Successful Procedures in Pulmonary Artery Stenting Did Not Increase Adverse Event Risk

In an effort to better determine adverse events and procedural success, researchers analyzed the effect of patient and procedural characteristics in pulmonary artery (PA) stenting. Findings were published in the Journal of the American College of Cardiology.

Researchers collected data from the National Cardiovascular Data Registry-IMPACT (Improving Pediatric and Adult Congenital Treatment) Registry. The registry holds data on pediatric and adult congenital heart disease catheterization. In this study, patients who underwent PA stenting between January 2011 and January 2014 were organized into 1 of 5 diagnostic categories.

Group 1 included all patients with tetralogy of Fallot (TOF) and TOF-like anatomy (including patients with pulmonary atresia, “hemitruncus,” or a TOF-type double outlet right ventricle); group 2 consisted of patients with a primary PA abnormality; group 3 included all nongroup 1 patients with a conotruncal abnormality; group 4 included all patients with a single ventricle; and group 5 included all other patients.

Due to the lack of a standardized definition of success, 2 definitions of PA stenting procedural success were created for patients with biventricular hearts and for patients with a single ventricle. The first definition was developed from previous studies and represented “a historical definition of procedural success and consisted of improvements in subpulmonic ventricular pressure and PA diameter.”

The second definition was developed and used to account for possible deficits in the historical definition. Aside from changes in ventricular pressure and PA size, the second definition also included “>50% gradient reduction across the stenosis to identify procedural success in patients with elevated pressure in the contralateral lung.” Researchers also used the ratio of post-procedure in-stent diameter to the pre-procedure distal diameter as a metric to determine improvement in PA size.

Data from a total of 1183 PA stenting procedures in 974 patients (mean age: 8.6 ± 9.8 years) were included in the analysis. Eighteen percent (n=211) of procedures were performed in patients with TOF or TOF-like diagnoses (group 1), 15% (n=182) in patients with primary PA stenosis (group 2), 9% (n=110) in patients with conotruncal abnormalities (group 3), 22% (n=262) in patients with a single ventricle (group 4), and 20% (n=234) in patients with a different diagnosis (group 5).

The mean pre-procedure PA diameter of the stenotic segment was 5.4 ± 3.4 mm, mean pre-procedure distal diameter was 9.0 ± 4.0 mm, and the mean post-procedure PA in-stent diameter was 9.5 ± 4.0 mm. The overall success rate for procedures in biventricular hearts was 76% (95% confidence interval [CI]: 73% to 79%) for definition 1 and 84% (95% CI: 82% to 86%) for definition 2. The number of procedures considered successful was significantly different for each definition (P<.001). Successful intervention in patients with a single ventricle occurred in 75% (95% CI: 70% to 80%) of cases.

Complications occurred in 14% (95% CI: 12% to 16%) of the procedures and 9% (95% CI: 7% to 11%) had a major adverse event (MAE). A total of 19 deaths occurred, 10 of which were associated with an urgent or emergent procedure, but none occurred in patients who had associated cardiac surgery.

“Successful interventions did not increase the risk for adverse events,” the authors wrote. “Instead, we found that patients who had a procedural success according to the second definition were significantly less like to have an MAE. Anatomic factors that decrease the probability of a successful outcome may also play a role in defining which patients are at highest risk for an MAE.”

Reference

Lewis MJ, Kennedy KF, Ginns J, et al. Procedural success and adverse events in pulmonary artery stenting. Insights from the NCDR. J Am Coll Cardiol. 2016;67(11):1327-1335.  doi: 10.1016/j.jacc.2016.01.025.