David B. Campbell

Aortic valve replacement and combined aortic valve replacement and coronary artery bypass grafting: predicting high risk groups

To determine which groups of patients are at highest risk for operative or late mortality, 259 consecutive patients who underwent operation between 1978 and 1984 were studied; 170 underwent aortic valve replacement and 89 underwent aortic valve replacement combined with coronary artery bypass grafting. Multivariate analysis of risk factors selected emergency operation and patient age older than 70 years as the strongest predictors for operative death. Although patients having aortic valve replacement and coronary artery bypass grafting had a higher operative mortality rate (13.5 versus 3.5%), the combined operation had no independent predictive effect on early or late results. At a mean follow-up time of 48 months after surgery, 72% of the survivors of operation were living, 10% were lost to follow-up and 18% were dead. Seventy-seven percent of long-term survivors were in New York Heart Association functional class I or II. The incidence of thromboembolism, paravalvular leak, bacterial endocarditis and hemorrhage each occurred at a rate of less than 1% per patient-year. The factors associated with late death were preoperative age, male sex, left ventricular end-diastolic pressure, cardiac index and functional class. Despite an increase in operative mortality, patients undergoing emergency operation were not at higher risk of late death. Operative mortality is concentrated among several high risk groups. For patients undergoing elective operation, operative mortality is low, especially if the patient is less than 70 years old. Late results are good for all groups of patients undergoing operation, including those who are at greater risk of dying at operation.

Risks of Mitral Valve Replacement and Mitral Valve Replacement with Coronary Artery Bypass

One hundred thirty consecutive patients who underwent mitral valve replacement (MVR) or MVR with coronary artery bypass grafting (CABG) using cold crystalloid cardioplegic solution were analyzed to determine operative mortality and risk factors. Twenty-eight patients had mitral stenosis (MS), 37 had mitral regurgitation (MR), 37 had mixed MS and MR, 23 had MR with coronary artery disease (CAD), and 5 had MS with CAD. Preoperative pulmonary artery pressure, pulmonary capillary wedge pressure, and cardiac index were not different among groups, but patients with MR and CAD had a significantly higher left ventricular end-diastolic pressure (LVEDP) and a significantly lower ejection fraction than other groups. Mortality was 7.1% for patients with MS, 5.4% for MR, 8.1% for mixed MS and MR, 0 for MS with CAD, and 21.7% for MR and CAD. Overall mortality was 9.2%. Eleven patients had emergency operations for cardiogenic shock with a mortality of 45%. Nineteen additional patients in New York Heart Association (NYHA) Functional Class IV had MVR or MVR plus CABG with a mortality of 26%. Sixteen patients required intraaortic balloon pump assistance, and 9 survived. Four patients with MR and CAD required the left ventricular assist device, and 3 survived. Excluding patients who had emergency operations, overall mortality was 5.8%. Excluding patients who had emergency operations and patients in NYHA Functional Class IV, overall mortality was 2%. Factors associated with death were cardiogenic shock, NYHA Class IV, LVEDP greater than 15 mm Hg (16% mortality), and age greater than 60 years (15% mortality).

Mortality of coronary artery bypass grafting before and after the advent of angioplasty

In an effort to determine whether the population of patients undergoing isolated coronary artery bypass grafting and the outcome of these operations have changed, we analyzed the records of two patient populations from our institution. Interventional cardiology techniques (angioplasty, thrombolysis) were not used at our institution before 1982. The records of 736 patients (group 1) who underwent isolated coronary artery bypass grafting from January 1975 to July 1981 were reviewed and compared with a group of 603 patients (group 2) who underwent operation from July 1985 to December 1987. The techniques of operation and myocardial preservation were virtually identical during the two periods. During the group 2 analysis period, 343 angioplasty procedures were performed. The patients in group 2 were significantly older, had increased preoperative New York Heart Association classification, had sustained more previous myocardial infarctions, and had more associated morbid medical conditions. There was a threefold increase in patients seen for reoperative revascularization procedures and a fourfold increase in emergency operations. Overall mortality, although not significantly different, did increase slightly from 2.69% in group 1 to 3.83% in group 2. Mortality after elective procedures remained essentially unchanged (2.05% for group 1 and 1.90% for group 2).

Rupture of left sinus of valsalva aneurysm into the pulmonary artery

Congenital sinus of Valsalva aneurysm is an uncommon lesion that frequently presents after rupture in adult life. This report describes a patient with a left sinus of Valsalva aneurysm that ruptured into the main pulmonary artery, a previously unreported anatomic variant. Anatomic and clinical features of previously reported cases of ruptured sinus of Valsalva aneurysm are reviewed.

Diltiazem Withdrawal Before Coronary Artery Bypass Surgery

The authors studied the effects of withdrawing oral diltiazem therapy on the subsequent course of coronary artery bypass graft surgery. Patients with severe coronary artery disease were divided into three groups using a prospective, controlled, randomized protocol. In group D (diltiazem-continuation) patients, diltiazem was administered 2.1 +/- 0.1 hours (mean +/- SEM) before anesthetic induction (n = 10). Group DW (diltiazem-withdrawal) patients received their final diltiazem dose 17.3 +/- 2.9 hours before anesthesia (n = 10). Group R was a reference group of patients not receiving diltiazem (n = 11; not randomized). Anesthesia was induced and maintained with fentanyl and pancuronium without use of halogenated anesthetics. No clinically important differences were detected in measured hemodynamics or drug requirements. Group D patients did not have a lower systemic vascular resistance (SVR) index (P greater than 0.31) or mean arterial pressure (P greater than 0.08) compared with group DW. Also, no evidence for a diltiazem withdrawal response was found, because group DW did not have either a higher SVR index (P = 0.99) or a higher pulmonary vascular resistance index (P = 0.99) compared with group R, and no severe myocardial ischemia, coronary artery spasm, or postoperative heart block were seen. Plasma diltiazem concentrations decreased significantly during CPB (P less than 0.0001), but showed overlap between groups D and DW. Plasma diltiazem concentration did not correlate significantly with simultaneous SVR. These data show the benign effects of both diltiazem administration and its acute withdrawal before coronary artery bypass surgery with high-dose fentanyl anesthesia.

Management of Infants with Coarctation of the Aorta

The results of surgery for symptomatic infants with coarctation of the aorta indicate that prompt surgery following appropriate resuscitation using inotropes and prostaglandin E1 has now become acceptable treatment worldwide. Controversy still exists as to the optimal procedure for coarctation—even though end-to-end anastomosis has a 30–60% restenosis rate, while our own use of the subclavian flap procedure continues to show that this is the preferred method of repair. Thus, in 59 infants under 1 year of age, there were two surgical deaths (3%), and only two infants (3%) had residual gradients > 5 mm Hg (15 and 20 mm Hg) on cardiac recatheterization (Table 1). Following repair using the subclavian flap technique, with either interrupted sutures or a continuous absorbable suture, no infant had a residual gradient. Postoperative systolic arm blood pressures were normal for the patients’ ages; and exercise studies done 4–6 years after repair were normal, with normal arm blood pressures and no significant arm-to-leg gradients.

COARCTATION OF THE AORTA IN INFANCY

Coarctation of the aorta is now recognized as a common cause of congestive heart failure and death in infants. In the past it has been classified as either an “infantile” (preductile) or an “adult” (juxtaductal or postductal) type. Recent studies by Rudolf [1] have shown that there are only two types of coarctation and that their development is influenced by hemodynamic molding. The preductal defect is better described as tubular hypoplasia of the isthmus proximal to a patent ductus arteriosus and often has associated intracardiac anomalies. The explanation for this frequent association in patients with intracardiac defects and tubular hypoplasia is a relative decrease in blood flow across the aortic valve which results in most of the ascending aortic flow going to the cephalic vessels.[2] The major portion of blood flow to the descending aorta is from the pulmonary artery through the ductus arteriosus. Little flow traverses the isthmus, resulting in isthmus hypoplasia (Fig. 72–1). In contrast, juxtaductal coarctation is characterized by a shelf-like narrowing opposite the patent ductus; this defect is less commonly associated with intracardiac lesions. Postductal coarctation represents a juxtaductal type in which distal migration of the coarctation shelf has occurred with time. It is rarely seen in newborns.

Monitoring and Perioperative Intervention in the Postoperative Patient with Heart Disease

The perioperative care of patients with preexisting cardiac disease is smoothest and easiest when preoperative assessment has identified patients at risk, and when such patients are invasively and intensively monitored in the postoperative period. Using real-time measurements of cardiovascular functions permits the physician to rationally decide on a course of drug support. Several clinical situations are presented in order to illustrate the relevance of these measurements for the management of the patient.