 0.002; -16.8 ± 5.7 vs. -23.0 ± 3.8%, P = 0.001).

CONCLUSION

Despite the complex anatomy, FPs can be assessed non-invasively in adults with sRV without prior systemic tricuspid valve surgery. The current guideline algorithm for diastolic dysfunction in acquired heart disease has limited applicability in this population. Given the limitations of Doppler in this heterogeneous population, strain analysis can be a helpful adjunct for estimation of FPs.

Heart failure in systemic right ventricle: Mechanisms and therapeutic options

d-loop transposition of the great arteries (d-TGA) and congenitally corrected transposition of the great arteries (cc-TGA) feature a right ventricle attempting to sustain the systemic circulation. A systemic right ventricle (sRV) cannot support cardiac output in the long run, eventually decompensating and causing heart failure. The burden of d-TGA patients with previous atrial switch repair and cc-TGA patients with heart failure will only increase in the coming years due to the aging adult congenital heart disease population and improvements in the management of advanced heart failure. Clinical data still lags behind in developing evidence-based guidelines for risk stratification and management of sRV patients, and clinical trials for heart failure in these patients are underrepresented. Recent studies have provided foundational data for the commencement of robust clinical trials in d-TGA and cc-TGA patients. Further insights into the multifactorial nature of sRV failure can only be provided by the results of such studies. This review discusses the mechanisms of heart failure in sRV patients with biventricular circulation and how these mediators may be targeted clinically to alleviate sRV failure.

Comparing Long-Term Sequelae of the Systemic Right Ventricle: An Overview of Single Versus Biventricular Arrangements

Patients with systemic right ventricles (RV) are at risk for heart failure and sudden cardiac death. Contributing factors to RV dysfunction include increased afterload from the systemic circulation, coronary insufficiency, progressive tricuspid valve regurgitation, the presence of residual lesions after palliation and arrhythmias. While all patients with a systemic right ventricle (SRV) are vulnerable to heart failure, there are distinct differences between patients with congenital dextro-transpostion of the great arteries (d-TGA) repaired by atrial switch, unrepaired congenitally corrected transposition of the great arteries (cc-TGA) and single systemic right ventricles palliated with a Fontan operation. Herein, we explore both the similarities and differences in progression of heart failure by phenotype as well as both the advancements and limitations in treatment options by each type of SRV.

The systemic right ventricle in adult congenital heart disease: why is it still such a challenge and is there any hope on the horizon?

PURPOSE OF REVIEW

Adult congenital heart disease patients with systemic right ventricle comprise a distinctly clinically challenging group of patients with increased morbidity and mortality. This article aims to review the different subgroups, most common complications and different treatment strategies.

RECENT FINDINGS

Most commons long-term complications include heart failure and arrhythmias. Heart failure medical therapy treatments include several new agents, which show promise in systemic right ventricle patients. In addition, interventional therapies to mitigate atrioventricular valve regurgitation, baffle/conduit stenosis are discussed. Furthermore, several electrophysiological approaches to manage tachyarrhythmias as well as bradycardias are discussed. There is ongoing excitement on the new medical as well as interventional therapies that could provide benefit in additional to standard goal-directed medical therapy.

SUMMARY

There is an array of medications as well as interventions aimed to treat patients with systemic right ventricle with limited benefits. A multidisciplinary approach with a prudent combination of such therapies to maximize benefit is imperative. This article reviews the data supporting such therapies.