Risks of morbidity and mortality in dialysis patients undergoing coronary artery bypass surgery. Northern New England Cardiovascular Disease Study Group.

BACKGROUND: Although dialysis patients are undergoing CABG with increasing frequency, large studies specifically comparing patient characteristics and procedure-related risks in this population have not been performed. METHODS AND RESULTS: We conducted a regional prospective cohort study of 15,500 consecutive patients undergoing CABG in northern New England from 1992 to 1997. We used multiple logistic regression analysis to examine associations between preoperative dialysis-dependent renal failure and postoperative events and to adjust for potentially confounding variables. The 279 dialysis-dependent renal failure patients (1.8%) were 4.4 times more likely to experience in-hospital mortality than were other CABG patients (12.2% versus 3.0%, respectively; P:<0.001). Dialysis-dependent renal failure patients were older and had more comorbidities and more severe cardiac disease than did other CABG patients. After adjusting for these factors in multivariate analysis, however, dialysis-dependent renal failure patients remained 3.1 times more likely to die after CABG (adjusted odds ratio [OR] 3.1, 95% CI 2.1 to 4.7; P:<0.001). Dialysis-dependent renal failure patients compared with other CABG patients also had a substantially increased risk of postoperative mediastinitis (3.6% versus 1.2%, respectively; adjusted OR 2.4, 95% CI 1.2 to 4.7; P:=0.011) and postoperative stroke (4.3% versus 1.7%, respectively; adjusted OR 2. 1, 95% CI 1.1 to 3.9; P:=0.016), even after controlling for potentially confounding variables. Risks of reexploration for bleeding were similar for patients with and without dialysis-dependent renal failure. CONCLUSIONS: Preoperative dialysis-dependent renal failure is a strong independent risk factor for in-hospital mortality and mediastinitis after CABG.

Surgical treatment of congenital unilateral pulmonary arterial stenosis with contralateral pulmonary hypertension.

This report describes the diagnosis and surgical treatment of a 48 year old patient with congenital right pulmonary arterial ostial stenosis, no intra- or extracardiac shunts and systemic levels of pressure in the main and left pulmonary artery with pulmonary vascular obstruction in the left lung. Operation consisted of a bypass graft of 10 mm woven Dacron from the main pulmonary artery to the distal right pulmonary artery producing an immediate 50 percent reduction in mean left pulmonary arterial pressure. Late postoperative evaluation revealed equal perfusion of both lungs, maintenance of the reduced pulmonary arterial pressure and improvement from New York Heart Association functional class IV to class I.

Interhospital transport of patients with ongoing intraaortic balloon pumping.

During a 5-year period (1979 to 1983), 50 consecutive patients undergoing continuous intraaortic balloon (IAB) pumping were transferred from Evanston Hospital to Northwestern Memorial Hospital (16 miles), where they underwent cardiac operation. All patients had cardiac catheterization before transfer. Indications for IAB were cardiogenic shock (9 patients), postinfarction angina (18 patients), unstable angina (9 patients), evolving myocardial infarction (3 patients), accelerating angina or hemodynamic instability during cardiac catheterization (9 patients) and prophylactic insertion for high-grade left main stenosis (2 patients). Transportation after stabilization was uneventful in all patients. All patients underwent operative coronary revascularization. There was concomitant mitral valve replacement in 3 patients, acute ventricular septal defect repair in 1 patient, aortic valve replacement in 1, and ventricular aneurysmectomy in 1. Three patients (5%) died postoperatively. Nine patients (20%) had complications directly related to IAB insertion. One patient required femoral-femoral arterial bypass preoperatively, 4 patients had postoperative lower limb ischemia treated by IAB removal or thrombectomy and 1 patient had thrombocytopenia (less than 60,000/mm3), 1 false aneurysm, 1 anterior compartment syndrome and 1 prolonged bleeding at the insertion site. Interhospital transfer with IAB pumping in progress should not be restricted to patients with cardiogenic shock, but can be effectively used for all patients who require preoperative IAB insertion.(ABSTRACT TRUNCATED AT 250 WORDS)

Tetralogy of Fallot with discrete fibrous subaortic stenosis.

This is the first reported case of discrete fibrous subaortic stenosis in tetralogy of Fallot. Transaortic excision of the subaortic membrane was readily accomplished. To detect this and other forms of left ventricular outflow-tract obstruction in tetralogy of Fallot before surgery, routine selective left ventriculography is advocated.

Oblique transseptal left atriotomy for optimal mitral exposure.

Twenty patients underwent mitral valve replacement or other surgical procedures within the left atrium with Dubost's transseptal left atriotomy. The left atrium was grossly enlarged in six patients. Exposure was considered to be excellent in 13 patients and poor in only two. One patient (with a second aortic and mitral valve replacement) required a permanent pacemaker after operation, none had a residual shunt at the atrial level, and none required reoperation for bleeding. The Dubost transseptal left atriotomy affords excellent exposure of left atrial structures, is easy to close, and does not increase the prevalence of postoperative rhythm disturbances.

Expanding indications for pediatric coronary artery bypass.

Pediatric coronary artery bypass has been done mostly for ischemic complications of Kawasaki disease. We reviewed our clinical experience between 1987 and 1994 with internal thoracic artery-coronary artery bypass in one infant and five children for varying indications. Indications for coronary bypass included Kawasaki disease (2), congenital left main coronary ostial stenosis, iatrogenic coronary cameral fistula, anomalous origin of the left coronary artery from the pulmonary artery, and single coronary artery traversing between the great arteries in a patient after cardiac transplantation. An additional cohort of 34 control patients of various ages and weights (1 day to 16.1 years, 2.6 kg to 62 kg) had angiographic measurements of the right coronary, left coronary, and left internal thoracic arteries with respect to the feasibility of performing coronary artery bypass. All six patients survived internal thoracic artery-left anterior descending coronary artery bypass without evidence of perioperative myocardial infarction. Postoperative angiographic studies in five and color Doppler echocardiography in one showed graft patency. Retrospective angiographic measurements in the 34 control patients showed that internal thoracic and coronary arteries are proportionately quite large in neonates and infants compared with those in older children and adolescents. Internal thoracic artery-coronary artery bypass should be considered for the expanding indications presented herein and when emergency intraoperative life-threatening situations present themselves. Long-term patency and reoperation rates have yet to be determined.

An eight-year experience with porcine bioprosthetic cardiac valves.

A total of 589 porcine bioprostheses were implanted in 509 patients from January, 1976, through December, 1983. Of the valves implanted, 390 were Hancock and 199 were Carpentier-Edwards. A total of 1,633 patient-years was accrued, with a mean follow-up of 38 months per patient. Two hundred eight patients had aortic valve replacement, 209 had mitral valve replacement, and 79 had multiple valve replacements, of which 46 were aortic and mitral replacements. The mortality for isolated aortic valve replacement was 5.8%; for isolated mitral replacement, 8.6%, and for all patients, 10.9%. Late mortality was 3.9% per patient-year. The actuarial survival rate at 5 years was 79% for aortic, 68% for mitral, and 76% for aortic-mitral valve replacement. There were 12 thromboembolic events (0.73% per patient-year). Two episodes occurred in patients with an aortic bioprosthesis, nine in patients with a porcine mitral valve, and one in a patient with mitral and tricuspid bioprosthetic valves. The probability of remaining free of thromboembolism at 5 years was 99% for the group having aortic valve replacement, 93% for those having mitral replacement, and 100% for the group having aortic-mitral valve replacements. Thirteen episodes of endocarditis occurred (0.8% per patient-year). Seven of the 13 patients died as a direct result of endocarditis. The probability of remaining free of prosthetic endocarditis at 5 years was 97% for the aortic valve replacement group, 95% for the mitral group, and 97% for the aortic-mitral group. There were 20 instances of xenograft failure (1.2% per patient-year). The probability of remaining free of valve failure at 5 years was 96% for the aortic valve replacement group, 93% for the mitral group, and 93% for the aortic-mitral replacement group. Primary tissue failure of a prosthesis occurred in seven patients, all with Hancock valves (0.43% per patient-year). As yet there has been no primary tissue failure of the Carpentier-Edwards prosthesis. There also appears to be a lower incidence of thromboembolism (Edwards, 0.3% per patient-year; Hancock, 0.8% per patient-year) and endocarditis (Edwards, 0.6% per patient-year; Hancock, 1.0% per patient-year). The low incidence of complications with the porcine bioprosthetic valve, especially the Carpentier-Edwards, encourages us to recommend its continued use, especially in situations in which anticoagulation is contraindicated.

Cardiac and renal responses to cross-clamping of the descending thoracic aorta.

The present study was performed to document the relative efficacy of commonly applied techniques used adjunctively during 1 hour of descending thoracic aortic cross-clamping. Renal and cardiac responses were determined by standard laboratory methods. There were four experimental groups: (1) heparin-bonded shunt; (2) partial femoral-femoral bypass; (3) sodium nitroprusside; (4) control. Each of the experimental groups showed abnormal hemodynamic responses during cross-clamping. Elevations in left ventricular end-diastolic pressure (LVEDP) and systolic blood pressure were common events during clamping, and cardiac output often decreased. Nevertheless, left ventricular performance curves after cross-clamping showed similar increases in left ventricular stroke work (LVSW) with increasing preload. In addition, left ventricular biopsy specimens showed preservation of myocardial high-energy phosphate stores and essentially normal ultrastructural integrity. Radioactive microspheres generally showed increased myocardial blood flow during and after cross-clamping, but no evidence of preferential subendocardial ischemia. Examination of renal function showed a marked decrease in urine output, glomerular filtration rate, and renal plasma flow during cross-clamping. Following the release of the cross-clamp, renal function returned to 50% to 85% of baseline status. Since we could find no major advantage of any of the techniques employed under the present experimental conditions, we suggest that all of the techniques should be part of the surgical armamentarium and the particular preoperative and/or intraoperative findings in a specific case should determine which technique is most appropriate for a given patient.

Serial assessment of left ventricular performance following coronary artery bypass grafting. Early postoperative results with myocardial protection afforded by multidose hypothermic potassium crystalloid cardioplegia.

Forty patients who recently underwent coronary artery bypass graft (CABG) operations had serial hemodynamic and scintigraphic studies. Multidose hypothermic potassium crystalloid cardioplegia was used for myocardial protection and newer techniques in anesthetic management and perioperative patient care were also employed. The method of equilibrium cardiac gated blood pool (GBP) scintigraphy was used to obtain perioperative changes in global ejection fraction (EF) and regional wall motion (RWM). Ninety percent of patients displayed a decrease in EF 2 hours postoperatively when compared to their preoperative values. This change was also associated with a fall in cardiac index (CI) and left ventricular stroke work index (LVSWI). Twenty-four hours postoperatively, EF and CI recovered to preoperative levels, but LVSWI remained depressed. Seven days postoperatively, global EF had improved to a value greater than the preoperative one (50% +/- 3% versus 57% +/- 4%, p < 0.05). Perioperative changes in RWM followed the same pattern as EF, but recovery in this index of regional contractility was faster than EF, since maximal improvement was observed 24 hours postoperatively. Thus transient left ventricular dysfunction is common immediately after CABG, but recent advances in myocardial protection and perioperative management are associated with short-term increases in regional and global left ventricular function documented by noninvasive GBP imaging.

Early and long-term improvement in left ventricular performance following coronary bypass surgery.

Changes in left ventricular performance after coronary artery bypass grafting (CABG) have been variable. Earlier studies based on contrast left ventriculography have shown occasional improvement in left ventricular function in patients with unstable angina or abnormal preoperative ventricular performance, but for the most part repeat cardiac catheterization several months after operation has shown no significant changes in global left ventricular contraction. In the past few years, advances in radiopharmaceutical technology have made the characterization of left ventricular wall motion accurate and highly reproducible. Since prognosis in patients with coronary artery disease and survival after CABG have been related to global ejection fraction (EF), we employed prospectively on analysis of short-term and long-term changes in EF after CABG utilizing multidose hypothermic potassium crystalloid cardioplegia as the method of myocardial protection. Concomitantly, newer techniques in anesthesia and perioperative patient management were employed to minimize myocardial damage in these patients. Postoperative scintigraphic evaluation showed a transient (2-hour) depression in left ventricular function, followed by recovery to preoperative levels at 24 hours and significant improvement in EF at 7 days. From 7 days to 8 months postoperatively, there was no further change in resting EF, but there was another significant exercise-induced increase in EF at the long-term examination. Thus, present advances in the multidisciplinary management of patients with coronary artery disease are associated with improvement in resting and exercise-related EF postoperatively.

Thoracic aortic imaging without angiography.

Imaging of the thoracic aorta without recourse to angiography has great theoretic appeal. We have used computerized tomography (CT) in the initial evaluation of 297 patients with suspected mediastinal disease. Nineteen of this group had important findings related to the thoracic aorta: aortic dissection (six), descending thoracic aortic aneurysm (nine), suspected aortic trauma (three), and suspected false aneurysm at a coarctation repair (one). In all cases, the aorta and related pathology were readily demonstrated by CT, aided by the intravenous infusion of contrast material. In 13 of 15 cases, aortic dissection and aortic aneurysm could be accurately diagnosed. In two instances of ascending aortic dissection, it was not possible to distinguish the false lumen from mural thrombus in an atherosclerotic aneurysm.

Tracheal stenosis. A method of dilation with use of the fiberoptic bronchoscope.

Tracheal stenosis is not an uncommon sequel of prolonged endotracheal intubation. In some cases, immediate reconstruction is not feasible. We use the flexible fiberoptic bronchoscope and a lucent, tapered endotracheal tube for tracheal dilation. The fiberoptic bronchoscope is passed through a special T connector into the endotracheal tube and used to guide the tube under direct vision through the stricture.

Aortic valve replacement with the Hancock porcine xenograft.

The Hancock porcine xenograft stabilized with the glutaraldehyde process was used for isolated aortic valve replacement in 71 patients from March, 1972, to July, 1975. Aortic stenosis was the primary diagnosis in 52 patients and aortic insufficiency in 19. There were 52 men and 19 women ranging in age from 18 to 82 years; 14 patients were older than 70 years. One patient was in Functional Class II, 50 in Class III, and 20 in Class IV preoperatively. Seventy-three patients undergoing Björk-Shiley aortic valve replacement during the same period are presented for comparison. The operative mortality was 3% (2 of the 71 patients); 4 of the remaining 69 patients (6%) died in the late postoperative period. No patient was placed on anticoagulation during the postoperative course, and there was 1 postoperative embolus in a patient with chronic atrial fibrillation (1.4%). With a mean follow-up period of 17 months, 60 patients are now in Functional Class I, 4 in Class II, and 1 in Class III. Seven patients have had transvalvular gradients and effective valve areas measured postoperatively that ranged from 32 to 5 mm Hg and 0.9 to 2.9 cm2 in 21 through 25 mm (OD) sizes.

Hybrid myocardial revascularization after previous left pneumonectomy.

Previous intrapericardial left pneumonectomy and irradiation necessitated an unorthodox, staged approach to myocardial revascularization in a patient with unstable angina pectoris, left main artery, and three-vessel coronary artery disease. A saphenous vein bypass graft was constructed from the descending thoracic aorta to the left anterior descending coronary artery via left thoracotomy, without cardiopulmonary bypass. Two days later the patient underwent stenting of the left main and circumflex coronary arteries. Recovery was uneventful.

Clinical experience with portable cardiopulmonary bypass in cardiac arrest patients.

To evaluate the use of portable cardiopulmonary bypass as a resuscitative tool and its impact on long-term survival of patients in cardiac arrest, we reviewed the results of 32 consecutive patients resuscitated by cardiopulmonary bypass for cardiac arrest or severe hemodynamic compromise at Northwestern Memorial Hospital over a 2-year period. Overall survival was 12.5%. Only 1 (3.4%) of the 29 patients who had cardiac arrest survived and left the hospital. All 3 patients who had severe hemodynamic compromise but not cardiac arrest were long-term survivors. Our study suggests that portable cardiopulmonary support systems used as a resuscitative tool do not prolong the survival of most cardiac arrest patients but may be useful for patients with shock due to mechanical causes and for those with profound hemodynamic compromise due to ischemia or myocardial infarction. Portable heart-lung machines can provide patients with excellent hemodynamic support; however, neurological or cardiac recovery is unlikely once cardiac arrest occurs.

A simplified technique for grafting the first septal perforating branch of the left anterior descending coronary artery.

A technique for facilitating the identification and grafting of the first septal perforating branch of the left anterior descending coronary artery is described. This technique makes endarterectomy of the vessel unnecessary.

Management of chronic sternal osteomyelitis.

The management of 2 patients in whom chronic sternal osteomyelitis developed after apparently uncomplicated coronary artery bypass operations is described. Each patient had become totally disabled because of chronic, draining sinus tracts. Eradication of the infection required total sternectomy and excision of all infected costal cartilage. Subsequent reconstruction was accomplished by using bilateral pectoralis major myocutaneous advancement flaps without any maneuvers to stabilize the anterior chest wall. Both patients have resumed full activity and have returned to work with only minimal residual compromise of pulmonary function.

Extended endocardial resection for the treatment of ventricular tachycardia and ventricular fibrillation.

A total of 40 patients with drug-refractory, life-threatening cardiac rhythm disturbances--ventricular tachycardia in 23 patients and ventricular fibrillation in 17 patients--underwent extended endocardial resection (EER) of scar tissue. Scarring was due to myocardial infarction in 38 patients, to previous congenital heart operation in 1 patient, and to sarcoidosis of the heart in 1. The EER procedure was directed by epicardial and endocardial mapping data whenever possible, and was usually combined with revascularization, aneurysmectomy, or, in 5 patients, mitral valve replacement. Operative mortality was 10%, incident to poor preoperative ventricular function and hemorrhage secondary to previous cardiac surgical procedures. Thirty-three of the 36 survivors (92%) are free of arrhythmia at follow-up periods ranging from 3 to 36 months (mean, 12.5 months); the arrhythmia in the remaining 3 patients is now drug controlled. Thirty-three patients had postoperative electrophysiological studies, and in 30 (91%), the arrhythmia was no longer inducible. The results of surgical treatment for ventricular tachycardia and ventricular fibrillation were similar. The results also proved satisfactory whether the EER procedure was directed by visual observation or mapping.

Changes in left ventricular performance related to perioperative myocardial infarction in coronary artery bypass graft surgery.

Strict electrocardiographic, enzymatic, scintigraphic, and hemodynamic criteria for perioperative myocardial infarction (MI) were defined and related to serial assessments of left ventricular performance during rest and exercise in patients seen early and late after coronary artery bypass graft operation. Global left ventricular performance was determined by radionuclide ventriculography from which changes in the pattern of serial postoperative ejection fractions (EF) were obtained. Patients were divided into two groups based on the presence or absence of perioperative MI, and were matched in pairs on the basis of preoperative EF and extent as well as location of coronary artery obstructions. The results indicate that neither short- nor long-term depression in resting EF occurred subsequent to perioperative MI. However, an exercise-related increase in EF eight months postoperatively was depressed in patients who had perioperative MI compared with those who did not. Patients with new Q waves and abnormal postoperative elevation in serum levels of the myocardial isoenzyme of creatine kinase (CK-MB) had a greater early decrease in EF compared with patients without evidence of perioperative MI. However, seven days after operation, the EF in both groups returned to preoperative levels. Patients with abnormal technetium 99m-pyrophosphate scintigrams had changes in perioperative EF similar to those in patients without MI. The presence of low cardiac output syndrome immediately after operation was associated with immediate and short-term decreases in EF, which were not seen in any of the other patient subgroups.

Clinical evaluation of the relative effectiveness of multidose crystalloid and cold blood potassium cardioplegia in coronary artery bypass graft surgery: a nonrandomized matched-pair analysis.

Controversy exists concerning the most effective method of myocardial protection during coronary artery bypass graft operations. Accordingly, we performed a matched-pair analysis between 25 patients receiving multidose hypothermic potassium crystalloid cardioplegia and 25 other patients receiving cold blood potassium cardioplegia. Patients were matched on the basis of preoperative ejection fraction (EF) and the number of anatomically similar stenotic coronary arteries. The adequacy of myocardial protection was assessed by serial perioperative determinations of radionuclide ventriculography, hemodynamic measurements, analyses of electrocardiograms and serum levels of MB-CK. We found that the level of myocardial protection was similar between unstratified groups. However, when subgroups were selected on the basis of prolonged aortic cross-clamp time (greater than ninety minutes) or impaired preoperative left ventricular function (EF less than 40%), there was a suggestion that cold blood cardioplegia may be advantageous.