Is ischemic mitral regurgitation an indication for surgical repair or replacement?

Mitral valve replacement in young patients: review and current challenges

Mitral valve repair is the ideal intervention for mitral valve disease with excellent long-term survival comparable to the age-matched general population. When the mitral valve is not repairable, mechanical prostheses may be associated with improved survival as compared with biological prostheses. Newer mechanical and biological valve prostheses have the potential to improve outcomes following mitral valve replacement in young patients. Patients presenting for mitral valve surgery after failed transcatheter mitral valve-in-valve have high rates of postoperative mortality and morbidity, exceeding those seen with reoperative mitral valve surgery, which poses issues in young patients who have a higher cumulative incidence of reintervention.

Functional Mitral Valve Regurgitation: Mitral Valve Repair or Replacement? Our "Road Map" for the Appropriate Strategy

Objectives: The optimal surgical approach for the treatment of functional mitral regurgitation (FMR) remains controversial. Current guidelines suggest that the surgical approach has to be tailored to the individual patient. The aim of the present study was to clarify further aspects of this tailored treatment. Methods: From 01/2006 to 12/2015, 390 patients underwent mitral valve (MV) surgery for FMR (ischemic n = 241, non-ischemic n = 149) at our institution. A regression analysis was used to determine the effect of MV repair or replacement on survival. The patients were analyzed according to the etiology of the MR (ischemic or non-ischemic), different age groups (<65 years, 65-75 years, and >75 years), LV function, and LV dimensions, as well as the underlying heart rhythm. Results: The overall survival rates for the repair group at 1, 5, and 8 years were 86.1 ± 1.9%, 70.6 ± 2.6%, and 55.1 ± 3.1%, respectively. For the same intervals, the survival rates in patients who underwent MV replacement were 75.9 ± 4.5%, 58.6 ± 5.4%, and 40.9 ± 6.4%, respectively (p = 0.003). Patients younger than 65 years, with an ischemic etiology of FMR, poor ejection fraction (<30%), severe dilatation of left ventricle (LVEDD > 60mm), and presence of atrial fibrillation had significantly higher mortality rates after MV replacement (HR, 3.0; CI, 1.3-6.9; p = 0.007). Patients between 65 and 75 years of age had a higher risk of death when undergoing mitral valve replacement (HR, 1.7; CI, 1.0-2.8; p = 0.04). In patients older than 75 years, the surgical approach (MV repair or replacement) had no effect on postoperative survival (HR, 0.8; CI, 0.4-1.3; p = 0.003). Conclusions: Our data demonstrate that, in patients younger than 65 years, the treatment of choice for FMR should be MV repair. This advantage was even more evident in patients with an ischemic origin of MR, a poor ejection fraction, a severe LV dilatation, and atrial fibrillation.

Outcome of Surgery for Ischemic Mitral Regurgitation Depends on the Type and Timing of the Coronary Revascularization

OBJECTIVE

Long-term outcomes of mitral valve (MV) repair versus MV replacement for ischemic mitral regurgitation (IMR) in patients undergoing either prior (PCR) or concomitant coronary revascularization (CCR) by surgery (CABG) or intervention (PCI) are uncertain.

METHODS AND RESULTS

Of 446 patients receiving MV surgery for IMR between July 2006 and December 2010, 125 patients-87 CCR (69.1%) and 38 PCR (30.9%)-were eligible for inclusion in the study. Survival was higher in CCR versus PCR at long-term follow-up (78.83% vs. 57.9%, p = 0.016). The incidence of MACCE was lower in the CCR compared to PCR at both hospital discharge (34.11% vs. 63.57%, p = 0.003) and at follow-up (34.11% vs. 65.79%, p = 0.0008). Patients receiving CABG or CABG with PCI in PCR had higher mortality risks after MV surgery than CCR patients (X² = 6.029, p = 0.014 and X² = 6.466, p = 0.011, respectively). Whereas in the PCR group, MV repair and MV replacement achieved similar survival probability (X² = 1.551, p = 0.213), MV repair in the CCR group led to improved survival compared to MV replacement (X² = 3.921, p = 0.048). In MV replacement, LAD-CABG improved survival compared to LAD-PCI (U = 15,000.00, Z = -2.373 p = 0.018), and a substantial impact of arterial IMA-LAD grafting was revealed in the Cox-regression analysis (HR 0.334, CI: 0.113-0.989, p = 0.048) as opposed to venous-LAD grafting (HR 0.588, CI: 0.166-2.078, p = 0.410).

CONCLUSION

Early treatment of IMR concomitant to coronary revascularization enhances long-term survival compared to delayed MV surgery after PCR. MV repair is not superior to MV replacement when performed late after coronary revascularization; however, MV repair leads to better survival than MV replacement when performed concomitantly with CABG with arterial LAD revascularization.

Surgical versus transcatheter mitral valve replacement in functional mitral valve regurgitation

Surgical mitral valve intervention for severe functional, or secondary mitral regurgitation is a viable option for patients deemed to be operative candidates and can be performed via traditional sternotomy or by minimally invasive techniques with similar outcomes. Transcatheter mitral valve replacement is an emerging technology with a potential role in the treatment of functional mitral valve regurgitation. A plethora of devices are currently in development and in various stages of clinical investigation. Operative approach to transcatheter mitral valve replacement varies from a percutaneous transseptal approach to a hybrid percutaneous/surgical apical approach. The Tendyne, Intrepid and Evoque systems show promising results from their early feasibility studies in treatment of patients with mitral regurgitation that were too high risk for surgery. In this review, we describe considerations for surgical and transcatheter mitral valve replacement for functional mitral valve regurgitation.

Predictors of hospital mortality after surgery for ischemic mitral regurgitation: the Toronto General Hospital experience

BACKGROUND

The benefit of mitral valve repair (MVr) over replacement in patients with severe ischemic mitral regurgitation (IMR) is still controversial. We report our early postoperative outcomes of repair versus replacement.

METHODS

Data were collected for patients undergoing first-time mitral valve surgery for severe IMR between 1990 and 2009 (n = 393). Patients who underwent combined procedures for papillary muscle rupture, post-infarction ventricular septal defect, endocarditis, or any previous cardiac surgery were excluded. Preoperative demographics, operative variables, and hospital outcomes were analyzed, and multivariable regression analysis was employed to identify independent predictors of hospital mortality.

RESULTS

Valve repair was performed in 42% (n = 164) of patients and replacement in 58% (n = 229). Patients who underwent replacement were older and had a higher prevalence of unstable angina, New York Heart Association Class IV symptoms, preoperative cardiogenic shock, preoperative myocardial infarction, peripheral vascular disease, renal failure, and urgent or emergency surgery (all p < .05). Unadjusted hospital mortality was higher in patients undergoing valve replacement (13% vs. 5%; p = .01). Valve repair was associated with a lower prevalence of postoperative low cardiac output syndrome. Multivariable analysis revealed that age, urgency of operation, and preoperative left ventricular (LV) function were independent predictors of hospital mortality. Importantly, MVr versus replacement was not an independent predictor of hospital mortality.

CONCLUSION

Our data did not suggest an early survival benefit to MVr over replacement for IMR. However, age, LV dysfunction, and the need for urgent surgery were independently associated with hospital mortality.

Surgical Management of Severe Ischaemic Mitral Regurgitation

BACKGROUND

Coronary artery bypass graft surgery (CABG) with mitral valve surgery is undisputed in severe ischaemic mitral regurgitation (IMR) treatment, but the controversy is whether mitral valve replacement (MVR) or mitral valvuloplasty (MVP) should be used.

METHODS

Data was collected from 130 cases of severe IMR patients who underwent CABG and MVP or MVR from June 2010 to June 2015 to compare the short-term efficacy of CABG with MVP or MVR in the treatment of severe IMR patients. There were 70 cases in the MVP group and 60 in the MVP group. The postoperative major cardiac cerebral vascular events and left ventricular ejection fraction (LVEF), left ventricular end-systolic diameter (LVESD), and left ventricular end-diastolic diameter (LVEDD) were recorded.

RESULTS

Eleven patients died in hospital, the remaining patients were followed up for 12 months; 18 patients died. The cumulative survival rate and the major cardiac cerebrovascular events were not significantly different. There was no significant change in LVEF, but LVEDD, LVESD and systolic pulmonary artery pressure (sPAP) improved significantly, and there was no difference between the groups. In the MVR group, the rate of postoperative moderate or severe mitral regurgitation patients was significantly less than that in the MVP group.

CONCLUSION

The short-term survival rate, reversal of left ventricular remodelling and major cardiac or cerebrovascular events post-CABG combined with MVP were not significantly different to those with CABG combined with MVR in the treatment of severe IMR, but long-term efficacy remains to be observed.

Mitral valve repair versus replacement

Degenerative, ischemic, rheumatic and infectious (endocarditis) processes are responsible for mitral valve disease in adults. Mitral valve repair has been widely regarded as the optimal surgical procedure to treat mitral valve dysfunction of all etiologies. The supporting evidence for repair over replacement is strongest in degenerative mitral regurgitation. The aim of the present review is to summarize the data in each category of mitral insufficiency and to provide recommendations based upon this data.

Ischemic mitral regurgitation: recent advances

This article reviews recent developments in the pathophysiology and management of ischemic mitral regurgitation. Recent imaging studies using three-dimensional echocardiography have added clarity to the mechanism responsible for this condition. This article also discusses recent studies on outcomes of surgical repair, including current results and potential risks of restrictive annuloplasty. Because of the limitations imposed by restrictive annuloplasty, adjunctive surgical methods focusing on the left ventricle or papillary muscles are being investigated to address this disease. In the interim, a downsized complete rigid or semirigid annuloplasty repair appears to offer good midterm outcomes.

Intraoperative TEE Assessment During Mitral Valve Repair for Degenerative and Ischemic Mitral Valve Regurgitation

Intraoperative assessment of the mitral valve (MV) in patients undergoing repair for MV regurgitation is a valuable support for the cardiac surgical team; results can be favored by adequate assessment tailored to the main condition affecting the MV. This article will review current available data for assessment of the MV in degenerative and ischemic mitral regurgitation.

The management of functional mitral regurgitation

Mitral regurgitation (MR) may be classified into two major categories: primary and secondary (functional). In primary MR, disease of the valve itself (eg, myxomatous degeneration, rheumatic disease) causes valve incompetence, producing left ventricular (LV) volume overload. To compensate, the left ventricle must enlarge in order to increase its volume-pumping capacity. If volume overload is prolonged and severe, the adverse effects of remodeling together with activation of deleterious neurohumoral systems leads to myocardial damage. It is quite clear that correction of the volume overload causes myocardial healing and reverse remodeling. Conversely, in secondary MR, the valve itself is normal. Ventricular dilatation and wall motion abnormalities cause papillary muscle displacement and annular dilatation, causing a normal mitral valve to leak. In this situation it is not clear whether or when correction of the MR is beneficial because the MR was not the primary cause of the LV dysfunction to begin with. Other areas of uncertainty include the type of correction to be used and whether burgeoning technologies for percutaneous valve repair will be useful.