Abbott

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shares rose early Thursday after the health care company said it has received conditional U.S. regulatory approval to test its drug-eluting stent.

The Chicago-based company said the Food and Drug Administration gave the OK for its ZoMaxx II drug-eluting stent.

The company will soon begin enrolling the first 250 patients for clinical trial of its ZoMaxx II device. The start of enrollment is consistent with anticipated U.S. approval for ZoMaxx in the second half of 2007. The trial will enroll 1,670 coronary artery disease patients in up to 80 centers.

Abbott is already conducting testing on its ZoMsxx I stent in more than 30 centers in Europe, Australia and New Zealand.

If successful, Abbott would join

Johnson & Johnson

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and

Boston Scientific

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as the only companies with U.S. approval for drug-eluting stents.

Medtronic

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is also developing a device for U.S. approval.

Drug-coated stents are meshlike metal tubes inserted into arteries after vessel-clogging plaque has been removed. The stents improve blood flow and reduce the risk of heart attack. Drug-coated stents, also known as drug-eluting stents, release chemicals into the arteries periodically to reduce the risk of arteries reclogging. Uncoated stents reduce the reclogging risk too, but the drug-coated devices are more effective.

Shares rose 34 cents, or 0.7%, to $47.95 in the premarket.