Treatment of moderate mitral regurgitation and coronary disease by coronary bypass alone: late results.

BACKGROUND: In cases of moderate mitral regurgitation and coronary artery disease operative strategy continues to be debated between coronary artery bypass grafting alone and concomitant valve replacement or repair. We previously reported on 58 patients with moderate mitral regurgitation who had coronary artery bypass grafting between 1977 and 1983. We present the late results for this original cohort (test group), and a matched control group of coronary artery bypass grafting patients without mitral regurgitation (n = 58). METHODS AND RESULTS: In the original cohort, the hospital mortality rate was 3.4% (2 of 58), and 80.4% (45 of 56) of hospital survivors were alive at the time of initial follow-up (mean, 4.3+/-2.3 years). Hospital mortality in the control group was 6.9% (4 of 58 patients). Follow-up was 98.2% (108 of 110 patients) complete, with a mean follow-up time of 10.3+/-5.5 years. Kaplan-Meier curves for hospital survivors showed similar 5- and 10-year survival rates between the two groups (p = 0.59). On multivariate analysis, age 65 years or more, congestive heart failure class III or IV, and pulmonary capillary wedge pressure more than 17 mm Hg were significant (p < 0.05) independent predictors of diminished survival in the test group. CONCLUSIONS: Patients with moderate mitral regurgitation and coronary artery disease treated solely with coronary artery bypass grafting had acceptable early and late results. Moderate mitral regurgitation at the time of revascularization does not always warrant operative correction.     

Three-dimensional mitral valve structure in predicting moderate ischemic mitral regurgitation improvement after coronary artery bypass grafting

Objective

Focusing on 3-dimensional mitral valve structure, this study investigated predictors for moderate ischemic mitral regurgitation (IMR) improvement after off-pump coronary artery bypass grafting (OPCAB).

Mild or moderate ischemic mitral regurgitation in patients undergoing off-pump coronary artery bypass grafting

BACKGROUND: There has been a debate, whether mild or moderate ischemic mitral regurgitation (IMR) should be repaired at the time of coronary bypass surgery. We assessed the early and midterm outcomes of patients with mild or moderate IMR who underwent isolated off-pump coronary artery bypass grafting (OPCAB). METHODS: We retrospectively reviewed records of 602 patients who underwent OPCAB between April 2001 and July 2004. Of those, 96 patients had mild or moderate MR (IMR group), and 506 had none or trivial MR (no IMR group). Preoperative and postoperative characteristics were compared between the groups. Furthermore, fates of grade of MR and functional status were investigated in patients with IMR. RESULTS: The preoperative mean New York Heart Association (NYHA) classes were 2.7 +/- 1.0 and 2.4 +/- 0.9 in the IMR and no IMR groups, respectively (p < 0.01). Operative mortality was similar between groups (1.0% in the IMR group and 0.4% in no IMR group, p = 0.41). The cumulative survival rate for the IMR group was 93.7% at 1 year and 90.1% at 4 years. The mean NYHA class was 1.1 +/- 0.4 (p < 0.0001) at 28.8 +/- 11.4 months after operation for the IMR group. The mean grade of mitral regurgitation diminished (from 2.2 +/- 0.4 to 1.1 +/- 0.6, p < 0.0001) soon after operation in patients with IMR, and remained so (1.1 +/- 0.8, p < 0.0001) during the follow-up period. CONCLUSIONS: Mild or moderate IMR could be improved with isolated OPCAB. The early and midterm functional outcomes of these patients were favorable.     

Mild to moderate mitral regurgitation in patients undergoing coronary bypass grafting: effects on operative mortality and long-term significance

BACKGROUND: Patients undergoing bypass grafting (CABG) often present with mitral regurgitation (MR). While surgical strategy for patients with either trace or severe MR is well established, the need for a valve procedure with mild (2) to moderate (3+) mitral regurgitation is controversial. METHODS: We reviewed 1,939 consecutive CABG patients (1987 to 1999). A preoperative echocardiogram performed when clinically indicated graded MR from 1 to 4+. Patient characteristics, hospital mortality, and long-term survival were compared between 167 patients with grade 2 to 3+ MR and controls. A multivariate analysis identified independent predictors for long-term mortality. RESULTS: The MR patients were more often female and older; had increased comorbidities including hypertension, diabetes, and heart failure; had more extensive coronary disease and worse left ventricular (LV) function; and required urgent surgery more often. Operative mortality was 0.8% in no MR patients and 1.8% in MR patients (p not significant). Long-term survival for MR patients with poor LV function (LV grade 3 to 4) was significantly lower (53% versus 75% at 10 years, p = 0.001). Independent predictors of poor long-term survival were advanced age, LV dysfunction, heart failure, diabetes, prior cerebrovascular accident, peripheral vascular disease, and no left internal mammary artery use. CONCLUSIONS: Coronary artery bypass graft patients with mild or moderate MR have worse baseline characteristics but operative mortality with CABG alone is not significantly increased. Long-term prognosis for MR patients with poor LV function is worse compared with patients with no MR but MR was not an independent predictor of long-term mortality. To determine whether surgical correction of MR would improve results, a prospective randomized trial seems warranted.     

Clinical outcomes of surgery of mitral valve regurgitation and coronary artery bypass grafting

The impact of etiology of associated mitral valve regurgitation and a valve procedure on operative and long-term outcomes after coronary bypass grafting surgery is yet to be clearly defined. Results of combined coronary artery bypass grafting and valve procedures for mitral valve regurgitation were retrospectively analyzed in 468 patients. The regurgitation was of ischemic in 45%, degenerative in 55% and 78% valve repairs, 22% valve replacements were performed. Severe coronary artery disease, acute myocardial infarction, low ejection fraction, ischemic mitral regurgitation, advanced heart failure symptoms, failure to use internal mammary artery, valve replacement surgery, and emergency operations are predictors of operative mortality. The 5-year survivals for propensity-matched patients of ischemic and degenerative disease were similar (66%), but 67% vs. 83%, respectively, for unmatched patients. Low ejection fraction (<35%), advanced age (>67 years), valve replacement surgery, residual mitral regurgitation, and severe coronary artery disease were predictors of poor long-term survival. Left ventricular remodeling processes, optimal valve procedure without residual mitral regurgitation and left ventricular function are important determinants of long-term outcome than the etiology of valve regurgitation.     

Late outcomes in patients with uncorrected mild to moderate mitral regurgitation at the time of isolated coronary artery bypass grafting

OBJECTIVES: Patients undergoing coronary artery bypass grafting often have untreated mild to moderate mitral regurgitation. The long-term outcome of these patients follows an uncertain course. The purpose of this study was to examine the late outcomes in patients with mild to moderate mitral regurgitation at the time of isolated coronary artery bypass grafting. METHODS: One hundred sixty-three patients with mild to moderate mitral regurgitation at the time of isolated coronary artery bypass grafting were identified from the prospectively collected cardiovascular database at Sunnybrook and Women's College Health Sciences Centre. These patients were matched 1:2 with patients who had isolated coronary artery bypass grafting without mitral regurgitation according to gender, age, left ventricular ejection fraction, New York Heart Association functional class, vascular disease, diabetes, extent of coronary disease, and year of surgery. There was 99% complete follow-up. Actuarial survival and event-free (death, myocardial infarction, stroke, cardiac hospitalization, and cardiac reintervention) survivals were compared by log-rank methods. Cox regression was used to assess the effects of the presence of mitral regurgitation on late survival and event-free survival. Preliminary postoperative follow-up echocardiography was available for 49 of the 163 patients with mitral regurgitation. RESULTS: There were 489 patients in the matched-cohort study, 163 with mitral regurgitation and 326 without. The average length of follow-up was 3.37 +/- 2.04 years. There was no difference in actuarial survival at 6 postoperative years (mitral regurgitation 81.0% vs no mitral regurgitation 84.7%, P =.9185). Event-free survival at 6 years was worse in the mitral regurgitation group (45.7% vs no mitral regurgitation 64.7%, P =.0258). Patients with mitral regurgitation had worse functional status (New York Heart Association class 3-4 20.0%, n = 30/150, vs no mitral regurgitation 8.1%, n = 25/307, P =.0046). After the matched variables were controlled for, the hazard ratios associated with the presence of mitral regurgitation by Cox regression were 0.958 (P =.7626) for survival and 1.198 (P =.0333) for event-free survival. The only other significant predictor of late survival was preoperative intra-aortic balloon pump insertion (hazard ratio 2.484, P =.0365). Of the patients who underwent follow-up echocardiography, 30.6% (n = 15/49) had progression of mitral regurgitation to moderate to severe degree at an average of 16.4 postoperative months. CONCLUSION: Overall late survival was not affected by the presence of mild to moderate degrees of mitral regurgitation in patients undergoing coronary artery bypass grafting. However, these patients had poorer event-free survival and worse late functional status. In a subset of patients with echocardiographic follow-up, the postoperative course of mitral regurgitation was variable, and nearly a third of these patients had worsening mitral regurgitation. Consideration should be given to repairing moderate mitral regurgitation in selected cases to improve long-term quality of life.     

Surgical results for mitral regurgitation from coronary artery disease

Results of coronary artery bypass grafting with and without mitral valve replacement were analyzed retrospectively in 101 patients with preoperative ischemic mitral regurgitation to determine the effects of severity and surgical treatment of mitral regurgitation on survival. Between 1980 and 1984, a total of 1,475 patients (mean age 59, 77% male) underwent coronary bypass. These patients were divided into three groups: (1) patients without ischemic mitral regurgitation who underwent isolated coronary bypass (1,374; 93%), (2) patients with ischemic mitral regurgitation who underwent isolated coronary bypass without valve replacement (85; 6%), and (3) patients with ischemic mitral regurgitation who underwent combined mitral valve replacement and coronary bypass (16; 1%). Preoperatively, patients with ischemic mitral regurgitation compared to those without regurgitation were significantly older (+6 years, p less than 0.001), had more severe coronary artery disease (p less than 0.001), a higher incidence of congestive heart failure (24% versus 5%, p less than 0.001) and recent myocardial infarction (16% versus 8%, p less than 0.01), and a lower mean ejection fraction (45% versus 61%, p less than 0.001). Operative mortality was significantly increased in patients with ischemic mitral regurgitation who underwent coronary bypass alone (p less than 0.01) and in those who underwent coronary bypass and mitral valve replacement (p less than 0.01)--11% and 19%, respectively--than in the coronary bypass patients without ischemic mitral regurgitation (3.7%). The severity of mitral regurgitation (0 to 4+) proved to be the most significant predictor of operative mortality. The actuarial survival rate at 5 years for the coronary bypass patients without ischemic mitral regurgitation was 85% compared to 91% (p less than 0.05) for the coronary bypass patients without ischemic mitral regurgitation. These results indicate that patients with ischemic mitral regurgitation have a higher prevalence of cardiac risk factors and are at an increased risk of operative mortality. Although the severity of the ischemic mitral regurgitation was strongly predictive of early survival, it proved to have an unexpectedly modest effect on long-term survival after surgical treatment.     

Late outcomes after isolated coronary artery bypass grafting for ischemic mitral regurgitation

Objectives: Although ischemic mitral regurgitation (IMR) is one of the most important issues to determine therapeutic strategy for ischemic heart disease, long-term outcome after coronary artery bypass grafting (CABG) for IMR is still unclear. It is also controversial how patients who would benefit from mitral valve (MV) surgery in combination with CABG should be identified. The purpose of this study is to elucidate late outcomes after isolated CABG for moderate IMR and to assess the indication of combined MV surgery. Methods: Two hundred and seventy-nine patients who had grade 2 or 3 IMR preoperatively and underwent isolated CABG between 1980 and 2002 in our institute were enrolled. Mitral regurgitation was assessed by 2-dimensional Doppler echocardiography and left ventriculography. Among them, 84 patients (30.1%) had left ventricular ejection fraction (LVEF) less than 30% and 186 patients (66.7%) had prior inferior myocardial infarction (MI). Results: One hundred and twenty-nine patients (46.2%) remained grade 2 or greater MR early postoperatively. Actuarial survival and freedom from cardiac events, analyzed by the Kaplan-Meier method, were 90.9% and 87.7% at 1 year, 79.2% and 68.8% at 5 years, 54.9% and 49.1% at 10 years and 48.8% and 18.9% at 15 years. Independent predictive risk factors for cardiac events, analyzed by multivariate analysis using the Cox proportional hazard model, were grade 2 or greater MR which remained early postoperatively (p=0.0002), LVEF<30% preoperatively (p=0.0006), no inferior MI preoperatively (p=0.007) and no internal thoracic artery-left anterior descending artery graft (p=0.049). More than a 15% decrease in LVEF at more than 3 years after the operation was seen despite patent bypass grafts in 17.2% of patients who received a late follow-up catheterization, although 41.4% of patients showed an increase or less than 5% decrease in LVEF during this period. Conclusion: Combined MV surgery with CABG for IMR should be considered in patients with poor LVEF or without prior inferior MI.     

冠心病合并二尖瓣关闭不全的外科治疗

目的　探讨冠心病合并二尖瓣关闭不全 (MR)的外科治疗方法。方法　 1994年 4月至2 0 0 0年 10月 ,同期手术治疗冠心病合并MR病人 34例 ,其中二尖瓣轻度反流 1例 ,中度反流 2 5例 ,重度反流 8例。二尖瓣的病理改变主要表现为单纯瓣环扩大、瓣叶脱垂或二尖瓣腱索断裂。手术均在低温体外循环下进行。二尖瓣成形 (MVP) 2 7例 ;单纯二尖瓣前交界或双交界折叠环缩 15例 ;脱垂瓣叶切除后再缝合 9例 ;二尖瓣前叶脱垂部分直接缝合到相应的后叶形成双孔二尖瓣 3例 ;应用二尖瓣瓣环 2 0例 ;二尖瓣置换 (MVR) 7例 ,均选择机械瓣。结果　无手术或住院死亡和严重并发症。超声心动图检查提示平均左室舒张末径为 (5 3 0± 6 3)mm ,与术前比较差异有显著性 (P <0 0 1)。 31例平均随访 2 9个月。无远期死亡。病人生活质量均明显提高。心功能I～II级 2 8例 ,III级 3例。超声心动图检查提示微量二尖瓣反流 6例 ,少至中度反流 3例。机械瓣功能正常。结论　冠心病合并中度以上MR应积极处理 ,二尖瓣成形应为首选     

Factors affecting regression of mitral regurgitation following isolated coronary artery bypass surgery.

OBJECTIVE: Fate of MR following CABG is variable. Predictors of MR regression following CABG alone are not known. METHODS: From our surgical registry, CABG patients with both pre-operative and post-operative resting echocardiograms at our institution were screened. Of the 523 patients identified, 92 had 3+ (n = 65) or 4+ (n = 27) MR on the pre-operative echocardiogram on a 0-4 scale, who had isolated CABG. MR regression was correlated with clinical, operative, electrocardiographic and echocardiographic variables. RESULTS: Patient characteristics: age 68+/-11 years, 62% male, and LVEF 37+/-15%. MR grade decreased from 3.3+/-0.5 to 2.3+/-1.2 post-CABG. Residual 3 or 4+ MR post-CABG was present in 43 (47%) patients. Regression of MR (n = 49) was associated with reductions in LV end-diastolic (P = 0.006) and end-systolic (P = 0.0005) dimensions, improvement in LVEF (P = 0.01), longer cross-clamp time (P = 0.04), use of beta-blockers (P = 0.04) and lower presence of CVA as a possible marker of lower atherosclerotic burden (P = 0.03). There was a trend towards increased mortality (P = 0.3) with residual 3-4+ MR over a mean follow-up of 3.9 years. CONCLUSIONS: In nearly half of patients with 3-4+ MR, MR does not regress with CABG alone. Residual MR may be associated with increased mortality. Regression of MR is related to LV size reduction and improvement in LV function. Presence of myocardial viability, adequate revascularization, lack of excessive atherosclerotic burden and therapy with beta-blockers and ace-inhibitors may be critical for MR regression following CABG alone.     

Factors affecting regression of mitral regurgitation following isolated coronary artery bypass surgery.

OBJECTIVE: Fate of MR following CABG is variable. Predictors of MR regression following CABG alone are not known. METHODS: From our surgical registry, CABG patients with both pre-operative and post-operative resting echocardiograms at our institution were screened. Of the 523 patients identified, 92 had 3+ (n = 65) or 4+ (n = 27) MR on the pre-operative echocardiogram on a 0-4 scale, who had isolated CABG. MR regression was correlated with clinical, operative, electrocardiographic and echocardiographic variables. RESULTS: Patient characteristics: age 68+/-11 years, 62% male, and LVEF 37+/-15%. MR grade decreased from 3.3+/-0.5 to 2.3+/-1.2 post-CABG. Residual 3 or 4+ MR post-CABG was present in 43 (47%) patients. Regression of MR (n=49) was associated with reductions in LV end-diastolic (P = 0.006) and end-systolic (P = 0.0005) dimensions, improvement in LVEF (P = 0.01), longer cross-clamp time (P = 0.04), use of beta-blockers (P = 0.04) and lower presence of CVA as a possible marker of lower atherosclerotic burden (P = 0.03). There was a trend towards increased mortality (P = 0.3) with residual 3-4+ MR over a mean follow-up of 3.9 years. CONCLUSIONS: In nearly half of patients with 3-4+ MR, MR does not regress with CABG alone. Residual MR may be associated with increased mortality. Regression of MR is related to LV size reduction and improvement in LV function. Presence of myocardial viability, adequate revascularization, lack of excessive atherosclerotic burden and therapy with beta-blockers and ace-inhibitors may be critical for MR regression following CABG alone.     

A case of ischemic mitral regurgitation treated by mitral annuloplasty (MAP) and coronary artery bypass grafting (CABG)]

A 79-year-old woman with a previous history of myocardial infarction, suffered acute myocardial infarction again. A coronary angiogram revealed triple vessel disease, and a left ventriculogram showed severe mitral regurgitation. The patient fell into cardiogenic shock after cardiac catheterization, and IABP was started. She underwent MAP and saphenous vein bypass grafting to the left anterior descending coronary artery and left circumflex coronary artery. Although the postoperative course was complicated by acute renal failure and respiratory dysfunction, the patient recovered from the operation and was discharged on the 137th postoperative day. Since the operative mortality of conventional valve replacement combined with CABG in ischemic mitral regurgitation has been high, we preferred MAP for this case.