Stewart M. Scott

Medical compared with surgical management of unstable angina. 5-year mortality and morbidity in the Veterans Administration Study.

We evaluated medical in comparison to surgical plus medical (surgical) treatment of unstable angina using a prospective randomized protocol that stratified patients by clinical presentation and by invasive evaluation of left ventricular (LV) function. Clinical presentations were as follows--type 1: progressive or new onset angina relieved by medication; type 2: prolonged bouts of angina poorly or incompletely relieved by medication. Abnormal LV function was arbitrarily defined as ejection fraction less than 0.50 or LV end-diastolic pressure 16 mm Hg or more. Of 468 patients, 237 were assigned to medical and 231 to surgical therapy. There were 374 type 1 and 94 type 2 patients. LV function was normal in 334 and abnormal in 134 patients. Compared with results at 24 months, this 60-month follow-up study showed important differences in survival for patients with three-vessel disease: 75% for medical and 89% for surgical patients (p less than 0.02). The cumulative 5-year rate of repeat hospitalizations for cardiac reasons was less with surgical patients for either clinical presentation. For type 1, medical patients had a 56% rate, and surgical patients had a 42% rate (p = 0.004). For type 2, medical patients had a 62% rate, and surgical patients had a 43% rate (p = 0.05). Overall mortality did not differ between the two treatments, and this remained true in type 1 versus type 2 patients and in those with normal versus abnormal LV function. However, regression analysis of medical and surgical groups with ejection fraction as a continuous variable showed that mortality of medical patients depended on ejection fraction (p = 0.004), whereas the mortality of surgical patients did not (p = 0.76), and survival in the surgical group was higher in the lowest ejection fraction tercile-73% for medical and 86% for surgical patients, p = 0.03. We conclude that surgery improves survival in patients with three-vessel disease and leads to fewer subsequent hospitalizations for cardiac reasons. An impaired ejection fraction had an adverse impact on survival of medical patients but not on surgical patients, and mortality in surgical patients was improved compared with medical patients in the lowest ejection fraction tercile.

Carotid Sinus Nerve Stimulation Treatment of Angina Refractory to Other Surgical Procedures

Abstract Carotid sinus nerve (CSN) stimulators were inserted in 13 patients with intractable angina pectoris following surgical procedures to increase myocardial blood flow and relieve their angina. In all patients the CSN stimulation assisted to some degree in relieving angina. In some, a variation of the stimulation level and pattern was necessary to relieve chest pain. Digitalis, diuretics, long-acting vasodilators, and occasionally narcotics, beta-adrenergic-receptor blocking agents, and nitroglycerin were necessary to control angina. The CSN stimulator is a useful adjunct to drug therapy in controlling angina pectoris. In 10 patients square-wave electromagnetic flow probe measurements showed a 21% decrease in bilateral common carotid artery blood flow during CSN stimulation. One of 3 patients with asymptomatic carotid arteriosclerotic plagues sustained a transient cerebrovascular accident following stimulator implantation. CSN stimulators are not recommended for patients with signs or symptoms of cerebrovascular disease because of the danger of cerebral embolization and reduction in cerebral blood flow during stimulation.

Opportunistic Endocarditis Following Open-Heart Surgery

The incidence of endocarditis following open-heart operations is declining, but the relative incidence of endocarditis by the opportunistic organisms, both bacterial and fungal, has increased. These opportunists require careful identification and sensitivity testing so that appropriate therapy can be planned. In cases of candida endocarditis, a positive precipitin test and elevated candida antibody titer may provide an earlier means of diagnosis than blood cultures. These patients should be treated promptly with adequate dosages of specific antimicrobial or antifungal agents. Reoperation should be considered early if there is evidence of valve dehiscence or embolic phenomena or if drug therapy fails to control the infection.

Innominate venous thrombosis: A rare complication of transvenous pacemaker electrodes

Abstract Thrombosis and occlusion of innominate veins or superior vena cava are extremely rare, but may be a major complication of transvenous pacing electrodes. These patients have the usual signs and symptoms of superior vena caval syndrome and should be managed with anticoagulation therapy.

Tension pneumoperitoneum and gastric rupture following cardiopulmonary resuscitation.

Inadvertent esophageal intubation during cardiopulmonary resuscitation following aortocoronary bypass grafting resulted in gastric rupture and tension pneumoperitoneum in a 65-year-old patient. Rapid hemodynamic deterioration necessitated emergency laparotomy with successful repair of the gastric rupture. The patients recovery was uneventful, and he was doing well at six months follow up. Awareness of this unusual complication may lead to early recognition and successful treatment.

Direct Blood Flow Studies of Clinical Internal Thoracic (Mammary) Arterial Implants

( LJANTITATION of the contribution of internal thoracic* arterial implant collaterals to myocardial blood flow in patients with ischemic heart disease has been a matter of concern. Washout of radioactive material injected into internal thoracic arterial implants seems to demonstrate significant flow rates and a perfusion pattern similar to that obtained with injections in normal coronary arteries.2 Coronary sinus pyruvate and lactate determinations have indicated a reversal of myocardial metabolism from an anaerobic to an aerobic basis following internal thoracic arterial implantation.2 These methods being indirect have disadvantages3 and have not proved conclusively that implant collaterals significantly perfuse ischemic myocardium. Exercise4 and stress ECG5 evaluations have not shown consistent improvement following internal thoracic arterial implantation. Some investigators have demonstrated improvement in myocardial function and significant amounts of internal thoracic arterial blood flow following implantation in animals.6 Others have found less improvement in function and smaller amounts of implant blood flow.8-10 To evaluate implant perfusion of ischemic myocardium more accurately, implant blood flow was measured directly with an electromagnetic flowmeter in a group of patients

Phrenic Nerve Stimulation as a Complication of the Implantable Cardiac Pacemaker

T HE implantable cardiac pacemaker has rapidly become an essential modality in the clinical management of medically refractory Stokes-Adams disease. In spite of increasing refinement in both the myocardial electrodes and the pacemaker, significant complications still occur and are discussed in representative papers by Chardack1 and Zoll.2 The unusual complication of phrenic nerve stimulation was recently encountered after insertion of a Chardack pacemaker. Since this proved to be troublesome and has not been previously reported, it seemed to be worth recording.

Pyrolytic carbon-coated vascular prostheses☆

Abstract Pyrolite carbon did not prevent thrombosis in small-caliber vascular grafts. The patency of 4-mm pyrolite carbon-coated grafts (Biolite) implanted in the carotid arteries of dogs was compared to that of uncoated Dacron grafts (Weavenit) and similar-size autogenous veins. There was no difference between coated and uncoated grafts and neither compared favorably with autogenous veins. Short-segment (3-cm-long) carbon-coated grafts healed in the same manner as uncoated grafts by becoming encased in fibrous tissue and developing a smooth neointimal lining. The clotting times on the surfaces of the healed grafts (both coated and uncoated) were the same as those on normal adjacent arteries. Areas of unhealed graft were thrombogenic and their surface clotting times were very short. With the scanning electron microscope, surface irregularities were observed on some coated grafts before they were implanted. These defects may have contributed to poor graft healing and thrombosis. Blood flows through both coated and uncoated prostheses were similar to those observed in normal carotid arteries. Compliances were measured when the animals were sacrificed. Coated and uncoated grafts were not significantly different from each other, but they and the vein grafts were significantly less compliant than normal artery. Graft length was found to be an important determinant of graft patency when 3-cm-long grafts were compared with 10-cm-long grafts.

Systemic Emboli due to Cloth Wear in a Starr-Edwards Model 2320 Aortic Prosthesis

Abstract The evolution of the different cloth coverings of Starr-Edwards prostheses is reviewed along with previously reported cases of wear of the cloth coverings. The first case of wear in the Model 2320 valve, which is covered with a combination of polypropylene over Teflon, is reported. Questions related to the problem are discussed.

Experience with the DeBakey-Surgitool Aortic Prosthetic Valve

The DeBakey-Surgitool aortic valve differs from popular cloth-covered prostheses by having a bare metal cage and a pyrolytic carbon ball. This valve was implanted in 37 patients. There were 7 operative deaths (19%), none of which was related to the valve design. Thirty survivors have been followed up to five years with 12 late deaths. The single thromboembolic event resulted in the only valve-related death. One patient developed a periprosthetic leak and another has hemolytic anemia. The incidence of thromboembolism in small series (3%) is comparable to that with the cloth-covered valves. This and the absence of complications related to cloth wear are important considerations when selecting a prosthesis.