Outcomes of a modified approach to transcatheter closure of perimembranous ventricular septal defects

OBJECTIVES

To describe the immediate and midterm results of a modified method for transcatheter closure of perimembranous ventricular septal defects (pmVSDs).

BACKGROUND

Transcatheter closure of pmVSDs has been associated with development of heart block due to impingement on the ventricular conduction system. Ventricular septal aneurysms (VSAs) are common; the VSA tissue can serve as a target for the device without necessitating direct contact with the conduction system.

METHODS

Between 2004 and 2011, 15 patients underwent transcatheter closure of a pmVSD utilizing a device implanted into a VSA. Catheterization reports were examined in addition to pre-closure, post-closure, and current clinical, ECG, and echocardiographic data.

RESULTS

The median age was 20 years (4-61 years), and the most common indication for closure was increasing LV dilation. Four different Amplatzer devices were utilized. Following device implantation there was a decrease in Qp:Qs (1.7-1.1) and in RV:LV pressure ratio (0.36-0.31). There were no deaths, no device embolizations, and no new heart block or PR interval prolongation. Three patients developed a new right bundle branch block (RBBB). The median follow-up time was 1.5 years (4 months to 7.1 years). Two patients required further procedures for important residual shunting. Six continued to have a "trivial/small" residual leak, but only one had any degree (mild) of residual LV dilation. None of the complications were significantly associated with age or weight at the time of procedure, original size of the VSD, or size or type of the device used.

CONCLUSION

Transcatheter closure of pmVSD with placement of the device into the VSA is safe and effective, and may result in fewer instances of atrioventricular block and valve abnormalities than have been reported with alternative methods of pmVSD device closure. Persistent VSDs and new RBBBs remain an important issue.

Prenatal diagnosis of atrial restriction in hypoplastic left heart syndrome is associated with decreased 2-year survival

OBJECTIVE

To compare the course of hypoplastic left heart syndrome (HLHS) patients diagnosed prenatally with any degree of atrial restriction with those without evidence of atrial restriction.

DESIGN

Retrospective, cohort.

METHODS

Prenatally diagnosed HLHS patients from August 1999 to January 2009 were categorized as nonrestrictive versus restrictive, defined by left atrial hypertension on pulmonary venous Doppler and/or an intact interatrial septum.

RESULTS

Of 73 total fetal patients identified, 49 were live-born. Survival at 2 years was 29/35 [83% confidence interval (CI): 59.5%-88.9%] for the nonrestrictive group and 6/14 (43% CI: 17.7%-6.0%) for the restrictive group (p<0.0001). Of those who underwent stage 1 palliation (35 with nonrestrictive and 10 with restrictive atrial septa), both groups had a similar incidence of preoperative acidosis and need for ventilation and inotropic support. Postoperatively, there was no difference between groups in ventilator days, length of stay, or survival to discharge. There was decreased survival at 2 years in the restrictive group, 60% (CI: 26.2%-87.8%) versus 83% (CI: 66.4%-93.4%) in the nonrestrictive group. Furthermore, a disproportionate number of interstage deaths was evident in the restrictive group.

CONCLUSIONS

Prenatal presence of any degree of atrial septal restriction in the setting of HLHS confers a significant survival disadvantage, with increases in both early and late mortality.

Cardiac magnetic resonance imaging correlates of exercise capacity in patients with surgically repaired tetralogy of Fallot

Objective exercise testing in patients with repaired tetralogy of Fallot frequently identifies gross deficiencies in exercise capacity. These findings are typically attributed to right ventricular dysfunction, pulmonary valve regurgitation, and pulmonary artery stenosis and are used to justify referrals for surgical or transcatheter interventions. However, the relation between right-sided cardiac abnormalities and exercise capacity in this patient group is poorly understood. Cardiac magnetic resonance imaging correlates of exercise capacity in 37 patients with repaired TOF were retrospectively examined. In conclusion, on multivariate analysis, right ventricular ejection fraction was the only cardiac magnetic resonance imaging predictor of percentage of predicted peak oxygen consumption, oxygen consumption at ventilatory anaerobic threshold, and oxygen pulse.

Transcatheter creation and enlargement of ventricular septal defects for relief of ventricular hypertension

OBJECTIVE

Creation or enlargement of a ventricular septal defect is indicated in rare clinical situations. In the setting of double-outlet right ventricle requiring single-ventricle palliation, left ventricular outflow tract obstruction caused by progressive restriction at the ventricular septal defect poses an uncommon but recognized dilemma. In this situation surgical ventricular septal defect enlargement may be desirable but risks damage to the atrioventricular valve or conduction system. We report the results of a novel technique for transcatheter creation or enlargement of ventricular septal defects as an alternative to reoperation when decompression of an isolated ventricle is indicated.

METHODS

Eight patients had undergone transcatheter ventricular septal defect enlargement or creation, and 3 of these patients had undergone 4 prior surgical attempts at left ventricular decompression. Ventricular aneurysms had developed in 3 patients before intervention.

RESULTS

Five patients underwent ventricular septal defect creation, and 3 patients underwent enlargement of existing ventricular septal defects. Initial intervention resulted in a decreased ventricular septal defect pressure gradient from 76.9 mm Hg to 20.3 mm Hg (P = .004). There was no procedural mortality or sustained heart block. Two patients had moderate-to-severe atrioventricular valve regurgitation, and 1 required surgical repair. At last follow-up, all ventricular septal defects remained patent, with recurrent obstruction in the majority of cases caused by muscular hypertrophy beyond the stent margins. In 1 patient a ventricular aneurysm has regressed in size. Repeat intervention reduced recurrent obstruction, but recurrence was the rule.

CONCLUSIONS

When reoperation is considered high risk, transcatheter creation and enlargement of ventricular septal defects is possible with excellent short-term results. Recurrent obstruction is common but responds to repeated intervention. Further studies are required to establish clinical benefit.