The principles of metabolic therapy for heart disease

Metabolic therapy involves the administration of a substance normally found in the body to enhance a metabolic reaction within the cell. This may be achieved in two ways. First, for some systems, a substance can be given to achieve greater than normal levels in the body so as to drive an enzymic reaction in a preferred direction. Second, metabolic therapy may be used to correct an absolute or relative deficiency of a cellular component. Thus, metabolic therapy differs greatly from most standard cardiovascular pharmacologic therapy such as the use of ACE Inhibitors b-blockers, statins and calcium channel antagonists that are given to block rather than enhance cellular processes. In this review we highlight some metabolic substances that have potential benefit in treating heart disease or improving outcomes after cardiovascular interventions. Glucose-insulin-potassium therapy is protective against myocardial ischaemia by elevating myocardial glycogen levels. Coenzyme Q(10) is a lipid-soluble antioxidant that plays a crucial role in cellular ATP production. Magnesium orotate, a key intermediate in the biosynthetic pathway of glycogen, has been shown to improve the energy status of the cell and improve recovery from cardioplegic arrest. The amino acid aspartate plays an important role in providing energy substrates for oxidative phosphorylation in the myocyte. By improving cellular energy production, metabolic therapy has the potential to benefit cardiac function during the stress of cardiac surgery, myocardial infarction and cardiac failure.