People who survive a heart attack are often left with damage to the heart muscle and an increased risk of heart failure. Injections delivered directly into the heart after a heart attack may limit this damage, a test in pigs shows.
A heart attack typically occurs when a blood clot shuts off the flow of blood and oxygen to a section of the heart muscle. When the flow is restored, enzymes called matrix metalloproteinases become overactive, causing scarring that compromises the heart’s pumping ability and increases the risk of heart failure, the heart’s inability to keep up with its workload.
The new treatment consists of a hydrogel similar to one found in the body mixed with a compound called TIMP-3, which gets slowly released from the gel after injection into the heart. TIMP-3 naturally inhibits matrix metalloproteinases. Shaina Eckhouse of the Medical University of South Carolina in Charleston and her colleagues describe the treatment in the Feb. 12 Science Translational Medicine.
The researchers induced nonlethal heart attacks in pigs and then treated some with the hydrogel containing TIMP-3s. Other pigs got hydrogel lacking TIMP-3s or a placebo injection. Pigs getting the TIMP-3-laden hydrogel had less heart damage and better heart function afterward.
S.R. Eckhouse et al. Local hydrogel release of recombinant TIMP-3 attenuates adverse left ventricular remodeling after experimental myocardial infarction. Science Translational Medicine. Vol. 6, February 12, 2014, p. 223ra21. doi: 10.1126/scitranslmed.3007244.
F. G. Spinale et al. Dynamic changes in matrix metalloproteinase activity within the human myocardial interstitium during myocardial arrest and reperfusion. Circulation. Vol. 118, Septemer 30, 2008, p. S16.doi: 10.1161/CIRCULATIONAHA.108.786640.
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