Characterization of Degenerative Mitral Valve Disease: Differences between Fibroelastic Deficiency and Barlow’s Disease

Degenerative mitral valve disease causing mitral valve prolapse is the most common cause of primary mitral regurgitation, with two distinct phenotypes generally recognized with some major differences, i.e., fibroelastic deficiency (FED) and Barlow’s disease. The aim of this review was to describe the main histological, clinical and echocardiographic features of patients with FED and Barlow’s disease, highlighting the differences in diagnosis, risk stratification and patient management, but also the still significant gaps in understanding the exact pathophysiology of these two phenotypes.

How to manage an athlete with mitral valve prolapse

Introduction Under the term degenerative mitral valve prolapse different pathophysiological and clinical entities coexist in a spectrum ranging from Barlow’s disease to fibroelastic deficiency, and represent the most common cause of mitral regurgitation in the general population and in athletes. Carrying a mitral valve prolapse is usually considered a benign condition for athletes, but recently the scientific literature has focused on the malignant, thus rare, arrhythmic mitral valve prolapse and its dramatic association with sudden cardiac death, so that specific features should be considered a red flag and prompt additional exams before clear for competition. Discussion As the athlete’s heart is morphologically accompanied by remodelling and dilatation of the cardiac chambers induced by exercise, it may be challenging to differentiate the degree of left ventricular and atrial dilation induced by significant mitral regurgitation from physiological remodelling, especially in endurance athletes. Conclusion This how-to article provides clinical and useful data to manage athletes with mitral valve prolapse and to distinguish high-risk athletes carrying the features of arrhythmic mitral valve prolapse.

Robotic Mitral Valve Repair Through Nonresectional Posterior Leaflet Remodeling

The nonresectional posterior leaflet remodeling technique through free margin running suture (FMRS) has been recently introduced for the management of complex degenerative lesions of the posterior mitral leaflet. It aims at providing a novel tool in the mitral surgeon’s armamentarium to improve the reproducibility and durability of repair, namely in cases characterized by more severe degenerative disease (Barlow and extensive fibroelastic deficiency lesions). Although FMRS can be performed through any surgical access, its features render it particularly adapted to minimally invasive mitral surgery. We describe for the first time the characteristics of FMRS in the context of robotic-assisted mitral repair. A stepwise approach is employed for presentation. The diffusion of robotic-assisted mitral repair has been limited by both economic and reproducibility issues; we hypothesize that FMRS may be helpful in improving the reproducibility of minimally invasive and robotic-assisted mitral surgery. We also discuss the initial clinical results of FMRS.

The Carpentier-Edwards classic and physio annuloplasty rings in repair of degenerative mitral valve disease: A retrospective study

BackgroundPhysio ring (SR) is considered an improved version of the Classic rigid ring (RR). Today, SR is more widely used in mitral valve (MV) repair. We sought to compare the long-term outcomes of repair with RR and SR in degenerative mitral valve disease.MethodsIn a computerized registry of our institution, 306 patients had isolated MV repair with either RR (139 patients) or SR (167 patients) ring between 2005 and 2015. Fifteen of them had concomitant tricuspid valve repair. Ninety-two (30.1%) had Barlow’s disease and 214 (69.9%) had fibroelastic deficiency. The patients had similar demographic and echocardiographic characteristics.ResultsThere were 4 (1.3%) operative mortalities. Mean follow-up time was 107.4 ± 13.2 months. Left ventricular end diastolic and end systolic diameters significantly improved in both groups but not between groups. Survival at 10 years was 84.6% (93.1% in RR and 91.5% in SR; p = 0.177) and 10-year freedom from recurrent MR ≥ 2 + was 74.5% (88.2% in RR and 86.3% in SR; p = 0.110). Reoperations for repair failure were 8 in RR and 6 in SR. By Cox regression analysis, Barlow’s disease, preoperative MR = 4 + and chordal shortening were predictors of repair failure. Old age (≥ 70 years), NYHA functional class IV and pulmonary artery systolic pressure (≥ 40 mmHg) were predictors of poor survival by univariate analysis.ConclusionLong-term outcomes of repair for degenerative MV disease with the Classic and Physio rings are comparable. Artificial chordal implantation should be used instead of chordal shortening for diseased chordae.

Identification of known and unknown genes associated with mitral valve prolapse using an exome slice methodology

PurposeAlthough a familial distribution has been documented, the genetic aetiology of mitral valve prolapse (MVP) is largely unknown, with only four genes identified so far: FLNA, DCHS1, DZIP1 and PLD1. The aim of this study was to evaluate the genetic yield in known causative genes and to identify possible novel genes associated with MVP using a heart gene panel based on exome sequencing.MethodsPatients with MVP were referred for genetic counselling when a positive family history for MVP was reported and/or Barlow’s disease was diagnosed. In total, 101 probands were included to identify potentially pathogenic variants in a set of 522 genes associated with cardiac development and/or diseases.Results97 (96%) probands were classified as Barlow’s disease and 4 (4%) as fibroelastic deficiency. Only one patient (1%) had a likely pathogenic variant in the known causative genes (DCHS1). However, an interesting finding was that 10 probands (11%) had a variant that was classified as likely pathogenic in six different, mostly cardiomyopathy genes: DSP (1×), HCN4 (1×), MYH6 (1×), TMEM67 (1×), TRPS1 (1×) and TTN (5×).ConclusionExome slice sequencing analysis performed in MVP probands reveals a low genetic yield in known causative genes but may expand the cardiac phenotype of other genes. This study suggests for the first time that also genes related to cardiomyopathy may be associated with MVP. This highlights the importance to screen these patients and their family for the presence of arrhythmias and of ‘disproportionate’ LV remodelling as compared with the severity of mitral regurgitation, unravelling a possible coexistent cardiomyopathy.