Racial and ethnic differences in response to treatment for Marfan syndrome

To determine whether racial/ethnic differences exist for the treatment of Marfan syndrome aortopathy. The 2014 Pediatric Heart Network randomised trial of losartan versus atenolol in Marfan syndrome paediatric and young adult patients showed no treatment differences in the rate of aortic root growth over 3 years; however, they did not examine racial/ethnic differences, and recent data suggest that angiotensin receptor blockers may have different pharmacologic effects in different racial/ethnic populations.

We performed a secondary analysis of public-use data from the Pediatric Heart Network randomised trial comparing the differences by race/ethnicity (non-Hispanic White, non-Hispanic Black, and Hispanic patients) amongst the treatment groups for the primary outcome of rate of aortic root enlargement by z score and secondary outcome of rate of change of absolute diameter of aortic root, z score and absolute diameter of ascending aorta, and blood pressure changes.

For aortic root enlargement by z score amongst non-Hispanic White patients, patients on losartan exhibited an annual z score change of -0.090 ± 0.016, compared to -0.146 ± 0.015 for those on atenolol (p = 0.01), favouring atenolol. For Hispanic and non-Hispanic Black patients, there was no difference in primary or secondary outcomes between treatment groups.

Non-Hispanic White patients had a small, but statistically significantly greater decrease in aortic root z score favouring atenolol over losartan. There were no significant differences amongst Hispanic or non-Hispanic Black patients, which may be due to relatively small size numbers. These findings may have important implications for medication selection by race/ethnicity in Marfan syndrome patients, which has not previously been evaluated in studies.