Search

Fibromuscular dysplasia (FMD) is a non-atherosclerotic vascular disease that may involve medium-sized muscular arteries throughout the body. The majority of FMD patients are women. Although a variety of genetic, mechanical, and hormonal factors play a role in the pathogenesis of FMD, overall, its cause remains poorly understood. It is probable that the pathogenesis of FMD is linked to a combination of genetic and environmental factors. Extensive studies have correlated the arterial lesions of FMD to histopathological findings of arterial fibrosis, cellular hyperplasia, and distortion of the abnormal architecture of the arterial wall. More recently, the vascular phenotype of lesions associated with FMD has been expanded to include arterial aneurysms, dissections, and tortuosity. However, in the absence of a string-of-beads or focal stenosis, these lesions do not suffice to establish the diagnosis. While FMD most commonly involves renal and cerebrovascular arteries, involvement of most arteries throughout the body has been reported. Increasing evidence highlights that FMD is a systemic arterial disease and that subclinical alterations can be found in non-affected arterial segments. Recent significant progress in FMD-related research has led to improve our understanding of the disease's clinical manifestations, natural history, epidemiology, and genetics. Ongoing work continues to focus on FMD genetics and proteomics, physiological effects of FMD on cardiovascular structure and function, and novel imaging modalities and blood-based biomarkers that can be used to identify subclinical FMD. It is also hoped that the next decade will bring the development of multi-centred and potentially international clinical trials to provide comparative effectiveness data to inform the optimal management of patients with FMD. [ABSTRACT FROM AUTHOR]

Background: We previously described a strong association between fibromuscular dysplasia (FMD) and spontaneous coronary artery dissection. Angiographic manifestations of coronary FMD aside from dissection were considered rare. However, we observed several coronary FMD angiographic abnormalities with corresponding optical coherence tomography abnormalities. Methods and Results: Baseline demographics and imaging of patients with suspected coronary FMD at Vancouver General Hospital were reviewed. Presence of multifocal (string-of-beads) extracoronary FMD was confirmed by 2 specialists. In these patients, coronary angiographic findings (excluding dissected segments) were reviewed and classified by 2 experienced angiographers for irregular stenosis, that is, stenosis with irregular borders in a focal or diffuse pattern with/without systolic accentuation; smooth stenosis, diffuse or focal; segmental dilatation/ectasia; and tortuosity. Optical coherence tomography was performed in a subset of patients. Of 32 patients with extracoronary FMD and suspected coronary involvement, 28 were women (88%), and their mean age was 59.4±9.9 years. Nineteen presented with myocardial infarction (13 caused by spontaneous coronary artery dissection), and 13 had stable symptoms. The observed coronary angiographic abnormalities included tortuosity in all cases (91% were moderate to severe), irregular stenosis in 59%, smooth stenosis in 19%, and segmental dilatation/ectasia in 56%. Fifteen patients had optical coherence tomography of the abnormal segments showing abnormalities, including multiple areas of patchy or diffuse intimal, medial or adventitial abnormalities with thickening/accumulation of varied reflectivities, macrophage infiltration, loss/duplication of elastic membranes, and cavitation. Conclusions: This is the first case series describing findings suggestive of angiographic and intracoronary manifestations of coronary FMD. Future studies should prospectively review these features in patients with extracoronary FMD. [ABSTRACT FROM AUTHOR]