Characteristics of Hearts at Necropsy in Patients Treated Chronically With Prednisone (The Corticosteroid Heart)

Update and breakthrough in cardiac xenotransplantation

PURPOSE OF REVIEW

Considerable advancements have been made in the field of cardiac xenotransplantation in the recent years, achieving prolonged survival of the life-supporting cardiac xenograft and paving the way toward first clinical implications.

RECENT FINDINGS

The combination of genetic modifications and novel immunosuppression with costimulation blockade, as well as supporting therapy with antiinflammatory treatment, growth prevention, and adaptation of the heart procurement system to reduce myocardial ischemia and reperfusion injury improves the overall cardiac xenograft function and overall survival in nonhuman primates. Through the newly identified xenoantigens and novel gene-editing techniques, further genetic modification of the porcine xenografts should be explored, to ensure clinical safety.

SUMMARY

With continuous progress in all fields of cardiac xenotransplantation, first clinical use in humans seems accomplishable. To ensure the clinical safety and to conform to the ethical regulations, further investigation of the infectious and immunological implications on humans should be explored prior to first clinical use. The first clinical use of cardiac xenotransplantation will be limited to only highly selected patients.

Massive Cardiomegaly (>1000 g Heart) and Obesity

Described herein are certain clinical and morphologic findings in 9 patients who at necropsy had hearts weighing >1000 g, a weight approximately 3 times normal. With the exception of 2 patients with hypertrophic cardiomyopathy, the common finding in the remaining 7 patients was obesity. None had valvular heart disease, the previously described major cause of massive cardiomegaly. Thus, obesity needs to be added to the causes of massive cardiomegaly, a cause not previously recognized. Electrocardiograms in 4 patients disclosed high total 12-lead QRS voltage on the electrocardiogram in only one despite the massive cardiomegaly.

Morphologic Findings in Donor (Transplanted) Hearts at Necropsy Early and Late After Orthotopic Heart Transplantation

Little necropsy information is available on donor hearts in place in recipients for varying periods. Necropsy studies were performed in 79 patients who had survived from 1 day to 17 years after orthotopic heart transplantation (OHT). At OHT, the 79 patients ranged in age from 3 to 70 years (mean 51), and at death, from 20 to 76 years (mean 54). The native hearts tended to be larger than the donor hearts in the 22 patients surviving ≤60 days and the donor hearts tended to be larger in the 57 patients surviving >60 days, suggesting that the donor hearts increased in weight with time. Cardiac adiposity increased with time. Grossly visible myocardial lesions were seen in 24 (30%) of the 79 cases: necrosis only in 20; fibrosis only in 2, and both in 2. One or more epicardial coronary arteries were narrowed >75% in cross-sectional area in 25 (32%), 1 of whom was in the group surviving ≤60 days. The right ventricular cavity was dilated in 73 cases (92%) and the left ventricular cavity in 39 cases. Evidence of graft rejection (lymphocytic infiltrates) was found in 50 patients (63%); in 8 (36%) of the 22 patients surviving ≤60 days, and in 42 (74%) of the 57 surviving >60 days. The lymphocytic infiltrates were largest in the subepicardial adipose tissue, next in myocardium, and least in endocardium. The quantity of the cellular infiltrates varied considerably among the patients. In conclusion, with time, the donor hearts tended to increase in weight, in the quantity of adipose tissue, in the amounts of coronary narrowing, in the frequency of ventricular cavity dilatation (particularly the right ventricle), and in the frequency of lymphocytic infiltrates (evidence of rejection).