Brain natriuretic peptide concentration in pericardial fluid is independently associated with atrial fibrillation after off-pump coronary artery bypass surgery

OBJECTIVES: Postoperative atrial fibrillation is associated with the increased incidence of morbidities and mortality. Predisposing determinants of atrial fibrillation development after off-pump coronary artery bypass grafting remain unclear. We hypothesized that pericardial fluid natriuretic peptide concentrations have a predictive value for developing postoperative atrial fibrillation in patients who have undergone off-pump coronary artery bypass grafting. METHODS: We prospectively measured atrial natriuretic peptide and brain natriuretic peptide concentrations in plasma and pericardial fluid in 42 consecutive patients undergoing off-pump coronary artery bypass grafting, then continuously observed the occurrence of atrial fibrillation following off-pump coronary artery bypass grafting until the time of discharge. RESULTS: Postoperative atrial fibrillation was documented in nine patients (21%, atrial fibrillation group), and not in 33 patients (no atrial fibrillation group). Between the groups, there was neither significant difference in plasma atrial natriuretic peptide concentrations nor in pericardial atrial natriuretic peptide concentrations. Plasma brain natriuretic peptide concentrations were comparable in both groups [56.2 (interquartile range 42.7-102.8) vs. 35.2 pg/ml (13.8-75.0), P=0.07]. Pericardial fluid brain natriuretic peptide concentrations were significantly higher in the atrial fibrillation group than in the no atrial fibrillation group [188.0 (124.8-411.0) vs. 39.3 pg/ml (10.0-88.4), P=0.0001]. In a multivariable logistic regression model, pericardial brain natriuretic peptide concentration was significantly associated with a higher risk of postoperative atrial fibrillation (odds ratio=3.0 every 50 pg/ml increase; 95% confidence interval, 1.1-8.6; P=0.04). CONCLUSION: Our results suggested that pericardial fluid brain natriuretic peptide concentration is independently associated with the development of atrial fibrillation after off-pump coronary artery bypass grafting.     

Clinical implication of atrial and brain natriuretic Peptide in coronary artery bypass grafting

Atrial natriuretic peptide and brain natriuretic peptide are known to be indices for heart failure. Atrial natriuretic peptide and brain natriuretic peptide changes in off-pump and on-pump coronary artery bypass grafting is hypothesized to be correlated to clinical implications of coronary artery bypass grafting. 20 consecutive off-pump and 20 consecutive on-pump coronary artery bypass grafting patients were studied. Perioperative atrial natriuretic peptide and brain natriuretic peptide values were measured and statistically analyzed in terms of 14 factors related to myocardial damage and recovery. Postoperative atrial natriuretic peptide plateaued on the third postoperative day and it decreased gradually down to the preoperative level by one month in the off-pump group. Postoperative brain natriuretic peptide plateaued, showed very slow decrease and it never reached down to the preoperative level. The peak brain natriuretic peptide level was correlated with aortic cross-clamp time, postoperative pleural effusion, and postoperative atrial fibrillation (p < 0.01). The atrial natriuretic peptide change reflected surgical prevention of ventricular remodeling. Brain natriuretic peptide > 450 microg.mL(-1) had strong predictive power for atrial fibrillation and pleural effusion and is a useful marker for management of coronary surgery patients.     

Predictors of atrial fibrillation after coronary artery bypass surgery

OBJECTIVE: Atrial fibrillation is one of the most common arrhythmias associated with not only increased morbidity after coronary artery bypass grafting but also increased healthcare costs. Many factors are associated with atrial fibrillation onset after coronary artery bypass grafting. We prospectively examined which factors could predict atrial fibrillation after coronary artery bypass grafting. METHODS: Fifty-seven consecutive patients (37 men, mean age=60.2+/-12 years) with sinus rhythm before coronary artery bypass grafting are included the study. Clinical, demographic, laboratory and echocardiographic characteristics are all evaluated prospectively. The maximum and minimum P-wave duration (P(max) and P(min)) were measured from the 12-lead surface electrocardiogram. The difference between the P(max) and the P(min) was calculated and defined as P-wave dispersion. Preoperative venous blood samples were taken for N-terminal proBrain natriuretic peptide level analysis. RESULTS: Ten (17%) patients had postoperative atrial fibrillation. Patients with postoperative atrial fibrillation were older (69.4+/-6 versus 58.2+/-12 years, P=0.01), had lower ejection fraction (44.1+/-8.9% versus 54.3+/-9; P=0.002), higher proBrain natriuretic peptide levels (538+/-136 pg/ml versus 293+/-359 pg/ml; P=0.03), longer P(max) (142.2+/-13.7 ms versus 120.8+/-21.2 ms; P=0.006) and longer P-wave dispersion (55.0+/-8.2 ms versus 41.3+/-14.3 ms; P=0.008) compared with the patients without atrial fibrillation. Univariate analysis showed that increased age (P=0.01), lower ejection fraction (P=0.02), enlargement of left atrium (P=0.02), increased P(max) (P=0.006) and increased P-wave dispersion (P=0.008) and increased level of preoperative proBrain natriuretic peptide (P=0.03) were associated with postoperative atrial fibrillation. Positive correlation was seen between the age and level of proBrain natriuretic peptide (r=0.322 and P=0.015). In multivariate analysis, age (P=0.05), lower ejection fraction (P=0.03), left atrial enlargement (P=0.05), longer P(max) (P=0.01) and P-wave dispersion (P=0.01) were found to be independent predictors of postoperative atrial fibrillation. CONCLUSION: Age, poor left ventricular functions, P(max) and P-wave dispersion are found to be independent predictors of atrial fibrillation after coronary artery bypass grafting.     

冠状动脉旁路移植术患者围手术期血浆脑利钠肽水平的变化及其意义

目的观察冠状动脉旁路移植术(CABG)患者围手术期血浆脑利钠肽(BNP)水平的变化并探讨其意义。方法72例非体外循环下行CABG患者,术前按NYHA心功能标准分级,超声心动检查测定左室射血分数(LVEF)等,分别于术前,术后5h、24h、72h及7d静脉取血测定血浆BNP水平,分析围手术期BNP的变化趋势,并与心功能分级、LVEF、术后心律失常的发生及激酸激酶同工酶(CK-MB)、肌钙蛋白I(TnI)等多因素进行相关性分析。结果72例患者术前血浆BNP水平与NYHA心功能分级呈正相关(r=0.829,P=0.00);与术前心肌梗死呈正相关(r=0.47,P=0.00);与LVEF呈负相关(r=-0.61,P=0.00)。血浆BNP术后5h开始上升,24h显著升高,72h达峰并开始下降,至7d时仍显著高于术前水平。术前及术后血浆BNP水平与术后心律失常的发生均呈正相关(r=0.394,P=0.001,r=0.26,P=0.031);而术后BNP水平与CK-MB、TnI等未发现相关关系。结论血浆BNP水平能反映CABG患者心功能状态。术后早期血浆BNP升高,一周时开始下降。BNP可以作为CABG围手术期心功能的参数。     

心脏康复促进冠状动脉搭桥术后患者体能恢复及不良情绪改善

目的观察心脏康复治疗对冠状动脉搭桥术后患者运动功能及不良情绪的改善作用。方法心脏外科拟行冠状动脉搭桥手术患者52例,将其随机分为康复组及对照组。两组患者均接受常规治疗,康复组在上述基础同时给予运动训练及心理干预。于术前、术后15天对入选患者进行6 min步行实验(6MWT)、左心室射血分数、汉密尔顿焦虑量表(HAMA)和汉密尔顿抑郁量表(HAMD)评定。结果与对照组比较,术后15天康复组患者6MWT明显提高(298.15±59.24 m比220.80±54.25 m,P<0.01),HAMA及HAMD评分显著降低(2.07±2.45分比5.48±3.32分及2.26±2.31分比6.36±3.81分,P<0.01)。与术前比较,康复组术后左心室射血分数也有改善(P<0.01);进一步分析发现,患者手术前后6MWT差值与手术前后HAMA及HAMD评分差值具有负相关性(r=-0.53,P<0.01;r=-0.60,P<0.01)。结论心理干预联合运动训练对冠状动脉搭桥术后患者不良情绪改善及运动能力恢复均有促进作用,值得临床推广应用。     

Role of preoperative atorvastatin administration in protection against postoperative atrial fibrillation following conventional coronary artery bypass grafting

Atrial fibrillation (AF) is one of the most common postoperative arrhythmias in patients who undergo coronary artery bypass grafting (CABG). The aim of this study was to evaluate the effect of preoperative atorvastatin on postoperative atrial fibrillation following coronary artery bypass grafting with cardiopulmonary bypass (CCABG). One hundred consecutive patients undergoing elective CCABG, without history of AF or previous statin treatment, were enrolled and randomly assigned to a statin group (atorvastatin 20 mg/d, n = 49) or a control group (placebo, n = 51) starting 7 days preoperatively. The primary endpoint was the occurrence of postoperative AF. C-reactive protein (CRP) levels were assessed in all selected patients before surgery and every 24 hours postoperatively until discharge from hospital. Atorvastatin significantly reduced the incidence of postoperative AF and postoperative peak CRP level versus placebo (18% versus 41%, P = 0.017; 129.3 ± 24.3 mg/L versus 149.3 ± 32.5 mg/L, P < 0.0001). Kaplan-Meier curves confirmed a significantly better postoperative atrial fibrillation-free survival in the statin group (χ(2) = 7.466, P = 0.006). Logistic regression analysis showed preoperative atorvastatin treatment was an independent factor associated with a significant reduction in postoperative AF (OR = 0.235, P = 0.007), whereas high postoperative CRP levels were associated with increased risk (OR = 2.421, P = 0.015). Preoperative atorvastatin administration may inhibit inflammatory reactions to prevent atrial fibrillation following coronary artery bypass grafting with cardiopulmonary bypass.     

1516例男性患者非体外循环冠状动脉旁路移植术中应用主动脉内球囊反搏危险因素Logistic分析

目的:非体外循环冠状动脉旁路移植术(OPCABG)是治疗冠心病主要手段之一。本文拟通过回顾性Logistic分析1 516例施行OPCABG男性患者,术中应用主动脉内球囊反搏(IABP)的独立危险因素,为此类患者提供手术依据和前瞻性判断。方法:采用麻醉科2007年11月至2009年2月OP-CABG围术期数据库,回顾性分析了1 516例记录齐全的男性患者OPCABG围术期资料。以术中应用IABP为因变量,将有统计学意义的单因素进行Logistic回归分析并评价各影响因素的作用大小。结果:术前射血分数(EF)<40%(OR=4.946,P=0.001)、搭桥数>3支(OR=2.340,P=0.007)、左主干病变(OR=2.857,P=0.001)、急诊(OR=4.816,P=0.001)和术中发生心房颤动(P=0.001,OR=12.188)为围术期应用IABP的独立危险因素。结论:术前EF<40%、旁路移植血管数>3支、左主干病变、急诊和术中发生心房颤动为术中应用IABP的独立危险因素,提示在遇到这类患者时,及早在术前应用IABP,对于OPCABG患者是有益的。     

Left main coronary artery stenosis: factors predicting cardiac events in patients awaiting coronary surgery

Although most patients with left main coronary artery stenosis undergo urgent coronary artery bypass grafting, limited information is available regarding the risk factors that might lead to cardiac events between angiographic diagnosis and surgery. We retrospectively reviewed 1,731 cases of coronary artery bypass grafting at our institution, 97 of which were performed in patients with significant (> or = 50%) left main coronary artery stenosis. These patients were placed in 1 of 2 groups: eventful waiting or uneventful waiting. We analyzed multiple preoperative variables, and the incidence of serious cardiac events (death, myocardial infarction, unstable angina, left ventricular failure, and life-threatening ventricular arrhythmias) during the waiting period between angiography and surgery Four patients (4.1%) experienced serious cardiac events while awaiting surgery (1 had non-ST-elevation myocardial infarction; 3 had life-threatening ventricular arrhythmias); none died. All the events occurred more than 24 hours after cardiac catheterization. Of the preoperative variables analyzed (acute coronary syndrome, age, history of diabetes, hypertension, hyperlipidemia, smoking, renal failure, severity of left main stenosis, right coronary artery involvement, ejection fraction, and use of intra-aortic balloon pump), only acute coronary syndrome predicted the incidence of preoperative cardiac events (P=0.001). The occurrence of severe cardiac events while patients await coronary artery bypass grafting is rare. Carefully selected patients with severe left main coronary artery stenosis can safely await surgery. Concomitant acute coronary syndrome and severe left main coronary artery stenosis indicate a high risk for cardiac events. Therefore, in patients with these conditions, emergency coronary artery bypass may be preferable.     

Effects of lesion complexity on baseline and postprocedural B-type natriuretic peptide levels in patients undergoing percutaneous coronary interventions

The time-related alteration of plasma B-type natriuretic peptide levels after percutaneous coronary interventions has been investigated chiefly in patients with acute coronary syndromes; very few data are available in patients with stable coronary artery disease. Therefore, we aimed to evaluate the alterations of plasma B-type natriuretic peptide levels, and the effects of lesion complexity on these levels, after elective percutaneous coronary interventions in stable coronary artery disease patients. We enrolled 103 of these patients and used modified American College of Cardiology/American Heart Association lesion morphology criteria to qualitatively evaluate the angiograms: type A and B1 lesions were categorized as simple, and type B2 and C lesions were designated as complex. Plasma B-type natriuretic peptide levels were determined before intervention and 1 and 24 hours afterwards. Median baseline B-type natriuretic peptide levels were significantly higher in patients who had complex lesions (n=53) (108 pg/mL) compared with those who had simple lesions (n=50) (33 pg/mL) (P <0.001), and this difference was maintained 1 and 24 hours after intervention (P = 0.003 and P = 0.001, respectively). However, for both lesion types, percutaneous coronary intervention procedures did not significantly alter plasma B-type natriuretic peptide levels (all P >0.05). On binary logistic regression analysis, age and lesion complexity were found to be independently associated with B-type natriuretic peptide levels. We conclude that, in stable coronary artery disease patients, elective percutaneous coronary intervention does not cause any significant alteration in plasma B-type natriuretic peptide levels. However, elevated levels are significantly associated with more complex lesions and with advanced age.     

Statins and postoperative risk of atrial fibrillation following coronary artery bypass grafting

Atrial fibrillation (AF) is a common complication after coronary artery bypass grafting. Atrial remodeling has been observed in AF and has been associated with the development of this arrhythmia. Because 3-hydroxy-3-methylglutaryl coenzyme A inhibitors (statins) have been demonstrated to modify remodeling, we hypothesized a protective role of statins against postoperative AF. We also hypothesized that extracellular matrix turnover and brain natriuretic peptide (BNP) might be related to such atrial remodeling. We studied 234 consecutive patients who underwent coronary artery bypass grafting (173 men; 65 +/- 9 years of age) in whom the occurrence of postoperative AF was monitored. In a subgroup of 66 patients, we measured plasma levels of matrix metalloproteinase-1 (MMP-1), its inhibitor, tissue inhibitor matrix metalloproteinase-1 (TIMP-1; as indexes of extracellular matrix remodeling), and N-terminus pro-BNP (related to left ventricular function) at baseline and at 24 hours after surgery. Of 234 patients, 66 (28.2%) developed postoperative AF. In multivariate analysis, previous AF was related to an increase in the development of AF (odds ratio 11.92, 95% confidence interval 2.37 to 59.98, p = 0.026), whereas statin use was related to a decrease in arrhythmia (odds ratio 0.52, 95% confidence interval 0.28 to 0.96, p = 0.038). A higher TIMP-1/MMP-1 ratio at 24 hours after surgery was present in those who did not develop postoperative AF (p = 0.043). Statin use was associated with increased TIMP-1 levels and TIMP-1/MMP-1 ratio (p = 0.027 and 0.036, respectively). No significant relations to N-terminus pro-BNP were seen. In conclusion, previous AF and nonuse of statins are significantly associated with AF after coronary artery bypass grafting. Statin use may be protective against AF after coronary artery bypass grafting, possibly due to alterations in the extracellular matrix and remodeling after coronary artery bypass grafting.     

颈动脉粥样硬化与冠状动脉旁路移植术后神经系统并发症相关性研究

目的:探讨颈动脉粥样硬化程度与非体外循环下冠状动脉旁路移植术后,神经系统并发症的关系。方法:连续选择择期行非体外循环下冠状动脉旁路移植术的患者475例,根据颈动脉超声结果分为四组:无狭窄、轻度、中度及重度狭窄,分析狭窄程度与术后神经系统并发症的关系及影响因素。结果:①四组患者之间年龄、脑卒中病史、糖尿病史及神经系统并发症比较,差异有统计学意义(P<0.05);②颈动脉狭窄患者术后神经系统并发症的发生率高于无颈动脉狭窄患者(χ2=3.851,P=0.050);③脑卒中病史(OR=1.835,95%CI:1.023～3.289,P<0.05)、颈动脉重度狭窄(OR=2.793,95%CI:1.296～6.018,P<0.05)与术后神经系统并发症相关(P<0.05)。结论:脑卒中病史、颈动脉重度狭窄是旁路移植术后神经系统并发症的危险因素。颈动脉不论狭窄程度,均可导致术后神经系统并发症发生率增高,低灌注可能为主要原因。     

QTc interval prolongation predicts postoperative mortality in heart failure patients undergoing surgical revascularization

QTc interval prolongation is associated with increased mortality rates in patients with advanced heart failure. We investigated the predictive value of prolonged QTc interval in 567 patients with heart failure who were undergoing coronary artery bypass graft surgery The patients were in New York Heart Association class III or IV, with left ventricular ejection fractions of 0.40 or less. Before surgery, the QT interval duration was measured in leads II and V4 of the standard electrocardiogram and corrected by use of the Bazett formula. The QTc interval was prolonged (>440 msec) in 243 patients (43%) and normal in 324 (57%). The 2 study groups--prolonged QTc versus normal QTc--did not differ in terms of age (62 +/- 11 years vs 64 +/- 10 years, P=0.65), sex (80% male vs 76% male, P=0.31), ejection fraction (0.29 +/- 0.08 vs 0.29 +/- 0.09, P=0.72), hypertension (82% vs 78%, P=0.34), or diabetes (11% vs 7%, P=0.10). Within 1 month after coronary artery bypass grafting, 22 of 243 patients (9.1%) in the prolonged QTc group died, compared with 5 of 324 in the normal QTc group (1.5%) (P=0.0001). QTc interval prolongation was the only independent predictor of postoperative mortality on multivariate analysis (P=0.002). We conclude that patients with heart failure and preoperative QTc interval prolongation have increased mortality rates after coronary artery bypass grafting.     

冠状动脉旁路移植术后早期心律失常与血浆脑钠肽水平关系的临床研究

目的调查冠状动脉旁路移植术后早期心律失常的发生率,探讨其发生与围手术期血浆脑钠肽水平等多因素的关系。方法连续收集130例接受冠状动脉旁路移植术患者,按术后早期是否发生心律失常分为心律失常组42例,非心律失常组88例,回顾性调查两组病人相关临床资料,检测术前及术后各时段血浆脑钠肽水平的变化,进行统计学分析。结果术后心律失常的发生率为32．3％。两组病人术前心肌梗死病史及左室射血分数有显著性差异,心律失常组病人术前、术后24 h、72 h及1周时的血浆BNP水平均明显高于非心律失常组。心律失常的发生与术后血清钾水平有关,而与病人的年龄、性别及桥支数无关。结论冠状动脉旁路移植术后早期心律失常的发生与术前及围术期心功能状态及术后血清钾水平有关。术前高的血浆脑钠肽水平可能是预测术后心律失常发生的重要指标。     

Diabetes in patients undergoing coronary artery bypass grafting. Impact on perioperative outcome

Summary Diabetes mellitus is an established risk factor related to significant morbidity and mortality after coronary artery bypass grafting. Data on 9682 patients undergoing coronary artery bypass grafting either with (n=8917) or without cardiopulmonary bypass (off-pump coronary artery bypass grafting; n=765) were subjected to an univariate analysis to identify potential associations between diabetes mellitus and 26 a priori selected perioperative outcome variables. Those having a significant association with diabetes were then subjected to a stepwise logistic regression model to identify the impact of diabetes as compared to additional 22 different a priori chosen patient related risk factors and treatment variables. Prevalence of outcome variables independently associated with diabetes has been determined in the subgroup of diabetics undergoing coronary artery bypass grafting with cardiopulmonary bypass or off-pump coronary artery bypass grafting surgery to evaluate the effect of avoiding cardiopulmonary bypass on perioperative patient outcome. Diabetes mellitus was defined as glucose intolerance either treated dietary, with oral hypoglycemics or with insulin. According to this definition of diabetes mellitus we found an overall prevalence of 37.1% (coronary artery bypass grafting with cardiopulmonary bypass: 37.5%; off-pump coronary artery bypass grafting: 32.5%). Eleven outcome variables having a significant association with diabetes were identified. Diabetes could be identified as an independent predictor of postoperative delirium, renal dysfunction and respiratory insufficiency. Prevalence of these three variables was lower in diabetics undergoing offpump coronary artery bypass grafting as in those undergoing coronary artery bypass grafting with cardiopulmonary bypass surgery reaching statistical significance with regard to postoperative delirium and respiratory insufficiency. In conclusion, diabetes mellitus is a significant independent predictor for three postoperative outcome variables in coronary artery bypass surgery. Avoiding cardiopulmonary bypass in diabetics seems to have a beneficial effect.     

Diabetes in patients undergoing coronary artery bypass grafting Impact on perioperative outcome

Diabetes mellitus is an established risk factor related to significant morbidity and mortality after coronary artery bypass grafting. Data on 9682 patients undergoing coronary artery bypass grafting either with (n=8917) or without cardiopulmonary bypass (off-pump coronary artery bypass grafting; n=765) were subjected to an univariate analysis to identify potential associations between diabetes mellitus and 26 a priori selected perioperative outcome variables. Those having a significant association with diabetes were then subjected to a stepwise logistic regression model to identify the impact of diabetes as compared to additional 22 different a priori chosen patient related risk factors and treatment variables. Prevalence of outcome variables independently associated with diabetes has been determined in the subgroup of diabetics undergoing coronary artery bypass grafting with cardiopulmonary bypass or off-pump coronary artery bypass grafting surgery to evaluate the effect of avoiding cardiopulmonary bypass on perioperative patient outcome. Diabetes mellitus was defined as glucose intolerance either treated dietary, with oral hypoglycemics or with insulin. According to this definition of diabetes mellitus we found an overall prevalence of 37.1% (coronary artery bypass grafting with cardiopulmonary bypass: 37.5%; off-pump coronary artery bypass grafting: 32.5%). Eleven outcome variables having a significant association with diabetes were identified. Diabetes could be identified as an independent predictor of postoperative delirium, renal dysfunction and respiratory insufficiency. Prevalence of these three variables was lower in diabetics undergoing offpump coronary artery bypass grafting as in those undergoing coronary artery bypass grafting with cardiopulmonary bypass surgery reaching statistical significance with regard to postoperative delirium and respiratory insufficiency. In conclusion, diabetes mellitus is a significant independent predictor for three postoperative outcome variables in coronary artery bypass surgery. Avoiding cardiopulmonary bypass in diabetics seems to have a beneficial effect.     

PCI对冠心病合并糖尿病行冠状动脉旁路移植的影响

目的 评价术前PCI对冠心病合并2型糖尿病患者行冠状动脉旁路移植术的影响.方法 回顾性分析2003年1月至2013年1月,上海交通大学医学院附属仁济医院心血管外科1848例冠状动脉旁路移植术患者,合并糖尿病352例.患者分为2组,术前PCI组106例,术前无PCI组246例.结果 围术期死亡率6.2%,PCI组死亡率16.04%,非PCI组死亡率2.03%.运用x2、t试验,logistic多因素回归分析表明,术前PCI史是影响围术期心功能、术后死亡、术后并发症发生的重要因素.结论 术前PCI是冠心病合并2型糖尿病行冠状动脉旁路移植围术期死亡、术后心血管不良事件发生的危险因素.     

Diagnostic accuracy of N-terminal pro-brain natriuretic peptide in the evaluation of postoperative left ventricular diastolic dysfunction

We compared the diagnostic accuracy of N-terminal prohormone brain natriuretic peptide (NT-proBNP) with that of echocardiography in the evaluation of left ventricular diastolic dysfunction after coronary artery bypass grafting. Thirty patients were studied prospectively. Patients who had recent myocardial infarction, unstable angina pectoris, or low ejection fraction with systolic dysfunction were excluded. Two blood samples were obtained: before anesthetic induction and on the 7th postoperative day. Levels of NT-proBNP were measured by electrochemiluminescence immunoassay. Comprehensive echocardiographic Doppler examinations were performed on admission and on the 7th postoperative day. Relationships between NT-proBNP levels and echocardiographic indices were evaluated by correlation, multiple linear regression, and receiver-operating characteristic curve analysis. There were significant and correlated worsenings in diastolic stage as determined both by echocardiographic indices and NT-proBNP levels. Early transmitral-to-early diastolic annular velocity ratio (E/Ea) was found to correlate with both NT-proBNP and postoperative diastolic functional stage (r=0.78, P <0.001). Mitral E/Ea was significantly more sensitive than were NT-proBNP levels in predicting diastolic functional stage. The area under the receiver-operating characteristic curve for NT-proBNP was significantly lower than that of mitral E/Ea (mean difference, 0.12; P=0.024). The NT-proBNP had 87.5% sensitivity and 55% specificity, whereas E/Ea had 87.5% sensitivity and 86.4% specificity. Plasma NT-proBNP levels are significantly related to mitral E/Ea ratio, which is a predictor of diastolic stage. Therefore, elevated NT-proBNP levels may indicate the time for a Doppler echocardiographic evaluation and identify a subgroup of patients at high risk who need closer monitoring during the early postoperative period.     

Atrial natriuretic factor release in postoperative cardiothoracic surgical patients

Immunoreactive atrial natriuretic factor (ANF) levels were measured preoperatively and for 5 days postoperatively in 22 patients undergoing cardiothoracic surgery. They were studied in 4 groups according to surgical procedure (mitral valve replacement, aortic valve replacement, coronary artery bypass grafting, and lung resection). The highest preoperative ANF levels were observed in the aortic valve group (mean 40.9 pmol/L) which were 2.5 (95% CI: 0.7 to 8.6) to 3.5 (95% CI: 0.9 to 13.9) times higher than the other groups. Values tended to peak on the 3rd and 4th postoperative days in all groups, although significantly elevated postoperative ANF concentrations occurred only in the coronary artery bypass group where the levels increased by a factor of 3.2 (95% CI: 1.3 to 7.5). As a separate part of the study, measurement of ANF release before, during, and after cardiopulmonary bypass in 6 patients tended to show a fall in ANF levels when on bypass, with a return to baseline levels on cessation of bypass.     

Rise and fall of B-type natriuretic peptide levels in patients with coronary artery disease and normal left ventricular function after cardiac revascularization

BACKGROUND: Recently, it was shown that B-type natriuretic peptide levels are increased in patients with acute coronary syndromes. AIMS: To assess the relation between B-type natriuretic peptide and ischemia in patients with stable and unstable angina pectoris with normal left ventricular function in relation to the extent of ischemia and response to revascularization. METHODS: Fifty-nine consecutive patients were enrolled in the study, patients were divided into two groups: stable angina patients (group I, n=18), and unstable coronary patients (group II, n=41). Baseline characteristics were compared with 15 age-matched and sex-matched participants. B-type natriuretic peptide levels were measured at baseline and 3, 7 and 90 days after coronary revascularization in group I and II. RESULTS: Patients with unstable angina pectoris had increased B-type natriuretic peptide levels compared with stable angina pectoris patients (B-type natriuretic peptide levels: controls 15.5+/-13 pg/ml, stable angina pectoris group 28.4+/-19 pg/ml, unstable angina pectoris group 104+/-81 pg/ml; P<0.01). A relationship between the number of affected coronary vessels and B-type natriuretic peptide was assessed (one-vessel 29.9+/-21 pg/ml, two-vessel 93.8+/-87 pg/ml, three-vessel 119+/-88 pg/ml; P<0.01). After revascularization, B-type natriuretic peptide levels decreased in groups I and II (25+/-20 vs. 39+/-28 pg/ml) and were similar after 90 days in percutaneous transluminal coronary angiograghy and in coronary artery bypass grafting groups (percutaneous transluminal coronary angiography 26+/-22 pg/ml, coronary artery bypass grafting 36+/-26 pg/ml; NS). CONCLUSIONS: B-type natriuretic peptide levels increase in unstable angina pectoris patients and are linked to the extent of coronary disease in patients with normal left ventricular systolic function, and returned to baseline level after surgical or catheter revascularization.     

Continuous insulin infusion improves postoperative glucose control in patients with diabetes mellitus undergoing coronary artery bypass surgery

Postoperative glucose control directly affects the incidence of deep sternal wound infection and death after patients with diabetes have undergone coronary artery bypass grafting. We compared the effect upon glucose control of continuous insulin infusion with that of glucometer-guided insulin injection after coronary artery bypass. Our prospective, randomized, controlled study involved patients with diabetes mellitus who underwent coronary artery bypass grafting in our hospital from January 2001 through January 2003. Immediately after surgery, patients were randomly assigned to receive continuous insulin infusion or conventional glucometer-guided injection to maintain blood glucose at a level between 150 and 200 mg/dL. The adequacy of postoperative blood glucose control and clinical outcome were evaluated.Of 93 patients studied, the incidence of sternal wound infection was 3.9% among infusion patients and 4.8% among injection patients (P=0.587). There was no significant difference in mortality rates (infusion, 3.9%; injection, 2.4%; P=0.573). Satisfactory blood glucose levels were achieved in significantly more patients undergoing infusion than injection (64.7% vs 28.6%, P <0.001). In the injection group, significantly more blood glucose measurements were required to achieve control (23.4 vs 16.5, P=0.001), and good control was attained much sooner in the infusion group (21.4 vs 30.5 hr, P=0.013). We conclude that continuous insulin infusion provides better control of postoperative blood glucose levels after coronary artery bypass grafting in patients with diabetes than does glucometer-guided insulin injection.