Predictors of sudden cardiac death after Mustard or Senning repair for transposition of the great arteries

Lead Extraction and Baffle Stenting in a Patient with Transposition of the Great Arteries

This case report discusses a 42-year-old male with dextro-transposition of the great arteries (D-TGA) status post Mustard repair and sick sinus syndrome status post dual-chamber pacemaker implant, who developed symptomatic superior vena cava (SVC) baffle stenosis. He was treated with a combined pacemaker extraction and subsequent SVC baffle stenting. The case highlights the complexities of treating SVC baffle stenosis in the presence of cardiac implantable devices and demonstrates the efficacy of this combined approach. Furthermore, the authors delve into the intricacies of D-TGA, its surgical history, and the long-term complications associated with atrial switch procedures.

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.

Arrhythmias in Adult Congenital Heart Disease Heart Failure

Heart failure and arrhythmias represent 2 major causes of mortality and morbidity in adults with congenital heart disease. Arrhythmias and heart failure are interdependent, and one may exacerbate the other. Treatment of one also has a positive impact on the other. Management approaches need to be multifaceted, including pharmacotherapy, optimization of hemodynamic status with catheter-based or surgical interventions, and specific management of arrhythmia with device or catheter ablation therapy.

Special Considerations for Mechanical Circulatory Support or Device Therapy in Adult Congenital Heart Disease Heart Failure

Heart failure has become the leading cause of mortality in adult congenital heart disease (ACHD) patients after the fifth decade of life. There is scanty evidence supporting the use of guideline-directed medical therapy in ACHD, especially in systemic right ventricle or single ventricle physiology. In complex patients, diagnosing heart failure and timely referral for advanced therapies are challenging. Mechanical circulatory support has been significantly developed over the past decade and has recently emerged as a feasible therapeutic option for these patients. This review summarizes current evidence of mechanical circulatory support in this population, its potential uses, and challenges.

Complex Congenital Heart Disease in the Adult

Congenital heart disease (CHD), a heterogeneous group of structural abnormalities of the cardiovascular system, is the most frequent cause of severe birth defects. Related to improved pediatric outcomes, there are now more adults living with CHD, including complex lesions, than children. Adults with CHD are at high risk for complications related to their underlying anatomy and past surgical palliative interventions. Adults with CHD require close monitoring and proactive management strategies to improve outcomes.

Arrhythmias in Patients with Congenital Heart Disease: An Ongoing Morbidity

With the aging of congenital heart disease (CHD) patients, the burden of arrhythmias is expanding. Atrial arrhythmias, especially intra-atrial reentrant tachycardia and atrial fibrillation, are the most prevalent forms of arrhythmia. Managing comorbidities, such as obesity, using pharmacotherapy, including antiarrhythmics and anticoagulants, and ablation therapy has become the cornerstone of arrhythmia management. Ventricular tachycardias are also not rare; however, except for tetralogy of Fallot patients, recommendations for the use of implantable cardioverter defibrillators for primary prevention in other CHD patients are still not well established. Patients with CHD might also present with atrioventricular blockages because of their anatomy or following a surgical procedure. The scope of this article is to review the current knowledge and discuss the future directions regarding arrhythmia management in CHD patients.

Ventricular Arrhythmias in Adults With Congenital Heart Disease, Part II: JACC State-of-the-Art Review

There are marked variations in the incidence of sudden cardiac death (SCD) and in the substrates for ventricular arrhythmias (VAs) across the gamut of congenital heart defects. In this 2-part review, patients with higher-risk forms of congenital heart disease (CHD) were conceptually categorized into those with discrete anatomic isthmuses for macro-reentrant ventricular tachycardia (VT) (Group A) and those with more diffuse or less well-defined substrates (Group B) that include patchy or extensive myocardial fibrosis. The latter category encompasses CHD lesions such as Ebstein anomaly, transposition of the great arteries with a systemic right ventricle (RV), and congenital aortic stenosis. For Group B patients, polymorphic VT and ventricular fibrillation account for a higher proportion of VA. The prognostic value of programmed ventricular stimulation is less well established, and catheter ablation plays a less prominent role. As cardiomyopathies evolve over time, pathophysiological mechanisms for VA among Groups A and B become increasingly blurred.

Overview of Long-Term Outcome in Adults with Systemic Right Ventricle and Transposition of the Great Arteries: A Review

The population of patients with a systemic right ventricle (sRV) in biventricular circulation includes those who have undergone an atrial switch operation for destro-transposition of the great arteries (d-TGA) and those with congenitally corrected transposition of the great arteries (ccTGA). Despite the life expectancy of these patients is significantly increased, the long-term prognosis remains suboptimal due to late complications such as heart failure, arrhythmias, and premature death. These patients, therefore, need a close follow-up to early identify predictive factors of adverse outcomes and to implement all preventive therapeutic strategies. This review analyzes the late complications of adult patients with an sRV and TGA and clarifies which are risk factors for adverse prognosis and which are the therapeutic strategies that improve the long-term outcomes. For prognostic purposes, it is necessary to monitor sRV size and function, the tricuspid valve regurgitation, the functional class, the occurrence of syncope, the QRS duration, N-terminal pro B-type natriuretic peptide levels, and the development of arrhythmias. Furthermore, pregnancy should be discouraged in women with risk factors. Tricuspid valve replacement/repair, biventricular pacing, and implantable cardioverter defibrillator are the most important therapeutic strategies that have been shown, when used correctly, to improve long-term outcomes.

Mid-Term Outlook Following Modified Senning's Operation for the Correction of Transposition of the Great Arteries: A Case Series and Review of Literature

At the time of writing, two patients who underwent modified Senning's operation (MSO) for the treatment of transposition of great arteries (TGAs) were followed up. At the time of surgery, the patients were three months and 15 years old, respectively. The duration of the follow-up was three years, during which there was a good prognosis, and hence no further invasive treatments were required. There was normal functioning of the right ventricle (RV) in both patients, with the exception of a minor baffle leak in the three-month-old patient. At the annual three-year follow-up, the tricuspid regurgitation (systemic atrioventricular valve) status was moderate in the three-year-old child and mild in the 18-year-old girl. Both patients maintained sinus rhythm and are assigned classification as New York Heart Association (NYHA) Classes I and II. This study aims to assess the midterm outlook after MSO in order to identify and manage future long-term complications. Our report shows a positive outcome in terms of survival and functional activities among children with d-TGA; however, there is a strong need for future research to evaluate the prognosis in the long term (LT) and to assess the functioning of RV.

Incidence and Clinical Predictors of Early and Late Complications of Implantable Cardioverter-Defibrillators in Adults With Congenital Heart Disease

BACKGROUND

The implantable cardioverter-defibrillator (ICD) has been proven to improve survival in adults with congenital heart disease (ACHD), but it is associated with a high rate of complications. We aimed to quantify the incidence of early (≤ 3 months; ECs) and late (> 3 months; LCs) complications in ACHD patients implanted with an ICD and to identify their clinical predictors.

METHODS

We retrospectively reviewed 207 patients who had ICD follow-up at Toronto General Hospital from 1996 to 2019.

RESULTS

The most common diagnoses were tetralogy of Fallot (32.4%), dextro-transposition of the great arteries (17.9%), and congenital corrected transposition of the great arteries (13%). No intraprocedural complications were observed. Median follow-up was 3.4 years (IQR 0.1-23). 24 patients (12%) developed EC (4 hematomas, 20 lead dislodgements). A total of 56 LCs occurred (46% lead failure, 21% infection, 11% prophylactic lead extraction, 9% neurologic pain, 9% erosion, 4% other) with an incidence rate of LCs of 18% per 5 person-years. Anatomic complexity (odds ratio 2.9; P = 0.02) and cardiac resynchronization therapy defibrillator implant (odds ratio 2.5; P = 0.04) were associated with ECs. Survival rates free from LCs were 92%, 86%, and 65%, respectively, after 1, 5, and 10 years. Presence of legacy leads (hazard ratio 2.9; P = 0.006) and subpulmonary ejection fraction (5% increase, hazard ratio 1.35; P = 0.031) were associated with LCs.

CONCLUSIONS

ACHD patients at risk of sudden cardiac death continue to benefit from newer device technology. However, these patients, particularly those with greater anatomic and device complexity, remain at increased risk of developing complications over their lifetime. Given the life expectancy of this population, careful consideration needs to be given when a device for primary prevention is being contemplated.

Wearable cardioverter-defibrillator (life-vest): A feasible bridging treatment in adult congenital heart disease

BACKGROUND

Wearable cardioverter-defibrillators (WCDs) are currently used in patients at temporarily heightened risk for sudden cardiac death (SCD) who are temporarily unable to receive an implantable cardioverter-defibrillator (ICD). WCD can safely record and terminate life-threatening arrhythmias through a non-invasive electrode-based system. The current clinical indications for WCD use are varied and keep evolving as experience with this technology increases.

METHODS

We reviewed and explored the data behind indications for WCD use and discuss its usefulness in congenital heart disease (CHD) patients.

RESULTS

We considered 8 consecutive patients (mean age 35.25 years, range 18-51 years, average duration of WCD use 4 months, range 3-6 months) with complex CHD, in which a WCD was used between June 2018 and January 2022. No sustained ventricular arrhythmias requiring shocks were recorded in the observation period. No inappropriate shocks were recorded. All the patients showed a good compliance and a very high mean wear time per day (21.2 ± 1 h a day). Four patients implanted a permanent device (3 CRT-D, 1 ICD), three underwent cardiac surgery at the end of the WCD period and one is still on the waiting list for the operation.

CONCLUSIONS

Larger trial could confirm the possible conceivable benefit from an extended use of the WCD in certain populations with complex CHD as in our case series, especially in patients with life-treating ventricular arrhythmias waiting for surgery for residual cardiac defects or in the early phases following the surgical/hemodynamic interventions, patients with tachycardiomyopathy expected to improve after the arrhythmias are removed and patients awaiting implantation of an ICD at high risk due to active infection.

Late outcome, therapy and systemic ventricular function in patients with a systemic right ventricle: data of the German National Register for Congenital Heart Defects

BACKGROUND

Adults with systemic right ventricle have a significant risk for long-term complications such as arrhythmias or heart failure.

METHODS

A nationwide retrospective study based on the German National Register for Congenital Heart Disease was performed. Patients with transposition of the great arteries after atrial switch operation or congenitally corrected TGA were included.

RESULTS

Two hundred and eight-five patients with transposition of the great arteries after atrial switch operation and 95 patients with congenitally corrected transposition of the great arteries were included (mean age 33 years). Systolic function of the systemic ventricle was moderately or severely reduced in 25.5 % after atrial switch operation and in 35.1% in patients with congenitally corrected transposition. Regurgitation of the systemic atrioventricular valve was present in 39.5% and 43.2% of the cases, respectively. A significant percentage of patients also had a history for supraventricular or ventricular arrhythmias. However, polypharmacy of cardiovascular drugs was rare (4.5%) and 38.5 % of the patients did not take any cardiovascular medication. The amount of cardiovascular drugs taken was associated with NYHA class as well as systemic right ventricular dysfunction. Patients with congenitally corrected transposition were more likely to receive pharmacological treatment than patients after atrial switch operation.

CONCLUSION

A significant portion of patients with systemic right ventricle suffer from a relevant systemic ventricular dysfunction, systemic atrioventricular valve regurgitation, and arrhythmias. Despite this, medication for heart failure treatment is not universally used in this cohort. This emphasises the need for randomised trials in patient with systemic right ventricle.

Cause‐Specific Mortality in Patients During Long‐Term Follow‐Up After Atrial Switch for Transposition of the Great Arteries

Background

Little is known about the cause of death (CoD) in patients with transposition of the great arteries palliated with a Mustard or Senning procedure. The aim was to describe the CoD for patients with the Mustard and Senning procedure during short‐ (<10 years), mid‐ (10–20 years), and long‐term (>20 years) follow‐up after the operation.

Methods and Results

This is a retrospective, descriptive multicenter cohort study including all Nordic patients (Denmark, Finland, Norway, and Sweden) who underwent a Mustard or Senning procedure between 1967 and 2003. Patients who died within 30 days after the index operation were excluded. Among 968 patients with Mustard/Senning palliated transposition of the great arteries, 814 patients were eligible for the study, with a mean follow‐up of 33.6 years. The estimated risk of all‐cause mortality reached 36.0% after 43 years of follow‐up, and the risk of death was highest among male patients as compared with female patients ( P =0.004). The most common CoD was sudden cardiac death (SCD), followed by heart failure/heart transplantation accounting for 29% and 27%, respectively. During short‐, mid‐, and long‐term follow‐up, there was a change in CoD with SCD accounting for 23.7%, 46.6%, and 19.0% ( P =0.002) and heart failure/heart transplantation 18.6%, 22.4%, and 46.6% ( P =0.0005), respectively.

Conclusions

Among patients corrected with Mustard or Senning transposition of the great arteries, the most common CoD is SCD followed by heart failure/heart transplantation. The CoD changes as the patients age, with SCD as the most common cause in adolescence and heart failure as the dominant cause in adulthood. Furthermore, the risk of all‐cause mortality, SCD, and death attributable to heart failure or heart transplantation was increased in men >10 years after the Mustard/Senning operation.

Atrial Arrhythmia Ablation in Patients With D-Transposition of the Great Arteries and Atrial Switch

BACKGROUND

Patients with D-transposition of the great arteries and atrial switch have a high incidence of atrial arrhythmias. We sought to analyze the arrhythmia substrate, ablation strategies, and outcomes for catheter ablation in this population.

METHODS

An in-depth analysis of all clinical and procedural data in patients with D-transposition of the great arteries, atrial baffles, and atrial arrhythmia ablation was performed.

RESULTS

A cohort of 32 patients (72% male, mean age 38±7 years) underwent ablation for non-AV nodal reentrant tachycardia atrial arrhythmias, and 4 patients underwent AV nodal reentrant tachycardia ablation. Cavotricuspid isthmus flutter (CTI-flutter) was the most common arrhythmia, encountered in 75% of patients, followed by scar-related intraatrial reentrant tachycardia (non-CTI intraatrial reentrant tachycardia, 53%) and focal atrial tachycardia (focal atrial tachycardia, 6%). Among the 32 patients, 26 underwent 31 procedures at our institution. For patients with prior outside intervention, the index ablation at our institution revealed CTI-dependent flutter in 3/5 cases. However, redo ablation after an index ablation with demonstrated bidirectional CTI block revealed different/new arrhythmia substrates (80% non-CTI intraatrial reentrant tachycardia, 40% focal atrial tachycardia). Achieving bidirectional block across the CTI often required ablating on both sides of the baffle (retroaortic access, 81%; using a baffle leak, 11.5%; or transbaffle puncture, 7.7%). Combined approaches were necessary in 19% to reach the critical tissue. Acute procedural success was 81%, and recurrence was documented in 58% of patients. Despite recurrence, clinical arrhythmia burden was significantly reduced post-ablation (P<0.001), with rare episodes, amenable to antiarrhythmic therapy. Redo ablation was required in 5 (19%) patients and uncovered new arrhythmia substrates. AV nodal reentrant tachycardia ablation also required transbaffle approaches in 3/4 patients.

CONCLUSIONS

CTI-dependent flutter was the most common arrhythmia in patients with Dextro-Transposition of the Great Arteries and atrial switch. Transbaffle approaches were often necessary, and, provided that bidirectional CTI block was achieved at the index ablation, late recurrence was due to different arrhythmia mechanisms. Despite recurrence, ablation was associated with significant clinical improvement.

A new score for life-threatening ventricular arrhythmias and sudden cardiac death in adults with transposition of the great arteries and a systemic right ventricle

AIMS

To investigate the incidence of major adverse ventricular arrhythmias and related events (MAREs) and to develop a stratification tool predicting MAREs in adults with a systemic right ventricle (sRV).

METHODS AND RESULTS

In a multicentre approach, all adults (≥16 years old) with a sRV undergoing follow-up between 2000 and 2018 were identified. The incidence of MAREs, defined as sudden cardiac death, sustained ventricular tachycardia, and appropriate implantable cardioverter-defibrillator (ICD) therapy, was analysed. The association of MAREs with clinical, electrical, and echocardiographic parameters was evaluated. A total of 1184 patients (median age 27.1 years; interquartile range 19.9-34.9 years; 59% male; 70% with atrial switch repair for D-transposition of the great arteries) were included. The incidence of MAREs was 6.3 per 1000 patient-years. On multivariate analysis, age, history of heart failure, syncope, QRS duration, severe sRV dysfunction and at least moderate left ventricular outflow tract obstruction were retained in the final model with a C-index of 0.78 [95% confidence interval (CI) 0.72-0.83] and a calibration slope of 0.93 (95% CI 0.64-1.21). For every five ICDs implanted in patients with a 5-year MARE risk >10%, one patient may potentially be spared from a MARE.

CONCLUSION

Sudden cardiac death remains a devastating cause of death in a contemporary adult cohort with a sRV. A prediction model based on clinical, electrocardiographic, and echocardiographic parameters was devised to estimate MARE risk and to identify high-risk patients who may benefit from primary prevention ICD implantation.

The Value of Continuous Electrocardiographic Monitoring in Pediatric Cardiology: A Local Center Experience

Objectives

This study aims to evaluate the value of Holter monitoring in pediatric cases and look for the best predictor for abnormal Holter monitoring.

Methodology

All patients referred with cardiac symptoms associated or possibly related to abnormal cardiac rhythm from January 2019 to December 2020 were retrospectively reviewed. The demographic, clinical, 12-lead electrocardiography (ECG), echocardiography, and Holter monitoring results were reviewed. Multinomial logistic regression analysis was used to assess the correlation between gender, age, type of symptoms, ECG, and echo abnormalities, and Holter monitoring results were analyzed.

Results

During the study period, a total of 189 Holter monitoring was performed for 187 patients. The mean age at the performance of Holter monitoring was 88.6 ± 57 months. The female/male ratio was 1.5:1. The commonest indications for Holter monitoring were abnormal 12-lead ECG (30.7%), palpitations (30.7%), syncopal attacks (12.7%), and chest pain (6.9%). Patients with congenital heart disease (CHD) pre- or post-cardiac intervention constitute 9% of the total Holter monitoring cases. Apart from sinus arrhythmia, 12-lead ECG was abnormal in 57 (30%) patients, with premature atrial complexes (PACs) being the most common abnormality. Echocardiography was abnormal in 67 (35.4%) cases, with secundum atrial septal defect (ASD) (6.3%) and mitral valve prolapse (5.8%) being the commonest abnormalities. The Holter monitoring was completely normal in 89 (47.1%) cases. The commonest Holter abnormalities were PACs (12.7%), supraventricular tachycardia (SVT) (5.8%), and premature ventricular complexes (PVCs) (4.8%). There were 24 patients with SVT, and eight of them had normal Holter monitoring. One patient with SVT had ablation by the electrophysiologist. Using the multinomial logistic regression analysis, significantly abnormal 12-lead ECG, the presence of CHD, and abnormal echocardiography predict the presence of abnormal Holter results with a statistically significant p-value.

Conclusion

Most pediatric arrhythmias are benign. Holter monitoring provides reassurance for the patient and family. Abnormal Holter monitoring is more often observed in patients with paroxysmal or persistently abnormal 12-lead ECG with or without associated cardiac abnormalities or cardiac interventions. The yield of Holter monitoring is low in children referred because of chest pain, palpitations, or syncope with no other cardiac symptoms and with a structurally and functionally normal heart.

Cardiac MRI predictors of adverse outcomes in adults with a systemic right ventricle

Aims

Predicting risk in individuals with a systemic right ventricle (SRV) remains difficult. We assessed the value of cardiac MRI (CMR) for predicting death, heart transplantation (HT), or need for a ventricular assist device (VAD) in adults with D‐transposition of the great arteries (DTGA) post Mustard/Senning and in adults with congenitally corrected transposition of the great arteries (ccTGA) at two large academic centres.

Methods and results

Between December 1999 and November 2020, 158 adult patients with an SRV underwent CMR. Indexed right ventricular end‐diastolic volume (RVEDVI), indexed right ventricular end‐systolic volume (RVESVI), right ventricular ejection fraction (RVEF), and right ventricular mass (RV mass) were determined by a core laboratory. Receiver operating curves, area under the curve (AUC), and cut‐points maximizing sensitivity and specificity for the endpoint for each CMR parameter were calculated. Over a median of 8.5 years, 21 patients (13%) met a combined endpoint of HT referral, VAD, or death. Each CMR parameter was significantly associated with the endpoint in both cohorts. The AUCs for RVEDVI, RVESVI, RVEF, and RV mass to predict the endpoint were 0.93, 0.90, 0.73, and 0.84 for DTGA and 0.76, 0.74, 0.71, and 0.74 for ccTGA, respectively. Optimized cut‐points for RVEDVI were calculated for DTGA and ccTGA and were 132 and 126 mL/m², respectively. RVEDVI cut‐points were simplified to 130 mL/m² for survival analysis, which was significantly associated with survival in both cohorts.

Conclusions

Cardiac MRI parameters are associated with an increased risk of death, HT, or VAD in patients with an SRV and should be considered to facilitate risk stratification.

Baffle Complications in Adults After Atrial Switch for Transposition of the Great Arteries

BACKGROUND

Baffle complications, ie, leakage or stenosis, after an atrial switch operation (AtrSO) for transposition of the great arteries (TGA) are difficult to detect with the use of routine transthoracic echocardiography (TTE). We examined baffle interventions and the prevalence of baffle complications.

METHODS

This dual-centre study followed TGA-AtrSO patients for the occurrence of baffle interventions. In addition, in 2017-2019, prevalence of baffle complications was determined in patients undergoing routine contrast-enhanced (CE) TTE including various hemodynamic conditions and computed tomography (CT). Baffle leaks were defined as right-to-left shunting on CE-TTE and baffle stenosis as a systemic venous baffle diameter of < 10 mm on CT.

RESULTS

In total, 67 TGA-AtrSO patients were followed to a median age of 38 (interquartile range 34-42) years, for a median of 9 (6-13) years. Baffle interventions were documented in 24 patients (36%). Cumulative risk of baffle interventions was 25% after 15 years of follow-up. Prevalence of baffle complications was determined in 29/67 patients. In total, 4 (14%) had patent baffles, 11 (38%) had leakage only, 5 (17%) had stenosis only, and 9 (31%) had both, while 24/29 (84%) were asymptomatic. Although baffle leaks were not associated with clinical characteristics, peak work rate during exercise TTE was lower in patients with vs without stenosis (89 ± 24 W vs 123 ± 21 W; P < 0.001).

CONCLUSIONS

Baffle complications are common in TGA-AtrSO. The cumulative risk of baffle interventions was 25% after 15 years of follow-up. CE-TTE uncovered asymptomatic baffle leakage in the majority of patients, especially with examination during exercise. CT revealed baffle stenosis in almost half of the patients, which was associated with decreased exercise tolerance. Awareness of these findings may alter clinical follow-up.

Electrophysiologic Management and Considerations for D-transposition of the Great Arteries After Atrial Baffle Repair

This unique case highlights the electrophysiologic management and risk assessment of sudden cardiac death in a 35-year-old woman with a history of D-transposition of the great arteries status post–Mustard atrial switch repair.

Potential of eHealth smart technology in optimization and monitoring of heart failure treatment in adults with systemic right ventricular failure

Aims

Patients with a systemic right ventricle (sRV) in the context of transposition of the great arteries (TGA) after atrial switch or congenitally corrected TGA are prone to heart failure and arrhythmias. This study evaluated feasibility, patient adherence, and satisfaction of a smart technology-based care pathway for heart failure treatment optimization in these patients.

Methods and results

Patients with symptomatic sRV failure eligible for initiation of sacubitril/valsartan were provided with four smartphone compatible devices (blood pressure monitor, weight scale, step counter, and rhythm monitor) and were managed according to a smart technology-based care pathway. Biweekly sacubitril/valsartan titration visits were replaced by electronical visits, patients were advised to continue measurements at least weekly after titration. Data of 24 consecutive sRV patients (median age 47 years, 50% female) who participated in the smart technology-based care pathway were analysed. Median home-hospital distance was 65 km (maximum 227 km). Most patients (20, 83.3%) submitted weekly measurements; 100% submitted prior to electronical visits. Titration conventionally occurs during a hospital visit. By implementing eHealth smart technology, 68 such trips to hospital were replaced by virtual visits facilitated by remote monitoring. An eHealth questionnaire was completed by 22 patients (92%), and 96% expressed satisfaction. After titration, 30 instances of remote adjustment of heart failure medication in addition to scheduled outpatient clinic visits occurred, one (4%) heart failure admission followed, despite ambulant adjustments. Five patients (21%) sent in rhythm registrations (n = 17), of these 77% showed sinus rhythm, whereas supraventricular tachycardia was detected in the remaining four registrations.

Conclusion

These data suggest that implementation of a smart technology-based care pathway for optimization of medical treatment sRV failure is feasible with high measurement adherence and patient satisfaction.

Narrative review of: risk stratification and implantable cardioverter-defibrillator therapy in adults with congenital heart disease

Fortunately, the population of adults with congenital heart disease (ACHD) is growing due to improved operation techniques. Life expectancy is continuously rising, nevertheless, sudden cardiac death is one of the leading causes of mortality in ACHD late after initial diagnosis. Risk stratification in ACHD remains challenging as large study results are missing, congenital defects and operation methods differ considerably between individual patients and results from acquired heart diseases are often not conferrable. The purpose of this narrative review is to objectively summarize the current knowledge on arrhythmogenic risk of ACHD and to give an overview on implantable cardioverter-defibrillator (ICD) therapy in this collective. Remarkable progress has been made in electrophysiological understanding of critical areas of slow conduction especially in patients with Tetralogy of Fallot (ToF). In patients with transposition of the great arteries after atrial baffling (Mustard/Senning procedure) atrial arrhythmias play a crucial role in sudden cardiac death. ICD therapy in ACHD may pose special technical challenges due to limited access for intracardiac leads. The introduction of the totally subcutaneous ICD improved therapeutic options for ACHD especially when contraindications for transvenous leads are present. Risk stratification in ACHD has to be seen as a team approach, requires thorough understanding of congenital heart defects and the operation techniques and needs unconventional technical approaches in some cases.

Predicting sudden cardiac death in adults with congenital heart disease

OBJECTIVES

To develop, calibrate, test and validate a logistic regression model for accurate risk prediction of sudden cardiac death (SCD) and non-fatal sudden cardiac arrest (SCA) in adults with congenital heart disease (ACHD), based on baseline lesion-specific risk stratification and individual's characteristics, to guide primary prevention strategies.

METHODS

We combined data from a single-centre cohort of 3311 consecutive ACHD patients (50% male) at 25-year follow-up with 71 events (53 SCD and 18 non-fatal SCA) and a multicentre case-control group with 207 cases (110 SCD and 97 non-fatal SCA) and 2287 consecutive controls (50% males). Cumulative incidences of events up to 20 years for specific lesions were determined in the prospective cohort. Risk model and its 5-year risk predictions were derived by logistic regression modelling, using separate development (18 centres: 144 cases and 1501 controls) and validation (two centres: 63 cases and 786 controls) datasets.

RESULTS

According to the combined SCD/SCA cumulative 20 years incidence, a lesion-specific stratification into four clusters-very-low (<1%), low (1%-4%), moderate (4%-12%) and high (>12%)-was built. Multivariable predictors were lesion-specific cluster, young age, male sex, unexplained syncope, ischaemic heart disease, non-life threatening ventricular arrhythmias, QRS duration and ventricular systolic dysfunction or hypertrophy. The model very accurately discriminated (C-index 0.91; 95% CI 0.88 to 0.94) and calibrated (p=0.3 for observed vs expected proportions) in the validation dataset. Compared with current guidelines approach, sensitivity increases 29% with less than 1% change in specificity.

CONCLUSIONS

Predicting the risk of SCD/SCA in ACHD can be significantly improved using a baseline lesion-specific stratification and simple clinical variables.

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 detection of ventricular arrhythmias in adults with congenital heart disease using an insertable cardiac monitor (EDVA-CHD study)

BACKGROUND

Sudden cardiac death (SCD) due to ventricular arrhythmias (VA) is an important mode of death in adults with congenital heart disease (CHD). Risk stratification is difficult in this heterogeneous population. Insertable cardiac monitors (ICM) may be useful for risk stratification. The purpose of the present study was to evaluate the use of ICM for the detection of VA in adults with CHD.

METHODS

In this prospective single-center observational study we included consecutive adults with CHD deemed at risk of VA who received an ICM between March 2013 and February 2019. The decision to implant an ICM was made in a Heart Team consisting of a cardiac electrophysiologist and a cardiologist specialized in CHD.

RESULTS

A total of 30 patients (mean age, 38 ± 15 years; 50% male) received an ICM. During a median follow-up of 16 months, 8 patients (27%) had documented nonsustained VA. Of these 8 patients, 3 (10%) received a prophylactic ICD. Furthermore, ICM-detected arrhythmias were present in 22 patients (73%) leading to a change in clinical management in 16 patients (53%). Besides the patients receiving an ICD, 10 patients (33%) had a change in their antiarrhythmic drugs, 6 patients (20%) underwent an electrophysiology study, and 1 patient (3%) received a pacemaker.

CONCLUSIONS

The detection of VA by the ICM contributed to the clinical decision to implant a prophylactic ICD. Furthermore, ICM-detected arrhythmias led to important changes in the clinical management. Therefore, long-term arrhythmia monitoring by an ICM seems valuable for risk stratification in adults with CHD.

Cardiac resynchronization and implantable defibrillators in adults with congenital heart disease

Cardiac resynchronization therapy (CRT) and implantable cardioverter defibrillators (ICDs) are well-established therapies for adult patients with heart failure that have been shown to improve morbidity and mortality. However, the benefits and indications for use in adults with congenital heart disease (ACHD) are less defined with no significant large prospective studies in this population. There are, however, multiple retrospective studies that demonstrate the efficacy of these devices in the ACHD population. These indicate a role for both CRT and ICDs in select patients with ACHD. The clinician and patient must balance the risks and benefits, summarized in complex evidence that reflects the heterogeneity of the ACHD patient group, and apply them in a patient-specific manner to optimize the utility of CRT and ICDs.

Predictors of Late Mortality in D-Transposition of the Great Arteries After Atrial Switch Repair: Systematic Review and Meta-Analysis

Background

Existing data on predictors of late mortality and prevention of sudden cardiac death after atrial switch repair surgery for D‐transposition of the great arteries (D‐TGA) are heterogeneous and limited by statistical power.

Methods and Results

We conducted a systematic review and meta‐analysis of 29 observational studies, comprising 5035 patients, that reported mortality after atrial switch repair with a minimum follow‐up of 10 years. We also examined 4 additional studies comprising 105 patients who reported rates of implantable cardioverter‐defibrillator therapy in this population. Average survival dropped to 65% at 40 years after atrial switch repair, with sudden cardiac death accounting for 45% of all reported deaths. Mortality was significantly lower in cohorts that were more recent and operated on younger patients. Patient‐level risk factors for late mortality were history of supraventricular tachycardia (odds ratio [OR] 3.8, 95% CI 1.4–10.7), Mustard procedure compared with Senning (OR 2.9, 95% CI 1.9–4.5) and complex D‐TGA compared with simple D‐TGA (OR 4.4, 95% CI 2.2–8.8). Significant risk factors for sudden cardiac death were history of supraventricular tachycardia (OR 4.7, 95% CI 2.2–9.8), Mustard procedure (OR 2.2, 95% CI 1.1–4.1), and complex D‐TGA (OR 5.7, 95% CI 1.8–18.0). Out of a total 124 implantable cardioverter‐defibrillator discharges over 330 patient‐years in patients with implantable cardioverter‐defibrillators for primary prevention, only 8% were appropriate.

Conclusions

Patient‐level risk of both mortality and sudden cardiac death after atrial switch repair are significantly increased by history of supraventricular tachycardia, Mustard procedure, and complex D‐TGA. This knowledge may help refine current selection practices for primary prevention implantable cardioverter‐defibrillator implantation, given disproportionately high rates of inappropriate discharges.

Arrhythmias in Adults With Congenital Heart Disease: What the Practicing Cardiologist Needs to Know

The expanding population of adults with congenital heart disease (CHD) combined with the pervasiveness of arrhythmias has resulted in the rapid growth of a dedicated sector of cardiology at the intersection between 2 subspecialties: electrophysiology and adult CHD. Herein, practical considerations are offered regarding urgent referral for catheter ablation of atrial arrhythmias, anticoagulation, and primary prevention implantable cardioverter-defibrillators (ICDs). Patients with Ebstein anomaly and ventricular pre-excitation should be referred promptly due to the high prevalence of multiple accessory pathways and increased incidence of atrial tachyarrhythmias, which may be poorly tolerated. In patients with transposition of the great arteries and atrial switch surgery, atrial arrhythmias should be managed without delay because they could provoke ventricular arrhythmias and sudden death. Other settings in which atrial arrhythmias can be poorly tolerated include single ventricle physiology and Eisenmenger syndrome. Long-term anticoagulation is generally indicated in patients with sustained intra-atrial reentrant tachycardia or atrial fibrillation and a mechanical valve, moderate or severe systemic atrioventricular valve stenosis, traditional risk factors for stroke, and/or moderate or complex CHD. The only class I indication for a primary prevention ICD is a systemic left ventricular ejection fraction ≤ 35%, with biventricular physiology, and New York Heart Association class II or III symptoms. ICD therapy is reasonable in selected adults with tetralogy of Fallot and multiple risk factors for sudden death identified by observational studies. Indications for ICDs in patients with systemic right ventricles and univentricular hearts are less well established, underscoring the need for future research to inform risk stratification.

Implantation of a subcutaneous implantable cardioverter defibrillator with right parasternal electrode position in a patient with D-transposition of the great arteries and concomitant AAI pacemaker: a case report

Background

Implantable cardioverter defibrillator (ICD) therapy is indicated in patients with structural heart disease who have had an aborted cardiac arrest (ACA). After atrial repair of d-transposition of the great arteries (d-TGA, Mustard repair) patients seem to be at a higher risk of failing intraoperative subcutaneous ICD (S-ICD) shock testing.

Case summary

We report the case of a 45-year-old patient with congenital heart disease (CHD) who suffered a cardiac arrest from ventricular fibrillation and was subsequently implanted with a S-ICD. We describe the challenges of ICD therapy in patients after Mustard procedure for d-TGA, with the additional challenge of concomitant AAI pacemaker therapy. In this patient, we opted for the implantation of an S-ICD, and detail the necessary considerations and operative technique employed in this patient. A right parasternal electrode position was chosen and intraoperative shock testing was successful.

Discussion

Patients after atrial switch surgery for d-TGA and ACA require careful consideration of the appropriate type of ICD therapy. Subcutaneous ICD implantation with right parasternal electrode position may be a viable option in these patients.

Surgical management of late-term pulmonary venous baffle stenosis after Senning operation

Although pulmonary venous baffle stenosis is not a common late complication after the Senning operation, surgical treatment is vital, when interventional methods fail to correct the pathology. Our patient was admitted to hospital with recurrent epistaxis and exertional dyspnea 6.5 years after the Senning procedure. The gradient in the pulmonary venous baffle was measured as 34 to 35 mmHg via transthoracic echocardiography. During surgical treatment, the calcified and retracted polytetrafluoroethylene flap was completely excised and porcine pericardial xenograft was used to cover the pulmonary venous baffle. At the end of the procedure, no significant gradient was detected via transesophageal echocardiography.

Implantable Cardioverter-defibrillators in Adult Congenital Heart Disease

With improved surgical techniques and medical therapies, many patients who are born with complex congenital heart defects are now living well into adulthood. As these patients age, an increasingly common cause of mortality is sudden cardiac death (SCD) from ventricular tachyarrhythmias. The implantable cardioverter-defibrillator (ICD) is a therapy with the ability to prevent some of these deaths; however, there are many diagnostic and technical challenges that remain in the congenital heart disease (CHD) population. We performed a literature review, searching PubMed for articles that examined the role of ICDs in CHD. We herein present the evidence for when to place an ICD in CHD patients, stratified by subtype as relevant. Then, we discuss the technical challenges and complications that are unique to this patient population. We conclude that, despite active work in the area, more research is needed given the small event rates and clinical variability within CHD populations.