Cardiac resynchronization therapy for adult congenital heart disease patients with a systemic right ventricle: analysis of feasibility and review of early experience

Techniques for Cardiac Resynchronization Therapy in Patients with Congenital Heart Disease

Cardiac resynchronization therapy (CRT) for congenital heart disease has shown promising suucess as an adjunct to medical therapy for heart failure. While cardiac conduction defects and need for ventricular pacing are common in congential heart disease, CRT indications, techniques and long term outcomes have not been well establaished. This is a review of the techniques nad short term outcomes of CRT for the following complex congenital heart disease conditions: single ventricle physiology, systemic right ventricle, and the subpulmonic right ventricle.

Prognostic Implications of Progressive Systemic Ventricular Dysfunction in Congenitally Corrected Transposition of Great Arteries

OBJECTIVES

The purpose of this study was to determine the risk factors for and prognostic implications of progressive right ventricular systolic dysfunction (RVD) in adults with congenitally corrected transposition of great arteries.

BACKGROUND

There are no effective therapies for RVD; hence the need to identify and modify risk factors for progressive RVD.

METHODS

RV systolic function was assessed by using RV longitudinal strain (RV-LS). The first echocardiogram (baseline echocardiogram) and all subsequent annual echocardiograms performed within 5 years from the baseline echocardiogram were analyzed. Progressive RVD (temporal decline in RV-LS) was assessed as the average annual change in RV-LS within 5 years of imaging follow-up.

RESULTS

Of 186 patients (mean age 40 ± 12 years), the RV-LS at baseline was -17% ± 4%, and the annual decline in RV-LS was -4% (95% CI: -6 to -2). The risk factors for progressive RVD were left ventricular (LV) systolic dysfunction, LV pacing, and systemic hypertension. Cardiovascular events (heart failure hospitalization, heart transplant, and death) occurred in 57 (27%) patients. Progressive RVD was associated with cardiovascular events, independent of RV systolic function at baseline. In subgroup analyses assessing impact of therapies (medical therapy, cardiac resynchronization therapy, and tricuspid valve replacement), only tricuspid valve replacement was associated with improvement in RV systolic function when performed before onset of RVD.

CONCLUSIONS

Patients with congenitally corrected transposition of great arteries were at risk for progressive RVD, and the risk factors for progressive RVD were LV pacing, systemic hypertension, and concomitant LV dysfunction. Further studies are required to determine whether strict blood pressure control and early tricuspid valve replacement will prevent progressive RVD.

Adults with Congenital Heart Disease and Arrhythmia Management

Arrhythmia management in adult congenital heart disease (ACHD) encompasses a wide range of problems from bradyarrhythmia to tachyarrhythmia, sudden death, and heart failure-related electrical dyssynchrony. Major advances in the understanding of the pathophysiology and treatments of these problems over the past decade have resulted in improved therapeutic strategies and outcomes. This article attempts to define these problems and review contemporary management for the patient with ACHD presenting with cardiac arrhythmia.

Emerging clinical applications of strain imaging and three-dimensional echocardiography for the assessment of ventricular function in adult congenital heart disease

Management of congenital heart disease (CHD) in adults (ACHD) remains an ongoing challenge due to the presence of residual hemodynamic lesions and development of ventricular dysfunction in a large number of patients. Echocardiographic imaging plays a central role in clinical decision-making and selection of patients who will benefit most from catheter interventions or cardiac surgery.. Recent advances in both strain imaging and three-dimensional (3D)-echocardiography have significantly contributed to a greater understanding of the complex pathophysiological mechanisms involved in CHD. The aim of this paper is to provide an overview of emerging clinical applications of speckle-tracking imaging and 3D-echocardiography in ACHD with focus on functional assessment, ventriculo-ventricular interdependency, mechanisms of electromechanical delay, and twist abnormalities in adults with tetralogy of Fallot (TOF), a systemic RV after atrial switch repair or in double discordance ventricles, and in those with a Fontan circulation.

A minimally invasive hybrid approach for cardiac resynchronization of the systemic right ventricle

BACKGROUND

Patients with systemic right ventricle (RV) often develop progressive heart failure and may benefit from cardiac resynchronization therapy (CRT); however, the optimal strategy for CRT has not been defined.

METHODS

A retrospective review of all the patients with systemic RV failure undergoing a hybrid transcatheter-surgical approach was performed. Procedural technique and outcomes are reported.

RESULTS

Six patients underwent detailed electroanatomical mapping of the systemic RV followed by a new hybrid approach targeting latest endocardial activation, which was followed by focused epicardial mapping. The exact site of latest endocardial activation was variable but localized to the basolateral RV in all cases. Sites of latest activation tended to be more superior during contralateral ventricular pacing versus intact atrioventricular conduction (P = 0.06). Latest endocardial activation at the targeted site occurred at 157 ms (interquartile range [IQR] = 120-181 ms) and corresponding epicardial activation at 174 ms (IQR = 140-198 ms), after the onset of the QRS complex. Following the hybrid CRT, the QRS duration decreased from a median of 193 to 147 ms and the fractional area of change increased from a median of 15.5% to 30% (P < 0.001). Patients were discharged to home after a median of 4 days. Of the three patients who were initially referred for transplant evaluation, two (66%) of them no longer met the criteria following CRT.

CONCLUSIONS

Whereas latest endocardial activation for the systemic RV appears to localize to the basolateral region, the optimal lead position may be variable. An approach utilizing endocardial mapping followed by a limited surgical incision and confirmation of latest activation may result in minimally invasive surgery and a favorable acute CRT response.

Cardiac resynchronization therapy in adults with congenital heart disease

Aims

In adults with congenital heart disease (CHD) heart failure is one of the leading causes of morbidity and mortality but experience with and reported outcome of cardiac resynchronization therapy (CRT) is limited. We investigated the efficacy of CRT in adults with CHD.

Methods and results

This was a retrospective study including 48 adults with CHD who received CRT since 2003 in four tertiary referral centres. Responders were defined as patients who showed improvement in NYHA functional class and/or systemic ventricular ejection fraction by at least one category. Ventricular function was assessed by echocardiography and graded on a four point ordinal scale. Median age at CRT was 47 years (range 18-74 years) and 77% was male. Cardiac diagnosis included tetralogy of Fallot in 29%, (congenitally corrected) transposition of great arteries in 23%, septal defects in 25%, left sided lesions in 21%, and Marfan syndrome in 2% of the patients. The median follow-up duration after CRT was 2.6 years (range 0.1-8.8). Overall, 37 out of 48 patients (77%) responded to CRT either by improvement of NYHA functional class and/or systemic ventricular function. There were 11 non-responders to CRT. Of these, three patients died and four underwent heart transplantation.

Conclusion

In this cohort of older CHD patients, CRT was accomplished with a success rate comparable to those with acquired heart disease despite the complex anatomy and technical challenges frequently encountered in this population. Further studies are needed to establish appropriate guidelines for patient selection and long term outcome.

Long-term outcome after atrial correction for transposition of the great arteries

Objective

This study assessed adult survival and morbidity patterns in patients who underwent atrial correction according to Mustard or Senning for transposition of the great arteries (TGA).

Methods

In 76 adult patients with TGA (59% male) after atrial correction, long-term survival and morbidity were investigated in three periods: early (<15 years postoperatively), midterm (15–30 years postoperatively) and late (>30 years postoperatively).

Results

The Mustard technique was performed in 41 (54%) patients, and the Senning technique was performed in 35 (46%) patients aged 3.1 (IQR: 2.1–3.8) and 1.0 (IQR: 0.6–3.1; p<0.01) years, respectively. Adult survival was 82% at 39.7 (IQR: 35.9–42.4) years postoperatively and exceeded 50 years in four patients. Supraventricular tachycardia (SVT) occurred in 51% of patients. The incidences of ventricular arrhythmia (0%, 8% and 13%; p<0.01), heart failure (0%, 5% and 19%; p<0.01) and surgical reinterventions (0%, 5% and 11%; p=0.01) increased from early to late follow-up. At last follow-up, RV function was depressed in 31 (46%) patients, and New York Heart Association functional class was ≥2 in 34 (48%) patients. Bradyarrhythmia, SVT and ventricular arrhythmia were associated with depressed RV function (OR: 4.47, 95% CI 1.50 to 13.28, p<0.01; OR: 3.74, 95% CI 1.26 to 11.14, p=0.02; OR: 14.40, 95% CI 2.80 to 74.07, p<0.01, respectively) and worse functional capacity (OR: 2.10, 95% CI 0.75 to 5.82, p=0.16; OR: 2.87, 95% CI 1.06 to 7.81, p=0.04; OR: 8.47, 95% CI 1.70 to 42.10, p<0.01, respectively).

Conclusions

In adult patients with TGA, survival was 82% at 39.7 (IQR: 35.9–42.4) years after atrial correction. Morbidity was high and included SVT as most frequent adverse event. Ventricular arrhythmias, heart failure and surgical reinterventions were common during late follow-up. Adverse events were associated with depressed right ventricle function and reduced functional class.

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.

Management of Systemic Right Ventricular Failure in Patients With Congenitally Corrected Transposition of the Great Arteries

In recent decades, significant progress has been made in the diagnosis and management of congenitally corrected transposition of the great arteries (ccTGA). Nevertheless, gradual dysfunction and failure of the right ventricle (RV) in the systemic circulation remain the main contributors to mortality and disability for patients with ccTGA, especially after adolescence. Anatomic repair of ccTGA effectively resolves the problem of failure of the systemic RV and has good early and midterm results. However, this strategy is applicable primarily in infants and children up to their teens and has associated risks and limitations, and new challenges can arise in the late postoperative period. Patients with ccTGA manifesting progressive systemic RV dysfunction beyond adolescence represent the major challenge. Several palliative options such as cardiac resynchronization therapy, tricuspid valve repair or replacement, pulmonary artery banding, and implantation of an assist device into the systemic RV can be used to improve functional status and to delay the progression of ventricular dysfunction in patients who are not suitable for anatomic correction of ccTGA. For adult patients with severe systemic RV failure, heart transplantation currently remains the only long-term lifesaving procedure, although donor organ availability remains one of the most limiting factors in this type of therapy. This review focuses on current surgical and medical strategies and interventional options for the prevention and management of systemic RV failure in adults and children with ccTGA.

Cardiac resynchronization therapy in congenital heart disease

Cardiac resynchronization therapy (CRT) is an established treatment option for adult patients suffering heart failure due to idiopathic or ischemic cardiomyopathy associated with electromechanical dyssynchrony. There is limited evidence suggesting similar efficacy of CRT in patients with congenital heart disease (CHD). Due to the heterogeneity of structural and functional substrates, CRT implantation techniques are different with a thoracotomy or hybrid approach prevailing. Efficacy of CRT in CHD seems to depend on the anatomy of the systemic ventricle with best results achieved in systemic left ventricular patients upgraded to CRT from conventional pacing. Indications for CRT in patients with CHD were recently summarized in the Pediatric and Congenital Electrophysiology Society (PACES) and the Heart Rhythm Society (HRS) Expert Consensus Statement on the Recognition and Management of Arrhythmias in Adult Congenital Heart Disease and are presented in the text.

The morphology of the coronary sinus in patients with congenitally corrected transposition: implications for cardiac catheterisation and re-synchronisation therapy

Patients with congenitally corrected transposition frequently benefit from re-synchronisation therapy or ablation procedures. This is likely to require catheterisation of the coronary sinus. Its anatomy, however, is not always appreciated, despite being well-described. With this caveat in mind, we have evaluated its location and structure in hearts with congenitally corrected transposition in order to reinforce the guidance needed by the cardiac interventionist. We dissected and inspected the coronary sinus, the oblique vein of the left atrium, and the left-sided-circumflex venous channel in eight heart specimens with corrected transposition and eight controls, measuring the orifice and length of the sinus and the atrioventricular valves. In two-thirds of the malformed hearts, the sinus deviated from its anticipated course in the atrioventricular groove, ascending obliquely on the left atrial inferior wall to meet the left oblique vein. The maximal deviation coincided in all hearts with the point where the left oblique vein joined the left-sided-circumflex vein to form the coronary sinus. We describe a circumflex vein, rather than the great cardiac vein, as the latter venous channel is right-sided in the setting of corrected transposition. The length of the sinus correlated positively with the diameter of the tricuspid valve (p=0.02). Compared with controls, the left oblique vein in the malformed hearts joined the circumflex venous channel significantly closer to the mouth of the sinus. The unexpected course of the coronary sinus in corrected transposition and the naming of the cardiac veins have important implications for venous cannulation and interpretation of images.

Is cardiac CT a reproducible alternative for cardiac MR in adult patients with a systemic right ventricle?

OBJECTIVE

20 % of patients with a systemic RV are pacemaker dependent, and unsuitable to undergo cardiac magnetic resonance (CMR). Multidetector row computed tomography (MDCT) could provide a reproducible alternative to CMR in these patients. The aim of this study was to compare variability of MDCT with CMR.

METHODS

Thirty-five patients with systemic RV underwent either MDCT (n = 15) or CMR (n = 20). Systemic RV volumes and ejection fraction were obtained, and intra- and interobserver variability for both modalities were assessed and compared.

RESULTS

We found the intra- and interobserver variability of volumes and function measurements of the systemic RV obtained with MDCT to be higher compared with those obtained with CMR. However, these differences in variability were not significant, the only exception being the interobserver variability of systemic RV stroke volume.

CONCLUSIONS

MDCT provides a reproducible alternative to CMR for volumes and function assessment in patients with a systemic RV.

Congenital Heart Defects in Adults : A Field Guide for Cardiologists

Advances in cardiology and cardiac surgery allow a large proportion of patients with congenital heart defects to survive into adulthood. These patients frequently develop complications characteristic of the defect or its treatment. Consequently, adult cardiologists participating in the care of these patients need a working knowledge of the more common defects. Occasionally, patients with congenital heart defects such as atrial septal defect, Ebstein anomaly or physiologically corrected transposition of the great arteries present for the first time in adulthood. More often patients previously treated in pediatric cardiology centers have transitioned to adult congenital heart disease centers for ongoing care. Some of the more important defects in this category are tetralogy of Fallot, transposition of the great arteries, functionally single ventricle defects, and coarctation. Through this field guide, we provide an overview of the anatomy of selected defects commonly seen in an adult congenital practice using pathology specimens and clinical imaging studies. In addition, we describe the physiology, clinical presentation to the adult cardiologist, possible complications, treatment options, and outcomes.

Coronary Arteries in Childhood Heart Disease: Implications for Management of Young Adults

Survival of patients with congenital heart defects has improved dramatically. Many will undergo interventional catheter or surgical procedures later in life. Others will develop atherosclerotic or post-surgical coronary heart disease. The coronary artery anatomy in patients with congenital heart disease differs substantially from that seen in the structurally normal heart. This has implications for diagnostic procedures as well as interventions. The unique epicardial course seen in some defects could impair interpretation of coronary angiograms. Interventional procedures, especially at the base of the heart, risk injuring unusually placed coronary arteries so that coronary artery anatomy must be delineated thoroughly prior to the procedure. In this review, we will describe the variants of coronary artery anatomy and their implications for interventional and surgical treatment and for sudden death during late follow-up in several types of congenital heart defects including: tetralogy of Fallot, truncus arteriosus, transposition of the great arteries, double outlet right ventricle, congenitally corrected transposition of the great arteries and defects with functionally one ventricle. We will also discuss the coronary abnormalities seen in Kawasaki disease.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: complex congenital cardiac lesions

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. They have distinctive forms of heart failure and their cardiac disease can be associated with pulmonary hypertension, thromboemboli, complex arrhythmias and sudden death. Medical aspects that need to be considered relate to the long-term and multisystemic effects of single ventricle physiology, cyanosis, systemic right ventricles, complex intracardiac baffles and failing subpulmonary right ventricles. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with CHD, there have been significant advances in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. Part III of the guidelines includes recommendations for the care of patients with complete transposition of the great arteries, congenitally corrected transposition of the great arteries, Fontan operations and single ventricles, Eisenmenger's syndrome, and cyanotic heart disease. Topics addressed include genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy risk and follow-up requirements. The complete document consists of four manuscripts, which are published online in the present issue of The Canadian Journal of Cardiology. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

Clinical practice: heart failure in children. Part II: current maintenance therapy and new therapeutic approaches

The current maintenance treatment for children with heart failure remains controversial: To a large extent, it is based on extrapolation of data derived from trials in adult populations. There are only a few randomized trials focused on the treatment of children with cardiac disease, especially in the subgroup with cardiomyopathy and heart failure. The goals of therapy are to maintain circulatory and end-organ function and to allow for recovery and reverse remodeling to occur. When maintenance therapy fails and medical treatment does not result in clinical improvement, the alternative of device therapy must be considered: In that case, the usual aim is to stabilize circulatory status, as a bridge to either recovery or to cardiac transplantation. Recently, carefully selected patients with electromechanical dyssynchrony of ventricular systolic function have demonstrated a benefit from biventricular pacing devices (cardiac resynchronization therapy), with improved functional capacity and quality of life and, in some patients, avoidance of the need for transplantation.

Brain natriuretic peptide as a biomarker of systemic right ventricular function in patients with transposition of great arteries after atrial switch operation

BACKGROUND

Assessment of systemic right ventricular (RV) function is inherently difficult. In adults, plasma brain natriuretic peptide (BNP) level has been shown to reflect systemic ventricular dysfunction. We sought to test the hypothesis that plasma BNP is a biomarker of systemic RV function in patients after atrial switch operation.

METHODS

We determined the RV function in 44 patients, 35 after Senning and 9 after Mustard operation, aged 19.7+/-4.0 years, by tissue Doppler echocardiography and determination of myocardial performance index (MPI). The results were compared to the left ventricular function of 14 age-matched controls. Their plasma BNP levels were correlated with indices of systemic ventricular function.

RESULTS

Compared with controls, the patients had greater MPI (p<0.001), lower systemic ventricular free wall-annular early diastolic (p<0.001), late diastolic (p<0.001), and systolic velocities (p=0.001), lower septal-annular early diastolic (p<0.001), late diastolic (p<0.001), and systolic velocities (p<0.001), and higher BNP levels (p=0.03). Plasma BNP levels correlated positively with MPI (r=0.43, p=0.001) and negatively with the free wall- and septal-annular myocardial velocities (r=-0.32 to -0.47, p<0.05). The area under the receiver operating characteristic curve for BNP to detect ventricular dysfunction (MPI >0.45) in patients was 0.67 (p=0.04). A BNP level of 36 pg/ml had a sensitivity of 55%, specificity of 86%, positive predictive value 80%, negative predictive value of 64%, and an accuracy of 70% for detecting systemic ventricular dysfunction.

CONCLUSIONS

Plasma BNP has modest accuracy in the detection of systemic RV dysfunction in patients after atrial switch operation.

Increased natriuretic peptide type B level after the second palliative step in children with univentricular hearts with right ventricular morphology but not left ventricular morphology

We analyzed the natriuretic peptide type B (BNP) and A (ANP) levels in the plasma of 38 children with stable functionally univentricular heart defects, 10 of whom had undergone the first palliative step (Shunt), 13 of whom had undergone the second palliative step (Glenn), and 15 of whom had completed total cavopulmonary connection (TCPC). The levels of BNP and ANP were significantly higher after the first palliative step, 31.6 ng/l (8.3-122) (median and range) and 101.2 ng/l (17.1-203), respectively, than after the Glenn procedure, 6.7 ng/l (0.0-16.0) and 23.6 ng/l (15.7-54.4), respectively, as well as after completed TCPC, 9.0 ng/l (0.0-39.1) and 20.9 ng/l (11.2-28.3), respectively, and, in a control group of children without heart defects, 5.8 ng/l (0.0-38.7) and 32.9 ng/l (11.7-212.1), respectively (p = 0.0003 and p = 0.0003, respectively). After the first palliative step, the BNP and ANP levels were the same in children with right and left ventricular morphology (p = 0.67 and p = 0.52, respectively). After unloading the ventricle (Glenn and TCPC together), BNP levels were higher in children with right ventricular morphology compared with those with left ventricular morphology and controls (p = 0.02). Children with functionally univentricular hearts in stable condition have increased BNP and ANP levels after the first palliative procedure. After the second and third palliative steps, the BNP and ANP levels were low and similar to those of children without heart defects. However, BNP levels in children with a systemic ventricle of right ventricular morphology were higher than those in children with left ventricular morphology.