Frank C. Seifert

Blood transfusion is associated with increased resource utilisation, morbidity and mortality in cardiac surgery.

The purpose of the present investigation was to examine the impact of blood transfusion on resource utilisation, morbidity and mortality in patients undergoing coronary artery bypass graft (CABG) surgery at a major university hospital. The resources we examined are time to extubation, intensive care unit length of stay (ICULOS) and postoperative length of stay (PLOS). We further examined the impact of number of units of packed red blood cells (PRBCs) transfused during PLOS. This is a retrospective observational study and includes 1746 consecutive male and female patients undergoing primary CABG (on- and off-pump) at our institution. Of these, 1067 patients received blood transfusions, while 677 did not. The data regarding the demography, blood transfusion, resource utilisation, morbidity and mortality were collected from the records of patients undergoing CABG over a period of three years. The mean time to extubation following surgery was 8.0 h for the transfused group and 4.3 h for the nontransfused group ( P <or= 0.001). The mean ICULOS for the transfused group was 1.6 d and 1.2 d for the nontransfused group ( P P <or= 0.001). In all patients and in patients with no preoperative morbidity, partial correlation coefficients were used to examine the effects of transfusion on mortality, time to extubation, ICULOS and PLOS. Linear regression model was used to assess the effect of number of PRBC units transfused on PLOS. We noted that PLOS increased with the number of PRBCs units transfused. Transfusion is significantly correlated with the increased time to extubation, ICULOS, PLOS and mortality. The transfused patients had significantly more postoperative complications than their nontransfused counterparts ( P <or= 0.001). The 30-day hospital mortality was 3.1% for the transfused group with no deaths in the nontransfused group ( P <or= 0.001). We conclude that the CABG patients receiving blood transfusion have significantly longer time for tracheal extubation, ICULOS, PLOS and higher morbidity and 30-day hospital mortality. Blood transfusion was an independent predictor of increased resource utilisation, postoperative morbidity and mortality.

Blood use in patients undergoing coronary artery bypass surgery: Impact of cardiopulmonary bypass pump, hematocrit, gender, age, and body weight

We investigated the impact of cardiopulmonary bypass pump (CPB), hematocrit, gender, age, and body weight on blood use in patients undergoing coronary artery bypass graft surgery at a major university hospital. Participants were 1235 consecutive patients undergoing primary coronary artery surgery over a period of 2 yr (1999 and 2000); 681 patients underwent coronary surgery with use of CPB, and 554 patients underwent off-pump coronary artery bypass surgery using a median sternotomy incision. There were 881 males and 354 females. Average packed red blood cells (PRBC) transfusion for patients on CPB was 3.4 U compared with 1.6 U for the off-pump group (P = <0.001). Patients on CPB received more frequent PRBC transfusion (72.5%) compared with 45.7% of off-pump patients (P = <0.001). Average PRBC transfusion for males was 2.2 U compared with 3.6 U for females (P = <0.001). A lower percentage of males (52.6%) than females (79.4%) received transfusion (P = <0.001). The impact of CPB, off-pump status, preoperative hematocrit <35%, gender, age ≥65 yr, and weight ≤83 kilograms using median values as cut points, on blood use was examined using logistic regression models. Use of CPB, preoperative hematocrit, (<35%) female gender, increasing age, and decreased body weight were significant predictors of transfusion (P = <0.001). Preoperative hematocrit <35% and use of CPB were the strongest predictors of PRBC transfusion.

Coronary and carotid operations under prospective standardized conditions: incidence and outcome

BACKGROUND No randomized trial has yet evaluated the hypothetical benefit of carotid endarterectomy with coronary artery bypass grafting. This prospective review was undertaken to determine the differences between observed and predicted complication rates, as well as to define new predictors and assess costs in a standardized population. METHODS A prospective nonrandomized study was undertaken over a 4-year period involving all coronary artery bypass graftings done at one institution. Operative procedure was standardized. All patients underwent preoperative screening for carotid disease. If 80% or more stenosis was present, combined coronary artery bypass grafting and carotid endarterectomy was performed. RESULTS Of 2,071 patients, 1,987 had coronary artery bypass grafting only. In that group there were 34 strokes (1.7%) and 41 deaths (2.0%). Eighty-four patients underwent combined coronary artery bypass grafting/carotid endarterectomy and in that group there were four strokes (4.7%) and five deaths (5.9%). Independent risk factors for postoperative stroke were age (odds ratio 1.09; 95% confidence interval 1.04, 1.3), hypertension (odds ratio 2.67; 95% confidence interval 1.22, 5.23), extensively calcified aorta (odds ratio 2.82; 95% confidence interval 1.34, 5.97), and bypass time (odds ratio 1.01; 95% confidence interval 1.00, 1.02). Cost of a stroke was significant (p < 0.05) in both groups. CONCLUSIONS Patients with carotid disease fall into a higher risk group than patients without it. This increased risk is not because of carotid disease alone. Patients without significant carotid disease, who suffered a perioperative stroke, fell into an even higher risk category. Furthermore, carotid endarterectomy was not a significant risk factor by either the univariate or the multivariate analysis.

Modeling Stroke Risk After Coronary Artery Bypass and Combined Coronary Artery Bypass and Carotid Endarterectomy

Background and Purpose— The goals of this study were to compare the ability of statewide and institutional models of stroke risk after coronary artery bypass (CAB) to predict institution-specific results and to examine the potential additive stroke risk of combined CAB and carotid endarterectomy (CEA) with these predictive models. Methods— An institution-specific model of stroke risk after CAB was developed from 1975 consecutive patients who underwent nonemergent CAB from 1994 to 1999 in whom severe carotid stenosis was excluded by preoperative duplex screening. Variables recorded in the New York State Cardiac Surgery Program database were analyzed. This model (model I) was compared with a published model (model II) derived from analysis of the same variables using New York statewide data from 1995. Predicted and observed stroke risks were compared. These formulas were applied to 154 consecutive combined CAB/CEA patients operated on between 1994 and 1999 to determine the predicted stroke risk from CAB alone and thereby deduce the maximal added risk imputed to CEA. Results— Risk factors common to both models included age, peripheral vascular disease, cardiopulmonary bypass time, and calcified aorta. Additional risk factors in model I also included left ventricular hypertrophy and hypertension. Risk factors exclusive to model II included diabetes, renal failure, smoking, and prior cerebrovascular disease. Our observed stroke rate for isolated CAB was 1.7% compared with a rate predicted with model II (statewide data) of 1.56%. The observed stroke rate for combined CEA/CAB was 3.9%. When the Stony Brook model (model I) based on patients without carotid stenosis was used, the predicted stroke rate was 2.8%. When the statewide model (model II), which included some patients with extracranial vascular disease, was used, the predicted stroke rate was 3.4%. The differences between observed and predicted stroke rates were not statistically significant. Conclusions— Estimation of stroke risk after CAB was similar whether statewide data or institution-specific data were used. The statewide model was applicable to institution-specific data collected over several years. Common risk factors included age, aortic calcification, and peripheral vascular disease. The observed differences in the predicted stroke rates between models I and II may be due to the fact that carotid stenosis was specifically excluded by duplex ultrasound from the patient population used to develop model I. Modeling stroke risk after CAB is possible. When these models were applied to patients undergoing combined CAB/CEA, no additional stroke risk could be ascribed to the addition of CEA. Such models may be used to identify groups at increased risk for stroke after both CAB and combined CAB/CEA. The ultimate place for CEA in patients undergoing CAB will be defined by prospective randomized trials.

Combined coronary artery bypass and carotid endarterectomy: long-term results.

PURPOSE We determined late survival, freedom from late stroke, and freedom from late cardiac events in patients treated by combined coronary artery bypass and carotid endarterectomy (CAB/CEA). METHODS All patients who underwent CAB/CEA in our institution between January 1994 and December 1999 were identified. Follow-up data were obtained from office records and telephone interviews. Endpoints included death from any cause, stroke, and non-fatal cardiac events (MI, CHF, percutaneous transluminal angioplasty with stenting, redo CAB). Data were expressed in life table format. RESULTS Over a 6-yr period 154 patients had combined CAB/CEA with a 3.9% postoperative stroke rate. Six patients (3.9%) died, leaving 148 patients for follow-up. Average follow-up was 38 +/- 23 months (range: 1-82 months). During the follow-up period two patients (1.4%) had late strokes and 17 patients (11%) had late non-fatal cardiac events. The late mortality rate was 13% (19 patients). Of the late mortalities, four were related to cardiac disease and one to stroke. Using Kaplan-Meier analysis, the 5-yr survival probability was 80 +/- 4.3%. The freedom from late ipsilateral neurologic events was 98 +/- 1.3% at 5 yr. The freedom from late cardiac events was 82 +/- 4.6% at 5 yr. CONCLUSIONS The large majority of patients with combined coronary and carotid artery disease can be expected to live for greater than 5 yr. Therefore, these patients should be considered candidates for prophylactic CEA for stroke prevention, even when their carotid lesions are asymptomatic. Successful CAB/CEA provides good long-term survival and freedom from late cardiac events, as well as excellent freedom from late stroke. Further reduction in perioperative events will make this operative approach even more attractive in patients with combined disease.

Effect of Coronary Artery Bypass Grafting on left Ventricular Diastolic Function

Because left ventricular (LV) diastolic function is abnormal in patients with coronary artery disease (CAD), pulsed Doppler echocardiography was used to evaluate LV filling before and after coronary artery bypass grafting (CABG). Filling was evaluated by Doppler in 2 studies: (1) in a group of 41 unpaired patients (11 with angiographically normal coronary arteries, 14 with CAD but without CABG and 16 at 1 week after CABG) and (2) in a group of 12 patients with CAD before and 1 week after CABG. Doppler sampling at the level of the mitral anulus was analyzed for the deceleration half-time and for the ratio of peak late (A) to peak early (E) filling velocity, measures reflecting early ventricular filling and the relative contribution of atrial contraction to ventricular filling. In the first study the deceleration half-time was significantly prolonged in both CAD and CABG groups. The late to early peak transmitral velocity ratio, however, was significantly prolonged only in the nonrevascularized CAD patients. In the second group of CAD patients studied before and 1 week after surgical revascularization, both the late to early peak transmitral velocity ratio and the deceleration half-time showed significant postoperative improvement. Thus, patients with CAD showed impairment in early LV filling and a compensatory increase in the proportion of filling with active atrial contraction. Successful CABG appears to result in normalization of early filling and decreased reliance on active atrial transport.

Sensing aberration by the automatic implantable cardioverter defibrillator during intraoperative testing.

A 50‐year‐old man underwent replacement of his automatic implantable cardioverter defibrillator (AICD) because a magnet test revealed severe battery depletion. He had had his unit implanted 18 months previously after an episode of sudden cardiac death. He had documented torsades de pointes and inducible ventricular tachycardia, confirmed by electrophysiologic study. Before a new unit was implanted thresholds were measured by an external cardioverter defibrillator. Ventricular fibrillation (VF) was induced by alternating current through a standard, line‐operated battery charger with stimulation delivered to the epicardium via rate‐sensing electrodes. VF was allowed to continue for 10 seconds before shock was delivered. Termination o/VF required 15 joules, which was higher than that required at initial implantation 18 months earlier. The new pulse generator was activated/or testing and VF was again induced. The AICD discharged after 12.3 seconds. Prior to wound closing, the AICD was deactivated by magnet. Instead of R‐wave synchronous beeping tones during deactivation, double beeping tones were heard. Electrogram recordings revealed abnormalities of the T‐wave and ST segment of the rate‐sensing electrodes, which were the cause of the tone irregularities. Stabilization of the T‐wave and ST segment occurred within 8 minutes and the tones became normal. The procedure was then completed.

Thrombus formation after successful stapler exclusion of the left atrial appendage.

A 67-year-old man with atrial fibrillation presented with stroke 7 weeks after stapler exclusion of his left atrial appendage (LAA), surgical maze procedure, and bioprosthetic aortic valve replacement. Transesophageal echocardiogram (mid-esophageal view at 90°) noted an excluded LAA without

Long‐Term Post‐CABG Survival: Performance of Clinical Risk Models Versus Actuarial Predictions

Clinical risk models are commonly used to predict short‐term coronary artery bypass grafting (CABG) mortality but are less commonly used to predict long‐term mortality. The added value of long‐term mortality clinical risk models over traditional actuarial models has not been evaluated. To address this, the predictive performance of a long‐term clinical risk model was compared with that of an actuarial model to identify the clinical variable(s) most responsible for any differences observed.

Intramural hematoma of the aorta: delayed pericardial tamponade.

Intramural hematoma of the aorta is a fatal disorder that remains poorly characterized. Recently, it has been accepted as a variant form of aortic dissection, where blood accumulates within the aortic media without the presence of an intimal tear. Clinically, it may present somewhat similar to dissection, and although optimal therapy remains controversial, current opinion supports surgery as the preferred method of treatment for intramural hematomas that involve the ascending aorta and aortic arch.