The Use of MitraClip in Secondary Mitral Regurgitation and Heart Failure.

Secondary (also known as functional) mitral regurgitation (MR) has increased substantially over the last several decades due to an increase in the prevalence of dilated cardiomyopathy (ischemic and non-ischemic). Mortality and morbidity in patients with dilated cardiomyopathy is much greater when associated with MR as compared to without MR. MR will result in further left ventricular (LV) volume overload, LV dilation, and pupillary muscle displacement resulting in deterioration of the severity of MR leading to a vicious cycle. Optimization of heart failure medical therapy, and cardiac resynchronization therapy for those that qualify, can improve severity of MR; however, significant MR will persist in certain patients. Transcatheter mitral valve repair to treat significant MR using the MitraClip (Abbott, Menlo Park, California), which grasps and coapts the posterior and anterior mitral valve leaflets, in appropriately selected patients with dilated cardiomyopathy and secondary MR has been shown to improve quality of life and prolong survival.

Floppy mitral valve/mitral valve prolapse: A complex entity with multiple genotypes and phenotypes.

Floppy mitral valve/mitral valve prolapse (FMV/MVP) is a common valvular abnormality affecting 2% to 3% of the general population. It occurs in a heterogeneous group of patients with varying and age dependent expressions. FMV/MVP can be familial or sporadic, isolated (called non-syndromic) or as a part of a well-defined syndrome of heritable connective tissue disorders or other diseases. A wide range of phenotypic expression exists ranging from asymptomatic to non-specific symptoms related to neuroendocrine or autonomic nervous system functional abnormalities, varying degrees of mitral regurgitation that may require interventional therapy, heart failure, infective endocarditis, cardiac arrhythmias and/or sudden cardiac death. FMV/MVP is predominantly considered a heritable disorder with clinical manifestations not present at birth, but appearing later in life. Though a variant gene may initiate the development of FMV/MVP, precise phenotypic expression may be related to multiple other molecular, genetic and epigenetic factors that modify the final expression of the disease. A better understanding of these mechanisms will help to better define the natural history of the disease, inhibit disease progression and even prevent the phenotypic expression of FMV/MVP.

Matrix Metalloproteinase Polymorphisms in Patients with Floppy Mitral Valve/Mitral Valve Prolapse (FMV/MVP) and FMV/MVP Syndrome.

BACKGROUND: It has been suggested that collagen abnormalities of the mitral valve are present in patients with floppy mitral valve (FMV)/mitral valve prolapse (MVP). Genetic factors determining collagen synthesis and degradation have not been well defined in these patients. This study was undertaken to determine whether selective polymorphisms of matrix metalloproteinase-2 (MMP2) or transforming growth factor-ß (TGFß), with known or putative effects on collagen turnover, are more frequent in FMV/MVP. METHODS: Single nucleotide polymorphisms (SNPs) in select genes related to collagen turnover, including MMP2 rs2285053, MMP2 rs243865, TGFß1 rs1800469, and TGFß2 rs900, were determined in 98 patients with FMV/MVP who had severe mitral regurgitation and compared to 99 controls. RESULTS: MMP2 rs243865 was the only SNP significantly associated with FMV/MVP as compared to the control (odds ratio 2.07, 95% CI 1.23-3.50, p = 0.006). MMP2 rs228503 was the only SNP significantly associated with the FMV/MVP syndrome as compared to patients with FMV/MVP without the syndrome (odds ratio 2.41, 95% CI 1.08-5.40, p = 0.032). CONCLUSION: The frequency of certain MMP2 polymorphisms is higher in patients with the FMV/MVP syndrome and patients with FMV/MVP without the syndrome. The data suggest that a genetic predisposition that alters collagen turnover may play a role in the pathogenesis and development of FMV/MVP.

Floppy Mitral Valve (FMV) - Mitral Valve Prolapse (MVP) - Mitral Valvular Regurgitation and FMV/MVP Syndrome.

Mitral valve prolapse (MVP) results from the systolic movement of a portion(s) or segment(s) of the mitral valve leaflet(s) into the left atrium during left ventricular (LV) systole. It should be emphasised that MVP alone, as defined by imaging techniques, may comprise a non-specific finding because it also depends on the LV volume, myocardial contractility and other LV hemodynamics. Thus, a floppy mitral valve (FMV) should be the basis for the diagnosis of MVP. Two types of symptoms may be defined in these patients. In one group, symptoms are directly related to progressive mitral regurgitation and its complications. In the other group, symptoms cannot be explained only by the degree of mitral regurgitation alone; neuroendocrine dysfunction has been implicated for the explanation of symptoms in this group of patients that today is referred as the FMV/MVP syndrome. When significant mitral regurgitation is present in a patient with FMV/MVP, surgical intervention is recommended. In patients with a prohibitive risk for surgery, transcatheter mitral valve repair using a mitraclip device may be considered. Furthermore, transcatheter mitral valve replacement may represent an option in the near future as clinical trials are underway. In this brief review, the current concepts related to FMV/MVP and FMV/MVP syndrome will be discussed.

Floppy mitral valve/mitral valve prolapse syndrome: Beta-adrenergic receptor polymorphism may contribute to the pathogenesis of symptoms.

BACKGROUND: Certain patients with floppy mitral valve (FMV)/mitral valve prolapse (MVP) may have symptoms that cannot be explained on the severity of mitral valvular regurgitation (MVR) alone; hypersensitivity to adrenergic stimulation has been suggested in this group defined as the FMV/MVP syndrome. METHODS: Ninety-eight patients (75 men, 23 women) with mitral valve surgery for FMV/MVP were studied. Of those 41 (42%) had symptoms consistent with FMV/MVP syndrome [29 men (39%), 12 women (52%)]; median age of symptom onset was 30 years (range 10-63 years) and median duration of symptoms prior to valve surgery was 16 years (range 3-50 years). Ninety-nine individuals (70 men, 29 women) without clinical evidence of any disease were used as controls. Genotyping of ß1 and ß2 adrenergic receptors was performed. RESULTS: ß-Adrenergic receptor genotypes (ß1 and ß2) were similar between control and overall FMV/MVP patients. Subgroup analysis of patients, however, demonstrated that the genotype C/C at position 1165 resulting in 389 Arg/Arg of the ß1 receptor was more frequent in women compared to those without FMV/MVP syndrome and to normal control women (p<0.025). This polymorphism may be related to hypersensitivity to adrenergic stimulation as reported previously in these patients. CONCLUSION: This study shows a large proportion of patients with FMV/MVP, predominantly women, had symptoms consistent with the FMV/MVP syndrome for many years prior to the development of significant MVR, and thus symptoms cannot be attributed to the severity of MVR alone. Further, women with FMV/MVP syndrome, symptoms at least partially may be related to ß1-adrenergic receptor polymorphism, which has been shown previously to be associated with a hyperresponse to adrenergic stimulation.

Coronary ostial stenosis after aortic valve replacement: successful treatment of 2 patients with drug-eluting stents.

Coronary ostial stenosis is a rare but potentially serious sequela after aortic valve replacement. It occurs in the left main or right coronary artery after 1% to 5% of aortic valve replacement procedures. The clinical symptoms are usually severe and may appear from 1 to 6 months postoperatively. Although the typical treatment is coronary artery bypass grafting, patients have been successfully treated by means of percutaneous coronary intervention.Herein, we present the cases of 2 patients in whom coronary ostial stenosis developed after aortic valve replacement. In the 1st case, a 72-year-old man underwent aortic valve replacement and bypass grafting of the saphenous vein to the left anterior descending coronary artery. Six months later, he experienced a non-ST-segment-elevation myocardial infarction. Coronary angiography revealed a critical stenosis of the right coronary artery ostium. In the 2nd case, a 78-year-old woman underwent aortic valve replacement and grafting of the saphenous vein to an occluded right coronary artery. Four months later, she experienced unstable angina. Coronary angiography showed a critical left main coronary artery ostial stenosis and occlusion of the right coronary artery venous graft. In each patient, we performed percutaneous coronary intervention and deployed a drug-eluting stent. Both patients were asymptomatic on 6-to 12-month follow-up. We attribute the coronary ostial stenosis to the selective ostial administration of cardioplegic solution during surgery. We conclude that retrograde administration of cardioplegic solution through the coronary sinus may reduce the incidence of postoperative coronary ostial stenosis, and that stenting may be an efficient treatment option.

First human implantation of a new rotary blood pump: design of the clinical feasibility study.

Surgical treatment of heart failure is emerging as one of the most challenging clinical dilemmas for patients with end-stage cardiac failure not amenable to medical treatment. One of the most intriguing techniques is the use of implantable left ventricular assist devices (LVADs) as a bridge to recovery. The early experience from our centre has shown that even short term post-cardiotomy mechanical assistance, after heart failure surgery, improves patient outcome; thus, a clinical feasibility study was designed. The hypothesis of the study is that reparative heart failure surgery combined with postoperative mechanical support, ventricular resynchronisation where indicated, and pharmacological treatment can maximise myocardial recovery. In the study a new, implantable, magnetically levitated, rotary pump will be used as a bridge to recovery. In this manuscript the first worldwide human implantation of a new, continuous-flow LVAD, the WorldHeart Rotary Pump (Levacor, WorldHeart Inc., Oakland CA), is reported. The design and the rationale of the feasibility study, the inclusion and exclusion criteria, and the primary and secondary end points of the clinical investigation, are delineated. In addition, the design of the new rotary pump, its general principles of operation, and the implantation technique are described.