Hypertrophic obstructive cardiomyopathy: the mitral valve could be the key.

OBJECTIVES: As we strongly believe that treating the mitral valve abnormalities is a key feature of hypertrophic obstructive cardiomyopathy (HOCM), we have systematically corrected both the anterior and posterior leaflet (PL) size and geometry. We have analysed our immediate results and at mid-term follow-up. METHODS: From March 2010 until June 2015, 16 patients with HOCM underwent surgical correction of obstruction. The mean age was 51 years old (range, 32-72 years). All were symptomatic being New York Heart Association (NYHA) class 3 (n = 4) or 4 (n = 12). All had systolic anterior motion at echocardiogram with severe mitral regurgitation (MR). Intraventricular gradient preoperatively was 73.5 mmHg (range, 50-120 mmHg). All patients underwent a double-stage procedure: first septal resection through (i) the aortic valve and (ii) the detached anterior leaflet (AL) of the mitral valve and at second, mitral valve repair by (i) reducing PL height (leaflet resection or artificial neochordae) (ii) increasing AL height with pericardial patch. RESULTS: There was no in-hospital or late death. All patients were Class 1 NYHA at latest follow-up. Control echocardiography showed no MR, mean rest intraventricular gradient was 15 mmHg (range, 9-18 mmHg). CONCLUSIONS: Our good mid-term results support the concept that HOCM is not only a septal disease and that the mitral valve pathology is a key component that should be addressed. For most patients, the ideal surgical treatment should consist in a two-step procedure. It is even necessary to be studied whether treating the mitral valve alone could not suffice.

Functional tricuspid regurgitation: a need to revise our understanding.

The assessment of the etiology and severity of functional tricuspid regurgitation (FTR) has many limitations, especially when tricuspid regurgitation (TR) is more than severe. Instead of relying solely on TR severity, a new approach not only takes into account the severity of TR, but also pays strict attention to tricuspid annular dilation (size), the mode of tricuspid leaflet coaptation, and tricuspid leaflet tethering-factors often influenced by right ventricular enlargement and dysfunction. To simplify things, we propose a new staging system for functional tricuspid valve pathology using 3 parameters that may more accurately reflect the severity of the disease: TR severity, annular dilation, and mode of leaflet coaptation (extent of tethering). We believe that by utilizing these parameters, cardiologists and cardiac surgeons will be offered a better system for appraisal and decision-making in FTR.

Technique for chordae replacement in mitral valve repair.

We describe a simple technique for implantation of neochordae in degenerative mitral regurgitation with elongated or ruptured chords. We have successfully performed 102 mitral valve repairs using this technique and achieved mitral valve competency with no more than trace regurgitation. The technique is easy to perform and reproducible.

Coronary artery bypass surgery with or without mitral valve annuloplasty in moderate functional ischemic mitral regurgitation: final results of the Randomized Ischemic Mitral Evaluation (RIME) trial.

BACKGROUND: The role of mitral valve repair (MVR) during coronary artery bypass grafting (CABG) in patients with moderate ischemic mitral regurgitation (MR) is uncertain. We conducted a randomized, controlled trial to determine whether repairing the mitral valve during CABG may improve functional capacity and left ventricular reverse remodeling compared with CABG alone. METHODS AND RESULTS: Seventy-three patients referred for CABG with moderate ischemic MR and an ejection fraction >30% were randomized to receive CABG plus MVR (34 patients) or CABG only (39 patients). The study was stopped early after review of interim data. At 1 year, there was a greater improvement in the primary end point of peak oxygen consumption in the CABG plus MVR group compared with the CABG group (3.3 mL/kg/min versus 0.8 mL/kg/min; P<0.001). There was also a greater improvement in the secondary end points in the CABG plus MVR group compared with the CABG group: left ventricular end-systolic volume index, MR volume, and plasma B-type natriuretic peptide reduction of 22.2 mL/m(2), 28.2 mL/beat, and 557.4 pg/mL, respectively versus 4.4 mL/m(2) (P=0.002), 9.2 mL/beat (P=0.001), and 394.7 pg/mL (P=0.003), respectively. Operation duration, blood transfusion, intubation duration, and hospital stay duration were greater in the CABG plus MVR group. Deaths at 30 days and 1 year were similar in both groups: 3% and 9%, respectively in the CABG plus MVR group, versus 3% (P=1.00) and 5% (P=0.66), respectively in the CABG group. CONCLUSIONS: Adding mitral annuloplasty to CABG in patients with moderate ischemic MR may improve functional capacity, left ventricular reverse remodeling, MR severity, and B-type natriuretic peptide levels, compared with CABG alone. The impact of these benefits on longer term clinical outcomes remains to be defined.

Assessment of platelet function in patients on antiplatelet therapy undergoing cardiac surgery: a review.

Increasing numbers of patients are undergoing cardiac surgery on dual antiplatelet therapy following previous percutaneous coronary intervention. The dilemma of stopping antiplatelet therapy prior to surgery with risk of stent thrombosis, versus continuation and risk of post-operative bleeding has received much debate. Currently, an accurate and standardised method of predicting antiplatelet drug efficacy has not yet been determined and significant inter-individual variance has been shown. This review focuses on the most widely used laboratory and point of care assays currently available to measure platelet function and recent published data evaluating these methods. Further studies may enable predictive values to be defined, to guide the practicing clinician in balancing the risk of thrombosis versus haemorrhage.

A method for early evaluation of a recently introduced technology by deriving a comparative group from existing clinical data: a case study in external support of the Marfan aortic root.

OBJECTIVE: During the early phase of evaluation of a new intervention, data exist for present practice. The authors propose a method of constructing a fair comparator group using these data. In this case study, the authors use the example of external aortic root support, a novel alternative to aortic root replacement. DESIGN: A matched comparison group, of similar age, aortic size and aortic valve function to those having the novel intervention, was constructed, by minimization, from among patients having conventional aortic root replacement in other hospitals during the same time frame. SETTING: Three cardiac surgical units in England. PATIENTS: The first 20 patients, aged 16-58 years with aortic root diameters of 40-54 mm, having external support surgery were compared with 20 patients, aged 18-63 years and aortic root diameters of 38-58 mm, who had conventional aortic root replacement, between May 2004 and December 2009. INTERVENTIONS: A pliant external mesh sleeve, customised by computer-aided design, encloses the whole of the ascending aorta. The comparator group had conventional aortic root replacement, 16 valve-sparing and four with composite valved grafts. MAIN OUTCOME MEASURES: Duration of cardiopulmonary bypass (CPB), myocardial ischaemic time, blood loss and transfusion of blood, platelets and clotting factors. RESULTS: Comparing total root replacement and customised aortic root support surgery: CPB (median (range)) was 134 (52-316) versus 0 (0-20) min; myocardial ischaemia 114 (41-250) versus 0 (0-0) min; 4 h blood loss was 218 (85-735) versus 50 (25-400) ml; and 9/18 had blood transfusion, 9/18 platelets and 12/18 fresh frozen plasma after root replacement versus 1/20, 0/20 and 0/20, respectively, for the novel surgery. CONCLUSIONS: Avoidance or large reductions in CPB, myocardial ischaemia and blood product usage were achieved with the novel surgery. These data are of use in decision analysis and health economic evaluation and are available early in evaluation before randomised trial data are available.

Truly stentless autologous pericardial aortic valve replacement: an alternative to standard aortic valve replacement.

OBJECTIVE: The aim of this study was to determine the feasibility and durability of truly stentless aortic valve replacement using autologous pericardium sutured directly onto the aortic wall. METHODS: Eleven patients (mean age, 55.9 years) requiring aortic valve replacement were recruited. A circular piece of pericardium about 8 cm in diameter was harvested and treated in 0.6% glutaraldehyde for 10 minutes. The aortic valve was excised and, with the use of specially designed instruments (CardioMend LLC, Santa Barbara, Calif), the sinotubular junction was sized and the pericardium was tailored to the required size and shape and then sutured directly onto the aortic wall. The reconstructed valve was assessed directly and by echocardiography at the end of the operation; it was assessed by echocardiography and cardiac magnetic resonance imaging at 6 months and yearly. Computed tomographic scan of the aortic valve to assess for valve calcification was performed at last follow-up. RESULTS: Hospital mortality was 0%. Mean follow-up was 6.5 years (range, 5.3-7.5 years). Freedom from structural valve deterioration, thromboembolism, endocarditis and reoperation was 100%, 100%, 72.7%, and 63.6%, respectively. There were 4 reoperations at 4, 13, 15, and 46 months, 3 of them owing to endocarditis and 1 owing to technical failure noted at the time of surgery. The remaining 7 patients are alive and well with a mean New York Heart Association class of 1.3 and normally functioning aortic valves with no calcification. CONCLUSIONS: Truly stentless aortic valve replacement using autologous pericardium sutured directly onto the aortic wall is safe and feasible and has excellent durability up to 7.5 years with no calcification.

Current status of surgery for degenerative mitral valve disease.

Degenerative mitral valve (MV) disease refers to a collection of ill-defined pathologies of the MV which manifest as mitral regurgitation (MR). Untreated MR may progress to heart failure and death. Recent advances in the surgical technique of MV repair have improved long-term surgical results to the extent that early surgery is advocated in most patients with severe MR even when asymptomatic to restore normal functional capacity and life expectancy. This article reviews the pathophysiology, evaluation, treatment, and results of surgical intervention for degenerative MR.

Ischemic mitral regurgitation: in search of the best treatment for a common condition.

Ischemic mitral regurgitation (IMR) is common after myocardial infarction. It results in a significantly increased risk of congestive heart failure and death. The assessment of these patients is challenging as IMR is a dynamic condition and varies in severity under different physiologic conditions, such as physical exertion and changes in left ventricle (LV) contractility. Assessment, therefore, includes both the mitral valve and the LV and needs to be done at rest and under conditions of stress. Treatment of IMR involves optimization of medical therapy for coronary artery disease, coronary artery revascularization, and mitral valve surgery. Most patients have mild IMR and undergo isolated coronary artery revascularization either by percutaneous coronary intervention or coronary artery bypass graft surgery (CABG). In those with severe IMR, mitral valve repair or replacement is indicated, especially if the patient is symptomatic or has impaired LV function or LV dilatation. The optimal treatment of moderate IMR is controversial; mitral valve repair at the time of CABG may be beneficial, but randomized controlled trials are needed. In selected patients with papillary muscle dyssynchrony, cardiac resynchronization therapy may also be helpful.

Tricuspid valve disease: pathophysiology and optimal management.

Tricuspid valve disease most commonly occurs secondary to left-sided heart valve disease, in particular mitral valve disease. It is a marker of adverse outcome, and patients with moderate or severe tricuspid regurgitation (TR) have a reduced survival rate. Primary TR is treated surgically if severe, and the patient is symptomatic. However, during concomitant left-sided heart valve surgery, moderate or severe secondary TR with either raised pulmonary artery pressures or tricuspid annular dilatation should also be treated. This article reviews the pathophysiology and current management of patients with tricuspid valve disease.

Rheumatic mitral valve disease: current surgical status.

Rheumatic heart disease is the most serious sequelae of rheumatic fever occurring in approximately 30% of rheumatic fever patients. Patients with acute rheumatic fever may develop varying degrees of pancarditis with associated valve disease, heart failure, and pericarditis. Worldwide, rheumatic heart disease remains a major health problem although its prevalence in the developed countries is much reduced. Involvement of the mitral valve results in mitral regurgitation and/or stenosis. Where surgery is indicated, mitral valve replacement is usually necessary although in some cases, mitral valve repair is possible.

Infective endocarditis of the mitral valve: optimal management.

Infective endocarditis continues to be associated with significant morbidity and mortality despite recent advances in its management and remains a serious and challenging condition requiring a multidisciplinary approach. Surgery is essential in at least 50% of cases. Surgical outcomes have improved with the introduction of newer techniques for valve reconstruction and also depend on many factors, including the underlying cause, causative organism, tissues involved, and host factors.

Towards comprehensive assessment of mitral regurgitation using cardiovascular magnetic resonance.

Cardiovascular magnetic resonance (CMR) is increasingly used to assess patients with mitral regurgitation. Its advantages include quantitative determination of ventricular volumes and function and the mitral regurgitant fraction, and in ischemic mitral regurgitation, regional myocardial function and viability. In addition to these, identification of leaflet prolapse or restriction is necessary when valve repair is contemplated. We describe a systematic approach to the evaluation of mitral regurgitation using CMR which we have used in 149 patients with varying etiologies and severity of regurgitation over a 15 month period. Following standard ventricular cine acquisitions, including 2, 3 and 4 chamber long axis views and a short axis stack for biventricular function, we image movements of all parts of the mitral leaflets using a contiguous stack of oblique long axis cines aligned orthogonal to the central part of the line of coaptation. The 8-10 slices in the stack, orientated approximately parallel to a 3-chamber view, are acquired sequentially from the superior (antero-lateral) mitral commissure to the inferior (postero-medial) commissure, visualising each apposing pair of anterior and posterior leaflet scallops in turn (A1-P1, A2-P2 and A3-P3). We use balanced steady state free precession imaging at 1.5 Tesla, slice thickness 5 mm, with no inter-slice gaps. Where the para-commissural coaptation lines curve relative to the central region, two further oblique cines are acquired orthogonal to the line of coaptation adjacent to each commissure. To quantify mitral regurgitation, we use phase contrast velocity mapping to measure aortic outflow, subtracting this from the left ventricular stroke volume to calculate the mitral regurgitant volume which, when divided by the left ventricular stroke volume, gives the mitral regurgitant fraction. In patients with ischemic mitral regurgitation, we further assess regional left ventricular function and, with late gadolinium enhancement, myocardial viability. Comprehensive assessment of mitral regurgitation using CMR is feasible and enables determination of mitral regurgitation severity, associated leaflet prolapse or restriction, ventricular function and viability in a single examination and is now routinely performed at our centre. The mitral valve stack of images is particularly useful and easy to acquire.

Secondary tricuspid regurgitation or dilatation: which should be the criteria for surgical repair?

BACKGROUND: Secondary tricuspid dilatation may or not be accompanied by tricuspid regurgitation (TR). Tricuspid dilatation can be objectively measured whereas TR can vary according to the preload, afterload, and right ventricular function. The purpose of this prospective study was to determine whether surgical repair of the tricuspid valve based on tricuspid dilatation rather than TR could lead to potential benefits. METHODS: Between 1989 and 2001, 311 patients underwent mitral valve repair (MVR). The tricuspid valve was examined in each patient. Tricuspid annuloplasty was performed only if the tricuspid annular diameter was greater than twice the normal size (> or = 70 mm) regardless of the grade of regurgitation. Patients in group 1 (163 patients; 52.4%) received MVR alone. Patients in group 2 (148 patients; 47.6%) received MVR plus tricuspid annuloplasty. RESULTS: Although not significant there was a difference with regard to hospital mortality (group 1 = 1.8%, group 2 = 0.7%) and actuarial survival rate (Kaplan-Meier: group 1 = 97.3%, 96.2%, and 85.5%; group 2 = 98.5%, 98.5%, and 90.3% at 3, 5, and 10 years, respectively). The New York Heart Association (NYHA) functional class was significantly improved in group 2 (group 1 = 1.59 +/- 0.84; group 2 = 1.11 +/- 0.31; p1). TR increased by more than two grades in 48% of the patients in group 1 and in only 2% of the patients in group 2 (p < 0.001). CONCLUSIONS: Remodeling annuloplasty of the tricuspid valve based on tricuspid dilation improves functional status irrespective of the grade of regurgitation. Considerable tricuspid dilatation can be present even in the absence of substantial TR. Tricuspid dilatation is an ongoing disease process that will, with time, lead to severe TR.