Management Of Ischemic Mitral Regurgitation Research Articles

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.

Ischaemic Mitral Regurgitation and the Role of Surgical Intervention

The correct management of ischaemic mitral regurgitation (IMR) in patients presenting for coronary artery bypass grafting (CABG) remains contentious. Although it is generally agreed that severe MR in patients presenting for CABG should be corrected and that mild MR can be left alone, there is no consensus as to the correct treatment for those patients with moderate MR undergoing CABG. Further, there has never been a prospective randomised trial looking at this issue. The data from retrospective reviews is conflicting. The available evidence clearly shows an increase in cardiac morbidity in those patients undergoing revascularisation who are left with significant MR. However, those retrospective studies comparing patients who have a mitral valve procedure with their CABG to those who undergo CABG alone have not consistently shown a benefit. This may be due to the retrospective nature of these reports. But it may also be due to the type of repairs being performed which may not be adequately addressing the specific pathology involved. The aim of this paper therefore is to evaluate the available evidence to help guide decision making in the treatment of ischaemic MR. The underlying pathophysiology of this condition is outlined and the various types of repair being advocated are reviewed. Although there is no clear answer to the question of optimal management of IMR at present, what is clear is that a prospective trial is urgently needed to guide us with the treatment of this clinical problem.

Echocardiographic Predictors of Successful Versus Unsuccessful Mitral Valve Repair in Ischemic Mitral Regurgitation

Mitral valve (MV) annuloplasty is the standard surgical technique for the management of ischemic mitral regurgitation (MR). However, < or = 1/3 of patients develop recurrent MR after annuloplasty. Therefore, we sought to identify the preoperative echocardiographic parameters that predict annuloplasty failure in patients with ischemic MR. Intraoperative transesophageal echocardiograms from 365 patients who underwent MV repair for ischemic MR were reviewed. Of the 365 patients, 297 (81%) had satisfactory outcomes with < 2+ MR, and 68 (19%) had recurrent MR (> or = 2+) during a mean follow-up of 269 days. The mitral annular parameters, including mitral annular diameter, tethering height, and tethering area of the mitral leaflets, were determined in 3 different echocardiographic views. On multiple logistic stepwise regression analysis, a higher mitral annular diameter, higher tethering area, and higher MR severity were identified as independent predictors for failure of MV repair (p < 0.0001). In conclusion, these results demonstrated that preoperative echocardiographic findings can be used to identify patients with ischemic MR at increased risk of repair failure. These echocardiographic measurements should be used to guide the cardiologist and cardiac surgeon in the choice of MV repair versus replacement in patients with ischemic MR.

Management of moderate ischemic mitral regurgitation demystified

Hats off to Campwala et al. [1] for demystifying the management of moderate ischemic mitral regurgitation (IMR). Despite all its limitations their study can be deemed as a landmark contribution to the existing literature on management of IMR. Although they have discussed factors predicting regression of IMR after isolated coronary artery bypass grafting (CABG) in the context of 3-4 þ IMR yet the findings of their study can be extrapolated to define the optimal management strategy for 2 þ IMR which is the most controversial grade of IMR viz a viz intervention on the mitral valve at the time of CABG. Although most surgeons would agree that severe IMR (34þ) should be corrected at the time of CABG and that trace to mild IMR (1þ) can probably be left alone, the optimal management of moderate IMR (2þ) remains controversial [2]. The pathophysiology of IMR is complex, and its presence may be related to several underlying processes that are often difficult to separate in a given patient [3]. Because of its complex pathophysiology and heterogeneous clinical presentation, the proper treatment of IMR is often debated, and the relative utility of revascularization—with and without concomitant mitral valve surgery—in the setting of moderate IMR is uncertain. Those favoring a conservative approach suggest that revascularizing ischemic areas will improve regional wall motion and correct the MR [4]. On the other hand, proponents of more liberal use of mitral annuloplasty in patients with moderate IMR at the time of CABG argue that CABG alone will not correct moderate IMR in many patients, especially those with scarring frommyocardial infarction and those with annular and ventricular dilatation [2]. The study by Campwala et al. [1] has once and for all solved this controversy by providing solid predictors of regression of IMR after CABG alone. As pointed out by Campwala et al. [1] regression of IMR is related to left ventricular (LV) size reduction and improvement in LV function. Hence, a corollary of this conclusion will be that in the presence of low ejection fraction and dilated LV, moderate IMR has to be corrected. On the other hand, in the

Ischemic Mitral Regurgitation: Revascularization Alone Versus Revascularization and Mitral Valve Repair

In this study we compared the surgical management of ischemic mitral regurgitation (IMR) by revascularization alone and by revascularization combined with mitral valve repair. We studied 355 patients who underwent revascularization alone (n = 168) or revascularization combined with mitral valve repair (n = 187) for IMR from March 1994 to September 2003. Preoperative and operative characteristics, postoperative mitral regurgitation severity, operative mortality, and late survival were examined for each surgical group. No differences were noted between the two groups in age, sex, history of diabetes or hypertension, and number of bypass grafts. The combined surgical group had a lower preoperative left ventricular ejection fraction (0.38 +/- 0.14 versus 0.44 +/- 0.15), greater severity of IMR, higher frequency of prior myocardial infarction, and longer cross-clamp and pump times (p < 0.01). The combined surgical group had a greater reduction in IMR grade (2.7 +/- 0.1 grades versus 0.2 +/- 0.1 grade), a lower postoperative IMR grade (0.9 +/- 0.1 versus 2.3 +/- 0.1), and a higher success with reduction of IMR by two or more grades (89% versus 11%) (p < 0.001). In patients with 3+ or 4+ IMR, both groups had similar operative mortality (11.0% in the combined group compared with 4.7% for revascularization alone, p = 0.11) and actuarial survival at 5 years (44% +/- 5% versus 41% +/- 7%, p = 0.53). Independently predictive of higher early mortality (< or = 30 days) by Cox analysis were longer pump time (p < 0.001) and older age (p < 0.02). Predictive of late mortality (> 30 days) were older age (p < 0.001), fewer bypass grafts (p < 0.01), and lower ejection fraction (p < 0.01). After adjustment for these variables, there was a trend (p = 0.08) toward a higher late survival with the combined surgical procedure. In patients with IMR, combined mitral valve repair and revascularization resulted in less postoperative mitral regurgitation and similar 5-year survival when compared with revascularization alone. Attempts to reduce pump time by using off-pump techniques may reduce early mortality in these high-risk patients.

Diagnosis and management of ischemic mitral regurgitation with the use of transesophageal echocardiography

Longabaugh, J. Peter MD*; Sheikh, Khalid H. MD*; Bengtson, James R. MD, MPH*; Rankin, J. Scott MD.†; De Bruijn, Norbert P. MD*; Heinle, Sheila K. MD*; Kisslo, Joseph MD* Author Information

Trends in the surgical management of ischemic mitral regurgitation: Effects of mitral valve repair

Trends in the surgical management of ischemic mitral regurgitation: Effects of mitral valve repair