[Cardiac surgery in renal transplant patients. Apropos of 24 cases]. / La chirurgie cardiaque chez le patient greffé rénal. A propos de 24 cas.

UNLABELLED: Results of cardiac surgery in renal transplant patients are not well documented. Immunosuppression as well as associated conditions in these patients, and the increased susceptibility of the renal allograft to the extracorporeal circulation (ECC) may alter the prognosis of renal transplant patients submitted to cardiac surgery. To evaluate this hypothesis, we reviewed the files of 24 patients (18 Male, 6 Female; age: 49 +/- 12 years) operated under ECC between 1978 and 1997. Twenty patients underwent coronary artery bypass surgery, 5 patients a valve replacement procedure (aortic and/or mitral), and one patient necessitated a Cabrol procedure for an ascending aorta aneurysm. Preoperatively, the majority of patients were in functional class (NYHA) IV (16 patients), and ejection fraction was > 50% in 18 patients. Two operative deaths secondary to cardiogenic shock were encountered. Five patients (23%) were reoperated for bleeding; 5 patients (23%) sustained a major infection (2 pneumonias, 2 mediastinitis and one wound infection) resulting in death in one patient; 5 patients (23%) were treated for arythmia; and 2 patients (9%) suffered a perioperative myocardial infarction. Serum creatinine levels did not increase significantly during hospitalization (p = 0.41 between extreme values). Mean follow-up (41 +/- 28 months) of the 20 survivors revealed recurrent angina in 5 patients and late death in 4 patients, cardiac-related in 3 cases. CONCLUSION: Cardiac surgery in renal transplant patients is subjected to a high morbidity and mortality. Mid-term prognosis is reserved especially in presence of associated conditions.

Haemodynamic interaction of high-dose fentanyl and increasing doses of vecuronium in patients undergoing myocardial revascularization.

BACKGROUND: Bradyarrhythmia has been reported with vecuronium when given with high dose narcotics. We hypothesized that if the bradycardic response is dependent on a vagal reaction mediated by narcotics, it should be independent of the vecuronium dose. A dose-related response of vecuronium on heart rate (HR) would be in favour of a chronotropic action of this agent. METHODS: We examined three induction techniques using high doses of fentanyl in which vecuronium was given in increasing doses. In addition, a reference group received a low dose of atracurium. Forty patients scheduled for elective CABG surgery were anaesthetized with fentanyl (50 mu g/kg) given over 5 min, and were randomly assigned to receive either 0.056, 0.14, 0.28 mg/kg of vecuronium or 0.28 mg/kg of atracurium. Haemodynamic measurements were obtained at the following intervals: before induction (time 0), after the administration of fentanyl (at 5 min), and 1, 2 and 5 min after tracheal intubation (at 10, 11 and 15 min). RESULTS: In vecuronium-treated groups, there were significant decreases in HR, mean arterial pressure, and cardiac output (P<0.05). There were no differences between the three vecuronium groups. Although the atracurium-treated group displayed no significant haemodynamic changes, 2 patients of this group developed HR < 40 bpm. CONCLUSIONS: Over the range of vecuronium doses studied, we observed a reduction in HR during induction for CABG surgery with high doses of fentanyl and vecuronium. This effect was not dose dependent and is likely related to a direct effect of a high-dose narcotic technique and/or due to a vagal stimulation regarding the airway procedure.

Coronary artery bypass using internal mammary artery branches.

The excellent long-term patency rates achieved with use of the internal mammary artery (IMA) to bypass the left anterior descending coronary artery have stimulated a variety of approaches to expand the use of this conduit in coronary bypass surgery. In this report we document our results using the two terminal branches of the IMA to bypass two arteries in a Y configuration. Sixty-seven patients received IMA Y grafts during a 6-month period in 1987. A total of 150 IMA branch anastomoses were performed (8 patients received bilateral IMA Y grafts). Fourteen of 67 patients were revascularized using IMA grafts only. Operative mortality was 2 of 67 (3%), and follow-up mortality was 5 of 67 (7.5%). Fifty-eight patients could be evaluated 37 +/- 2.7 months later. Clinically 36% of patients reported some recurrence of angina and 12 of 47 (25%) had a positive electrocardiographic stress test. Four patients were reoperated on (2 redo coronary artery bypass grafting, 2 transplants). Sixty (40%) of the 150 branch anastomoses could be evaluated objectively and 30 (50%) were patent. Five (8.5%) were stenotic and 25 (41.5%) were occluded (overall patency rate, 58.5%). We conclude that although the use of IMA Y grafts is a technically feasible means to increase IMA usage, extended application of this technique cannot be recommended unless improved patency rates can be demonstrated.

Coronary artery bypass profile in Canada and the United States.

This study compares computer registry data on coronary bypass surgery from several centres in Canada and the United States to assess current trends in patient profile, and looks at demand and resources available for this form of treatment. A computerized registry established at the Royal Victoria Hospital in 1982 was used to document the profile of patients undergoing coronary artery bypass graft. Comparing 1988 to the previous six years (1982-87), a significant increase was found in patients with unstable angina (P less than 0.001) and abnormal left ventricular function (P less than 0.015) among those operated. The incidence of emergency operations also increased (P less than 0.001). The patient profile was similar to that of the Toronto university hospital population and many major United States university hospitals. The incidence of coronary artery bypass graft per 100,000 population, however, is much greater in the United States than in Canada (120 versus 56). Resources in many Canadian centres appear to be insufficient to meet demand for this type of surgical intervention.

Desmopressin acetate in uncomplicated coronary artery bypass surgery: a prospective randomized clinical trial.

Bleeding in coronary artery bypass procedures increases morbidity and exposes patients to the risks associated with blood transfusion. Desmopressin acetate (DDAVP), a synthetic vasopressin analogue, may limit bleeding during cardiac surgery. In a prospective randomized trial, the authors evaluated the ability of DDAVP to reduce perioperative bleeding during uncomplicated coronary bypass operations. Sixty-two patients who underwent coronary artery bypass grafting were randomized to receive intraoperatively either a placebo or DDAVP. Both groups were similar with respect to operative characteristics and preoperative hematologic profiles, von Willebrand factor levels increased postoperatively in both placebo (2.77 +/- 1.06 versus 2.17 +/- 1.51 U) and DDAVP groups (2.75 +/- 0.94 versus 1.80 +/- 0.88 U). Only the increase in the DDAVP groups was significant (p less than 0.001). There was no difference in total blood loss between the placebo (1826 +/- 849 ml) and DDAVP groups (1716 +/- 688 ml). Total red cell transfusions were similar in placebo (3.4 +/- 1.3 units of blood) and DDAVP groups (3.6 +/- 0.8 units). These results do not support the intraoperative use of DDAVP to reduce perioperative bleeding in routine coronary artery bypass surgery.

Medtronic-Hall prosthesis: valve related deaths and complications.

The purpose of this retrospective study was to assess the clinical performance of the Medtronic-Hall prosthesis based on a review of all valve related complications over a period of nine years. From January 1978 until December 1986, 502 prostheses were implanted in 450 patients. There were 200 aortic valve replacements, 198 mitral valve replacements and 52 double valve replacements. There were 234 associated procedures performed, the most frequent being coronary grafting in 129 patients and tricuspid annuloplasty in 35 patients. The mean age of the patients (230 men and 220 women) was 54.08 +/- 11.7 years. Preoperatively, 92.2% were in NYHA class III or IV. Early mortality was 7.1% and late mortality 16.7%. The follow-up totalled 1733 patient-years (mean 49.8 +/- 31.7 months). Over a period of nine years, the valve related complication rate was 4.4% per patient-year. Thromboembolic events occurred in 37 patients (2.1% per patient-year), anticoagulant related hemorrhage in 23 patients (1.3% per patient-year), endocarditis in 11 patients (0.6% per patient-year), perivalvular leak in six patients (0.3% per patient-year) and death and reoperation in 28 patients (1.6% per patient-year). At eight and one-half years, the survival rate was 71.28 +/- 2.7% for the whole group. The actuarial rate of patients free from all valve related complications was 75.92 +/- 2.7%, rate of freedom from thromboembolism was 86.01 +/- 2.4%, freedom from anticoagulant related hemorrhage was 92.7 +/- 1.6%, freedom from endocarditis was 97.17 +/- 0.8%, freedom from perivalvular leak was 98.27 +/- 0.7% and freedom from death and reoperation was 90.70 +/- 1.9%.(ABSTRACT TRUNCATED AT 250 WORDS)

The Medtronic-Hall cardiac valve: 7 1/2 years' clinical experience.

Clinical information on the Medtronic-Hall valve prosthesis was obtained by reviewing the records of 379 patients, 164 of whom had aortic valve replacement (AVR), 163 of whom had mitral valve replacement (MVR), and 52 of whom had double valve replacement over 90 months (1,225 patient-years) (mean follow-up, 42.01 +/- 1.3 months [+/- standard error]). Mean age was 53.8 +/- 12 years. One hundred ninety-three patients (50.9%) had some type of concomitant operation, such as tricuspid annuloplasty, coronary artery bypass grafting, or resection of ascending aortic aneurysm. Ninety-one percent were in New York Heart Association (NYHA) Functional Class III or IV preoperatively. Early mortality and late mortality were 7.7% (29 patients) and 13.5% (51 patients), respectively. The actuarial survival at 7 1/2 years was 74.1 +/- 2.7% for the total group and 69.0 +/- 4.5% for those having AVR, 81.0 +/- 3.2% for those having MVR, and 67.0 +/- 8.9% for those having double valve replacement. All patients but 2 were maintained on a regimen of chronic anticoagulation with warfarin sodium. Twenty-six thromboembolic episodes occurred (2.1/100 patient-years): 13 after MVR (2.3/100 patient-years), 11 after AVR (2.1/100 patient-years), and 2 after double valve replacement (1.4/100 patient-years). Four thromboembolic episodes were fatal; no valve thrombosis occurred. There were no structural failures. Of the 350 late survivors, 92% were in NYHA Functional Classes I and II. Total valve-related complications have been minimal.(ABSTRACT TRUNCATED AT 250 WORDS)

Fifty-four months' experience with an improved tilting disk valve (Medtronic-Hall).

Between 1978 and 1982, 230 consecutive patients underwent valve replacement with the Medtronic-Hall valve prosthesis. There were 95 patients with aortic valve replacement (AVR), 107 with mitral valve replacement (MVR) and 28 with aortic and mitral valve replacement (DVR). Operative mortality was 7.8%. Follow-up studies included 212 patients with a mean follow-up time of 26.5 months. Incidence of thromboembolism was 1.2%/patient year after AVR, 2.4%/patient year after MVR and 0 after DVR. Freedom from any kind of complications was 80% at 3 years. Recatheterization showed mean pressure gradients of between 0.0 and 6.0 mmHg in aortic prostheses and between 0.0 and 3.5 mmHg in mitral prostheses. It is concluded that the Medtronic-Hall valve prosthesis is a durable substitute with a low complication rate and good hemodynamic performance.

Autoimmune myocarditis: a clinical entity.

In a case of myocarditis electron microscopic and immunoflourescent studies of a transmural myocardial biopsy specimen indicated an autoimmune process. Extensive inflammatory cell infiltration, immunoglobulin and complement deposition along the sarcolemma and in the interstitium, and capillary endothelial injury were found. After a short course of immunosuppressive therapy the inflammatory process was replaced by collagenous scarring and lymphocytic depletion; the blood vessels were then normal. Earlier therapy in such cases may be lifesaving.

Myocardial infarction after aortocoronary bypass: etiologic factors.

To ascertain the frequency and probable determinants of myocardial infarction after aortocoronary bypass, two groups of patients were studied: a group of 20 patients who underwent valve replacement of repair of congenital anomalies and a group of 24 patients who underwent aortocoronary bypass. Postoperative myocardial infarction was diagnosed by an increase in serum creatine phosphokinase concentration to a minimum of 1200 IU in two consecutive samples. The frequency of myocardial infarction differed between the groups, being only 5% in group 1 but 20.4% in group 2. In the patients undergoing coronary artery surgery, the duration of bypass, the aortic cross-clamp time and the vent site did not influence the rate of infarction. However, the incidence of myocardial necrosis did correlate with the number of vessels bypassed. In no case was the clinical course influenced by the infarction. Our results suggest that the frequency of perioperative infarction is higher in coronary artery surgery than in other adult cardiac surgery, and that the most important determining factor is the number of diseased vessels.