Augmentation index and the evolution of aortic disease in marfan-like syndromes.

Background: The augmentation index at a heart rate of 75 beats/min (AIx@HR75) and central pulse pressure (CPP) can be measured noninvasively with applanation tonometry (APT). In this observational study, we investigated the relationship between AIx@HR75, CPP and aortic disease in patients with Marfan-like syndromes.

Methods: We performed APT in 78 consecutive patients in whom classic Marfan syndrome (MFS) had been excluded (46 men and 32 women aged 34 +/- 13 years). These patients comprised 9 persons with MFS-like habitus, 6 with a bicuspid aortic valve (BAV), 5 with MASS phenotype, 3 with vascular type of Ehlers-Danlos syndrome (EDS), 3 with familial thoracic aortic aneurysm, 2 with Loeys-Dietz syndrome (LDS), 1 with mitral valve prolapse syndrome, 1 with familial ectopia lentis, and 48 persons with Marfan-like features but no defined syndrome. During 20 +/- 18 months after APT, we observed progression of aortic diameters in 15 patients, and aortic surgery or aortic dissection in 3 individuals.

Results: All 11 patients with Marfan-like syndromes and progression of aortic disease exhibited AIx@HR75 > or =11%, including 8 individuals with aortic diameters < or =95th percentile of normal at baseline. Similarly, all 7 individuals without any defined syndrome but progression of aortic diameters exhibited AIx@HR75 >11%, including 6 individuals with aortic diameters < or =95th percentile at the time of APT. Aortic disease did not evolve at AIx@HR75 <11%. CPP is also related to aortic disease progression.

Conclusions: Aortic disease evolution relates to AIx@HR75 and CPP in Marfan like syndromes. Larger studies with comprehensive clinical and echocardiographic follow-up over long time intervals will be required to establish APT for prediction of aortic disease evolution in Marfan-like syndromes.