Initial Coronary Artery Bypass Grafting Research Articles

Relationship between Haemoglobin A1C Values and Recurrent Cardiac Events

This study set out to analyse the impact of baseline glycosylated haemoglobin A1c (HbA1c) values on the incidence of recurrent cardiac events in patients prescribed optimal secondary prevention medications and receiving aggressive cardiac risk factor management. This was a retrospective study conducted at Kaiser Permanente Colorado and included adults followed by a clinical pharmacy specialist-managed cardiac risk service (CPCRS) with an incident cardiac event and an HbA1c value measured within 1 year prior or 60 days after the incident cardiac event was identified. Cox proportional hazards models were constructed to assess the relationship between HbA1c levels and recurrent cardiac events (assessed as continuous and categorical measures) after adjustment for potential confounding variables. Of 5663 patients identified within an incident cardiac event between January 1999 and March 2005, 1270 (22.4%) patients had a baseline HbA1c value recorded. Of these 1270 patients, 215 (16.9%) had a recurrent cardiac event. Compared with the 'no recurrent event' cohort, the 'recurrent event' cohort were younger, less likely to have undergone an initial coronary artery bypass graft, and more likely to have undergone percutaneous coronary intervention with or without stent. The recurrent event cohort was also less likely to have purchased an HMG-CoA reductase inhibitor ('statin') [p = 0.043] at the time of the incident cardiac event. There was no significant difference in mean baseline HbA1c value between the cohorts. There were also no significant differences between the cohorts when categorized by baseline HbA1c <7% as referent compared with > or =7% to <8%, > or =8% to <9%, > or =9 to <10%, and > or =10%. Moreover, there was no significant difference between cohorts when HbA1c values <7% were compared with values >7% in the unadjusted analysis. Results remained non-significant after adjustment for sex, incident cardiac event type, baseline age, ss-blocker use, statin use and hyperlipidaemia. The results of this study suggest that an abnormal HbA1c is not predictive of recurrent cardiac events among patients with cardiovascular disease when other cardiovascular risk factors are being aggressively treated and appropriate secondary prevention medications are being taken. However, larger studies are warranted to validate these findings.

Clinical and Angiographic Correlates of Short- and Long-Term Mortality in Patients Undergoing Coronary Artery Bypass Grafting

Differences in the clinical and angiographic factors associated with short- and long-term outcomes in patients undergoing coronary artery bypass grafting (CABG) are less known. Accordingly, differences were examined in clinical and angiographic correlates of short- and long-term mortality after CABG in 8,229 patients undergoing initial CABG enrolled in the Duke Cardiovascular Disease Database (1995 to 2002). Logistic regression and Cox proportional hazard modeling were performed to determine independent correlates of 30-day and long-term mortality. Death occurred in 2.4% at 30 days and 17.6% beyond 30 days at a median follow-up of 6 years in patients who underwent CABG. Multivariable models identified older age, lower left ventricular ejection fraction, lower or higher body mass index, cerebrovascular disease, lack of internal mammary artery use, and lower cholesterol to be associated with increased risk of both events. Although hemodynamic status (preoperative myocardial infarction, New York Heart Association class, and cardiogenic shock), female gender, and minority race were associated with 30-day death; co-morbid conditions (serum creatinine, chronic lung disease, diabetes, previous heart failure, peripheral vascular disease, and left main disease) were associated with increased long-term (beyond 30 days) death (c indexes 0.76 and 0.79 for the short- and long-term mortality models, respectively). In conclusion, our study suggested that correlates of acute and long-term death were different in patients undergoing CABG. These differences should be kept in context when counseling patients undergoing CABG and may help facilitate targeted strategies to improve short- and long-term mortality risks after CABG.

Right Gastroepiploic Artery Grafting for Saphenous Vein Graft Pseudoaneurysm

Saphenous vein graft pseudoaneurysms are an unusual but potentially fatal complication of coronary artery bypass grafting because of their high risk of rupture or thromboembolism. We experienced the case of a 58-year-old man with a saphenous vein graft pseudoaneurysm with a floating thrombus that had developed 17 years after the initial coronary artery bypass grafting. The prevention of thromboembolism during a surgical procedure has been crucial for this type of operation. We developed the idea of in situ revascularization using the right gastroepiploic artery under the beating heart on cardiopulmonary bypass followed by an aneurysmectomy under an arrested heart.

The PRoject of Ex-vivo Vein graft ENgineering via Transfection IV (PREVENT IV) trial: Study rationale, design, and baseline patient characteristics

Coronary artery bypass graft (CABG) surgery with autologous vein graft (VG) conduit is one of the most frequently performed operations in the United States. Unfortunately, many VGs become occluded during long-term follow-up largely because of neointimal hyperplasia. A novel approach to preventing neointimal hyperplasia is with the double-stranded oligonucleotide edifoligide (Corgentech Inc, South San Francisco, Calif). Edifoligide inhibits E2F, a transcription factor that activates cell-cycle genes responsible for neointimal hyperplasia. PREVENT IV is a phase-III, multicenter, randomized double-blind placebo-controlled trial of ex vivo treatment of autologous VGs with edifoligide in patients undergoing initial CABG surgery. The primary end point is VG failure, defined as death or > or =75% stenosis in a treated VG at 12- to 18-month angiographic follow-up. Secondary end points include major adverse cardiac events through at least 5 years and adverse events through 30 days. Enrollment of 3014 patients from 107 sites was completed on October 22, 2003. The baseline and procedural characteristics of the PREVENT IV population are generally well matched to a contemporary population of patients undergoing initial CABG from the Society of Thoracic Surgeons National Database. Angiographic follow-up is ongoing and scheduled to be completed in March 2005. The PREVENT IV data will establish whether VG pretreatment with an E2F transcription factor decoy, edifoligide, can improve graft patency and reduce the long-term morbidity and mortality of patients undergoing CABG surgery.

Improved Survival in Asymptomatic Diabetic Patients With High-Risk Spect Imaging Treated With Coronary Artery Bypass Grafting

The Bypass Angioplasty Revascularization Investigation trial demonstrated that symptomatic diabetics with multivessel coronary artery disease had a survival advantage with initial coronary artery bypass grafting (CABG) versus percutaneous coronary intervention (PCI). No published study has examined different treatments and outcome in asymptomatic diabetics. This study group consisted of 826 asymptomatic diabetics (age 62+/-12 years; 76% men) without known coronary artery disease who had abnormal myocardial perfusion during stress single photon emission computed tomography (SPECT). SPECT images were classified as low-, intermediate-, and high-risk. Early revascularization (CABG or PCI < or =4 months after SPECT) was performed in 76 patients. Survival (follow-up, 5.3+/-3.3 years) was compared in patients treated with CABG, PCI, or medical therapy. Revascularization (CABG or PCI) was performed in 54 of 261 patients with high-risk scans and was independently associated with improved survival (chi2=4.55; P=0.03 after multivariate adjustment). Subset analysis demonstrated that the survival advantage was confined to patients treated with CABG (n=39), with a 5-year survival CABG at 85%, PCI at 72%, and medical therapy at 67% (P=0.02 for 3 groups). Although CABG was associated with better survival, mortality remained high (3% per year). There was no survival advantage by treatment for patients with less-severe SPECT abnormalities. These nonrandomized data suggest that CABG improves survival in asymptomatic diabetic patients with high-risk SPECT, although revascularization was performed infrequently in these patients. These results parallel those of the Bypass Angioplasty Revascularization Investigation trial in symptomatic diabetic patients.

Left main stem coronary disease: the case for percutaneous coronary intervention in a high risk patient with complex disease

1 Current in-hospital mortality after initial coronary artery bypass graft surgery (CABG) in unprotected LMCA without myocardial infarction (MI) is 2.3% in highly experienced centres. 2 Therefore, the procedure has...

Three-Day Magnesium Administration Prevents Atrial Fibrillation After Coronary Artery Bypass Grafting

The efficacy of magnesium administration in preventing the occurrence of atrial fibrillation after coronary artery bypass grafting surgery remains controversial. Optimal dose and timing of the administration also await clarification. The purpose of this study was to assess the effect of 3-day postoperative infusion of magnesium on postoperative atrial fibrillation and to find factors that can influence the efficacy of this treatment. After institutional review board approval, a retrospective study was conducted reviewing 200 consecutive patients who underwent isolated, initial coronary artery bypass grafting operation. The first 100 patients did not receive the prophylactic treatment, whereas the next 100 patients were treated with magnesium postoperatively. Patients in the magnesium-treated group received 10 mmol (2.47 g) of magnesium sulfate (MgSO4 * 7H2O) infused daily for 3 days after surgery. The incidence of postoperative atrial fibrillation was 35% in the untreated group compared with 16% in the magnesium-treated group (p = 0.002). Multivariate logistic regression analysis revealed that advanced age, decreased left ventricular ejection fraction, and absence of magnesium therapy were independent predictors of postoperative atrial fibrillation. For patients receiving the magnesium therapy, advanced age and decreased ejection fraction were the independent factors that predicted the arrhythmia. Postoperative 3-day magnesium infusion is effective in reducing the incidence of atrial fibrillation occurring after coronary artery bypass grafting surgery. However, in older patients or in patients with reduced left ventricular function, magnesium treatment alone is insufficient for prophylaxis of postoperative atrial fibrillation.

Impact of mitral insufficiency on reoperative coronary artery surgery in ischemic cardiomyopathy patients?

To determine the impact of mitral insufficiency on survival after reoperative coronary artery bypass grafting (CABG) in ischemic cardiomyopathy patients. We retrospectively studied 891 (Initial 708, Redo 183) consecutive CABG patients (1993-2002) with ejection fraction (EF) 35% or less. mean age=67.0+/-10.5 yrs, men=77.1%, EF=26.4+/-7.4%, mean CCS=3.47+/-0.73, mean NYHA=3.50+/-0.68. There were 180 (Initial 141, Redo 39) patients with 3/4+mitral regurgitation (MR). Late survival statistics of cohorts were compiled using National Death Index. At a mean follow-up period of 3 years, reoperative CABG with MR (Redo/MR+) survival was 41.7+/-9.2% (n=39), which was worse than reoperative CABG without MR (Redo/MR-) survival of 71.8+/-4.1% (n=144, P=0.0003), initial CABG with MR (Initial/MR+) survival of 68.5+/-4.2% (n=141, P=0.014) and initial CABG without MR (Initial/MR-) survival of 76.2+/-2.0% (n=567, P<0.0001). By multivariate analysis, congestive heart failure (P=0.029), 3/4+MR (P=0.044) were independent predictors of Redo late mortality. In contrast, renal failure on dialysis, stroke, no angina, age >65 yrs, absence of hypercholesterolemia, EF<26% but not 3/4+MR were independent predictors of Initial late mortality. In subset analysis, adverse impact of 3/4+MR on late survival was greatest in Redo with EF<26%. The 3- and 5-yr late survival were only 44.4 and 26.8% (P=0.041). Concomitant mitral valve repair (MVrep) was performed in 100 (Initial 75, Redo 25) patients. MVrep in Initial/MR+patients achieved similar late survival as Initial/MR- patients. MVrep did not produce the same late survival benefit in Redo/MR+ patients. (1) Mitral insufficiency has a greater survival impact on redo than initial CABG patients with ischemic cardiomyopathy. (2) Mitral insufficiency and congestive heart failure are the primary independent predictors of late survival following redo CABG. (3) Mitral repair has less neutralizing effect on late survival in redo than initial CABG patients.

Comparison of quality of life after repeat versus initial coronary artery bypass grafting

One-year health status improvements in 62 patients with previous coronary artery bypass grafting (CABG) were compared with those of 628 patients undergoing initial CABG using the Seattle Angina Questionnaire (SAQ). Adjusted analyses revealed that repeat CABG conferred similar 1-year improvements in health status compared with patients undergoing a first CABG (changes in SAQ Physical Limitation score [SAQ-PL: repeat CABG 25 ± 27 vs first CABG 20 ± 27; p = 0.30], Quality of Life score [SAQ-QoL: 34 ± 24 vs 35 ± 5; p = 0.87], and Angina Frequency score (SAQ-AF: 35 ± 40 vs 25 ± 24; p = 0.03]).

Characteristics of Patients with Patent versus Closed Left Internal Thoracic Artery Grafts before Redo Revascularization

BACKGROUND: The aim of this study was to examine the impact of internal thoracic artery (ITA) graft patency on clinical course between initial and redo coronary artery bypass grafting (CABG). METHODS: 82 patients out of 553 redo CABG between 1990 and 1999 underwent ITA grafting to the left anterior descending artery (LAD) and vein grafting to other vessels at initial revascularization. At reoperation 54 patients (group I) showed a patent ITA, while 28 patients (group II) showed ITA occlusion. All patients underwent coronary angiography prior to initial and redo CABG. RESULTS: Absence of angina after initial CABG and time to redo operation was longer in group I (I vs. II: 5.1 ± 3.3 vs. 3.4 ± 3.6 years, p = 0.01; 6.0 ± 3.2 vs. 3.9 ± 3.6 years, p = 0.03; respectively). The incidence of myocardial infarction (MI) in the lateral/posterior myocardium was higher in group I (I vs. II: 38.9 % vs. 14.3 %; p = 0.021). MI rate of the anterior wall was comparable between both groups. Rate of interventional revascularization between operation was significantly lower in group I (I vs. I: 11.1 % vs. 32.1 %; p = 0.019). The rate of stenoses in the circumflex coronary artery (RCX) and the right coronary artery (RCA) increased significantly in group I compared to group II (p = 0.002 for RCX of 80–95 %; p = 0.034 for RCX > 95 %; p = 0.047 for RCA > 95 %). The number of occluded vein grafts to RCX and RCA was higher in group I (I vs. II: 48 % vs. 22 %, p = 0.028; 50 % vs. 17 %, p = 0.023; respectively). CONCLUSIONS: The angina-free interval after initial CABG between operations is longer in patients with patent ITA. However, the increase of lesions number in native vessels as well as in vein grafts is significantly higher in RCX and RCA systems in such patients due to a longer period between operations compared to patients with closed ITA. Hence, the risk for MI in the lateral/posterior myocardium in RCX/RCA territories is higher, which remains undetected in many cases because of sufficient perfusion of the anterior wall by patent ITA.

Management of mild to moderate aortic valve disease during coronary artery bypass grafting.

The long term survival of patients with mild to moderate aortic valve disease who do not have valve replacement at the time of coronary artery bypass grafting (CABG) is unknown. Therefore we have reviewed our experience with such patients. We reviewed the medical records of consecutive patients between June 1978 and December 1996, and identified 40 patients with mild to moderate aortic valve disease, who underwent CABG, without valve replacement (study group). Mean preoperative aortic gradient was 34 mmHg and mean intraoperative gradient 20 mmHg. Eleven patients underwent valve inspection, and an equal number, underwent valve repair. The records of 61 other patients with severe aortic valve disease, who underwent concomitant aortic valve replacement (AVR) and CABG (control group), were also reviewed. Survival was significantly better in the control group. Eleven patients (27.5%) in the study group underwent reoperation for AVR, with no operative mortality. Multivariate analysis confirmed valve replacement at initial CABG to be the only predictor of survival (beta=0.586,P=0.038) Preoperative gradient <40 mmHg, intraoperative gradient <20 mmHg, age over 70, sex, aortic stenosis and valve pathology did not predict survival in the study group. Patients with mild to moderate aortic valve disease undergoing coronary artery bypass grafting may be best served by valve replacement, rather than repair, inspection or no procedure.

Intravenous magnesium sulfate prophylaxis for atrial fibrillation after coronary artery bypass surgery

Objective: Atrial fibrillation is a rhythm disorder commonly seen early after coronary artery bypass grafting, and it increases morbidity. Methods: To investigate the effectiveness of magnesium sulfate in the prophylaxis of atrial fibrillation, we conducted a prospective, randomized, placebo-controlled clinical study on 200 consecutive patients in whom we performed elective and initial coronary artery bypass grafting operations. In each group 50% of patients underwent beating-heart operations. In the treatment group 100 patients (76 men and 24 women; mean age, 57.63 ± 9.68 years) received 24.34 mEq (3 g) of magnesium sulfate in 100 mL of saline solution that was administered over 2 hours (50 mL/h) preoperatively, perioperatively, and at postoperative days 0, 1, 2, and 3. In the control group 100 patients (74 men and 26 women; mean age, 59.96 ± 9.29 years) received only 100 mL of saline solution according to the same administration schedule as the treatment group. Results: Atrial fibrillation developed in 15 patients from the treatment group and in 16 patients from the control group. The arrhythmia developed after 37.87 ± 12.76 and 45.26 ± 15.27 hours in the treatment and control groups, respectively. Although a significant relationship was found between low magnesium sulfate levels and increased incidence of atrial fibrillation (P <.05), when the incidence of postoperative atrial fibrillation is concerned, no significant difference was found between the 2 groups (P >.05). Also, no significant difference was found between operations with cardiopulmonary bypass and beating-heart operations in terms of atrial fibrillation incidence (P >.05). However, atrial fibrillation extended the duration of hospital stay in both groups (P <.05). Conclusion: Our findings indicate that magnesium sulfate infusion alone is not sufficient for the prophylaxis of atrial fibrillation.J Thorac Cardiovasc Surg 2003;125:344-52

Relationship of extent of revascularization with angina at one year in the bypass angioplasty revascularization investigation (BARI)

OBJECTIVESTo determine the relative degree of revascularization obtained with bypass surgery versus angioplasty in a randomized trial of patients with multivessel disease requiring revascularization (Bypass Angioplasty Revascularization Investigation [BARI]), one-year catheterization was performed in 15% of patients.BACKGROUNDComplete revascularization has been correlated with improved outcome after coronary artery bypass grafting (CABG) but not with percutaneous transluminal coronary angioplasty (PTCA). Relative degrees of revascularization after PTCA and surgery have not been previously compared and correlated with symptoms.METHODSConsecutive patients at four BARI centers consented to recatheterization one year after revascularization. Myocardial jeopardy index (MJI), the percentage of myocardium jeopardized by ≥50% stenoses, was compared and correlated with angina status.RESULTSAngiography was completed in 270 of 362 consecutive patients (75%) after initial CABG (n = 135) or PTCA (n = 135). Coronary artery bypass grafting patients had 3 ± 0.9 distal anastomoses and PTCA patients had 2.4 ± 1.1 lesions attempted at initial revascularization. At one year, 20.5% of CABG patients had ≥1 totally occluded graft and 86.9% of vein graft, and 91.6% of internal mammary artery distal anastomotic sites had <50% stenosis. One year jeopardy index in surgery patients was 14.1 ± 11%, 46.6 ± 20.3% improved from baseline. Initial PTCA was successful in 86.9% of lesions and repeat revascularization was performed in 48.4% of PTCA patients by one year. Myocardial jeopardy index one year after PTCA was 25.5 ± 22.8%, an improvement of 33.8 ± 26.1% (p < 0.01 for greater improvement with CABG than PTCA). At one year, 29.6% of PTCA patients had angina versus 11.9% of surgery patients, p = 0.004. One-year myocardial jeopardy was predictive of angina (odds ratio 1.28 for the presence of angina per every 10% increment in myocardial jeopardy, p = 0.002). Randomization to PTCA rather than CABG also predicted angina (odds ratio 2.19, p = 0.03).CONCLUSIONSIn this one-year angiographic substudy of BARI, CABG provided more complete revascularization than PTCA, and CABG likewise improved angina to a greater extent than PTCA.

Clinical correlates of the initial and long-term cost of coronary bypass surgery and coronary angioplasty

Background Medical costs vary substantially among patients. Understanding the baseline factors that predict subsequent cost may allow better selection of therapy for individual patients. Understanding the postprocedure events that increase cost should help to improve efficiency and effectiveness of coronary revascularization. Methods Data on 4-year costs were collected from patients randomly assigned to coronary angioplasty or bypass surgery as part of the BARI (Bypass Angioplasty Revascularization Investigation) trial. Regression models first examined factors known at the time of randomization that prospectively predicted initial procedure cost and long-term cost. Subsequent models tested the value of postrandomization events as explanatory variables for cost. Results The independent baseline predictors of higher initial percutaneous transluminal coronary angioplasty cost included 3-vessel disease (+12%) and acute presentations (+22%), whereas the independent predictors of higher initial coronary artery bypass grafting cost included the number of comorbid conditions (+5% per condition) and female sex (+7%). The independent baseline predictors of 4-year cost included heart failure (+26%), diabetes (+22%), comorbidity (+10%), and angioplasty assignment in patients with 2-vessel disease (–15%). Postrandomization models showed higher initial and long-term costs were strongly correlated with the number of repeat revascularization procedures (+30% to +128%) and the occurrence of clinical complications (+8% to +131%). Conclusions Two-vessel disease identifies patients likely to have lower costs after angioplasty, whereas heart failure, comorbid conditions, and diabetes identify patients likely to accrue higher costs after either angioplasty or bypass surgery. Long-term costs can be potentially reduced by interventions that decrease procedural complications or reduce the need for repeat revascularization. (Am Heart J 1999;138:376-83.)

Coronary artery bypass grafting in patients with previous mediastinal radiation therapy

Objectives: Our objectives were to characterize the outcome of coronary artery bypass grafting in patients with previous mediastinal radiation therapy and to identify special features of this condition that relate to surgical management. Patients and methods: We conducted a retrospective review of 47 patients (28 women, 19 men) with a mean age of 63.5 ± 12.8 years (range 31.0-82.9 years) from 1976 through December 1996 undergoing coronary artery bypass graft after mediastinal radiation therapy. Results: The mean interval between mediastinal radiation therapy and coronary artery bypass grafting was 15.1 ± 9.8 years (range 1.1-37.8 years). In the 44 patients with isolated coronary surgery, operative mortality was 3 patients (6.8%). Sternal wound infection occurred in 3 patients (6.8%). Actuarial survival at 1 and 5 years was 87.2% ± 4.9% and 71.6% ± 7.1%, respectively. Total follow-up was 293.7 patient-years (mean 6.2 ± 5.1 years). There were 17 late deaths (malignancy, n = 7; heart failure, n = 6; stroke, n = 1; other noncardiac causes, n = 2; and sudden death, n = 1). Twelve of 43 discharged patients had the development of valvular disease demonstrated by follow-up echocardiography. Conclusions: The early results of coronary artery bypass grafting for the treatment of ischemic heart disease after mediastinal radiation therapy are good. Late survival, however, is limited by malignancy, either recurrent or new, and the development of heart failure. Inasmuch as 25 other patients after radiation therapy required concomitant valve surgery and 12 of 43 (28%) discharged patients had later development of valvular disease, with 2 requiring reoperation, careful assessment of any valvular lesion is important during the initial coronary artery bypass grafting. Careful follow-up, including regular echocardiographic screening, is recommended in this patient population. (J Thorac Cardiovasc Surg 1999;117:1136-43)

A comparison of coronary artery bypass grafting and percutaneous transluminal coronary angioplasty in patients on hemodialysis

The hospital records of 22 patients on hemodialysis undergoing coronary artery bypass grafting, and 19 others undergoing percutaneous transluminal coronary angioplasty were reviewed to compare the outcomes of these procedures in this population. Evidence of previous myocardial infarction or triple vessel or left main coronary artery disease was more common in patients undergoing coronary artery bypass graft than those undergoing percutaneous transluminal coronary angioplasty. Perioperative mortality and complication rates following coronary artery bypass graft (4.5% and 41%, respectively) were similar to those following percutaneous transluminal coronary angioplasty (5.3% and 42%). Cardiac event-free rates at 18 months by life-table analysis following coronary artery bypass graft and percutaneous transluminal coronary angioplasty were 87±16% and 40±14%, respectively. Survival at 18 months were 67±17% following coronary artery bypass graft and 69±14% following percutaneous transluminal coronary angioplasty. Cardiac events were observed to occur in three patients undergoing coronary artery bypass graft at a median of 10 months, and in nine patients following percutaneous transluminal coronary angioplasty at a median of 6 months. One patient required percutaneous transluminal coronary angioplasty after the initial coronary artery bypass graft. Seven patients required repeat percutaneous transluminal coronary angioplasty, and two patients underwent coronary artery bypass graft after initial percutaneous transluminal coronary angioplasty. Although these conclusions are limited by the retrospective nature of the study, it is concluded that coronary artery bypass graft can be performed with morbidity and mortality equivalent to percutaneous transluminal coronary angioplasty, and provides better cardiac event-free rates than percutaneous transluminal coronary angioplasty in patients on hemodialysis. Percutaneous transluminal angioplasty does not appear to be justified in this population because of its unacceptably high restenosis and cardiac event rates.

Reoperative coronary artery bypass procedures: risk factors for early mortality and late survival.

The number of coronary artery disease reoperations is increasing. The aim of this paper is to identify risk factors and evaluate the results of REDO coronary artery bypass grafting (CABG). Between January 1984 and October 1994, 594 patients underwent REDO-CABG and 3157 underwent primary-CABG. The mean age was 62 years with 84% men. Hypertension, hyperlipidemia, insulin dependent diabetes, smoking and renal insufficiency were all more frequent in the REDO-group. A significantly higher number of patients undergoing REDO-CABG were in the Canadian Cardiovascular Society (CCS) angina class 3 and 4, had instable angina, had left main stem stenosis of greater than 70% and 3-vessel disease compared to those undergoing primary-CABG. The mean preoperative left ventricular function (LVEF) was 49.8 (REDO) vs. 58.2%, with a P value of less than 0.001. The overall postoperative mortality rate for REDO-operations was 9.6 (57/594) vs. 2.8% for primary-CABG. Patients with a reoperative interval of more than 1 year had an 8.9% mortality rate, compared to those reoperated less than 1 year after the initial CABG, where the mortality was 21% with a P value of less than 0.05. Postoperative low cardiac output syndrome, intraaortic balloon pump support, prolonged ventilatory support (> 24 h), hemorrhage and gastrointestinal complications were prominent features of the REDO-group (all P < 0.01). Urgent operation, CCS class 3 and 4, LVEF of less than 40%, generalized arteriosclerotic disease and advanced age (> 80 years) were independent risk factors for postoperative death in both groups. Preoperative renal insufficiency, diabetes and short interval from primary-CABG were added risk factors in the REDO-group. The 5-years survival rate after REDO-CABG was 89%, while the cardiac event-free survival rate was 79% and at 7 years 84 and 62%, respectively. Reoperative CABG is effective, but has an increased operative mortality and morbidity. The long-term results are encouraging. Unstable angina, poor preoperative left ventricular function, renal insufficiency, insulin dependant diabetes and an interval shorter than 1 year of the initial operation were independent riskfactors for mortality.

Aortic valve replacement after previous coronary artery bypass grafting

As the population ages, an increasing number of patients with previous coronary artery bypass grafting (CABG) will require subsequent aortic valve replacement (AVR). This study examined outcome of AVR after previous CABG and reviewed possible indications for valve replacement at the time of initial myocardial revascularization. Between March 1975 and December 1994, 145 patients had AVR after previous CABG. Sixty-three patients (43%) had their initial CABG elsewhere. Reoperation for AVR was the second cardiac procedure in 137 patients and the third in 8. Redo CABG with AVR was done in 66 (46%). There were 118 men and 27 women. The mean age at CABG was 64 +/- 7.9 years; for AVR this was 71 +/- 7.6 years. In 2 young patients accelerated calcific aortic stenosis occurred in the setting of renal failure. Significant aortic stenosis did not appear to be addressed at initial CABG in 3 patients. Transaortic valvular gradient, as measured by cardiac catheterization, increased by 10.4 +/- 7.0 mm Hg/y. Twenty-four patients (16.6%) died. The mortality for AVR alone or for AVR + redo-CABG was 15 of 125 patients (12%). For patients having more complicated procedures, the mortality was 9 of 20 (45%). Nine patients (6.2%) suffered a postoperative cerebrovascular accident. Low preoperative ejection fraction measured by echocardiography, sternal reentry problems, complexity of operation, and prolonged cross-clamp and bypass times were significant factors associated with mortality. Age at AVR, interval between operations, the extent of underlying native coronary artery disease, the state of the previously placed bypass conduits, and methods of myocardial preservation were not significant predictors of operative mortality. On multivariate analysis there was only one significant value: prolonged cross-clamp time. Aortic valve replacement after previous CABG is associated with a mortality that is higher than that seen after repeat CABG or repeat AVR. It seems prudent, therefore, to use liberal criteria for AVR in those patients who require coronary revascularization and who, at the same time, have mild or moderate aortic valve disease.

Supraventricular tachycardia after coronary artery bypass grafting surgery and fluid and electrolyte variables

Objective To explore the relationship between fluid and electrolyte variables and the development of supraventricular tachycardia (SVT) after coronary artery bypass grafting (CABG) surgery. Design Retrospective chart review. Random selection from a list obtained from the medical records department and with use of the International Classification of Diseases code to identify patients under-going their initial CABG. Setting Medical records department of a southeastern 600-bed urban referral hospital with a large cardiovascular surgical program. Patients Forty patients experiencing SVT and 40 patients not experiencing SVT during their stay in an intensive care unit after CABG. Outcome Measure Fluid and electrolyte variables and the development of SVT in the intensive care unit after CABG. Variables Data collected included preoperative demographic variables such as age and gender; previous history of SVT, congestive heart failure, cardiac arrest, previous surgery, diabetes, hypertension, valve disease, tobacco use, obesity; preoperative and postoperative medications; postoperative laboratory values of potassium, calcium, and magnesium; intravenous intake; hourly urine output; and chest tube drainage. Results Demographic variables revealed that patients with SVT were older ( p=0.001) and had a higher incidence of preoperative SVT ( p=0.04). Although groups did not differ by numbers of patients with high or low potassium, calcium, or magnesium, patients receiving additional intravenous potassium by bolus after surgery had a higher incidence of SVT ( p=0.02). Patients who lost blood via the chest tube at a rate greater than 100 ml per hour for at least 1 hour after surgery had a higher incidence of SVT ( p=0.02). Patients with a urine output greater than 300 ml per hour for longer than 9 hours had an increased incidence of SVT ( p=0.02). In the patients experiencing SVT, 62% had it occur 24 to 48 hours after surgery. Conclusions These data suggest that shifts in fluid and electrolytes may be important characteristics of patients in whom SVT will develop, which could lead to better identification and nursing management of SVT and improve hemodynamic status, patient recovery, and cost after CABG.

Preoperative Cardiac Function Affects Clinical and Economic Outcomes in Patients Presenting for Initial Elective Coronary Artery Bypass Graft Surgery

Preoperative Cardiac Function Affects Clinical and Economic Outcomes in Patients Presenting for Initial Elective Coronary Artery Bypass Graft Surgery