A group of investigators found that a mutation in the catechol-O-methyltransferase (COMT) gene can put heart surgery patients at risk of developing shock and kidney failure. These patients also did not respond well to noradrenaline post surgery.
Scientists from Charite Universittsmedizin Berlin, the Max Delbruck Center for Molecular Medicine Berlin-Buch, and the Austin Hospital in Melbourne collaborated on the research. Their results appear in the Journal of the American Society of Nephrology in a paper called “Decreased Catecholamine Degradation Associates with Shock and Kidney Injury after Cardiac Surgery.”
Certain variants of the COMT gene have long been suspected to play a role in shock and kidney failure in patients following heart surgery. The COMT enzyme is involved in metabolizing norepinephrine, a drug that is given to patients post surgery to stimulate their blood flow and to normalize their blood pressure.
The researchers thus investigated the COMT in 260 patients who underwent heart bypass surgery in their study published in the Journal of the American Society of Nephrology. They showed show that the genetic variant they call LL can lower the activity of the COMT enzyme. As a result, LL patients are more likely to develop shock and kidney failure.
In addition, LL patients who experience shock do not respond very well to treatment with norepinephrine, since it cannot fully be metabolized. As a result, too much norepinephrine remains in the body and the drug is no longer effective.
The researchers therefore suggest that “perhaps more suitable hemodynamics could be achieved in LL patients were they given vasopressin rather than noradrenaline, and acute kidney injury might be attenuated by avoidance of cardiopulmonary bypass and nephrotoxic medication.”