The American Medical Association (AMA) today urged the U.S. Department of Justice to block the proposed acquisition of Aetna, Inc. by CVS Health Corporation, and shared with federal regulators an exhaustive AMA analysis indicating the proposed merger would likely substantially diminish competition in many health care markets to the detriment of patients. The 29-page analysis compiled by the AMA noted that the merger is expected to increase premiums due to an increase in market concentration in 30 of 34 Medicare Part D regional markets. In 10 of 34 Medicare Part D regional markets, the deal would exceed a threshold set by federal antitrust guidelines for a merger that should be presumed likely to enhance market power. Full story.