Serum myoglobin does not predict cardiac allograft rejection.

Noninvasive studies are useful, but limited, in detecting rejection among cardiac allograft recipients. Because an elevated serum myoglobin level is a sensitive indicator of necrosis in acute myocardial infarction, we postulated that myoglobin levels might correlate with the presence, absence, or degree of rejection. Therefore we prospectively measured serum myoglobin levels at the time of endomyocardial biopsy in 45 heart transplant recipients and correlated these levels with biopsy scores (grade 0 through grade 4). There was no significant difference in mean myoglobin levels among patients with grade 0 biopsy scores and those with grade 1 through grade 4 scores. Serial myoglobin levels and endomyocardial biopsy specimens were obtained in five patients during a 4- to 9-week period; no significant directional change in myoglobin levels appeared to correlate with changes in endomyocardial biopsy score. In addition, a normal myoglobin level did not exclude, nor did an elevated level confirm, any grade of rejection. We conclude that neither the absolute level nor a directional change in serum myoglobin is useful in identifying rejection among heart transplant recipients.

Aortic dissection in cardiac allograft recipients. A report of two cases.

Aortic dissection in cardiac allograft recipients has not been reported previously, to our knowledge. We have observed two fatal aortic dissections in heart transplant recipients: one in the immediate postoperative period and one occurring 5 years after transplantation. We discuss the clinical presentations, pathologic findings, possible pathogenetic mechanisms, and risk factors. Because the frequency of aortic dissection after heart transplantation appears to be relatively low (< 1%), such disease may be clinically unsuspected. Given the uniformly poor outcome observed in our two patients, we suggest that increased awareness of the possible development of aortic dissection after heart transplantation may result in improved survival of affected patients.

Posttransplantation hemodynamics and exercise function are not affected by body-size matching of donor and recipient.

Because the number of heart transplantations performed is limited by the number of available donor hearts, many centers have expanded the acceptable criteria for donor hearts in an attempt to provide a sufficient number of donors for the number of patients awaiting heart transplantation. Traditionally, body-size matching has been an important criteria for matching donors with potential heart transplant recipients. Although initially thought to be detrimental, studies have shown no difference in survival of patients who receive hearts from smaller donors, but heart performance in this subset of patients who receive undersized hearts has not been extensively examined. We assessed exercise capacity and 1-year posttransplantation hemodynamics in 72 consecutive adult orthotopic heart transplant recipients, grouped according to donor-recipient weight ratio and the ratio of donor to recipient body surface area. Total exercise time and relative oxygen consumption were not significantly different among three groups of patients grouped according to donor-recipient body weight ratio as follows: low, 0.60 to 0.79; mid, 0.80 to 1.0; high, more than 1.0. No difference was noted among the three donor-recipient weight ratio groups with respect to 1-year posttransplantation hemodynamics. Similarly, 1-year posttransplantation hemodynamics were not different between patients with a body surface area ratio of less than 1.0 versus those with a body surface area ratio of 1.0 or more. Differences in pretransplantation hemodynamics or graft preservation did not affect our results. Neither donor-recipient weight ratio nor body surface area ratio correlated with any posttransplantation hemodynamic measurement.(ABSTRACT TRUNCATED AT 250 WORDS)

Isradipine for treatment of acute hypertension after myocardial revascularization.

OBJECTIVE: To evaluate the efficacy and duration of action of iv isradipine in the control of postoperative hypertension immediately after myocardial revascularization. DESIGN: Prospective, phase 2 trial. SETTING: Surgical ICU, university hospital. PATIENTS: Twenty-one (15 male, six female) patients, ages 49 to 75 yr (mean 65 +/- 5), undergoing elective myocardial revascularization. INTERVENTIONS: Twenty-one patients with postoperative hypertension after coronary artery bypass graft surgery received iv isradipine, a new dihydropyridine calcium-channel antagonist. Mean duration of the isradipine infusion was 96.9 +/- 29 min. Mean dose of isradipine, indexed to weight, was 16.63 +/- 6.66 micrograms/kg (n = 20). MEASUREMENTS AND MAIN RESULTS: Twenty of the 21 patients achieved satisfactory BP control. The reduction in mean arterial pressure (MAP), first noted at the 15-min point, was maximal at 1 hr when MAP decreased from 102 +/- 9 mm Hg baseline to 81 +/- 5 mm Hg (p less than .01), accompanied by a significant (p less than .01) decrease in systemic vascular resistance from 1753 +/- 339 baseline to 1180 +/- 229 dyne.sec/cm5. The CVP, pulmonary artery diastolic pressure, and pulmonary artery occlusion pressure did not change significantly. Heart rate and cardiac index increased; however, stroke volume index did not change. CONCLUSIONS: Isradipine is an acceptable agent for the treatment of hypertension in this setting.

Endomyocardial biopsy: variations in venous access for endomyocardial biopsy in cardiac transplantation.

With the increasing number of cardiac transplantation procedures performed worldwide, a strategy for endomyocardial biopsy techniques has evolved at our institution. Specific approaches for venous access for biopsy purposes are described. These include approaches via the right internal jugular vein, right external jugular vein, left subclavian vein, and the femoral veins. Particular emphasis is placed on the technical nuances of each approach. In approximately 2,000 endomyocardial biopsies performed on 155 transplant patients from 1984-1989, only two major complications occurred, only one of which required operative intervention. This was a perforated right ventricle, and the patient recovered after repair without further sequelae. No pneumothoraces or infection occurred during this time period. With proper understanding of regional anatomy, fluoroscopic appearance, and experience, endomyocardial biopsies can be performed with an extremely low incidence of major or minor complications.

Successful heart transplantation in recipients with recent preoperative pulmonary emboli.

Acute pulmonary embolus (less than 6 weeks old) has been considered an absolute contraindication to heart transplantation for fear of the potential problems of lung abscess, empyema, bronchopleural fistula, and systemic sepsis in an immunosuppressed patient. It is difficult to adhere to this principle because 30% to 50% of patients with dilated cardiomyopathy may have an acute pulmonary embolus and would be excluded from transplantation. Several centers have considered such patients for heart transplantation if they are young, on maximal medical therapy, and in extremis. The surgical management of the postoperative pulmonary problems can include bronchoscopy, antibiotics, surgical drainage, decortication, and pulmonary resection with or without muscle flaps. We describe our approach to two such patients who were managed successfully with lobectomies and latissimus dorsi muscle flaps to seal the bronchus and fill the pleural space.

Sternotomy closure with Parham bands.

The closure of a median sternotomy incision requires secure bony approximation to prevent postoperative pain, sternal click, and/or nonunion of bone. The standard technique of sternotomy closure involves the use of stainless steel wires for reapproximation of the sternum. These wires occasionally break or pull through bone, resulting in instability of either a portion of the sternum or the entire sternum. Presented here is our technique for sternotomy closure that provides secure closure with reduced postoperative morbidity.