Changes in aortic distensibility and pulse wave velocity assessed with magnetic resonance imaging following beta-blocker therapy in the Marfan syndrome.
It has been shown that beta-adrenergic blocking agents may reduce the rate of aortic root dilation and the development of aortic complications in patients with the Marfan syndrome. This may be due to beta-blocker-induced changes in aortic stiffness, of which distensibility and pulse wave velocity are in vivo measurable derivatives. We studied changes in distensibility at 4 levels of the aorta and pulse wave velocity along the entire aorta after 2 weeks of beta-blocker therapy in 6 Marfan syndrome patients and in 6 healthy volunteers, using magnetic resonance imaging (MRI) combined with brachial artery blood pressure measurements. In both groups, mean blood pressure decreased significantly (Marfan: 86 +/- 6 vs 78 +/- 5 mm Hg, p <0.05; control: 80 +/- 8 vs 73 +/- 3 mm Hg, p <0.05) (all data expressed as mean +/- 1 SD). At baseline, the Marfan syndrome patients exhibited decreased distensibility at the level of the ascending aorta (2 +/- 1 vs 6 +/- 2 10(-3)mm Hg(-1), p <0.01) and increased pulse wave velocity (6.2 +/- 0.4 vs 3.9 +/- 0.4 ms(-1), p <0.01) compared with control subjects. Only the Marfan syndrome patients had a significant increase in aortic distensibility at multiple levels and a significant decrease in pulse wave velocity after beta-blocker therapy (ascending aorta distensibility: 2 +/- 1 vs 4 +/- 1 10(-3)mm Hg(-1), p <0.05; abdominal aorta distensibility: 5 +/- 2 vs 8 +/- 3 10(-3)mm Hg(-1), p <0.05; pulse wave velocity: 6.2 +/- 0.4 vs 5.0 +/- 1.0 ms(-1), p <0.05). Thus, aortic stiffness in Marfan syndrome, together with mean blood pressure, is reduced by beta-blocker therapy, and MRI is well suited to detect these changes by measuring distensibility and pulse wave velocity.
Department of Cardiology, Academic Medical Center, Amsterdam, The Netherlands.
M
M
Groenink
A
A
de Roos
B J
BJ
Mulder
J A
JA
Spaan
E E
EE
van der Wall
D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000367:Age Factors; D001011:Aorta / Q000187:drug effects* / Q000503:physiopathology*; D001262:Atenolol / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects; D016022:Case-Control Studies; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008382:Marfan Syndrome / Q000188:drug therapy* / Q000503:physiopathology*; D008790:Metoprolol / Q000627:therapeutic use; D008875:Middle Aged; D011673:Pulsatile Flow / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects
D000319:Adrenergic beta-Antagonists; D001262:Atenolol; D008790:Metoprolol