Common genetic variants improve risk stratification after the atrial switch operation for transposition of the great arteries.

BACKGROUND: Clinical factors are used to estimate late complication risk in adults after atrial switch operation (AtrSO) for transposition of the great arteries (TGA), but heterogeneity in clinical course remains. We studied whether common genetic variants are associated with outcome and add value to a clinical risk score in TGA-AtrSO patients. METHODS AND RESULTS: This multicenter study followed 133 TGA-AtrSO patients (aged 28 [IQR 24-35] years) for 13 (IQR 9-16) years and examined the association of genome-wide single-nucleotide polymorphisms (SNPs) with a composite endpoint of symptomatic ventricular arrhythmia, heart failure hospitalization, ventricular assist device implantation, heart transplantation, or mortality. Thirty-two patients (24%) reached the endpoint. The genome-wide association study yielded one genome-wide significant (p < 1 × 10-8) locus and 18 suggestive loci (p < 1 × 10-5). A genetic risk score constructed on the basis of independent SNPs with p < 1 × 10-5 was associated with outcome after correction for the clinical risk score (HR = 1.26/point increase [95%CI 1.17-1.35]). Risk stratification improved with a combined risk score (clinical score + genetic score) compared to the clinical score alone (p = 2 × 10-16, C-statistic 0.95 vs 0.85). In 51 patients with a clinical intermediate (5-20%) 5-year risk of events, the combined score reclassified 32 patients to low (<5%) and 5 to high (>20%) risk. Stratified by the combined score, observed 5-year event-free survival was 100%, 79% and 31% for low, intermediate, and high-risk patients, respectively. CONCLUSIONS: Common genetic variants may explain some variation in the clinical course in TGA-AtrSO and improve risk stratification over clinical factors alone, especially in patients at intermediate clinical risk. These findings support the hypothesis that including genetic variants in risk assessment may be beneficial.

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.

Medication in adults after atrial switch for transposition of the great arteries: clinical practice and recommendations.

AIMS: Heart failure is the main threat to long-term health in adults with transposition of the great arteries (TGA) corrected by an atrial switch operation (AtrSO). Current guidelines refrain from recommending heart failure medication in TGA-AtrSO, as there is insufficient data to support the hypothesis that it is beneficial. Medication is therefore prescribed based on personal judgements. We aimed to evaluate medication use in TGA-AtrSO patients and examine the association of use of renin-angiotensin-aldosterone system (RAAS) inhibitors and ß-blockers with long-term survival. METHODS AND RESULTS: We identified 150 TGA-AtrSO patients [median age 30 years (interquartile range 25-35), 63% male] included in the CONCOR registry from five tertiary medical centres with subsequent linkage to the Dutch Dispensed Drug Register for the years 2006-2014. Use of RAAS inhibitors, ß-blockers, and diuretics increased with age, from, respectively, 21% [95% confidence interval (CI) 14-40], 12% (95% CI 7-21), and 3% (95% CI 2-7) at age 25, to 49% (95% CI 38-60), 51% (95% CI 38-63), and 41% (95% CI 29-54) at age 45. Time-varying Cox marginal structural models that adjusted for confounding medication showed a lower mortality risk with use of RAAS inhibitors and ß-blockers in symptomatic patients [hazard ratio (HR) = 0.13 (95% CI 0.03-0.73); P = 0.020 and HR = 0.12 (95% CI 0.02-0.17); P = 0.019, respectively]. However, in the overall cohort, no benefit of RAAS inhibitors and ß-blockers was seen [HR = 0.93 (95% CI 0.24-3.63); P = 0.92 and HR = 0.98 (0.23-4.17); P = 0.98, respectively]. CONCLUSION: The use of heart failure medication is high in TGA-AtrSO patients, although evidence of its benefit is limited. This study showed lower risk of mortality with use of RAAS inhibitors and ß-blockers in symptomatic patients only. These findings can direct future guidelines, supporting use of RAAS inhibitors and ß-blockers in symptomatic, but not asymptomatic patients.

Common Genetic Variants Contribute to Risk of Transposition of the Great Arteries.

RATIONALE: Dextro-transposition of the great arteries (D-TGA) is a severe congenital heart defect which affects approximately 1 in 4,000 live births. While there are several reports of D-TGA patients with rare variants in individual genes, the majority of D-TGA cases remain genetically elusive. Familial recurrence patterns and the observation that most cases with D-TGA are sporadic suggest a polygenic inheritance for the disorder, yet this remains unexplored. OBJECTIVE: We sought to study the role of common single nucleotide polymorphisms (SNPs) in risk for D-TGA. METHODS AND RESULTS: We conducted a genome-wide association study in an international set of 1,237 patients with D-TGA and identified a genome-wide significant susceptibility locus on chromosome 3p14.3, which was subsequently replicated in an independent case-control set (rs56219800, meta-analysis P=8.6x10-10, OR=0.69 per C allele). SNP-based heritability analysis showed that 25% of variance in susceptibility to D-TGA may be explained by common variants. A genome-wide polygenic risk score derived from the discovery set was significantly associated to D-TGA in the replication set (P=4x10-5). The genome-wide significant locus (3p14.3) co-localizes with a putative regulatory element that interacts with the promoter of WNT5A, which encodes the Wnt Family Member 5A protein known for its role in cardiac development in mice. We show that this element drives reporter gene activity in the developing heart of mice and zebrafish and is bound by the developmental transcription factor TBX20. We further demonstrate that TBX20 attenuates Wnt5a expression levels in the developing mouse heart. CONCLUSIONS: This work provides support for a polygenic architecture in D-TGA and identifies a susceptibility locus on chromosome 3p14.3 near WNT5A. Genomic and functional data support a causal role of WNT5A at the locus.

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.

Myocardial Deformation in the Systemic Right Ventricle: Strain Imaging Improves Prediction of the Failing Heart.

BACKGROUND: Predicting heart failure events in patients with a systemic right ventricle (sRV) due to transposition of the great arteries (TGA) is important for timely intensification of follow-up. This study assessed the value of strain compared with currently used parameters as predictor for heart failure-free survival in patients with sRV. METHODS: In participants of a multicentre trial, speckle-tracking echocardiography (STE) was performed to assess global longitudinal strain (GLS), mechanical dispersion (MD), and postsystolic shortening (PSS). Cox regression was used to determine the association of STE parameters with the combined end point of progression of heart failure and death, compared with cardiovascular magnetic resonance (CMR) and computed tomography (CT) derived parameters. RESULTS: Echocardiograms of 60 patients were analyzed (mean age 34 ± 11 years, 65% male, 35% congenitally corrected TGA). Mean GLS was -13.5 ± 2.9%, median MD was 49 (interquartile range [IQR] 30-76) ms, and 14 patients (23%) had PSS. During a median 8 (IQR 7-9) years, 15 patients (25%) met the end point. GLS, MD, and PSS were all associated with heart failure-free survival in univariable analysis. After correction for age, only GLS (optimal cutoff > -10.5%) and CMR/CT-derived sRV ejection fraction (optimal cutoff < 30%) remained associated with heart failure-free survival: hazard ratio (HR) 8.27, 95% confidence interval (CI) 2.50-27.41 (P < 0.001), and HR 4.34, 95% CI 1.48-12.74 (P = 0.007), respectively). Combining GLS and ejection fraction improved prediction, with patients with both GLS > -10.5% and sRV ejection fraction < 30% at highest risk (HR 19.69, 95% CI 4.90-79.13; P < 0.001). CONCLUSIONS: The predictive value of GLS was similar to that of CMR/CT-derived ejection fraction. The combination of GLS and ejection fraction identified patients at highest risk of heart failure and death. Easily available STE parameters can be used to guide follow-up intensity and can be integrated into future risk prediction scores.

22q11.2 deletion syndrome is associated with increased mortality in adults with tetralogy of Fallot and pulmonary atresia with ventricular septal defect.

BACKGROUND: 22q11.2 Deletion syndrome (22q11.2DS) is common in patients with tetralogy of Fallot (TOF) or pulmonary atresia with ventricular septal defect (PA/VSD) and is associated with worse outcomes in children. Whether this impaired prognosis is also translated into adulthood is unknown, as data in adult patients are limited. We aimed to compare long-term outcomes in adults with TOF or PA/VSD both with and without 22q11.2DS. METHODS: This study prospectively followed a nationwide multicenter cohort of TOF or PA/VSD patients with genetically confirmed presence or absence of 22q11.2DS, from inclusion in the Dutch national CONCOR registry for adults with congenital heart disease (CHD) onward. Outcome measures included all-cause mortality, cardiac mortality, need for pulmonary valve replacement (PVR), ventricular arrhythmias (VA), pacemaker implantation, and ICD implantation. RESULTS: In total, 479 patients were included (277 (58%) male, median age 28 [IQR; 21-37] years, 62 (13%) with PA/VSD, 34 (7%) with 22q11.2DS). During a median follow-up of 11 [IQR; 6-13] years, 52 (11%) patients died (8 with 22q11.2DS and 44 without 22q11.2DS). Patients with 22q11.2DS had significant decreased survival after 12 years (76% [95% CI; 62-93]) compared to patients without 22q11.2DS (89% [95% CI; 86-92], p = 0.008). 22q11.2DS was associated with increased risk of all-cause mortality and cardiac-mortality, independent of age, sex, and PA/VSD. No association was found between 22q11.2DS and late complications i.e. PVR, VA, pacemaker, or ICD implantation. CONCLUSIONS: Adults with TOF or PA/VSD with 22q11.2DS have a significantly worse survival than adults without this deletion. In patients with TOF or PA/VSD, genetic analysis for the presence of 22q11.2DS is important for risk stratification and genetic counseling.

High burden of drug therapy in adult congenital heart disease: polypharmacy as marker of morbidity and mortality.

AIMS: To assess medication use in adult congenital heart disease (ACHD) patients compared to the age- and sex-matched general population, identify patterns of pharmacotherapy, and analyse associations between pharmacotherapy and adverse outcomes in ACHD. METHODS AND RESULTS: Data of 14 138 ACHD patients from the CONCOR registry [35 (24-48) years, 49% male] and age- and sex-matched referents (1:10 ratio) were extracted from the Dutch Dispensed Drug Register for the years 2006-14. Adult congenital heart disease patients had more cardiovascular and non-cardiovascular drugs than referents (median 3 vs. 1, P < 0.001). Polypharmacy, defined as ≥5 dispensed drug types yearly, was present in 30% of ACHD and 15% of referents {odds ratio [OR] = 2.47 [95% confidence interval (CI) 2.39-2.54]}. Polypharmacy was independently associated with female sex [OR = 1.92 (95% CI 1.88-1.96)], older age [for men: OR = 2.3/10 years (95% CI 2.2-2.4) and for women: OR = 1.6/10 years (95% CI 1.5-1.6); Pinteraction < 0.001], and ACHD severity [mild: OR = 2.51 (95% CI 2.40-2.61), moderate: OR = 3.22 (95% CI 3.06-3.40), severe: OR = 4.87 (95% CI 4.41-5.38)]. Cluster analysis identified three subgroups with distinct medication patterns; a low medication use group (8-year cumulative survival: 98%), and a cardiovascular and comorbidity group with lower survival (92% and 95%, respectively). Cox regression revealed a strong association between polypharmacy and mortality [hazard ratio (HR) = 3.94 (95% CI 3.22-4.81)], corrected for age, sex, and defect severity. Polypharmacy also increased the risk of hospitalization for adverse drug events [HR = 4.58 (95% CI 2.04-10.29)]. CONCLUSION: Both cardiovascular and non-cardiovascular medication use is high in ACHD with twice as much polypharmacy compared with the matched general population. Patients with polypharmacy had a four-fold increased risk of mortality and adverse drug events. Recognition of distinct medication patterns can help identify patients at highest risk. Drug regimens need repeating evaluation to assess the appropriateness of all prescriptions. More high-quality studies are needed to improve ACHD care with more evidence-based pharmacotherapy.

Use of Pulmonary Inhalants Remains Remarkably High After Atrial Septal Defect Closure.

BACKGROUND: Post-repair atrial septal defects (ASD) patients are frequently discharged from follow-up, but the extent of pulmonary symptoms long-term post-repair is unknown. Methods and Results: The national CONgenital CORvitia registry was linked to the national Drug Registry to investigate all ambulatory-dispensed pulmonary inhalants for 2006-2014. ASD patients were compared with age- and sex-matched referents from the general population. A total of 1,959 adult patients (age 42±17 years; 66% female; 1,223 [62%] repaired) were included. Compared with the referents, ASD patients had more inhalant use, even at long-term post-repair follow-up (OR=1.81 [95% CI 1.62-2.03]; P<0.001). CONCLUSIONS: ASD patients had 2-fold higher inhalant use compared with referents even at long-term post-repair follow-up, suggesting persistent pulmonary functional impairment.

Origins and consequences of congenital heart defects affecting the right ventricle.

Congenital heart disease is a major health issue, accounting for a third of all congenital defects. Improved early surgical management has led to a growing population of adults with congenital heart disease, including patients with defects affecting the right ventricle, which are often classified as severe. Defects affecting the right ventricle often cause right ventricular volume or pressure overload and affected patients are at high risk for complications such as heart failure and sudden death. Recent insights into the developmental mechanisms and distinct developmental origins of the left ventricle, right ventricle, and the outflow tract have shed light on the common features and distinct problems arising in specific defects. Here, we provide a comprehensive overview of the current knowledge on the development into the normal and congenitally malformed right heart and the clinical consequences of several congenital heart defects affecting the right ventricle.

A Rare Case of Primary Meningococcal Myopericarditis in a 71-Year-Old Male.

We describe a case of primary meningococcal C pericarditis with myocardial involvement in a 71-year-old male that is thus far the oldest patient with isolated meningococcal pericardial disease and only the third patient with primary meningococcal myopericarditis described in English literature. Our patient was successfully treated by full sternotomy and surgical drainage combined with intravenous ceftriaxone. Mild symptoms unresponsive to anti-inflammatory treatment and leukocytosis may guide clinicians towards the correct diagnosis. It is important to recognize this cause of pericarditis as the relatively mild clinical presentation may rapidly progress into tamponade and right-sided heart failure.