It has been a tough month for interventional cardiology. First, the hospital chain HCA confirmed in its Aug. 6 investor call that it had been approached by the civil division of the U.S. Attorneys Office in Miami seeking reviews of its catheterization labs. Meanwhile, further up the East Coast, Exeter Hospital in Exeter, N.H., has been screening patients this month who underwent treatment in its cath lab who may have been infected with Hepatitis C.