Mitral Valve Prolapse in Marfan Syndrome
Abstract & Commentary
By Michael H. Crawford, MD
Source: Rybczynski M, et al. Frequency and age-related course of mitral valve dysfunction in the Marfan syndrome. Am J Cardiol. 2010;106:1048-1053.
The incidence and significance of mitral valve prolapse (MVP) in patients with Marfan syndrome is poorly understood. Thus, these investigators from Germany prospectively studied patients with classic Marfan syndrome (Ghent criteria). Echocardiograms were performed at 6- to 12-month intervals in 174 patients for a mean of 4.4 years. MVP was present in 82 (40%); severe mitral regurgitation (MR) in 25 (12%); and mitral valve endocarditis in five (2.5%). Any degree of MR was present in 57%. The risk of severe MR and endocarditis increased with age. The presence of MVP was most strongly associated with skeletal involvement, as compared to other classic features of Marfan (p < 0.001). Severe MR was more common in sporadic Marfan vs. familial forms (p < 0.006). The authors concluded that MVP is common in Marfan syndrome and is associated with an increased risk of severe MR and endocarditis.
The incidence of MVP in this large series of patients is much higher than the 1%-2% estimated in the general population. The number of patients going on to develop severe MR or endocarditis seems higher than MVP series in non-Marfan patients. So, it appears that MVP in this patient population is associated with a higher frequency of complications. One reason may be that half of the Marfan patients exhibited bi-leaflet MVP, which is much less common in non-Marfan MVP.
More patients with Marfan had some degree of MR, as compared to those who had MVP (57% vs. 40%), as would be expected, since MR can have many causes including senescence. However, severe MR was only observed in those with MVP. The study population included subjects aged 0-77 years of age, but severe MR was rare in children. Thus, Marfan syndrome patients should have more frequent echocardiographic screening so that the window for surgical intervention is not missed.