Abstract 10395: Did Prescription Practice Change After Publication of a Landmark Trial for Children and Young Adults with Marfan Syndrome

Abstract

Intro: The Pediatric Heart Network (PHN) trial of β-blockers (BB) vs. angiotensin receptor blockers (ARB) for aortic root dilation in Marfan Syndrome showed similar efficacy, but its impact on prescribing practices is unknown. We hypothesized there would be an increase in single and combination use of BB and ARB after publication in 2014. Methods: Prescription data (2007-2016) were derived from outpatient encounters (IBM Marketscan) for children and young adults aged 6 mo to 25 yrs diagnosed with Marfan Syndrome who had ≥4 encounters with an adult or pediatric cardiologist or geneticist. Excluding 2014 as washout, data were divided into 2 time periods: 2007-2013 and 2015-2016. Categories included BB, ARB, angiotensin converting enzyme inhibitors (ACEI), combination (BB/ARB and/or BB/ACEI), and no drug use. We performed interrupted time-series analysis to assess the immediate level change and the change in slope for the prescription trend. We reported odds ratios (OR) and 95% confidence intervals (CI) from logistic regressions with generalized estimating equation methods to account for correlation of prescriptions within subjects. Results: Of 1499 patients (mean age 14.1 yrs, 59% female), BB had a downtrend [OR 0.91 (0.89, 0.93), p<0.001] and ARB trended higher [OR 1.12 (1.07, 1.18), p<0.001] 2007-2013, while combination, ACEI, and no drug use remained stable. There was no immediate effect after publication (2013-2015). Although the trend persisted for BB and ARB use (see Figure), the change in slope was not significant (2015-2016). Combination, ACEI and no drug use remained consistent. Conclusions: In short term follow-up, the impact of the PHN trial on prescription practices for aortic root dilation in Marfan Syndrome in children and young adults did not reach statistical significance. This may be due to early adoption of ARBs with subsequent confirmation of their usefulness. Longer term data are needed to fully explore the trial’s impact on practice change.