beta-receptor downregulation in congenital heart disease: A risk factor for complications after surgical repair?

Abstract

Background. Neurohormonal activation in children with heart failure due to congenital heart disease leads to downregulation of myocardial beta-receptors that may influence the postoperative course after cardiothoracic surgery. Methods. Myocardial biopsies of 26 children (aged 14 4 months) were obtained from the right atrium during cardiac surgery. Patients were allocated to either of two groups based on the duration of their intensive care unit stay: group 1 comprised those who stayed less than 7 days (n = 17), whereas group 2 comprised those who stayed more than 7 days, plus 3 infants who died during the early postoperative course (n = 9). For beta(1)- and beta(2)-mRNA quantitation, real-time polymerase chain reaction with fluorescence-labeled products was used. Results. Values for myocardial beta-receptor gene expression were twice as high in group 1 children compared with group 2 (beta(1)-receptor 0.12 +/- 0.07 versus 0.06 +/- 0.03, p = 0.0016; beta(2)-receptor 0.12 +/- 0.07 versus 0.06 +/- 0.03, p = 0.0071). beta-Receptor gene expression in 16 children who received standard treatment for heart failure averaged lower than in the 10 children who received additional propranolol. Conclusions. beta-Receptor downregulation due to congestive heart failure has an impact on the postoperative course in children with congenital disease and depends on heart failure therapy. (C) 2002 by The Society of Thoracic Surgeons.