Coronary artery bypass surgery in patients on chronic hemodialysis. A case-control study

STUDY OBJECTIVE: To determine the morbidity and mortality of cardiac catheterization and coronary artery bypass surgery in patients on chronic hemodialysis. DESIGN: Retrospective case-control study. SETTING: A referral-based university hospital. PATIENTS: Sixteen consecutive patients on chronic hemodialysis who had catheterization and bypass surgery: 30 controls matched for age, sex, year of operation, severity of coronary disease, left ventricular function, hypertension, diabetes, and urgency of surgery: and 34 consecutive controls having bypass surgery. MEASUREMENTS AND MAIN RESULTS: No major complications of catheterization occurred. Of 16 patients on dialysis, 7 had urgent surgery within 24 hours of catheterization. One patient on dialysis and 3 consecutive controls died, but none of the matched controls died. Postoperative morbidity was increased in the hemodialysis group as measured by the duration of mechanical ventilation (4.7 +/- 2.3 compared with 1.5 +/- 0.8 days in matched controls [mean +/- SE]), the duration of hemodynamic support (4.2 +/- 2.3 compared with 0.8 +/- 0.2 days), the length of stay in the intensive care unit (6.4 +/- 2.4 compared with 2.8 +/- 0.9 days), and the length of postoperative stay in the hospital (15.4 +/- 2.1 compared with 10.8 +/- 1.1 days) (all P less than 0.05). Four intraoperative myocardial infarctions occurred in patients on dialysis compared with two patients in the case-matched controls. Differences in morbidity between the two control groups were not significant. CONCLUSIONS: Morbidity is increased in patients on hemodialysis having coronary artery bypass surgery compared with controls matched for severity of coronary disease; however, the outcome in all but one patient on dialysis was good. Bypass surgery is an acceptable treatment for patients on dialysis with advanced coronary artery disease. Because urgent surgery is often needed in these patients, earlier evaluation of the need for revascularization may improve clinical results.     

The influence of cardiopulmonary bypass flow characteristics on the clinical outcome of 1820 coronary bypass patients

OBJECTIVE: To determine whether pulsatile perfusion is clinically beneficial for adult cardiac operations. METHODS: Data concerning consecutive patients undergoing isolated coronary bypass surgery (n=1820) from January 1, 1997 to July 31, 1999 were reviewed. RESULTS: Nine hundred fifteen patients received pulsatile perfusion (PP) while perfusion in the remaining 905 patients was nonpulsatile (NP). Patients in the PP group were older (64.0 +/- 9.2 years versus 63.1 +/- 9.9 years) and experienced more of the following: urgent operations (42.4% versus 38.0%), preoperative intra-aortic balloon pump (4.8% versus 1.8%), preoperative cerebrovascular accidents (CVA; 3.1% versus 1.3%) and renal insufficiency (10.5% versus 7.0%). The PP group had higher incidence of early postoperative mortality (2.6% versus 1.5%), CVA (3.1% versus 1.3%), need for dialysis (3.2% versus 2.2%) and longer hospital stay (9.2 +/- 8.3 days versus 8.5 +/- 5.8 days). The incidence of postoperative myocardial infarction and renal dysfunction was similar in both groups (2.0% versus 2.2% and 3.3% versus 3.9% respectively; not significant). Because of the significant difference in preoperative parameters for the PP and NP groups, the following three statistical techniques were used to isolate the effect of perfusion characteristics on operative outcome: multiple regression, propensity score and risk stratification. Multivariate analysis did not find PP to be protective against mortality, morbidity and mortality, and CVA or for the development of postoperative renal dysfunction. When propensity score analysis was applied, the incidence of cardiac morbidity and mortality was strongly associated with the quintile (first quintile 6.7%, fifth quintile 27.0%, P<0.001). Multivariate analysis including quintiles did not find PP to be an independent predictor for mortality or for morbidity and mortality. Risk stratification was performed for age and for preoperative creatinine clearance levels. In all groups, PP did not seem to reduce the incidence of morbidity, morbidity and mortality, or the development of postoperative renal dysfunction. In patients with preoperative renal dysfunction, mean postoperative creatinine levels and the need for dialysis following surgery were similar in the PP and NP groups. CONCLUSION: Pulsatile flow does not appear to offer any clinical benefit over nonpulsatile flow for cardiac surgery patients.     

Renal protection for coronary angiography in advanced renal failure patients by prophylactic hemodialysis. A randomized controlled trial.

OBJECTIVES: We performed a study to determine whether prophylactic hemodialysis reduces contrast nephropathy (CN) after coronary angiography in advanced renal failure patients. BACKGROUND: Pre-existing renal failure is the greatest risk factor for CN. Hemodialysis can effectively remove contrast media, but its effect upon preventing CN is still uncertain. METHODS: Eighty-two patients with chronic renal failure, referred for coronary angiography, were assigned randomly to receive either normal saline intravenously and prophylactic hemodialysis (dialysis group; n = 42) or fluid supplement only (control group; n = 40). RESULTS: Prophylactic hemodialysis lessened the decrease in creatinine clearance within 72 h in the dialysis group (0.4 +/- 0.9 ml/min/1.73 m(2) vs. 2.2 +/- 2.8 ml/min/1.73 m(2); p < 0.001). Compared with the dialysis group, the serum creatinine concentrations in the control group were significantly higher at day 4 (6.3 +/- 2.3 mg/dl vs. 5.1 +/- 1.3 mg/dl; p = 0.010) and at peak level (6.7 +/- 2.7 mg/dl vs. 5.3 +/- 1.5 mg/dl; p = 0.005). Temporary renal replacement therapy was required in 35% of the control patients and in 2% of the dialysis group (p < 0.001). Thirteen percent of the control patients, but none of the dialysis patients, required long-term dialysis after discharge (p = 0.018). For the patients not requiring chronic dialysis, 13 patients in the control group (37%) and 2 in the dialysis group (5%) had an increase in serum creatinine concentration at discharge of more than 1 mg/dl from baseline (p < 0.001). CONCLUSIONS: Prophylactic hemodialysis is effective in improving renal outcome in chronic renal failure patients undergoing coronary angiography.     

Coronary artery bypass grafting in patients with dialysis-dependent renal failure

Myocardial infarction and other cardiovascular events constitute the leading causes of death in dialysis-dependent, end-stage renal disease patients. Due to growth in the elderly population, the number of uremic patients who need surgical revascularization is likely to increase. Whether or not coronary artery bypass grafting is safe for patients on long-term dialysis remains a great concern. We retrospectively reviewed all cases of elective or urgent isolated coronary artery bypass grafting in our hospital, from 1 January 1998 through 31 March 2003, and identified 23 consecutive patients with dialysis-dependent renal disease (Group D). Twenty-two of them were on hemodialysis, and 1 was on peritoneal dialysis; the mean duration of dialysis was 19.2 +/- 22.5 months. We chose 69 matched non-dialysis patients who underwent bypass grafting in 2001 to serve as our control group (ND). Preoperative, operative, and postoperative data on these patients were compared. Group D consisted of 14 men and 9 women with a mean age of 63.8 +/- 9.9 years, and the mean number of distal anastomoses was 3.5 +/- 1.2. There were no significant differences between the 2 groups in preoperative factors, intubation time, intensive care unit stay, major complications, and 30-day mortality. However, uremic patients had a greater tendency to bleed, longer postoperative hospital stays, and more late deaths. We conclude that under a well-prepared dialysis program and meticulous perioperative management, coronary artery bypass grafting can be performed in dialysis-dependent patients, with increased but acceptable perioperative morbidity and mortality risks.     

Leukodepletion improves renal function in patients with renal dysfunction undergoing on-pump coronary bypass surgery: a prospective randomized study

BACKGROUND: We aimed to show the impact of leukodepletion on renal function in patients undergoing on-pump coronary revascularization. PATIENTS AND METHODS: Fifty patients awaiting elective on-pump coronary revascularization with normal preoperative cardiac functions and with plasma creatinine levels ranging between 1.5 and 2.0 mg/dL were prospectively randomized into two groups: on-pump CABG with (group A: n = 25) and without leukodepletion (group B, n = 25). Renal glomerular and tubular injury were assessed by urinary alpha glutathione s-transferase (GST), plasma creatinine, and blood urea nitrogen (BUN) levels. RESULTS: The patients consisted of 14 females and 36 males with a mean age of 57.6 +/- 5.3 years. In the leukodepletion group, the mean levels of creatinine, BUN and urinary GST were found to be decreased on the first, third and fifth postoperative days compared with the control group. There was no mortality. Three patients in the control group needed postoperative dialysis. CONCLUSION: Patients with renal dysfunction undergoing on-pump CABG surgery seem to benefit from leukodepletion as a measure to prevent tubular damage and renal impairment compared with a control group.     

Renal outcome following on- and off-pump coronary artery bypass graft surgery

A prospective study was carried out to compare the outcomes of patients with preexisting non-dialysis-dependent renal dysfunction who underwent coronary artery bypass grafting with or without cardiopulmonary bypass. Elective off-pump coronary artery bypass was performed in 29 patients with renal dysfunction. Their results were compared with those of a similar group of 35 patients who underwent the conventional on-pump coronary artery grafting. There was a significant deterioration in creatinine clearance in the on-pump group on days 1, 2, and 4 after surgery, while creatinine clearance in the off-pump group remained close to the baseline level. Both groups had improved to the preoperative creatinine clearance values on follow-up at 4 weeks. It was concluded that off-pump surgery provided better renal protection than the conventional on-pump technique in patients with preexisting non-dialysis-dependent renal dysfunction.     

Perioperative advantages of off-pump coronary artery bypass grafting.

For the first time in Japan, off-pump coronary artery bypass grafting (OPCAB) was compared with the conventional on-pump technique, retrospectively examining the morbidity associated with coronary artery bypass grafting (CABG) and assessing the efficacy of OPCAB. In 2000, 158 patients underwent CABG: 95 patients (60%) had OPCAB (Group I) and 63 patients (40%) had conventional CABG (Group II). The operating time, length of intensive care unit (ICU) stay, ventilation time, postoperative bleeding, transfusion, postoperative renal function, occurrence of stroke, and early graft patency were examined in both groups. There were no hospital deaths in either group. The operating time, ICU stay, and ventilation time were significantly (p < 0.0001, p = 0.013, and p < 0.0001, respectively) shorter in Group I (351 +/- 85 min, 3.0 +/- 1.4 days, and 5.1 +/- 2.8h) than in Group II (449 +/- 112 min, 3.6 +/- 1.8 days, and 13.7 +/- 18.0 h). The postoperative blood loss within 12h and the transfusion volume were significantly (p = 0.0004 and p < 0.0001, respectively) smaller in Group I (480 +/- 210 ml and 300 +/- 490ml) than in Group II (720 +/- 430ml and 1,230 +/- 1,180 ml). Peak serum blood urea nitrogen and creatinine concentrations (excluding patients with preoperative chronic renal failure, ie a preoperative serum creatinine > 1.5 mg/dl) were significantly (p < 0.0001 and p < 0.0001, respectively) lower in Group I (16.2 +/- 15.2mg/dl and 0.81 +/- 0.72 mg/dl) than in Group II (19.2 +/- 7.6 mg/dl and 0.92 +/- 0.28 mg/dl). There were no perioperative strokes in Group I, but 6.4% of Group II patients suffered a stroke. There was no significant difference in graft patency between the groups (95.6% vs 94.9%). OPCAB reduced the mortality and morbidity of coronary revascularization, with a shorter operating time and more rapid recovery from surgery.     

体外循环与非体外循环下行CABG对肾功能不全患者肾功能影响的比较

目的:比较在体外循环与非体外循环下行冠状动脉旁路移植术（CABG）对患者肾功能的影响。方法: 我院40位择期行CABG的慢性肾功能不全患者,随机分为两组,每组20例,分别在在体外循环与非体外循环下行CABG。术前及术后1、3、7 d测定血肌酐值并计算肌酐清除率。结果: 体外循环组患者术后血肌酐值显著高于非体外循环组,其肌酐清除率较术前显著下降。结论:肾功能不全患者在体外循环与非体外循环下行CABG,前者更易加重肾功能损害。     

Cardiac surgery in patients on chronic hemodialysis: short and long-term survival

OBJECTIVE: Open-heart surgery carries a high risk for hemodialysis patients. This study focuses on the short and long-term outcomes of hemodialysis patients undergoing heart surgery. DESIGN: The study was carried out as a retrospective analysis in the Department of Cardiothoracic Surgery in a large university-affiliated hospital. PATIENTS: 115 hemodialysis patients underwent cardiac surgery in our department between 1 July 1996 and 31 July 2006. 67.5 % (77 patients) underwent isolated coronary artery bypass grafting (CABG), 13.2 % (15 patients) underwent isolated aortic valve replacement (AVR) and 20.2 % (23 patients) underwent mitral valve surgery or combined valve and coronary artery bypass grafting or multiple valve surgery. METHODS: The relationship between several variables (age, sex, hypertension, diabetes, and previous myocardial infarction, type of disease, preoperative ejection fraction, and congestive heart failure) and operative (30 days) mortality and late survival was analyzed. RESULTS: The overall 30-day mortality was 18.3 % (21 patients). It was 13 % (10/77 patients) for the isolated CABG group and 13.3 % (2/15) for the isolated AVR group. Patients undergoing combined valve and coronary surgery or multiple valve surgery had a higher perioperative mortality of 39.1 % (9/23) compared to the isolated CABG and isolated AVR patients. Perioperative death was also higher in patients with moderate and severe LV dysfunction, and in patients with diabetes. The duration of dialysis periods was not related to perioperative death. Mean follow-up was 26.4 +/- 29.7 months (0.1 to 104 months). Actuarial survival at 1 year and 5 years was 76 % and 55 % for isolated CABG, 59 % and 21 % for isolated AVR, and 44 % and 33 % for all other cases, respectively (log rank P = 0.001). CONCLUSION: Patients on dialysis have a high risk of perioperative mortality and poor long-term survival rates. Mortality is higher and survival is worse after combined CABG and valve-related procedures or multiple valve surgery than after isolated CABG and AVR.     

The prognostic implications of further renal function deterioration within 48 h of interventional coronary procedures in patients with pre-existent chronic renal insufficiency

BACKGROUND: Acute deterioration in renal function is a recognized complication after coronary angiography and intervention. OBJECTIVES: The goal of this study was to determine the impact on acute and long-term mortality and morbidity of contrast-induced deterioration in renal function after coronary intervention. METHODS: We studied 439 consecutive patients who had a baseline serum creatinine > or = 1.8 mg/dL (159.1 /micromol/L) who were not on dialysis who underwent percutaneous coronary intervention in a tertiary referral center. All patients were hydrated before the procedure, and almost all received ioxaglate meglumine; 161 (37%) patients had an increase in serum creatinine > or = 25% within 48 h or required dialysis and 278 (63%) did not. In-hospital and out-of-hospital clinical events (death, myocardial infarction, repeat revascularization) were assessed by source documentation. RESULTS: Independent predictors of renal function deterioration were left ventricular ejection fraction (p = 0.02) and contrast volume (p = 0.01). In-hospital mortality was 14.9% for patients with further renal function deterioration versus 4.9% for patients with no creatinine increase (p = 0.001); other complications were also more frequent. Thirty-one patients required hemodialysis; their in-hospital mortality was 22.6%. Four patients were discharged on chronic dialysis. The cumulative one-year mortality was 45.2% for those who required dialysis, 35.4% for those who did not require dialysis and 19.4% for patients with no creatinine increase (p = 0.001). Independent predictors of one-year mortality were creatinine elevation (p = 0.0001), age (p = 0.03) and vein graft lesion location (p = 0.08). CONCLUSIONS: For patients with pre-existing renal insufficiency, renal function deterioration after coronary intervention is a marker for poor outcomes. This is especially true for patients who require dialysis.     

Effects of statins on renal function after aortic cross clamping during major vascular surgery

Ischemic reperfusion injury is an important cause of renal dysfunction after major vascular surgery and increases postoperative morbidity and mortality. The aim of the present study was to assess the effect of statins on renal function in patients at high risk for renal dysfunction, that is, those who underwent suprarenal aortic cross clamping-declamping. Seventy-seven patients (28 statin users, 57 men; mean age 69 +/- 8 years) with normal preoperative renal function requiring suprarenal aortic cross clamping-declamping during vascular surgery from 1995 to 2005 were studied. Creatinine levels were obtained before surgery and on days 1, 2, 3, 7, and 30 after surgery. An analysis-of-variance model for repeated measurements was applied to compare creatinine levels between statin users and nonusers, with adjustment for clamping time and blood loss. There were no differences in baseline clinical characteristics, preoperative creatinine levels (0.93 vs 0.96 mg/dl, p = 0.59), and glomerular filtration rate (79 vs 73 ml/min, p = 0.1). Postoperative creatinine levels during the 30 days after surgery were significantly lower in statin users than in nonusers (analysis-of-variance p <0.01, 1.17 vs 1.98 mg/dl). Postoperative hemodialysis was required (temporarily) in 7 patients (9.1%), all statin nonusers. These findings suggest an association between statin use and preserved renal function after suprarenal aortic clamping.     

Coronary surgery in dialysis-dependent patients with end stage renal failure

The number of patients with dialysis-dependent end stage renal failure (ESRF) and coronary heart disease (CAD) has increased in recent years. Coronary artery bypass grafting (CABG) has become the standard treatment for CAD in this patient group, but is still considered as a risk procedure due to increased mortality and morbidity. In a retrospective study we analyzed our clinical results of isolated CABG in 40 dialysis-dependent patients with ESRF (5 female and 35 male, mean age 65+/-8.4 years) and the use of extracorporeal circulation. The perioperative control group comprised 51 patients (10 female and 41 male, mean age 67+/-7.3 years) with normal renal function and isolated CABG. Demographic and preoperative data were comparable in both groups. Hospital mortality was 2.5% in patients with ESRF and 0% in patients with normal renal function. Morbidity was comparable in both groups. The mean number of grafts was 3.1+/-0.9 in the dialysis group and 2.9+/-0.8 in the control group. In the follow-up of the dialysis group (34+/-23 months) 8 patients died. CABG in patients with dialysis-dependent ESRF can be performed with good clinical results and morbidity comparable to patients with normal renal function.     

Large and small artery compliance changes during hemodialysis

BACKGROUND: Cardiovascular disease is the major cause of mortality and morbidity in patients undergoing hemodialysis. Reduced arterial compliance is an independent predictor of cardiovascular mortality in end stage renal disease and can be measured noninvasively using pulse wave analysis technology. METHODS: Ten chronic hemodialysis patients were evaluated using pulse wave analysis to determine large and small vessel compliance before hemodialysis, midway through the treatment, and at the end of the treatment. Serum calcium was measured before and after hemodialysis. RESULTS: No significant changes in systolic blood pressure (BP), diastolic BP, pulse pressure, or heart rate occurred during hemodialysis. A significant decrease in small vessel compliance (C2) occurred during the treatment, with the mean C2 decreasing from 5.6 +/- 2.7 mL/mm Hg x 10 predialysis to 3.3 +/- 1.5 mL/mm Hg x 10 midway through the treatment (P = .04) and to 3.9 +/- 4.3 mL/mm Hg x 10 at the end of the dialysis treatment. There was no significant change in large vessel compliance (C1). Serum calcium increased significantly during the dialysis treatment from 8.0 +/- 1.2 mg/dL to 9.8 +/- 0.9 mg/dL (P = .003). CONCLUSIONS: Significant decreases in small artery compliance occur without systolic or diastolic BP changes during routine hemodialysis. A significant increase in serum calcium also occurred during hemodialysis. Measurements of arterial compliance during hemodialysis may be an important tool to identify patients with vascular responses, which may place them at greater risk for cardiovascular disease.     

Impact of preoperative renal dysfunction on cardiac surgery results

Results of cardiac surgery were analyzed using a database that included plasma creatinine levels in 2,214 patients, of whom 507 had preoperative renal dysfunction (creatinine clearance < 0.9 mL x s(-1) x m(-2)). Logistic regression and propensity score analyses found preoperative renal dysfunction to be an independent predictor of morbidity and mortality. Plotting preoperative creatinine clearance against morbidity and mortality revealed an exponential increase in morbidity and mortality when preoperative creatinine clearance was < 0.84 mL x s(-1) x m(-2). Patients were stratified for age, operative procedure, and comorbidity. In all stratified groups, preoperative creatinine clearance < 0.84 mL x s(-1) x m(-2) was associated with similar exponential increases in morbidity and mortality. In patients with preoperative renal dysfunction, elevated plasma creatinine levels persevered for 6 months postoperatively. Dialysis beyond postoperative day 10 was required in < 2% of patients with preoperative plasma creatinine of 160-200 micro mol x L(-1) and in 5% in those with creatinine > 200 micro mol x L(-1) (p < 0.05). Actuarial survival was significantly reduced (< 90% at 18 months postoperatively) in patients with preoperative renal dysfunction.     

An analysis of the association between preoperative renal dysfunction and outcome in cardiac surgery: estimated creatinine clearance or plasma creatinine level as measures of renal function

STUDY OBJECTIVES: Preoperative renal dysfunction is a risk factor for adverse events in cardiac surgery. This study compared creatinine clearance (ClCr), estimated from the Cockroft and Gault formula, and plasma creatinine level as predictors of outcome after cardiac surgery. DESIGN: Prospective, observational. SETTING: University hospital. PATIENTS: A total of 6,364 cardiac surgical patients. METHODS: The measured outcomes were postoperative renal failure requiring dialysis, and mortality and major morbidity. For each outcome, two multivariable risk models were developed, using either estimated ClCr as a measure of renal function, or plasma creatinine level. Risk-adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated for each outcome. Discrimination was compared using receiver operating characteristic (ROC) curves. RESULTS: For each 10 mL/min/1.73 m(2) decrement of estimated ClCr, the ORs for renal failure requiring dialysis, mortality, and major morbidity in the whole population were 1.52 (95% CI, 1.35 to 1.67), 1.27 (95% CI, 1.19 to 1.35), and 1.18 (95% CI, 1.14 to 1.21), respectively; for each 0.2 mg/dL increment of plasma creatinine, ORs were 1.20 (95% CI, 1.15 to 1.26), 1.08 (95% CI, 1.04 to 1.13), and 1.12 (95% CI, 1.09 to 1.15), respectively. The areas under the ROC curves for prediction of renal failure requiring dialysis were 0.83 with both risk models. For prediction of mortality and major morbidity, areas under the ROC curves were 0.83 and 0.72, respectively, with the models using estimated ClCr, and 0.74 and 0.65, respectively, with the models using plasma creatinine level (p < 0.001 vs estimated ClCr for both outcomes). In patients with normal plasma creatinine levels (n = 4,603), estimated ClCr remained a significant predictor of each outcome with similar ORs, but plasma creatinine level was not a predictor of any outcome. CONCLUSION: The risk-adjusted association between preoperative renal dysfunction and adverse events after cardiac surgery is stronger with estimated ClCr than with plasma creatinine level, particularly in patients with normal plasma creatinine levels. The routine preoperative estimation of ClCr may improve the identification of higher-risk cardiac surgical patients.     

Off-pump revascularization for significant left ventricular dysfunction

Left ventricular dysfunction is a predictor of perioperative morbidity and mortality in on-pump coronary artery bypass grafting. Obligatory global myocardial ischemia and injury induced during crossclamping as well as adverse systemic effects of cardiopulmonary bypass may induce a disproportionately greater overall physiologic insult in patients with poor ventricular function. All patients undergoing nonemergency off-pump coronary artery bypass by a single surgeon during an 18-month period were retrospectively analyzed. Two groups with preoperative ejection fraction classified as poor (10%-35%; n = 31) or normal (55%-80%; n = 60) were compared. The mean ejection fractions were 26% +/- 1% and 63% +/- 1% respectively, p < 0.000001. In those with significant left ventricular dysfunction, there were 2.8 +/- 0.1 grafts per patient, time to extubation was 8.4 +/- 1.2 hours, and discharge was after 4.9 +/- 0.6 days. These results were statistically equivalent to those in the group with normal left ventricular function. There was no intraaortic balloon pump insertion or mortality in either group. This technique provides an effective means of safely revascularizing patients with significant left ventricular dysfunction, and it may provide a valuable alternative approach in patients with ischemic cardiomyopathy.     

Emergency coronary artery bypass surgery preserves global and regional left ventricular function after intravenous tissue plasminogen activator therapy for acute myocardial infarction

Emergency coronary bypass surgery was performed in 24 (6.2%) of 386 consecutive patients enrolled in the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) Multicenter Trial. Intravenous tissue plasminogen activator was administered 2.6 +/- 0.7 h and bypass surgery was performed 7.3 +/- 1.9 h after the onset of infarction. Infarct artery patency was achieved in 21 (88%) of the 24 patients (pharmacologically in 18 or mechanically with coronary angioplasty in 3) in the catheterization laboratory before bypass surgery. The indication for surgery was left main or equivalent coronary artery disease in 7 patients, coronary anatomy unsuitable for angioplasty in 4 patients and unsuccessful coronary angioplasty in 13 patients. A coronary perfusion catheter was inserted before surgery in 11 of 13 patients with unsuccessful angioplasty. All three deaths occurred postoperatively in patients with preoperative cardiogenic shock. Three patients required surgical reexploration for postoperative hemorrhage. Comparison of preoperative and predischarge contrast left ventriculograms demonstrated significant preservation of global (left ventricular ejection fraction 49 +/- 6 to 56 +/- 6%; p = 0.008) and regional (standard deviation/chord -2.6 +/- 0.5 to -1.5 +/- 1.1; p = 0.001) left ventricular function. Emergency coronary bypass surgery can be performed with a low morbidity and mortality in patients treated with intravenous tissue plasminogen activator therapy for acute myocardial infarction. Such therapy is associated with significant preservation of global and regional (infarct zone) left ventricular function.     

Intra-aortic balloon pump use does not affect the renal function in patients undergoing off pump coronary artery bypass surgery

Renal dysfunction is known to occur during cardiac surgery. A few factors such as perioperative hypotension, use of potential nephrotoxic therapeutic agents, radio opaque contrast media in the recent past, intra-aortic balloon pump (IABP) and cardiopulmonary bypass have been blamed as the contributing factors to the causation of postoperative renal dysfunction in cardiac surgical patients. At times, in patients with renal failure and low cardiac output status, one may face the dilemma if the use of IABP is safe. We undertook this prospective observational study to determine the degree of possible renal injury when IABP is used by measuring serial values of serum creatinine and Cystatin C. Elective patients scheduled for off-pump coronary artery bypass surgery requiring preoperative use of IABP were included in this study. Cystatin C and serum creatinine levels were checked at fixed intervals after institution of IABP. Twenty-two patients were eligible for enrolment to the study. There was no significant change in the values of serum creatinine; from the basal value of 1.10 ± 0.233 to 0.98 ± 0.363 mg /dL (P value >0.05). Cystatin C levels significantly decreased from the basal level of 0.98 ± 0.29 to 0.89 ± 0.23 (P value <0.05). Contrary to the belief, Cystatin C, the early indicator of renal dysfunction decreases suggesting absence of renal injury after the use of IABP. Absence of elevation of cystatin C levels in our study suggests the lack of potential of the IABP to cause renal dysfunction in patients who received elective IABP therapy preoperatively.     

Predictors of prolonged mechanical ventilation after on-pump coronary artery bypass grafting

The predictors of prolonged mechanical ventilation and subsequent morbidity after cardiac surgery are ill defined. Our aim was to evaluate them. Four hundred and seventy consecutive patients undergoing coronary artery bypass grafting on cardiopulmonary bypass (CPB) between January and June 2002 were retrospectively analysed for preoperative predictors of prolonged ventilation, which included age, gender, ejection fraction (EF), renal function, diabetes, angina status, severity of the disease (New York Heart Association class), number of vessels diseased and chronic lung disease. Intraoperative variables such as prolonged CPB, aortic cross clamp time, intra-aortic balloon pump (IABP) usage, inotropes and postoperative variables like temperature on arrival at intensive care unit(ICU), IABP usage, organ dysfunction, inotropes and reintervention (reintubation and re-exploration) were also analysed. Prolonged ventilation was defined as > or = 24 hours and these patients were included in group I (n=22). Patients requiring less than 24 hours ventilation (n=448) were included in group II. Stepwise logistic regression analysis was performed. The average age of patients was 56.9 +/- 8.8 years with male predominance (88.4%). The overall perioperative mortality was 2.1% (10 patients) with Group I showing mortality rate of 36.3% (8 patients). In multivariate analysis, predictors of prolonged ventilation were found to be EF <40% (odds ratio, (OR) 13.38), preoperative renal dysfunction [OR 4.06 (serum creatinine > 1.2 mg%)], prolonged CPB, > 120 min (OR 9.6) and reintervention in the form of re-exploration or reintubation in the ICU (OR 13.8). Identification of perioperative variables, which may lead to prolonged ventilation may allow the development of strategies to optimize the patient's condition and ICU management.     

Favorable early and long-term prognosis following coronary bypass surgery therapy for myocardial infarction: results of a multicenter trial. TAMI Study Group

Coronary bypass surgery was performed before hospital discharge on 82 (21%) of 386 consecutive patients enrolled in the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) multicenter trial of intravenous tissue plasminogen activator and coronary angioplasty for acute myocardial infarction. Time from infarct symptom onset to coronary bypass surgery was 7.3 +/- 1.9 hours for 24 patients operated upon on an emergency basis and 9.3 +/- 5.2 days for 58 patients having late in-hospital surgery. There were no operative deaths and five in-hospital deaths in the surgical group, all of which occurred in patients with preoperative cardiogenic shock. Although patients in the surgical group were older (59.7 +/- 10.4 years versus 54.9 +/- 10.2 years; p = 0.03), had more extensive coronary artery disease (42% three-vessel disease versus 11%; p = 0.001), and had a higher incidence of anterior wall myocardial infarction (48% versus 39%; p = 0.02), in-hospital mortality for the surgical group (6%) was similar to that in 301 patients not undergoing surgery (7%) in this trial. For patients discharged from the hospital, mortality at 1 year was 2.5% in the surgical group and 1.8% in patients not having coronary bypass surgery before hospital discharge. At a 1 year follow-up, there were no significant differences in the frequency of cardiac or noncardiac-related hospitalizations or in event-free survival between surgical and nonsurgical groups. The majority of patients in both groups considered themselves to be in excellent or good condition. Coronary bypass surgery can be performed with low morbidity and mortality rates in close temporal association to acute myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)