Effects of preoperative glucose-insulin-potassium on myocardial glycogen levels and on complications of mitral valve replacement

Myocardial glycogen content was increased from a mean of 25.8 +/- 3.7 to 40.3 +/- 4.2 mumol/gm (p less than 0.0001) by an infusion of glucose, insulin, and potassium before mitral valve replacement. Patients who had received such an infusion and who had a higher myocardial glycogen content had a lower incidence of postoperative hypotension, less serious postoperative arrhythmias, and fewer serious complications after elective mitral valve replacement.     

The effect of concomitant radiofrequency ablation and surgical technique (repair versus replacement) on release of cardiac biomarkers during mitral valve surgery

All patients undergoing heart surgery experience a certain amount of nonspecific myocardial injury documented by the release of cardiac biomarkers and associated with poor outcome. We investigated the role of unipolar radiofrequency ablation of atrial fibrillation on the release of cardiac biomarkers in 71 patients undergoing mitral valve surgery and concomitant left atrial ablation case-matched with 71 patients undergoing isolated mitral surgery. The study was powered to detect a 3 ng/mL difference. There was no difference between the 2 groups in terms of cardiac troponin I (10 +/- 5.3 versus 12 + 10.4 ng/mL; P = 0.7) or creatine kinase-MB (50 +/- 21.8 versus 57 +/- 62.0 ng/mL; P = 0.5) release. Postoperative peak cardiac troponin I levels had univariate associations with the duration of cardiopulmonary bypass (P = 0.002) and aortic cross-clamping (P = 0.001) and with the surgical technique (15 +/- 12 ng/mL for mitral valve replacement versus 9 +/- 4.8 for mitral valve repair; P = 0.0007) at univariate analysis. Mitral valve replacement was the only independent predictor of postoperative peak release of cardiac troponin I identified with multivariate analysis (P = 0.005). Radiofrequency ablation of atrial fibrillation does not significantly increase cardiac biomarker release compared with isolated mitral surgery; mitral valve repair is associated with less release of cardiac biomarkers compared with mitral valve replacement.     

Is mitral valve surgery safe in octogenarians?

OBJECTIVE: To evaluate the outcomes of mitral valve surgery in octogenarians. METHODS: Data were collected prospectively from January 1996 to March 2004 at two surgical centers. Of 1386 consecutive patients with mitral valve surgery, 58 (4.2%) were aged > or = 80 years. Survival data were analyzed using Cox proportional hazards modeling and Kaplan-Meier actuarial log rank statistics. RESULTS: Octogenarians were similar to younger patients for the presence of pre-operative hypertension, hyperlipidemia, diabetes mellitus, and smoking history. Octogenarians had a higher incidence of cerebrovascular disease (19.0 versus 7.8%, P = 0.003), urgent in-hospital surgery (55.2 versus 28.6%, P < 0.001), and presence of ischemic disease requiring combined mitral valve plus revascularization surgery (72.4 versus 41.0%, P < 0.001). Mitral valve repair was performed in a similar proportion of octogenarians and younger patients (44.8 versus 45.6%). Thirty-day mortality for octogenarians was significantly higher than younger patients (15.5 versus 5.6%, P = 0.002), and actuarial survival of octogenarians was significantly decreased (P = 0.009). However, 52.3% of the octogenarians were alive at 7-years following surgery. Independent predictors of mortality from multivariate risk adjusted modeling of the entire cohort were: emergency surgery (hazards ratio [HR] = 2.94, P < 0.001), combined mitral valve plus revascularization surgery (HR = 2.27, P < 0.001), mitral valve replacement (HR = 1.85, P < 0.01), and age > or = 80 years (HR = 1.80, P = 0.02). CONCLUSIONS: Octogenarians undergoing mitral valve surgery have significantly greater incidence of urgent surgery, ischemic disease requiring combined revascularization surgery, and have decreased rates of survival. While caution is required when operating on these higher risk elderly patients, overall 52.3% of the octogenarians are alive at 7-years following surgery, which is greater than the survival of octogenarians in the community. The greatest survival benefit within octogenarians occurred when mitral valve repair was possible over replacement. Further study will more clearly define subgroups of octogenarians with potentially greater benefit from mitral valve surgery.     

Neurocognitive deficit following mitral valve surgery.

OBJECTIVE: Neurocognitive deficit is an important complication in patients undergoing open heart surgery. The aim of this prospective, contemporary study was to objectively measure neurocognitive brain function following mechanical mitral valve replacement and mitral valve repair. METHODS: Forty consecutive, unselected patients (mechanical valve replacement n=20, mean age 65+/-14; valve repair n=20, mean age 64+/-7, P=0.896) entered this prospective, contemporary study. Neurocognitive function was objectively measured by means of P300 auditory evoked potentials (peak latencies, ms) and two standard psychometric tests (Mini Mental State Examination, Trailmaking Test A (TTA)), preoperatively, 7 days and 4 months postoperatively. RESULTS: Before operation, neurocognitive brain function was comparable in both patients groups (mechanical valve replacement versus valve repair: P300 potentials 374+/-25 versus 378+/-46 ms; P=0.791 and TTA 57+/-15 versus 54+/-10 s; P=0.552). Following mechanical valve replacement, neurocognitive function continuously worsened (7 day-follow-up: P300 potentials 392+/-28, P=0.001 versus preop and TTA 65+/-17, P=0.0001; 4-month follow-up: P300 potentials 406+/-39, P=0.0004; TTA 69+/-17, P=0.0001). Interestingly, neurocognitive brain function was unaffected in patients undergoing valve repair (7-day follow-up: P300 potentials 386+/-40, P=0.890 versus preop and TTA: 53+/-10, P=0.644; 4-month follow-up: P300 potentials 374+/-36, P=0.166 and TTA 54+/-11, P=0.147). At 4-month follow-up, patients with mechanical prostheses performed worse as compared to valve repair (P300 potentials: P=0.024; TTA P=0.014). CONCLUSION: As shown by P300 auditory evoked potentials and Trailmaking Test A, there is marked neurocognitive damage related to mechanical valve replacement, whereas mitral valve repair does not affect neurocognitive function. This finding supports the beneficial effect of mitral valve repair over mechanical valve replacement in the decision-making tree of borderline cases, which are suitable for both types of procedure.     

Chordal preservation improves postoperative ventricular performance following valve replacement for chronic mitral regurgitation

Worsening of left ventricular performance had been recognized after mitral valve replacement for mitral regurgitation. The effects of chordal preservation on ventricular performance after mitral valve replacement have been assessed. Twelve patients with mitral regurgitation were allocated to group A (undergoing mitral valve replacement with chordal preservation), or to group B (undergoing mitral valve replacement with chordal excision). Transoesophageal echocardiography was recorded simultaneously with radial artery and pulmonary capillary wedge pressures. Load was varied by withdrawal of blood from a venous line of cardiopulmonary bypass and/or nitroglycerine bolus. Ventricular performance was assessed by the slope of peak systolic pressure—end-systolic volume relation (Eps), and by the slope of the left ventricular stroke work — end-diastolic volume relationship. Eps significantly decreased immediately after mitral valve replacement (P < 0.02), with no difference among two groups. Eps gradually increased to preoperative levels 10 days after surgery. Pre-load recruitable stroke work also significantly decreased after mitral valve replacement (P = 0.01). The decrease was significantly larger in group B (P < 0.04). These data support the hypothesis that chordal preservation during mitral valve replacement has beneficial effects on left ventricular performance. Copyright © 1996 The International Society for Cardiovascular Surgery.     

Acute affect of mitral calve replacement on extravascular lung water in patients receiving colloid or crystalloid priming of cardiopulmonary bypass

Despite numerous studies on extravascular lung water (EVLW) in patients undergoing coronary artery bypass surgery, few data are available on the perioperative time course of EVLW in patients undergoing mitral valve replacement for mitral valve insufficiency (MVI). We have investigated 26 patients undergoing elective mitral valve replacement in order to determine the influence of the preoperative degree of mitral valve insufficiency (degree III or IV) and the effect of different priming solutions for cardiopulmonary bypass. Crystalloid priming with Ringer's lactate was compared with human albumin priming solution. Measurement of EVLW was performed using the thermo-dye dilution technique, before and 1, 6 and 24 h after surgery. Before operation, EVLW is increased significantly in patients with MVI degree IV (MVI-degree IV) compared with patients with degree III (MVI-degree III) and patients undergoing coronary artery bypass surgery. During the postoperative time course a significant decrease in EVLW was observed in patients with MVI-degree IV whereas in patients with MVI-degree III the amount of EVLW did not change. However, compared with patients undergoing coronary artery bypass surgery, EVLW remained above normal in both groups. There was no interaction between the type of priming solution and the postoperative time course of EVLW, and no differences in respiratory variables or duration of mechanical ventilation were observed between groups.      

Ischemic mitral valve reconstruction and replacement: comparison of long-term survival and complications.

OBJECTIVE: This study reviews the 223 consecutive mitral valve operations for ischemic mitral insufficiency performed at New York University Medical Center between January 1976 and January 1996. The results for mitral valve reconstruction are compared with those for prosthetic mitral valve replacement. METHODS: From January 1976 to January 1996, 223 patients with ischemic mitral insufficiency underwent mitral valve reconstruction (n = 152) or prosthetic mitral valve replacement (n = 71). Coronary artery bypass grafting was performed in 89% of cases of mitral reconstruction and 80% of cases of prosthetic replacement. In the group undergoing reconstruction, 77% had valvuloplasty with a ring annuloplasty and 23% had valvuloplasty with suture annuloplasty. In the group undergoing prosthetic replacement, 82% of patients received bioprostheses and 18% received mechanical prostheses. RESULTS: Follow-up was 93% complete (median 14.6 mo, range 0-219 mo). Thirty-day mortality was 10% for mitral reconstruction and 20% for prosthetic replacement. The short-term mortality was higher among patients in New York Heart Association functional class IV than among those in classes I to III (odds ratio 5.75, confidence interval 1.25-26.5) and was reduced among patients with angina relative to those without angina (odds ratio 0.26, confidence interval 0.05-1.2). The 30-day death or complication rate was similarly elevated among patients in functional class IV (odds ratio 5.53; confidence interval 1.23-25.04). Patients with mitral valve reconstruction had lower short-term complication or death rates than did patients with prosthetic valve replacement (odds ratio 0.43, confidence interval 0.20-0.90). Eighty-two percent of patients with mitral valve reconstruction had no insufficiency or only trace insufficiency during the long-term follow-up period. Five-year complication-free survivals were 64% (confidence interval 54%-74%) for patients undergoing mitral valve reconstruction and 47% (confidence interval 33%-60%) for patients undergoing prosthetic valve replacement. Results of a series of statistical analyses suggest that outcome was linked primarily to preoperative New York Heart Association functional class. CONCLUSIONS: Initial mortalities were similar among patients undergoing prosthetic replacement and valve reconstruction. Poor outcome was primarily related to preexisting comorbidities. Patients undergoing valve reconstruction had fewer valve-related complications. Valve reconstruction resulted in excellent durability and freedom from complications. These findings suggest that mitral valve reconstruction should be considered for appropriate patients with ischemic mitral insufficiency.     

Impact of Cox maze procedure on outcome in patients with atrial fibrillation and mitral valve disease

OBJECTIVE: We sought to determine whether the Cox maze procedure provides additional benefit to patients with atrial fibrillation undergoing mitral valve operations. METHODS: Between May 1992 and August 2000, we performed 258 Cox maze procedures with mitral valve replacement (n = 147) or mitral valve repair (n = 111). We compared the outcomes of these patients with those of 61 control patients with preoperative atrial fibrillation who underwent mitral valve replacement alone during the same interval. The three cohorts were similar in age, sex, and proportion of patients in preoperative New York Heart Association functional class 3 or 4. RESULTS: Although 5-year survivals were similar among the groups (94% for mitral valve replacement alone, 95% for mitral valve replacement plus maze, and 97% for mitral valve repair plus maze), freedoms from atrial fibrillation at 5 years were significantly higher in the mitral valve replacement plus maze group (78%) and the mitral valve repair plus maze group (81%) than in the mitral valve replacement group (6%, P <.0001). Freedoms from stroke at 5 years were 97% for the mitral valve replacement plus maze group, 97% for the mitral valve repair plus maze group, and only 79% for mitral valve replacement group (P <.0001). Multivariable analysis with Cox hazard model revealed that the most significant risk factor for late stroke was the omission of the Cox maze procedure (P =.003). CONCLUSIONS: The addition of the Cox maze procedure to mitral valve repair and replacement was safe and effective for selected patients. Elimination of atrial fibrillation significantly decreased the incidence of late stroke.     

Mitral valve repair and replacement for rheumatic disease

OBJECTIVES: Mitral valve repair may be technically feasible in patients with suitable anatomy, but the appropriateness of repair for rheumatic disease remains controversial. We evaluated our late outcomes after mitral repair and replacement for rheumatic disease. METHODS: Five hundred seventy-three patients underwent mitral valve surgery for rheumatic disease at our institution from 1978-1995. Follow-up was 98% complete (mean, 68 +/- 46 months). Survival and morbidity were evaluated by Kaplan-Meier analysis and Cox regression, including propensity score analysis. RESULTS: Mean age was 54 +/- 14 years, 55% of patients had congestive heart failure, 22% were undergoing redo mitral valve surgery, and 9% also underwent coronary bypass. Mitral stenosis was present in 53%, regurgitation in 15%, and both in 32%. Valve repair was performed in 25%, bioprosthetic replacement was performed in 28%, and a mechanical valve was placed in 47%. Patients undergoing repair were younger and less likely to be undergoing reoperation or to have atrial fibrillation than those undergoing replacement (P =.001). The operative mortality rate was 4. 2%. Better late cardiac survival was independently predicted by valve repair rather than replacement (P =.04) after adjustment for baseline differences between patients. Freedom from reoperation was greatest (P =.005) but that from thromboembolic complications was worst (P <.0001) after mechanical valve replacement. Twenty-three patients underwent reoperation after initial repair, with no operative deaths. CONCLUSIONS: Mechanical valves minimize reoperation but limit survival and increase thromboembolic complications. Patients undergoing valve repair had improved late cardiac survival independent of their preoperative characteristics. Rheumatic mitral valves should be repaired when technically feasible, accepting a risk of reoperation, to maximize survival and reduce morbidity.     

Paravalvular leakage after mitral valve replacement: improved long-term survival with aggressive surgery?

BACKGROUND: Following mitral valve replacement, surgical closure of paravalvular leaks is usually advised in severely symptomatic patients and in those requiring blood transfusions for persisting haemolysis. However, the long-term prognosis of less symptomatic patients or those not needing blood transfusions is unknown. METHODS: Between 1987 and 1997, we observed 96 patients with mitral paravalvular leakage. A paraprosthetic leak was diagnosed after a median time of 119 days (range: 1 day-23 years) after primary mitral valve replacement. During an average follow-up of 5 years (range: 1-23 years), 50/96 patients were referred for surgical closure. RESULTS: Compared with patients who received conservative treatment, those referred for surgery had a significantly lower mean preoperative haematocrit (P = 0.002) with a higher proportion of patients being in the NYHA class III/IV (P = 0.03). Age, gender, left ventricular function and number and size of leaks did not differ between the groups. The 30-day postoperative mortality for valve reoperation was 6% (3/50); during follow-up three further patients died, resulting in an overall mortality rate of 12%. In the group treated conservatively there was a mortality rate of 26% (12/46). Thus, the actuarial survival for patients referred for surgery was 98, 90 and 88% after 1, 5 and 10 years, compared with 90, 75 and 68% for patients treated conservatively (long-rank P = 0.03). In addition, there was a significant increase in mean haematocrit levels (P = 0.0001) and an improvement in NYHA class III/IV symptoms (P = 0.002), vertigo (P = 0.001) and fatigue (P = 0.001) after surgery. CONCLUSIONS: Following mitral valve replacement, a more aggressive surgical treatment is recommended for patients with paraprosthetic leaks. Surgery should be offered to less symptomatic patients, as well as those not requiring blood transfusion.     

Anti-inflammatory effect of high-dose insulin treatment after urgent coronary revascularization surgery

Background:  The administration of insulin has been shown to exert cardioprotective and immunomodulatory properties. Ischemia and inflammation are typical features of acute coronary syndrome, thus it was hypothesized that high-dose glucose–insulin–potassium (GIK) treatment could suppress the systemic inflammatory reaction and attenuate myocardial ischemia–reperfusion injury in patients with unstable angina pectoris after urgent coronary artery bypass surgery.
Methods:  Forty patients with unstable angina pectoris scheduled for urgent coronary artery bypass surgery and cardiopulmonary bypass were randomly assigned to receive either high-dose insulin treatment (short-acting insulin 1 IU/kg/h with 30% glucose 1.5 ml/kg/h administered separately) or control treatment (saline). Blood glucose levels were targeted to 6.0–8.0 mmol/l in both groups by adjusting the rate of glucose infusion in the GIK group and by additional insulin in the control group as needed.
Results:  High-dose insulin treatment was associated with significantly lower average C-reactive protein (23.8 vs. 40.1 mg/l, P = 0.008) and free fatty acid levels (0.22 vs. 0.41 mmol/l, P = < 0.001) post-operatively. Average blood glucose levels were comparable during the intensive care unit (ICU) stay (7.1 vs. 6.9 mmol/l, P = 0.5) and 95% of the control patients received supplemental insulin. The pro-inflammatory cytokine response [interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor-α (TNF-α)] did not differ between the groups and beneficial effects on myocardial injury were not detected.
Conclusions:  High-dose insulin treatment has potential anti-inflammatory properties independent of its ability to lower blood glucose levels. Even profound suppression of free fatty acid levels, the attenuation of myocardial ischemia–reperfusion injury was not detected.     

A comparison of repair and replacement for mitral valve incompetence

A total of 101 reparative and 389 valve replacement operations, isolated or combined with tricuspid annuloplasty or operations for coronary artery disease, were done for mitral incompetence (1975 to July 1, 1983). The patients undergoing repair as a group were younger and had less hemodynamic and functional derangement than those undergoing replacement. The prevalence of repair was less (p less than 0.001) for two surgeons than for the other four, even when possible differences in patient populations were taken into account by multivariate analysis. Five-year survival rate, including hospital deaths, was 76% after valve repair and 56% after valve replacement (p = 0.005). However, by multivariate analysis, valve replacement rather than repair was only possibly (p = 0.14) a risk factor. (Multivariate analysis in all patients undergoing mitral valve repair in the period 1967 to 1985 [n = 210] did not find the type of annuloplasty to be a risk factor.) The incidence of reoperation was no different after repair or replacement and there was no increase in the risk of reoperation late after repair. Endocarditis early or late after operation occurred in 11 of the 389 patients undergoing mitral replacement and in none of those undergoing repair (p = 0.08). The functional status of the patients was not different between the two groups. These data, and the experience of others, indicate the advantages of repairing rather than replacing the incompetent mitral valve whenever possible.     

Minimally Invasive Approach for Redo Mitral Valve Surgery: A True Benefit for the Patient

ABSTRACT Objectives Redo mitral valve surgery via sternotomy is associated with a substantial morbidity and mortality. This study evaluated a minimally invasive technique for mitral valve redo procedures. Material and Methods: Out of a series of 394 patients undergoing mitral valve repair or replacement via a right minithoracotomy, 39 patients underwent redo mitral valve surgery (59 ± 13 years, 23 female). Previous cardiac surgeries included 17 patients with mitral valve repair, 6 patients with mitral valve replacement, 3 patients with aortic valve replacement, 2 patients with atrial septal defect closure, and 11 patients with coronary artery bypass grafting (CABG). In all cases, femoro-femoral cannulation was performed. The port access technique was applied in patients undergoing redo valve surgery. In patients with prior CABG, the operation was performed using deep hypothermia and ventricular fibrillation. Results: In all cases, sternotomy was avoided. The mitral valve was replaced in 20 patients and repaired in 19. Time of surgery and cross-clamp time were comparable with the overall series (168 ± 73 [redo] vs 168 ± 58 min and 52 ± 21 [redo] vs 58 ± 25 min). Mortality was 5.1%. One patient had transient hemiplegia due to the migration of the endoclamp. All other patients had uneventful outcomes and normal mitral valve function at 3-month's follow-up. Conclusion: Redo mitral valve surgery can be performed safely using a minimally invasive approach in patients with a previous sternotomy. The right lateral minithoracotomy offers excellent exposure. It minimizes the need for cardiac dissection, and thus, the risk for injury. Avoiding a resternotomy increases patient comfort of redo mitral valve surgery.     

心脏基础液在心脏瓣膜置换术后的应用

目的探讨心瓣膜置换术后应用心脏基础液补充钾、镁和保护心肌细胞的作用。方法９２例心脏瓣膜置换术后患者随机分为２组：对照组４９例和基础液组４３例。２组于手术结束后,分别应用极化液和心脏基础液于１８小时、４８小时和７２小时时查血钾、血镁和心肌酶。结果基础液组比对照组血钾、血镁明显升高且稳定（Ｐ＜０．０５）,其心肌酶亦比对照组明显下降（Ｐ＜０．０１）。结论在心瓣膜置换术后应用基础液能稳定地补充血钾、血镁及保护心肌细胞     

Mitral valve surgery in infants and children

The pre-operative findings and surgical results of forty-three patients under thirteen years of age undergoing mitral valve surgery, are presented. Eight underwent surgery for mitral stenosis. Four had open mitral valvotomy with a satisfactory result, one developed severe regurgitation which required mitral valve replacement. Two had primary valve replacement and two had excision of a mitral subvalvar diaphragm. Thirty five children underwent surgery for mitral regurgitation. Twelve had a mitral annuloplasty. Two of these developed further regurgitation which required mitral valve replacement. Twenty one children had primary mitral valve replacement. The results and choice of valve replacement are discussed.     

Influence of systemic lupus erythematosus on procedure selection and outcomes of patients undergoing isolated mitral valve surgery

Abstract Background: Cardiovascular disease is the main cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). SLE as a risk factor for adverse outcomes during mitral surgery has not been studied. The purpose of this investigation was to compare procedure selection and outcomes of patients with and without SLE. Methods: The 2005–2008 Nationwide Inpatient Sample database was searched to identify patients ≥18 years of age undergoing isolated mitral repair or replacement. Patients with and without SLE were compared on baseline characteristics and hospital outcomes. Within patients with SLE, those undergoing repair and replacement were compared. Results: SLE patients comprised 0.9% (620/70,969) of the isolated mitral valve surgery population. Patients with SLE were significantly younger, more likely to be female, less likely to be white, had higher Charlson comorbidity index, and less often presented electively. Patients with SLE had a higher incidence of prolonged hospitalization (LOS > 10 days; 44.4% vs. 34.7%, p = 0.0392). Mortality was similar for patients with and without SLE undergoing isolated mitral valve surgery (OR = 0.76, 95% CI 0.28–2.05, p = 0.5821). Patients with SLE were less likely to have mitral valve repair (27.1% vs. 45.6%, p = 0.0002). Baseline characteristics were similar between SLE repair and replacement subsets. Median LOS was higher for replacement (10 days vs. 7 days, p = 0.0014). Hospital mortality was 0% for SLE mitral repair patients and <4.0% for SLE replacement patients. Conclusions: Patients with SLE present for isolated mitral valve surgery at a much younger age and with worse preoperative profiles. Although mitral repair rates were lower in patients with SLE, hospital outcomes were excellent, and comparable to those of patients without SLE. (J Card Surg 2012;27:29–33)     

人工二尖瓣舒张期最大跨瓣压与左心房压力的相关性

目的 分析二尖瓣置换或修复术患者舒张期最大跨瓣压与左心房压力(LAP)的相关性.方法 选择行心肺转流(CPB)下二尖瓣置换或修复手术的瓣膜病患者20例,男9例,女11例,年龄18～80岁,术中行经食管超声心动图(TEE)监测.于心脏复跳后CPB停机前、左心房引流管拔除前,分别采用左心房引流管测量LAP,TEE测量人工二...     

The risk of thromboembolism and hemorrhage following mitral valve replacement. A comparative analysis between the porcine xenograft valve and Ionescu-Shiley bovine pericardial valve

To ascertain the risk of thromboembolism and anticoagulant-related hemorrhage following mitral valve replacement with bioprostheses, an 8 year retrospective study between two groups of patients was analyzed. Group I included 206 patients undergoing mitral valve replacement with porcine xenograft valves. They were placed on a regimen of long-term oral anticoagulation (greater than 8 weeks, mean 6 months). Follow-up was 524.3 patient-years, mean 30.5 months. There were 24 thromboembolic events (4.6% per patient-year), four of which were fatal. Actuarially, 80.7% +/- 4.3% are free of thromboembolism at 8 years. There were 12 instances of major bleeding episodes, for a linearized incidence of 2.5% per patient-year; two were fatal. Group II included 322 patients undergoing mitral valve replacement with a bovine pericardial valve. They were placed on a program of short-term anticoagulation (6 weeks only). Follow-up was 1,106 patient-years, mean 46.4 months. There were four thromboembolic episodes (none fatal), an incidence of 0.36% per patient-year. Seven bleeding episodes occurred, 0.63% per patient-year; none was fatal. The difference between the groups reached statistical significance (p less than 0.001). The low risk of thromboembolism with the bovine pericardial valve appears to be due to its superior hydraulic characteristics. Use of this valve allows mitral valve replacement without long-term oral anticoagulation and the associated risk of anticoagulant-related hemorrhage.     

Comparison of minithoracotomy and conventional sternotomy approaches for valve surgery

OBJECTIVE: To compare patients undergoing valve surgery through a minithoracotomy approach with a matched group undergoing conventional valve surgery. DESIGN: Control study. SETTING: University hospital, single center. PARTICIPANTS: Forty-one consecutive patients scheduled for valve surgery by minithoracotomy approach were matched with a similar group of patients operated on by the sternotomy approach. INTERVENTIONS: Criteria for matching included type of valve procedure (aortic valve replacement or mitral valve repair), age, surgeons, and left ventricular function. Two surgeons performed the surgical procedures. Perioperative care was standardized for all patients. Operative and postoperative data were recorded.MEASUREMENTS AND MAIN RESULTS: The 41 pairs of patients were correctly matched, except for left ventricular function (n = 1). Twenty patients underwent mitral valve repair and 62 aortic valve replacement. Preoperative demographic data and clinical characteristics were similar in both groups. Cardiopulmonary bypass, aortic clamping, and surgery times were longer in the minithoracotomy group (p < 0.05). In 3 patients, the minithoracotomy approach had to be converted into a sternotomy during the surgical procedure for better visualization. Minithoracotomy patients had significantly increased postoperative total blood loss (p < 0.05). No difference was found between the groups for extubation time and intensive care or in-hospital lengths of stay. CONCLUSION: These results suggest that valve surgery is feasible in many cases through minithoracotomy. Nevertheless, this approach increases surgical complexity and in this comparative study no significant benefit was shown.     

The diabetic disadvantage: historical outcomes measures in diabetic patients undergoing cardiac surgery -- the pre-intravenous insulin era

Seven percent of the United States population is diabetic. However, diabetics are two to five times more likely to develop cardiovascular disease and therefore populate 30% of open heart procedures in this country. In addition, it has been well documented that diabetic cardiac surgery patients are further disadvantaged with worse outcomes following those procedures. This has been termed the "Diabetic Disadvantage." To benchmark these specific disadvantages, we evaluated the short- and long-term outcomes for diabetics and nondiabetics undergoing coronary artery bypass graft (CABG), CABG/valve, and aortic or mitral valve replacement surgery before the broader acceptance and use of intravenous insulin infusions in this patient population in 2001. All such patient records (n = 1,369,961) from the Society of Thoracic Surgeons national database operated on between 1990 and 2000 were assessed for short-term outcomes. Ten-year survival was evaluated among 36,835 patients from the Northern New England Cardiovascular Disease Study Group longitudinal registry. The diabetic population was found to have higher rates of 30-day mortality, deep sternal wound infection, stroke, and longer length of stay than the nondiabetic population. In addition, diabetic patients had approximately two-fold worse 10-year survival. All differences were statistically significant (P < 0.001). In summary, The Diabetic Disadvantage in the pre-intravenous insulin era is characterized by worse short- and long-term outcomes for diabetic patients undergoing cardiac surgery in the United States and Canada.