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Ann Thorac Surg 2007;83:2017-2028
© 2007 The Society of Thoracic Surgeons
Division of Cardiac Surgery, The Johns Hopkins Medical Institutions, Baltimore, Maryland
Accepted for publication February 7, 2007.
* Address correspondence to Dr Conte, Division of Cardiac Surgery, Johns Hopkins Medical Institutions, Blalock 618, 600 North Wolfe St, Baltimore, MD 21287 (Email: jconte{at}csurg.jhmi.jhu.edu).
Presented at the Fifty-third Annual Meeting of the Southern Thoracic Surgical Association, Tucson, AZ, Nov 8–11, 2006.
| Dr Conte discloses that he has a financial relationship with Chase Medical Corp.
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Abstract |
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 Top Abstract IntroductionMaterial and MethodsResultsCommentNotice From the American...DiscussionAcknowledgmentsReferences |
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Methods: We retrospectively reviewed SVR patients between January 2002 and December 2005. Patients were grouped into those with and without LMI. Lateral wall myocardial infarction patients were further subdivided into those with anterior-lateral and anterior-inferior-lateral MI. Extent of LMI was assessed intraoperatively as less than 25%, 25% to 49%, 50% to 75%, and more than 75% of the lateral wall. Follow-up was 100%.
Results: Seventy-eight patients underwent SVR; all had anterior MI. Forty-one percent (32 of 78) had LMI; 19% (6 of 32) had anterior-lateral MI; and 81% (26 of 32) had anterior-inferior-lateral MI. The remaining 59% (46 of 78) comprised the no-LMI group. Among LMI patients, 6% (2 of 32) had more than 75% involvement of the lateral wall. Lateral wall myocardial infarction patients were more likely to be New York Heart Association (NYHA) class IV preoperatively. There were 2 operative deaths in the LMI group. Surgical ventricular restoration significantly improved ejection fraction and end-systolic volume index for patients with and without LMI. Sixty-three percent of patients (20 of 32) with LMI and 83% of patients (38 of 46) without LMI improved to NYHA class I/II at follow-up. Three-year Kaplan-Meier survival for LMI patients was 67%, which trended toward a decreased survival versus patients without LMI (85%; p = 0.18). Three-year Kaplan-Meier survival for anterior-lateral MI patients was 100%, and for anterior-inferior-lateral MI patients, it was 60%. Lateral wall myocardial infarction involving >50% of the lateral wall was a significant predictor of mortality (odds ratio = 8.3, 95% confidence interval: 1.3 to 54.1, p = 0.03).
Conclusions: Cardiac function is improved after SVR for patients with and without LMI. However, anterior-inferior-lateral MI and LMI involving 50% or more of the lateral wall may predict mortality. Our results should prompt further investigation to determine the role of SVR for patients with LMI.
Congestive heart failure (CHF) remains a leading public health concern, with a prevalence of 5 million patients in the United States alone [1]. In Western society, the majority of these patients have CHF secondary to ischemic cardiomyopathy. Currently, patients with CHF have a poor 2-year survival of approximately 50% with optimal medical therapy [2, 3]. Limitations in medical therapy and the paucity of surgical alternatives have led to poor survival among CHF patients.
Surgical ventricular restoration (SVR) is an alternative therapy for some CHF patients with ischemic cardiomyopathy. Surgical ventricular restoration attempts to reverse the maladaptive morphologic changes of postinfarction ventricular remodeling by reducing the size of the left ventricle and restoring a more normal elliptical shape to the chamber, thereby reducing myocardial wall stress and improving ventricular function. Commonly accepted indications for SVR include anterior wall myocardial infarction (MI) with subsequent left ventricular dilatation, akinetic or dyskinetic segments, and reconstructable coronary artery disease [4–10]. Outcomes after SVR have been reported a number of ways. Many centers have demonstrated excellent survival for appropriate patients with improvements in ejection fraction (EF), left ventricular morphology and volumes, and New York Heart Association (NYHA) functional class after SVR [4–10]. Some have shown that SVR improves mechanical dyssynchrony [11] and reduces abnormal elevations in blood levels of neurohormones associated with CHF [12]. In one of the more elegant physiologic studies done to date, Tulner and colleagues [13] used conductance catheters to show that SVR normalized left ventricular volumes, improved measures of systolic function, reduced left ventricular wall stress, decreased mechanical dyssynchrony, and improved mechanical efficiency.
Owing to the small, relatively fixed number of patients who will receive a transplant and the lack of effective alternatives for transplant candidates and noncandidates alike, we recently expanded our inclusion criteria and have offered SVR to patients with multiterritory MI [10], who were traditionally considered to be high-risk candidates. We showed that these patients could benefit from SVR and concluded that a critical amount of viable myocardium is necessary for a successful outcome regardless of the location of infarction (anterior, inferior, or lateral wall alone or in combination). Some of these patients had a lateral wall MI (LMI). No investigator to date has performed a systematic evaluation of the impact of LMI on outcomes after SVR. We hypothesized that a LMI may portend a worse outcome than an anterior wall MI, alone or in conjunction with an inferior wall MI, because of its contribution to ventricular function and mitral valve competence. Therefore, we reviewed our SVR experience to analyze the impact of LMI on cardiac function and survival after this procedure.
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Material and Methods |
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The extent of full-thickness LMI was estimated as involving less than 25%, 25% to 49%, 50% to 75%, or more than 75% of the lateral wall. Infarct location and the extent of lateral wall involvement was assessed preoperatively by MRI (including short and long axis, and CINE views of the heart) with gadolinium contrast to localize areas of transmural hyperenhancement on delayed sequence, when available. A single surgeon (J.V.C.) then reviewed the MRI to better identify areas of viable myocardium and guide the intraoperative observation of the opened left ventricle. During intraoperative inspection, the surgeon assessed the extent of infarction of each wall and prospectively completed a detailed map depicting the location and extent of full-thickness infarction (Fig 1). Our SVR exclusion criteria included the presence of hypokinesis without akinetic or dyskinetic segments, and poor basilar function. We did not exclude patients with preoperative pulmonary hypertension [14].
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Operative Technique
Our surgical technique has been previously described [9, 10, 14]. Surgical ventricular restoration was performed after coronary artery bypass grafting (CABG) and mitral valve repair/replacement, if indicated. As described in our previous work [9, 10, 14], an interventricular sizing device was used in most patients to aid in the ventricular reconstruction. The size of the device was selected based on an optimal LVEDVI of 50 to 60 mL/m2 body surface area. When necessary, LMI was addressed with a linear plication extending from the base of the infarction to the apex, as previously illustrated [10]. The plication consists of running a continuous polypropylene suture from the base of the area of infarction to the apex, taking bites on both sides of the infarcted tissue in such a fashion to exclude the scarred area.
Statistical Analysis
Statistical analyses were performed with SPSS 12.0 software (SPSS, Chicago, Illinois). Preoperative clinical characteristics, MRI and echocardiographic data, and postoperative clinical data were compared between patients with and without LMI using Student’s t test and Fisher’s exact test, where appropriate. When comparing patients without LMI to those with LMI involving 50% or more and those with LMI involving less than 50% of the lateral wall, a Student’s t test was used to compare the two latter groups versus the no-LMI group individually to independently assess any differences in MRI and echocardiographic data. We also conducted an analysis of variance (ANOVA) to compare MRI and echocardiographic data among the three groups. Cox regression analysis was used to determine if LMI was a predictor of mortality in patients undergoing SVR. A second Cox regression analysis was performed to determine predictors of mortality for the LMI group alone. Variables included in the Cox regression analyses included age, sex, NYHA class IV, smoking history, hypertension, hyperlipidemia, diabetes mellitus, three-vessel coronary artery disease, recent MI (less than 30 days), extent of LMI, anterior-inferior-lateral MI, mitral regurgitation requiring a mitral valve procedure, EF, LVESVI, and pulmonary hypertension. Kaplan-Meier with log-rank analysis was used to estimate survival and freedom from adverse outcomes.
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Results |
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TopAbstractIntroductionMaterial and MethodsResultsCommentNotice From the American...DiscussionAcknowledgmentsReferences |
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Ejection Fraction, Left Ventricular Volumes, and Mitral Regurgitation
Magnetic resonance imaging and echocardiography demonstrated that patients with and without LMI had similar preoperative EF, LVESVI, LVEDVI, and SVI. Surgical ventricular restoration significantly improved EF, LVESVI, and LVEDVI for both groups (Table 2). When comparing patients with LMI and those without LMI, there were no significant differences in postoperative EF, LVESVI, LVEDVI, or SVI. We also compared outcomes in various combinations of wall infarctions (anterior versus anterior-inferior versus anterior-lateral versus anterior-inferior-lateral) and found no difference in postoperative EF or left ventricular volumes.
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Hospital Course, Postoperative Complications, and Procedures
Length of stay data and postoperative complications are listed in Table 3. Defibrillator placement was necessary in 4 patients with LMI and 8 patients without LMI (p = 0.75). Furthermore, 4 patients with LMI and 2 patients without LMI required left ventricular assist device implantation (p = 0.22) within the first 2 years. One patient without LMI subsequently underwent cardiac transplantation after SVR. Postoperative complication rates were also similar when analyzing patients with anterior, anterior-inferior, anterior-lateral, or anterior-inferior-lateral MI.
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Twenty-five percent of patients (8 of 32) with LMI died at late follow-up, a rate significantly greater than the late mortality rate for patients without LMI (4.3%; 2 of 46; p = 0.01); all 8 late deaths were among LMI patients with anterior-inferior-lateral MI. Of the 8 LMI patients who died at late follow-up, 1 had more than 75% involvement, 2 had 50% to 75% involvement, 4 had 25% to 49% involvement, and 1 had less than 25% involvement of the lateral myocardial wall. Causes of late mortality in the LMI group were cardiac causes (n = 1), sepsis (n = 3), renal failure (n = 1), massive gastrointestinal bleeding (n = 1), cancer (n = 1), and unknown cause (n = 1). The causes of death for the 2 late mortalities among patients without LMI were CHF related (n = 1) and unknown cause (n = 1).
When comparing the late mortality rate based on location of MI, patients with anterior-inferior-lateral MI had a late mortality of 30.8% (8 of 26), which was significantly greater than for patients with isolated anterior MI (3.1%; 1 of 32; p = 0.008) and trended toward a worse mortality rate when compared with patients who had anterior-inferior MI (7.1%, 1 of 14; p = 0.12) and anterior-lateral MI (0 of 6; p = 0.29).
Total follow-up for our entire series is 1,372 patient-months (range, 0.5 to 45). Three-year Kaplan-Meier survival (including hospital deaths) for all patients undergoing SVR was 76.7% ± 5.2%. Kaplan-Meier survival (including hospital deaths) for SVR patients with LMI at 3 years was 66.9% ± 8.6%, which trended toward decreased survival when compared with patients without LMI, which was 85.5% ± 5.6% (Fig 4A). Survival for patients without LMI, LMI involving less than 50% of the lateral wall, and LMI involving 50% or more of the lateral wall were not statistically different at 3 years (Fig 4B), although patients with 50% or more involvement trended toward decreased survival. Freedom from left ventricular assist device, cardiac transplantation, and death for patients with versus without LMI were similar (Fig 5).
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We compared preoperative and postoperative cardiac function when dividing our SVR cohort into patients without LMI, LMI with less than 50% involvement, and LMI with 50% or more involvement of the lateral myocardial wall (Table 4). Surgical ventricular restoration significantly improved EF, LVESVI, and LVEDVI for LMI patients with less than 50% involvement and for patients without LMI. Lateral wall myocardial infarction patients with 50% or more involvement showed a significant improvement in EF; LVESVI and LVEDVI showed trends toward improvement in this group, but were not quite statistically significant. Interestingly, LMI patients with 50% or more involvement did show significant improvement in SVI; this was also significantly greater than the postoperative SVI for patients without LMI.
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On ANOVA, the three groups differed significantly when comparing preoperative LVESVI; LVEDVI trended toward significance. Preoperative EF and SVI were similar among the three groups on ANOVA. Postoperatively, LVESVI, LVEDVI, and SVI were significantly different among the three groups on ANOVA, despite the similar EF. Fifty percent of LMI patients (4 of 8) with 50% or more involvement had a mitral valve procedure for significant mitral regurgitation, compared with 34.8% (16 of 46) without LMI (p = 0.45).
Cox Regression Model
Cox regression analysis for predictors of mortality in all SVR patients identified a history of recent MI (less than 30 days before SVR; odds ratio = 6.1; 95% confidence interval: 1.1 to 33.9; p = 0.04) and LMI involving 50% or more of the lateral myocardial wall (odds ratio = 8.3; 95% confidence interval: 1.3 to 54.1; p = 0.03) as predictors of mortality. Cox regression analysis for predictors of mortality in SVR patients with LMI did not identify any predictors of mortality.
Functional Outcomes
Surgical ventricular restoration significantly improved functional outcomes for patients with LMI. Preoperatively, 100% of patients were in NYHA class III or class IV, which improved to 37.5% (12 of 32) at follow-up (p < 0.0001; Fig 7). Forty-one percent of LMI patients (13 of 32) improved to NYHA class I, and 21.9% (7 of 32) improved to NYHA class II. Among the 26 patients with anterior-inferior-lateral MI, 53.8% (14 of 26) improved to NYHA class I or II. All 6 patients with anterior-lateral MI improved to NYHA class I or II. Fifty percent of LMI patients (4 of 8) with 50% or more involvement of the lateral wall and 66.0% (16 of 24) with less than 50% involvement of the lateral wall improved to NYHA class I or II. Of patients without LMI, 86.4% (38 of 44) in preoperative NYHA class III or IV improved to class I or II at follow-up. Patients without LMI were more likely to be in NYHA class I or II postoperatively, although this was not quite statistically significant (82.6% versus 62.5%; p = 0.07).
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Comment |
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Surgical ventricular restoration is generally limited to patients with isolated anterior wall MI or isolated inferior wall MI. Many surgeons consider patients with MI in two or three left ventricular vascular territories as high-risk candidates, eliminating many potential CHF patients who may benefit from SVR. Owing to the limited medical and surgical options for CHF patients with multiterritory MI and observing the rapid decline of patients with multiterritory MI treated with optimal medical therapy alone, we expanded our SVR inclusion criteria to include patients with multiterritory MI [10]. In this previous study, we reported outcomes and survival in our initial experience with multiterritory MI patients. We found a trend toward decreased survival for multiterritory MI patients versus those with isolated anterior MI on Kaplan-Meier analysis, but it did not reach statistical significance. That may have been due to the small number of patients in that cohort. Interestingly, both groups had similar cardiac function postoperatively. We hypothesized at that time that a critical amount of viable myocardium was necessary to achieve good results.
In the present study, we sought to determine if the presence of an LMI in addition to an anterior MI had any impact on survival. We studied the impact of the extent of lateral wall infarction (less than 50%, or 50% or more involvement) as well as the presence of LMI in various regional combinations (anterior-lateral versus anterior-inferior-lateral) on survival and some qualitative and quantitative outcome measures. We found that patients with LMI showed similar improvements in cardiac function, but the survival rate for patients with LMI trended toward a decreased survival. Cox regression analysis identified LMI with 50% or more involvement of the lateral wall as a significant risk factor for mortality. Patients with less than 50% involvement demonstrated similar improvements in cardiac function and survival versus patients without LMI.
Kaplan-Meier survival for CHF patients with LMI was 67% at 3 years, which is improved compared with the early survival for class III and IV CHF patients treated with optimal medical therapy [18, 19, 20], but is less than for patients undergoing SVR with anterior infarction alone in our and others’ series [4–8]. As our data show, patients with LMI are arguably a sicker group of patients, with a greater number of patients in preoperative NYHA class IV. Although survival was not found to be significant on log-rank analysis, we believed that the reduced survival is real. However, when compared with optimal medical therapy, we think that SVR offers an important treatment option for these patients, particularly those who are not candidates for heart transplantation or destination therapy with a left ventricular assist device. None of the deaths in this series was of a patient who was a candidate for heart transplantation, and that may be a reasonable consideration for those who are candidates and have three-territory infarctions with 50% or more lateral wall involvement. Longer follow-up is necessary to make definitive conclusions about outcomes of SVR versus medical therapy, heart transplantation, and destination therapy with ventricular assist devices.
We also assessed the impact of anterior-lateral MI versus anterior-inferior-lateral MI to determine if the addition of inferior MI contributed to the trend in survival. The 3-year Kaplan-Meier survival among LMI patients with inferior involvement (anterior-inferior-lateral MI) was lower than the survival for LMI patients without inferior involvement (anterior-lateral MI), although not statistically significant. When comparing the LMI patients with three-territory involvement (anterior-inferior-lateral MI) versus those without LMI (anterior-inferior MI), the former group had a lower 3-year survival, although not statistically significant. Moreover, when evaluating survival among patients without LMI, the 3-year Kaplan-Meier survival was similar for those with inferior involvement (anterior-inferior MI) and without inferior involvement (isolated anterior MI). These data illustrate that the presence of inferior wall involvement in the absence of LMI has little impact on survival, but among patients with LMI, the addition of inferior wall involvement decreases survival. It is important to note that patients with anterior-inferior-lateral MI had a significantly higher rate of late deaths in this study than did patients with isolated anterior MI, even though our Kaplan-Meier analysis did not find a significant difference in 3-year survival. That is most likely due to a type II statistical error, and a larger cohort with longer follow-up may uncover true statistical differences between these groups.
Coronary artery bypass grafting is a pivotal component of SVR, and myocardial revascularization of viable muscle most likely plays a significant role in the improvement seen in these patients. How to identify and quantify the independent effect of SVR alone on improving cardiac function remains unknown. A small number of patients in our study who did not undergo revascularization at the time of SVR owing to previous revascularization or because of poor distal targets did show improved cardiac function. Based on this, we believe that the benefits of SVR are "real," but as yet unquantified. We look forward to the results of the Surgical Treatment for Ischemic Heart Failure (STITCH) trial to shed light on this matter.
Mitral regurgitation is common among patients with left ventricular dilatation. Chamber dilatation causes teathering of mitral valve chords, which restricts leaflet motion, reducing leaflet coaptation and leading to mitral regurgitation [21]. Although some patients may demonstrate improved mitral valve function after SVR alone, our current preference is to perform a mitral valve procedure in all patients who demonstrate worse than mild mitral regurgitation preoperatively. In this study, the rate of concomitant mitral procedures were similar between patients with and without LMI. That may be due to the similar left ventricular volumes preoperatively between patients with and without LMI, instead of the presence of an LMI.
It is important to note that 6 of the 7 LMI patients who had a mitral valve procedure had an anterior-inferior-lateral MI. Perhaps the reason that more patients in the anterior-inferior-lateral group did not have more mitral procedures is that many of these patients had an inferior wall plication, which brings the papillary muscles closer together and toward the mitral annulus. That decreases chordal teathering and reduces the degree of mitral regurgitation. The degree of preoperative and postoperative mitral regurgitation was similar between patients with and without LMI. These data illustrate that the degree of preoperative and postoperative mitral regurgitation alone is not likely to be the cause of the difference in survival between patients with and without LMI.
The question of how much critical viable myocardium is necessary for a successful outcome after SVR remains unknown, but this current study sheds light on the impact of LMI on outcomes. We found that LMI patients with less than 50% involvement of the lateral wall on intraoperative assessment showed similar improvements in cardiac function and survival when compared with patients without LMI. However, when involvement exceeded 50% or more of the lateral wall, there were statistically significant differences in clinical outcomes, despite significant improvements in EF. As a result, we are more cautious in offering SVR to patients with large lateral wall infarctions who are also candidates for heart transplantation. Increasing the number of territories involved with MI also seems to portend a worse outcome, although in this study, the findings were not statistically significant. All of these findings point toward reduced survival with less functional myocardium. Traditional thinking has been that preservation of the basilar portion of the heart is critical for successful outcomes after SVR. In reality, it may be that it is the quantity and not the location of the muscle that is more important.
Magnetic resonance imaging has substantially improved assessment of cardiac function, especially in the setting of MI and left ventricular dilatation. Magnetic resonance imaging clearly delineates areas of wall thinning which can be addressed with SVR and can identify areas of viable myocardium using gadolinium. It is also useful in measuring function, volumes, and left ventricular shape, as well as localizing and quantifying infarcted myocardium. Magnetic resonance imaging techniques, however, are affected by the interference from medical devices such as pacemakers and defibrillators, which many patients in our study had before SVR. This fact, along with the retrospective nature of this study, limited our ability to use MRI and other diagnostic modalities as effectively as we would have liked. It certainly limited the type and amount of data we presented in this paper.
Currently, we perform SVR on most patients with retained basilar function. However, advances in MRI technology may allow us to quantify the function of individual left ventricular segments of the lateral wall, inferior wall, and the base of the left ventricle to more appropriately select suitable candidates for SVR. One of our current efforts is to use MRI technology to develop an SVR scoring system to predict successful outcomes with SVR. In addition to MRI data, this score will also take into account variables that may portend worse outcomes, including but not limited to severe pulmonary hypertension, three-territory myocardial infarction, and acute MI. Our hope is the SVR score, and not the location of the infarction, will guide us in selecting the best patients for SVR.[15, 17]
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Notice From the American Board of Thoracic Surgery |
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TopAbstractIntroductionMaterial and MethodsResultsCommentNotice From the American...DiscussionAcknowledgmentsReferences |
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To be admissible to the Part II (oral) examination, a candidate must have successfully completed the Part I (written) examination.
A candidate applying for admission to the certifying examination must fulfill all the requirements of the Board in force at the time the application is received.
Please address all communications to the American Board of Thoracic Surgery, 6333 N St. Clair St, Suite 2320, Chicago, IL 60611; telephone: (312) 202-5900; fax: (312) 202-5960; e-mail: info{at}abts.org.
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Discussion |
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TopAbstractIntroductionMaterial and MethodsResultsCommentNotice From the American...DiscussionAcknowledgmentsReferences |
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One of the most important conclusions of the RESTORE Group at long-term follow-up data was that ejection fraction is an important predictor of long-term survival in patients undergoing SVR, and I think a particular contribution of your work is that it is directing all of us to make the preoperative assessment of remaining left ventricular function more quantitative and more anatomically accurate. Along these lines, I would like to ask you two questions.
First, what are the prospects for developing an MRI measurement to determine the degree of lateral wall involvement preoperatively so that we can use it during our preoperative decision-making? Also, what are the prospects for potentially developing an MRI index that would take into account remaining ventricular mass in the left ventricle in general?
I noted that the actuarial survival in some of your high-risk groups falls below what would be expected for patients having gold standard treatment, which would be heart transplantation. When you are evaluating patients who would be candidates for either SVR or heart transplantation, what hard criteria do you use to rule patients out from SVR based your actuarial survival in the 60% range at 3 years? Thank you.
DR NWAKANMA: Thank you very much for those thoughtful questions. Regarding your first question, what are the prospects to determine the degree of LMI preoperatively and developing an MRI index. We actually have started working on this very important question. We are working with our radiology colleagues to determine how we can preoperatively assess the extent of involvement of the myocardium by myocardial infarction and also to develop a scoring risk whereby we can say that if preoperatively on MRI the patient has a certain scoring risk, then the patient may be a poor candidate for SVR. So we are currently working on that project and hoping to come up with an answer very soon. I will have to ask you to please repeat your second question.
DR SONG: The second point was that your actuarial survival in patients with greater than 50% lateral wall involvement was fairly low at 3 to 5 years, less than what would be expected after heart transplant, for instance. So when you are evaluating patients who would be candidates for either SVR or transplantation, are there hard criteria that you are using to divert patients more toward transplant directly rather than SVR?
DR NWAKANMA: Most of the patients who undergo SVR with lateral myocardial wall infarction, when I showed the clinical characteristics, you could see that they are all class III or IV patients. So these are, by far, very, very high risk patients who for one reason or the other may not be candidates for heart transplantation.
DR SONG: The reason I raise the issue is because looking at your demographics it looked like the mean age was still in the low 60s, and there was a relatively low incidence of renal failure, so it appears that some of these patients could be considered for transplantation as well as SVR.
DR NWAKANMA: Doctor Conte, would you like to comment on that?
DR JOHN CONTE (Baltimore, MD): The majority of those patients, certainly all of the class IV patients and some of the class III patients, were not transplant candidates. Many of these patients are patients who are almost rescue therapy type patients. These aren’t patients who undergo drive-by SVR in the setting of elective CABG for unstable angina. These are people who present with advanced heart failure, and we are trying to come up with an appropriate therapy based on that.
DR KIT V. AROM (Bangkok, Thailand): Great paper and I enjoyed it very much. I saw your slides with cardiac MRI. Did you use cardiac MRI to measure the infarct size preoperatively? And if you did, was the infarct size particularly on the lateral wall changed after SVR?
DR NWAKANMA: We did not measure the size of the infarct postoperatively. The main assessment was made on intraoperative assessment of the length of lateral wall involvement. But like I said in my answer to Dr Song’s question, we are looking retrospectively at all our previous patients’ MRIs to determine if there are certain characteristics, including the length of wall involvement and other indices that can predict outcome and then come up with a scoring risk.
DR KEVIN D. ACCOLA (Orlando, FL): In patients with global ischemia, do you think there is a role for other types of regional wall motion viability studies such as thallium or nuclear studies, which we initially utilized when we started doing restoration procedures? Also an interesting observation. You stated that your patients with more global ischemia actually had less mitral valve repairs than some of those with just anterior akinesis. I would be interested in your comments regarding criteria to either repair the mitral valve or replace it, as I noticed you had a number of replacements, which have been shown to increase mortality. Thank you.
DR JOHN CONTE: The general philosophy that we have is anybody who has at least moderate MR will have a mitral procedure performed. In that group of patients who have two and three territory infarctions with the inferior wall involved, usually there is a plication of the inferior wall. If you think about the pathophysiology of ischemic MR in those patients, it is usually restriction of the papillary muscles, and in doing a plication, if you bring the muscle mass up toward the posterior annulus, you are going to reduce some of that tethering, and in the majority of these patients that did decrease the MR down to moderate or less, and so no repairs were done in that group.
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Acknowledgments |
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= anterior; 
= anterior-inferior; 
= anterior-lateral; 
= anterior-inferior-lateral.)
50% Involvement of the Lateral Myocardial Wall
= postoperative.)