Atrial Septal Defects in the Adult

Tbx5-dependent pathway regulating diastolic function in congenital heart disease

At the end of every heartbeat, cardiac myocytes must relax to allow filling of the heart. Impaired relaxation is a significant factor in heart failure, but all pathways regulating the cardiac relaxation apparatus are not known. Haploinsufficiency of the T-box transcription factor Tbx5 in mouse and man causes congenital heart defects (CHDs) as part of Holt-Oram syndrome (HOS). Here, we show that haploinsufficiency of Tbx5 in mouse results in cell-autonomous defects in ventricular relaxation. Tbx5 dosage modulates expression of the sarco(endo)plasmic reticulum Ca(2+)-ATPase isoform 2a encoded by Atp2a2 and Tbx5 haploinsufficiency in ventricular myocytes results in impaired Ca(2+) uptake dynamics and Ca(2+) transient prolongation. We also demonstrate that Tbx5 can activate the Atp2a2 promoter. Furthermore, we find that patients with HOS have significant diastolic filling abnormalities. These results reveal a direct genetic pathway that regulates cardiac diastolic function, implying that patients with structural CHDs may have clinically important underlying anomalies in heart function that merit treatment.

Predictors of atrial arrhythmias after device closure of secundum type atrial septal defects in adults

Atrial tachyarrhythmias (ATs) contribute substantially to morbidity in adult patients with secundum atrial septal defects (ASDs). The purpose of this study was to prospectively determine the incidence of AT in adults with an ASD and identify predictors of AT occurrence after closure. This was a prospective study of 200 adult patients undergoing closure of a secundum ASD. Arrhythmic events were defined as sustained or symptomatic AT requiring treatment. Twenty percent of patients (mean age 50 +/- 17 years; 26% men) referred for ASD closure had a history of AT. Early follow-up was available for 90% of patients, and the prevalence of AT was 17%. Of 171 patients with late follow-up (mean 1.9 +/- 0.9 years), data were available for 90%. AT was detected in 16% of these patients. Closure resulted in alleviation of symptoms (p <0.001), but symptoms alone did not identify patients at risk of recurrent AT. After closure of the ASD, the likelihood of remaining arrhythmia free was highest in patients without a history of AT (p = 0.001) and those <40 years at closure (p = 0.04). In conclusion, transcatheter ASD closure in patients without a history of arrhythmias and those <40 years of age conferred the highest likelihood of a patient remaining arrhythmia free in follow-up. An arrhythmia-specific treatment strategy should be considered for patients with documented established AT before ASD closure, in addition to shunt relief.

Pulmonary hypertension in older adults

Pulmonary hypertension is a frequently encountered problem in older patients. True idiopathic pulmonary arterial hypertension can also be seen and requires careful exclusion in older patients. Institution of therapies must be tempered with an appreciation of individual comorbidities and functional limitations that may affect patients' ability to comply and benefit from the complex treatments available for pulmonary arterial hypertension. This article reviews the existing data on the various forms of pulmonary hypertension presenting in older patients and on appropriate therapy in this challenging population.

Adult congenital heart disease: a 2008 overview

INTRODUCTION

During the past decades, health care of patients born with congenital heart disease (CHD) has improved substantially, leading to a growing population of adult survivors.

SOURCE OF DATA

Using the recently published and relevant data on adult CHD (ACHD), we reviewed the most common congenital heart defects and discussed important related issues.

AREAS OF AGREEMENT

Adults with CHD most often require specialized medical or surgical care in a tertiary centre. However, this population also need local follow-up; general practitioners and other specialists therefore have to face the complexity of their disease. AREAS OF CONTROVERSIES: Management of pregnancy, non-cardiac surgery, arrhythmias and endocarditis prophylaxis may be challenging in patients with CHD and should be adapted to their condition.

GROWING POINTS

The present article summarizes key clinical information on ACHD for the benefit of physicians who are not specialized in this field. Areas timely for developing research Research efforts and education strategies are greatly needed in order to optimize the care of patients with ACHD.

Patent ductus arteriosus: lack of evidence for common treatments

Patent ductus arteriosus (PDA) is a common diagnosis among extremely premature infants, especially in those with lung disease. Treatments are often used to close the PDA. Despite nearly three decades of research, the question of whether the benefits of treatments to prevent ductal patency or promote closure outweigh the risks of these treatments remains unanswered. The authors rarely use treatments designed to close the PDA. This article reviews three considerations in support of this restrained approach: rates of spontaneous closure of the ductus arteriosus; adverse effect of persistent ductal patency; and benefits and risks of treatments for closure.

Pathogenic mechanisms of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a complex disease that causes significant morbidity and mortality and is clinically characterized by an increase in pulmonary vascular resistance. The histopathology is marked by vascular proliferation/fibrosis, remodeling, and vessel obstruction. Development of PAH involves the complex interaction of multiple vascular effectors at all anatomic levels of the arterial wall. Subsequent vasoconstriction, thrombosis, and inflammation ensue, leading to vessel wall remodeling and cellular hyperproliferation as the hallmarks of severe disease. These processes are influenced by genetic predisposition as well as diverse endogenous and exogenous stimuli. Recent studies have provided a glimpse at certain molecular pathways that contribute to pathogenesis; these have led to the identification of attractive targets for therapeutic intervention. We will review our current understanding of the mechanistic underpinnings of the genetic and exogenous/acquired triggers of PAH. The resulting imbalance of vascular effectors provoking pathogenic vascular changes will also be discussed, with an emphasis on common and overarching regulatory pathways that may relate to the primary triggers of disease. The current conceptual framework should allow for future studies to refine our understanding of the molecular pathogenesis of PAH and improve the therapeutic regimen for this disease.

Evaluating Operability in Adults with Congenital Heart Disease and the Role of Pretreatment with Targeted Pulmonary Arterial Hypertension Therapy

Despite recent advances in cardiac surgery that have allowed repair of congenital heart defects at a very young age, pulmonary arterial hypertension (PAH) secondary to congenital heart disease (CHD) remains a major problem. In its most severe form, the Eisenmenger syndrome, PAH and its complications result in a significant increase in morbidity and mortality and also greatly affect the quality of life of patients.

Stroke after surgical treatment of sinus venosus type atrial septal defect: percutaneous treatment

BACKGROUND AND PURPOSE

Sinus venosus-type atrial septal defect can be associated with anomalous drainage of the upper right pulmonary vein into the superior vena cava. Surgical correction provides reconstruction of superior vena cava and rerouting of the pulmonary vein into the left atrium.

SUMMARY OF CASE

We report the case of a young woman who experienced 2 strokes 11 years after surgical repair of sinus venosus-type atrial septal defect.

CONCLUSIONS

Interventional treatment resolved the superior vena cava stenosis, rerouted the pulmonary vein into the left atrium and abolished the right to left shunt.

Transcatheter versus surgical closure of secundum atrial septal defect in adults: impact of age at intervention. A concurrent matched comparative study

OBJECTIVES

To compare the short- and mid-term outcomes of surgical (SUR) vs. transcatheter closure of secundum atrial septal defect (ASD) using Amplatzer septal occluder (ASO) in adults with a very similar spectrum of the disease; and to identify predictors for the primary end point.

DESIGN

Single-center, concurrent comparative study. Surgically treated patients were randomly matched (2:1) by age, sex, date of procedure, ASD size, and hemodynamic profile.

SETTING

Tertiary referral center.

PATIENTS

One hundred sixty-two concurrent patients with ASD submitted to ASO (n = 54) or SUR closure (n = 108) according with their preferences.

MAIN OUTCOME MEASURES

Primary end point was a composite index of major events including failure of the procedure, important bleeding, critical arrhythmias, serious infections, embolism, or any major cardiovascular intervention-related complication. Predictors of these major events were investigated.

RESULTS

Atrial septal defects were successfully closed in all patients, and there was no mortality. The primary event rate was 13.2% in ASO vs. 25.0% in SUR (P = .001). Multivariate analysis showed that higher rate of events was significantly associated with age >40 years; systemic/pulmonary output ratio <2.1; and systolic pulmonary arterial pressure >50 mm Hg; while in the ASO group the event rate was only associated with the ASD size (>15 cm(2)/m(2); relative risk = 1.75, 95% confidence interval 1.01-8.8). There were no differences in the event-free survival curves in adults with ages <40 years.

CONCLUSIONS

The efficacy for closure ASD was similar in both groups. The higher morbidity observed in SUR group was observed only in the patients submitted to the procedure with age >40 years. The length of hospital stay was shorter in the ASO group. Surgical closure is a safe and effective treatment, especially in young adults. There is certainly nothing wrong with continuing to do surgery in countries where the resources are limited.