Treatment with losartan instead of more conventional atenolol yielded no significant difference in aortic-root dilation in children and young adults with Marfan’s syndrome over 3 years, according to a new study published in the New England Journal of Medicine and presented simultaneously at the American Heart Association’s Scientific Sessions.
In a randomized trial, researchers identified 608 children and young adults with Marfan’s syndrome and randomized them to treatment with either losartan (267) or atenolol (268) for 3 years. The participants were between the ages of 6 months and 25 years, had been diagnosed with Marfan’s syndrome according to the original Ghent criteria, and possessed a z score of 3.0 for maximum aortic-root diameter indexed to body surface area. The baseline subgroups were predefined as aortic-root z score being less than 4.5 vs. at or greater than 4.5, young adult vs. child, and previous use of beta-blocker (yes vs. no).
The results indicate that the baseline-adjusted annual rate of change in the aortic-root z score did not differ substantially between the losartan and atenolol groups: –0.107 ± 0.013 and –0.139 ± 0.013 standard deviation units, respectively (P = .08). Both data groups were significantly less than 0, however, indicating that both treatments were effective in decreasing aortic-root z scores. Younger patients in both groups experienced greater decreases in aortic-root z scores, but one was not significantly more than the other (P = .002 and P < .001 for losartan and atenolol, respectively).
“We did not find the expected advantage of angiotensin-receptor blockade therapy over beta-blocker therapy,” wrote the authors, led by Dr. Ronald V. Lacro of Boston Children’s Hospital’s Department of Cardiology (N. Engl. J. Med. 2014 [doi:10.1056/NEJMoa1404731]).
There were “small but significant differences favoring atenolol in the average annual change in the absolute diameter and z score for the aortic annulus, but there were no significant differences in the diameter or z score for the ascending aorta,” according to the investigators.
“This finding was unexpected, without a clear physiological explanation,” wrote Dr. Lacro and his associates.
The study was supported by a grant from the National Institute of Health’s National Heart, Lung, and Blood Institute. The authors reported no other financial conflicts of interest.