April 01, 2016
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Pulmonary artery stenting linked to high procedural success, adverse event rates

Results from a registry analysis indicated high rates of procedural success after pulmonary artery stenting, but adverse events after treatment are also common.

Patients with biventricular hearts and an ostial stenosis were more likely to be treated successfully, whereas single-ventricular hearts, low body weight and need for emergency procedures significantly increased the risk for death or a major adverse event, the researchers wrote.

The analysis included data collected from the National Cardiovascular Data Registry-IMPACT Registry on 1,183 pulmonary artery stenting procedures performed in 974 patients between 2011 and January 2014. Citing the lack of a standardized definition for procedural success, the researchers identified the following criteria for success according to whether patients had biventricular hearts or single-ventricle palliation:

  • In patients with biventricular hearts (78%), an increase in pre-procedure diameter of more than 50% and/or a subpulmonic ventricular pressure decrease of more than 20% (definition 1); or a ratio of in-stent minimum diameter to pre-stent distal diameter of more than 80%, a 25% reduction in right ventricular pressure or a 50% decrease in pulmonary artery gradient (definition 2).
  • In patients with single-ventricle palliation (22%), a ratio of post-stent pulmonary artery vessel diameter to pre-stent distal pulmonary artery diameter of 1 or greater.

Among patients with biventricular hearts, the procedural success rate was 76% according to definition 1 and 84% according to definition 2 (P < .001 for difference). The single-ventricle success rate was 75%. Procedure success did not differ significantly according to treatment indication, the researchers wrote.

Results from multivariate analyses indicated that procedural success was associated with ostial stenosis in patients with biventricular hearts, regardless of the success definition used (RR = 1.12, 95% CI, 1.03-1.22 for definition 1; RR = 1.08; 95% CI, 1.01-1.16 for definition 2). Distal diameter before treatment was also significantly associated with success under both definition 1 (RR = 0.93; 95% CI, 0.91-0.96) and definition 2 (RR = 0.99; 95% CI, 0.97-0.99). None of the evaluated variables were associated with procedural success among single-ventricle patients.

Complications occurred in 14% of procedures, including 9% in which a patient died or experienced a major adverse event. Factors associated with incidence of mortality or major adverse events on multivariate analysis included weight less than 4 kg (RR for weight of 4 kg or higher = 0.34; 95% CI, 0.14-0.83), single-ventricle palliation (RR = 2.26; 95% CI, 1.54-3.33) and emergency procedure status (RR = 4; 95% CI, 2.31-6.92). Among biventricular patients specifically, procedural success according to definition 2 was associated with lower risk for major adverse events (RR = 0.49; 95% CI, 0.27-0.9), whereas success according to definition 1 was not (RR = 0.74; 95% CI, 0.43-1.29).

“[Pulmonary artery] stenting can be successfully achieved in most cases, but adverse events are common,” the researchers wrote. “These findings should inform referring physicians and operators regarding patient selection before [pulmonary artery] stenting. ... Further study is necessary to elucidate mechanisms to minimize patient risk and further validate definitions of procedural success.” – by Adam Taliercio

Disclosure: The researchers report no relevant financial disclosures.