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In children with perimembranous ventricular septal defects (VSDs), closure with a catheter-delivered occluder device is safe, providing midterm outcomes similar to those of open-heart surgery, according to a study published online February 5, 2014, ahead of print in the Journal of the American College of Cardiology. The less invasive strategy also substantially reduces procedural complications. 

Investigators led by Jian Yang, MD, PhD, of Fourth Military Medical University (Xi’an, China), randomized 229 children (aged 3 to 8 years) to transcatheter implantation of the Shanghai pmVSD occluder (Lepu Medical Technology, Beijing, China; n = 114) or surgical closure (n = 115) at 3 Chinese centers between January 2009 and July 2010.

In-Hospital Measures Favor Transcatheter Treatment

Transcatheter device deployment was successful in all patients, although a second device was required in 3 subjects. Procedure time, hospital and ICU stays, and volume of blood transfusion were lower in the transcatheter group compared with the surgical group (table 1).

Table 1. Procedural Outcomes: Surgery vs Transcatheter Approach^a

^a P < 0.001 for all comparisons.

Death, stroke, or neurological deficit was not seen in either group. No major adverse events occurred in the transcatheter group, whereas 1 event was observed in the surgical group (bleeding requiring thoracic re-exploration). There were more than one-third fewer minor adverse events in the transcatheter group compared with the surgical group (7 vs 32; P < 0.001).

At discharge, all of the transcatheter patients were asymptomatic and did not require further treatment.

At 24 hours postprocedure, levels of alanine aminotransferase, aspartate aminotransferase, and creatinine were all higher in the surgical group (P < 0.01). In addition, within 72 hours, the area under the curve for both CK-MB and cardiac troponin I release was greater among surgical than transcatheter patients (P < 0.001).

Transesophageal echocardiography showed that 97 of 99 ventricular septal defects in the surgical group were closed 3 days after the operation. Two patients had residual shunts and 2 experienced mild tricuspid insufficiencies. In the transcatheter group, small shunts through the occluder were seen in slightly more than a quarter of patients (27.7%), but all shunts had diminished at 3-month follow-up. In addition, 1 patient developed asymptomatic new tricuspid insufficiency.

At a median 2-year follow-up, no deaths, neurological deficits, thromboembolisms, or cases of endocarditis were reported in either group. All patients were in New York Heart Association class I-II, with normal sinus rhythm. There was no difference in decrease in Z score for left ventricular end diastolic dimension between the groups (P = 0.319), and no differences in closure rate, adverse events, or complications.

Study Population Not Representative?

This is the first randomized comparison of open heart surgery with transcatheter device closure for VSD, Ziyad M. Hijazi, MD, MPH, of Rush University Medical Center (Chicago, IL), told TCTMD in a telephone interview. However, he noted, the study population was limited to children at least 3 years old, whereas in the United States the majority of patients with VSD receive surgery during infancy.

In a telephone interview with TCTMD, Doff B. McElhinney, MD, MS, of NYU Langone Medical Center (New York, NY), echoed that point, adding that the study sample may not reflect the broader population of patients with such defects who need closure, in terms of both demographic and lesion characteristics. Another trial limitation, he noted, is that its objectives were not clearly spelled out.

Improved Design, Good Technique Equals Less Heart Block

In earlier studies involving the Amplatzer occluder (St. Jude Medical, St. Paul, MN), the transcatheter procedure was associated with a relatively high risk of complete AV block, Dr. Hijazi observed. The absence of the complication in the current study may be due to the Shanghai device’s being made of softer, nitinol material, which causes less friction and compressive force on the conduction system adjacent to the septal defect, he said.

Dr. Yang and colleagues also point to several technical issues they believe were instrumental in the success of transcatheter closure:

• Selecting the best catheter and wire to facilitate defect crossing
• In aneurysmal-type defects, placing the occluder inside the aneurysmal sac
• Avoidance of an oversized device
• Strict adherence to exclusion criteria such as low body weight and age younger than 3 years

Moreover, the procedure is technically demanding, with a steep learning curve, Dr. Hijazi commented, and the study centers had highly experienced operators.

Recently, St. Jude Medical redesigned its original Amplatzer occluder, offering a new iteration intended to minimize mechanical trauma, Dr. Hijazi reported, and limited clinical trials involving the new device have shown promising results. In addition, multiple other reports from China have also shown strong outcomes with closure devices, Dr. McElhinney added, but he cautioned that the Chinese devices have not undergone the same regulatory scrutiny that they would receive in the United States.

Dr. McElhinney also cautioned that the 2-year follow-up of the current study does not quell concern about the longer-term risk of heart block. “These devices will be in the body for decades, and heart block has been reported many years later,” he noted.

A First Step to Becoming the ‘Treatment of Choice’?

Nonetheless, the “benefits of avoiding cardiopulmonary bypass, reducing the psychological impact, and offering the less painful and less uncomfortable percutaneous intervention are extremely attractive for both patients and physicians,” the authors say. Striking a simultaneously hopeful and cautious note, Dr. McElhinney added, “The idea of these devices being an alternative to surgery is exciting and hopefully this represents a good early step in substantiating that. But in the bigger picture, it remains preliminary.” 

Dr. Hijazi predicted that as positive data accumulate, transcatheter closure will become “the treatment of choice for straightforward membranous ventricular septal defect.” However, he added, such defects are frequently associated with other cardiac conditions, and “those [cases] should be left to the surgeon.”

Study Details

The groups were similar with regard to baseline characteristics. Most patients in both the surgical group (56.6%) and transcatheter group (65.3%; P = 0.531) were treated because of hemodynamic changes. However, 17 patients in the surgery group and 21 in the transcatheter group had no left ventricular enlargement and were enrolled mainly due to symptoms such as refractory pneumonia, congestive heart failure, delayed growth, exercise intolerance, and frequent colds.

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