Gene Test Determines Risk of Heart Surgery Complications
The
researchers studied the gene that encodes the enzyme
catechol-O-methyltransferase (COMT). 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
(noradrenalin), a drug that is given to patients post-surgery to stimulate
their blood flow and to normalize their blood pressure.
Professor
Duska Dragun, MD, Charité, Professor Friedrich Luft, MD (Experimental and ClinicalResearchCenter
, MDC) and Dr. Wolf-Hagen Schunck (MDC) studied the COMT gene in 260 patients
who underwent heart bypass surgery. They were able to 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 the activity of the COMT enzyme is lowered
in LL patients, norepinephrine cannot fully be metabolized. As a result, too much norepinephrine remains in the body
and the drug is no longer effective.
Therefore,
the researchers suggest that “perhaps, more suitable hemodynamics could be
achieved in LL patients were they given vasopressin rather than noradrenaline (norepinephrine)
and acute kidney injury might be attenuated by avoidance of cardiopulmonary
bypass and nephrotoxic medication.” Larger clinical trials are necessary to show
whether patients need to undergo genetic testing prior to heart surgery to
determine their risk for shock and kidney failure.
Decreased Catecholamine Degradation Associates with Shock and Kidney
Injury after Cardiac Surgery
Anja Haase-Fielitz,*† Michael Haase,*†
Rinaldo Bellomo,* Gavin Lambert,‡ George Matalanis,§
David Story,§ Laurie Doolan,§ Brian Buxton,§
Geoff Gutteridge,* Friedrich C. Luft,II Wolf-Hagen Schunck,¶
and Duska Dragun†**
*Department of Intensive Care, Austin Health,
Melbourne, Australia; †Department of Nephrology and Intensive Care Medicine,
Campus Virchow Clinic, Medical Faculty of the Charité, Berlin, Germany; ‡Baker Heart Research
Institute, Melbourne, Australia; §Departments of Anaesthesiology and Cardiac
Surgery, Austin Health, Melbourne, Australia; _Experimental and Clinical
Research Center, Max Delbrück Center for Molecular Medicine and HELIOS
Klinikum, Berlin, Germany; ¶Max Delbrück Center for Molecular Medicine, Berlin,
Germany; **Center for Cardiovascular Research, Charité, Berlin, Germany
Barbara Bachtler
Press and Public Affairs
Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch
Robert-Rössle-Straße 10; 13125 Berlin; Germany
Phone: +49 (0) 30 94 06 - 38 96
Fax: +49 (0) 30 94 06 - 38 33
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