High-Tech Look at Heart Valves: A new...

High-Tech Look at Heart Valves: A new diagnostic imaging technique may help thousands of patients with a potentially faulty artificial heart valve determine whether they should have the device removed, according to a study. Doctors and patients have struggled with whether to replace 45,000 Bjork-Shiley Convexo-Concave valves implanted from 1979 through 1986. The valves have fractured in 572 patients, leading to death in about two-thirds of them. The valve was sold by the Shiley Inc. unit of drug maker Pfizer Inc., which removed it from the market. Using a high-resolution X-ray technique called cineradiography, researchers have been able to determine for the first time which valves are at risk for fracture, according to the study, published Thursday in the New England Journal of Medicine. Siemens, a maker of heart-imaging systems, worked with researchers to magnify pictures of the device. The researchers could then determine if the legs of a strut that holds the valve in place had broken, a precursor to a complete fracture. Faulty valves could be replaced before they broke. The researchers studied 315 patients with large sizes of replacement mitral valves, which serve the left side of the heart and are most prone to breakage. The imaging showed that 11 patients had valves where a leg of the strut was definitely or probably broken. After removal, 10 of the valves were found to be faulty and one was intact. One patient died during surgery. The researchers noted that the Food and Drug Administration has not yet reviewed the technique. The agency’s approval is typically required for federal health care programs to pay for the screening.