As If Percutaneous ASD Closure Needed More Proof

Abstract

One of the most important achievements in cardiovascular medicine over the past several decades has been the success and widespread adoption of less invasive, transcatheter treatment for a variety of congenital heart conditions, particularly atrial septal defect (ASD). Widespread acceptance of the role of percutaneous treatment of ASD as the standard of care follows nearly two decades of clinical studies defining those patients best suited to this technology in both the pediatric and adult congenital heart population. Despite all of the progress made in reducing procedural adverse events by defining anatomic and physiologic parameters for success, questions remain about the early post procedural outcomes of adult patients undergoing ASD closure whether by surgical or percutaneous means. Such knowledge would be of immense benefit to cardiologists and cardiac surgeons counselling their adult congenital heart patients about the risks, benefits and alternatives available to manage their unrepaired atrial septal defects. In this issue of Structural Heart, Mojadidi et al. report a systematic review of hospitalization data for surgical and percutaneous closure of ASD during a recent 2-year period using the Nationwide Readmissions Database (NRD), an administrative database developed by the Agency for Healthcare Research and Quality for the Healthcare Cost and Utilization Project. Hospitalization characteristics and relevant comorbidities were identified using the corresponding International Classification of Diseases, Ninth Edition, Clinical Modification [ICD-CM 9] codes. Propensity score matching was conducted to evaluate the 30-day rates and causes of readmission following surgical repair compared with percutaneous closure in adult patients 18 years of age or older. The authors made a concerted effort in their statistical modeling to adjust for variables in patient and hospital characteristics. During the period from 2013 to 2014 the authors identified nearly 300,000 hospitalizations in the United States with a primary diagnosis of secundum atrial septal defect. Of these, nearly half were adult patients. Within this group, a total of 4,616 patients underwent ASD closure; 3,004 by percutaneous technique and 1,612 by open heart surgery. After propensity scoring, a total of 1,564 surgical closures were matched to 983 percutaneous repairs in a 2:1 fashion. 30-day readmissions were then compared in both the unadjusted and adjusted cohorts. The authors found a significantly higher rate of readmissions in the surgical cohort in both the unadjusted and adjusted sample pairs. In the unadjusted cohort sampling, the odds ratio for surgical versus percutaneous readmission was 1.99 while in the propensity adjusted cohort the odds ratio climbed to 3.43. Similarly, multivariable logistic regression models defined the odds ratios between nearly 2.2 and 2.4 favoring percutaneous repair. Patients who underwent surgical ASD repair also experienced an expected higher median length of stay of the index hospitalization of 8.8 days compared with 5.2 days for the percutaneous treatment group. Also, not surprisingly, the cost of index hospitalization for the surgical closure group of $169,513 was significantly greater than the $105,189 cost of the percutaneous closure group. Finally, important differences in the reason for readmission appeared in this analysis. While the most common reason for readmission in the surgical cohort was postpericardiotomy syndrome, the most common diagnosis in the percutaneously treated group was atrial fibrillation or flutter. The limitations imposed by the methodology of this study are openly discussed by the authors. Using a large administrative database and applying an observational, retrospective non-randomized analysis, made identification of confounding variables difficult. That said, the authors took appropriate steps to carry out a rigorous propensity scoring approach to match the observational groups as much as possible. Furthermore, the large data sets represented in this realworld analysis of outcomes from both smaller, communitybased hospitals and from larger metropolitan hospitals and teaching institutions provides insights lacking from previous studies based on selective single center or large institution multicenter experience. This represents the first time that researchers have applied this methodology of using “big data” to answer important questions in the management of a common congenital heart condition in adult patients. The findings of this study are consistent with other, previously reported and less rigorous studies showing both a safety and cost benefit to percutaneous treatment of ASD. What the authors have achieved in this study goes well beyond what was previously known by focusing on the rates and reasons for hospital readmission in the first 30 days following ASD treatment comparing percutaneous closure to surgical repair. By analyzing discharge and readmission data from a large, contemporary cohort of patients treated for ASD the authors have convincingly demonstrated lower peri-procedural complication rates in percutaneous closure group compared with surgery. They