Early and Late Effects of Cardiac Resynchronization Therapy in Adult Congenital Heart Disease

Long Term Efficacy and Safety of Cardiac Resynchronization Therapy in Adult Congenital Heart Disease Patients: A Single Center Cohort Study

Heart failure constitutes a major cause for morbidity amongst patients with adult congenital heart disease (ACHD). Cardiac resynchronization therapy (CRT) is a recommended therapeutic measure for patients with heart failure. Data on the efficacy and safety of CRT amongst patients with ACHD is limited. This study analyzed data from a retrospective cohort of patients with ACHD and implantation of CRT between 2015 and 2022. The primary outcome was echocardiographic response to CRT, defined as either: (1) an increase in systemic ventricular ejection fraction (EF) of ≥ 5% in patients with baseline EF <50% (therapeutic efficacy) or (2) maintenance of EF in patients with EF ≥ 50% (preventative efficacy). The outcomes were assessed by subgroups of systemic left or right ventricle ventricle. In a cohort of 45 patients, mean age was 54 ± 14 years, 26 patients had a systemic left ventricle (57.8%) and 19 patients had a systemic right ventricle (42.2%). The average follow-up was 5.2 ± 0.5 years. Primary outcome amongst patients with reduced EF at baseline was achieved in 69.0%; and in 92.3% amongst patients with preserved EF at baseline. There was no significant difference in the response to CRT as per systemic left or right ventricle (p = 0.15) or per baseline EF (p = 0.10). Complications occurred in 28.9% of patients. In conclusion, CRT appears to be effective in patients with ACHD in reducing rates of heart failure, regardless of baseline EF or systemic ventricle morphology. The percentage of patients with a safety outcome was relatively high and highlights the need for careful patient selection.

Role of subpulmonary right ventricle in sudden cardiac death in adults with congenital heart disease

Despite improved childhood survival of congenital heart disease (CHD) as a result of advances in management, late-onset sudden cardiac death (SCD) from malignant ventricular arrhythmias remains a leading cause of mortality in adults with CHD. Preventing SCD in these patients requires an understanding of the underlying pathophysiological mechanisms. Many CHD patients experience significant hemodynamic stress on the subpulmonary right ventricle (RV), leading to pathologic remodeling. Unlike acquired heart disease in which left ventricular pathology is prevalent, RV pathologies are crucial in the SCD pathogenesis in CHD patients. This review examines the mechanisms and management of SCD related to subpulmonary RV pathologies in CHD patients.

Interventional Cardiac Electrophysiology for the Management of Adults With Congenital Heart Disease

Congenital heart disease (CHD) is the most common congenital anomaly in newborns. Advances in catheter and surgical techniques led to the majority of these patients surviving into adulthood, leading to evolving challenges due to the emergence of long-term complications such as arrhythmias. Interventional electrophysiology (EP) has had remarkable advances over the last few decades, and various techniques and devices have been explored to treat adult patients with CHD. This comprehensive review aims to summarize findings from recent studies exploring advances in the use of interventional electrophysiology to manage adult patients with CHD. While pacemaker therapy has some indications in adults with CHD, various long-term consequences include pacing-induced cardiomyopathy and complications requiring reintervention. Cardiac resynchronization therapy has shown promising results in some studies to treat CHD patients with heart failure, although further research to clarify guidelines is encouraged. Implantable cardiac defibrillators have demonstrated clear benefits in CHD patients and are indicated for primary prevention of sudden cardiac death, although selection criteria for secondary prevention of sudden cardiac death are uncertain. Catheter ablation has also been used for various atrial and ventricular arrhythmias in patients with CHD with high success rates, although the likelihood of success depends on patient characteristics and the type of arrhythmia, and multidisciplinary assessment is encouraged to improve the chance of successful therapy.

Outcomes of cardiac resynchronization therapy in congenital heart disease: A meta-analysis and systematic review

INTRODUCTION

Cardiac resynchronization therapy (CRT) is a standard treatment for patients with heart failure with reduced ejection fraction. However, there is still a gap of evidence in congenital heart disease (CHD) patients regarding resynchronization therapy.

METHODS

We performed a meta-analysis and systematic review of CHD patients who received CRT implantation. We comprehensively searched the databases of MEDLINE, EMBASE, and Cochrane database from inception to June 2023. Studies that reported response rate to CRT, total mortality rate, change in QRS duration, change in left ventricular ejection fraction, and change in New York Heart Association functional class were included.

RESULTS

A total of 14 studies were included in the study. There were 10 studies that reported response rates after implantation. The overall response rate to CRT in CHD patients was 68% (95% confidence interval [CI] 61%-75%, I2 32%). The response rates in patients with systemic right ventricle (RV), systemic left ventricle (LV), and single ventricle were 58% (95% CI 46%-70%, I2 0%), 80% (95% CI 74%-86% I2 14%), and 67% (95% CI 49%-80% I2 0%). Response to CRT in systemic RV was inferior to systemic LV with an odds ratio of 0.38 (95% CI 0.15-0.95, I2 38%). The total mortality rate from seven studies was 12% (95% CI 8%-18%, I2 55%). The parameters which represented ventricular dyssynchrony improved after CRT implantation.

CONCLUSION

The overall response rate to CRT in CHD was 68%. Patients with systemic RV had a lower response rate to CRT when compared to patients with systemic LV. The total mortality rate after CRT implantation was 12%.

Novel Therapeutic Strategies in Heart Failure in Adult Congenital Heart Disease: of Medicines and Devices

PURPOSE OF REVIEW

This paper reviews the latest literature on the growing field of heart failure in the adult congenital heart disease population.

RECENT FINDINGS

After highlighting the increasing prevalence and a few of the unique potential causes, including the concept of early senescence, this review begins with novel medical management strategies such as the angiotensin II receptor blocker and neprilysin inhibitors and sodium glucose cotransporter-2 inhibitors. Then, it addresses the latest applications of percutaneous techniques like implantable hemodynamic monitoring, transcatheter pulmonary and aortic valve replacement, and mitral clips. Cardiac resynchronization therapy and novel lymphatic system imaging and intervention are then described. Finally, the use of mechanical support devices, temporary and durable, is discussed as well as heart and combined heart and liver transplantation. There have been recent exciting advances in the strategies used to manage adult congenital heart disease patients with heart failure. As this population continues to grow, it is likely we will see further rapid evolution in this field.

2023 HRS/APHRS/LAHRS guideline on cardiac physiologic pacing for the avoidance and mitigation of heart failure

Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

2023 HRS/APHRS/LAHRS guideline on cardiac physiologic pacing for the avoidance and mitigation of heart failure

Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

Late Outcomes of Pediatric and Congenital Heart Disease Patients Following Cardiac Resynchronization Therapy

BACKGROUND AND OBJECTIVES

Cardiac resynchronization therapy (CRT) is an effective treatment for heart failure. However, in pediatric and congenital heart disease (CHD) patients, current adult indications cannot be directly applied because of heterogeneity in anatomy and diagnosis. Therefore, CRT responses and clinical outcomes in these patients were investigated to derive possible candidates for CRT.

METHODS

This study retrospectively analyzed 16 pediatric and CHD patients who underwent CRT implantation at a single center in early (0.7±0.2 year) and late (4.7±0.3 years) follow-up period after CRT.

RESULTS

The median age at CRT implantation was 2.5 (0.3-37.2) years, and median follow-up duration was 6.3 (0.1-13.6) years. Thirteen had non-transvenous CRT. Two had congenital complete atrioventricular (AV) block with previous right ventricular pacing, 5 had dilated cardiomyopathy (DCM) with left bundle branch block, and 9 had CHD. The mean ejection fraction of the systemic ventricle increased from 28.1±10.0% to 44.3±21.0% (p=0.003) in early and 51.8±16.3% (p=0.012) in late outcome. The mean functional class improved from 3.1±0.9 to 1.8±1.1 after CRT (p=0.003). Twelve patients (75%) showed improvement in ventricular function or functional class after CRT. Proportion of responders differed between patients without CHD (2/2 patients with complete AV block and 5/5 with DCM, 100%) and those with CHD (5/9, 56%), although statistical significance was not reached (p=0.088).

CONCLUSIONS

CRT improved ventricular function and functional status according to the underlying condition in pediatric and CHD patients. However, further large and longer-term studies are needed to establish the guideline for the patient selection of CRT in these patients.

Cardiac Resynchronization Therapy for Adult Patients With a Failing Systemic Right Ventricle: A Multicenter Study

Background

The objective of this international multicenter study was to investigate both early and late outcomes of cardiac resynchronization therapy (CRT) in patients with a systemic right ventricle (SRV) and to identify predictors for congestive heart failure readmissions and mortality.

Methods and Results

This retrospective international multicenter study included 13 centers. The study population comprised 80 adult patients with SRV (48.9% women) with a mean age of 45±14 (range, 18–77) years at initiation of CRT. Median follow‐up time was 4.1 (25th–75th percentile, 1.3–8.3) years. Underlying congenital heart disease consisted of congenitally corrected transposition of the great arteries and dextro‐transposition of the great arteries in 63 (78.8%) and 17 (21.3%) patients, respectively. CRT resulted in significant improvement in functional class (before CRT: III, 25th–75th percentile, II–III; after CRT: II, 25th–75th percentile, II–III; P =0.005) and QRS duration (before CRT: 176±27; after CRT: 150±24 milliseconds; P =0.003) in patients with pre‐CRT ventricular pacing who underwent an upgrade to a CRT device (n=49). These improvements persisted during long‐term follow‐up with a marginal but significant increase in SRV function (before CRT; 30%, 25th–75th percentile, 25–35; after CRT: 31%, 25th–75th percentile, 21–38; P =0.049). In contrast, no beneficial change in the above‐mentioned variables was observed in patients who underwent de novo CRT (n=31). A quarter of all patients were readmitted for heart failure during follow‐up, and mortality at latest follow‐up was 21.3%.

Conclusions

This international experience with CRT in patients with an SRV demonstrated that CRT in selected patients with SRV dysfunction and pacing‐induced dyssynchrony yielded consistent improvement in QRS duration and New York Heart Association functional status, with a marginal increase in SRV function.

Cardiac resynchronization therapy in patients with congenital heart disease and systemic right ventricle

BACKGROUND

Although patients with systemic right ventricle (SRV) represent a significant proportion of patients with congenital heart disease (CHD) implanted with cardiac resynchronization therapy (CRT), there are limited and conflicting data in this specific patient group.

OBJECTIVE

We aimed to analyze outcomes of patients with SRV implanted with a CRT device.

METHODS

Data were analyzed from an observational, retrospective, multicenter cohort study including all patients with CHD implanted with a CRT device from 6 French centers from 2004 to 2020. Response to CRT was defined as an increase in systemic ventricular ejection fraction of ≥10% and/or an improvement in New York Heart Association functional class by at least 1 grade.

RESULTS

A total of 85 patients with CHD were enrolled (mean age 39.8 ± 20.0 years; 55 [64.7%] males; 25 defibrillators [29.4%]), including 31 patients with SRV (36.5%) (mean age 43.9 ± 19.8 years; 16 [51.6%] males). The mean change in QRS duration after implantation was similar as compared with patients with systemic left ventricle (-46 ± 26 ms vs -35 ± 32 ms; P = .16). During a mean follow-up of 5.1 ± 3.5 years, late complications included 2 lead dysfunctions (6.5%), 3 CRT-related infections (9.7%), and 1 inappropriate implantable cardioverter-defibrillator shock (3.2%). The proportion of CRT responders at 6, 12, and 24 months were 82.6%, 80.0%, and 77.8% in patients with SRV vs 66.7%, 64.3%, and 69.6% in patients with systemic left ventricle (P = NS).

CONCLUSION

In this multicenter cohort, one-third of patients with CHD implanted with a CRT device had SRV. CRT in patients with SRV was associated with a high rate of responders, comparable to that of patients with systemic left ventricle.

Clinical Course Long After Atrial Switch: A Novel Risk Score for Major Clinical Events

Background

Patients with transposition of the great arteries corrected by an atrial switch operation experience major clinical events during adulthood, mainly heart failure (HF) and arrhythmias, but data on the emerging risks remain scarce. We assessed the risk for events during the clinical course in adulthood, and provided a novel risk score for event‐free survival.

Methods and Results

This multicenter study observed 167 patients with transposition of the great arteries corrected by an atrial switch operation (61% Mustard procedure; age, 28 [interquartile range, 24–36] years) for 13 (interquartile range, 9–16) years, during which 16 (10%) patients died, 33 (20%) had HF events, defined as HF hospitalizations, heart transplantation, ventricular assist device implantation, or HF‐related death, and 15 (9%) had symptomatic ventricular arrhythmias. Five‐year risk of mortality, first HF event, and first ventricular arrhythmia increased from 1% each at age 25 years, to 6% (95% CI, 4%–9%), 23% (95% CI, 17%–28%), and 5% (95% CI, 2%–8%), respectively, at age 50 years. Predictors for event‐free survival were examined to construct a prediction model using bootstrapping techniques. A prediction model combining age >30 years, prior ventricular arrhythmia, age >1 year at repair, moderate or greater right ventricular dysfunction, severe tricuspid regurgitation, and mild or greater left ventricular dysfunction discriminated well between patients at low (<5%), intermediate (5%–20%), and high (>20%) 5‐year risk (optimism‐corrected C‐statistic, 0.86 [95% CI, 0.82–0.90]). Observed 5‐ and 10‐year event‐free survival rates in low‐risk patients were 100% and 97%, respectively, compared with only 31% and 8%, respectively, in high‐risk patients.

Conclusions

The clinical course of patients undergoing atrial switch increasingly consists of major clinical events, especially HF. A novel risk score stratifying patients as low, intermediate, and high risk for event‐free survival provides information on absolute individual risks, which may support decisions for pharmacological and interventional management.

Cardiac resynchronization therapy for the failing systemic right ventricle: A systematic review

Patients with a systemic right ventricle (SRV) are at high risk for development of heart failure early in life. An SRV is encountered in patients with congenitally corrected transposition of the great arteries (CCTGA) or dextro-transposition of the great arteries (DTGA) with previous atrial switch repair (Mustard or Senning procedure). Progressive heart failure is one of the leading cause of mortality in these patients. Therefore, cardiac resynchronization therapy (CRT) has gained increasing momentum for use in this challenging congenital heart disease (CHD) population. However, current guidelines differ in recommendations for CRT in patients with an SRV as evidence supporting CRT has thus far only been described in case reports and retrospectively in relatively small study populations. In fact, the European Society of Cardiology Guideline for the management of grown-up congenital heart disease consider CRT to be 'experimental' in this population. This systematic review critically summarizes current literature on CRT in SRV patients and provides future perspectives for further research in this challenging and growing CHD population.

Diagnosis and treatment of right ventricular dysfunction in congenital heart disease

Right ventricular (RV) function is important for clinical status and outcomes in children and adults with congenital heart disease (CHD). In the normal RV, longitudinal systolic function is the major contributor to global RV systolic function. A variety of factors contribute to RV failure including increased pressure- or volume-loading, electromechanical dyssynchrony, increased myocardial fibrosis, abnormal coronary perfusion, restricted filling capacity and adverse interactions between left ventricle (LV) and RV. We discuss the different imaging techniques both at rest and during exercise to define and detect RV failure. We identify the most important biomarkers for risk stratification in RV dysfunction, including abnormal NYHA class, decreased exercise capacity, low blood pressure, and increased levels of NTproBNP, troponin T, galectin-3 and growth differentiation factor 15. In adults with CHD (ACHD), fragmented QRS is independently associated with heart failure (HF) symptoms and impaired ventricular function. Furthermore, we discuss the different HF therapies in CHD but given the broad clinical spectrum of CHD, it is important to treat RV failure in a disease-specific manner and based on the specific alterations in hemodynamics. Here, we discuss how to detect and treat RV dysfunction in CHD in order to prevent or postpone RV failure.

Implantable cardiac electronic device therapy for patients with a systemic right ventricle

The systemic right ventricle (SRV), defined as the morphological right ventricle supporting the systemic circulation, is relatively common in congenital heart disease (CHD). Our review aimed at examining the current evidence, knowledge gaps and technical considerations regarding implantable cardiac electronic device therapy in patients with SRV. The risk of sinus node dysfunction (SND) after atrial switch repair and/or complete heart block in congenitally corrected transposition of great arteries requiring permanent pacing increases with age. Similar to acquired heart disease, indication for pacing includes symptomatic bradycardia, SND and high degree atrioventricular nodal block. Right ventricular dysfunction and heart failure also represent important complications in SRV patients. Cardiac resynchronisation therapy (CRT) has been proposed to improve systolic function in SRV patients, although indications for CRT are not well defined and its potential benefit remains uncertain. Amongst adult CHD, patients with SRV are at the highest risk for sudden cardiac death (SCD). Nevertheless, risk stratification for SCD is scarce in this cohort and implantable cardioverter-defibrillator indication is currently limited to secondary prevention. Vascular access and the incidence of device-related complications, such as infections, inappropriate shocks and device system failure, represent additional challenges to implantable cardiac electronic device therapy in patients with SRV. A multidisciplinary approach with tertiary expertise and future collaborative research are all paramount to further the care for this challenging nonetheless ever increasing cohort of patients.

Early and Late Effects of Cardiac Resynchronization Therapy in Adult Congenital Heart Disease

Background

There are limited data about cardiac resynchronization therapy (CRT) in adult congenital heart disease. We aimed to assess early and late outcomes of CRT among patients with adult congenital heart disease.

Methods and Results

We retrospectively studied 54 patients with adult congenital heart disease (median age, 46 years; range, 18–73 years; 74% men) who received CRT implantation (biventricular paced >90%) between 2004 and 2017. Clinical and echocardiographic data were analyzed at baseline and early (mean±SD: 1.8±0.8 years) and late (4.7±0.8 years) follow‐up after CRT. Compared with baseline, CRT was associated with significant improvement at early follow‐up in New York Heart Association functional class, QRS duration, and cardiothoracic ratio (P<0.05 for all); improvement in New York Heart Association class was sustained at late follow‐up. Among patients with a systemic left ventricle (LV; n=39), there was significant increase in LV ejection fraction and reduction in LV end‐systolic volume at early and late follow‐up (P<0.05 for both). For patients with a systemic right ventricle (n=15), there was a significant early but not late reduction in systemic right ventricular basal and longitudinal diameters. Eleven patients died, and 2 had heart transplantation unrelated to systemic ventricular morphological characteristics. Thirty‐five patients (65%) responded positively to CRT, but only baseline QRS duration was predictive of a positive response.

Conclusions

CRT results in sustained improvement in functional class, systemic LV size, and function. Patients with a systemic LV and prolonged QRS duration, independent of QRS morphological characteristics, were most likely to respond to CRT.