Getting the bad news about your artificial heart valve.

When the manufacturer of a medical device alone bears the responsibility for alerting recipients that the device may be defective, there is a certain temptation to gloss over the risk. The story of the Bjork-Shiley Convexo-Concave heart valve is a case in point. If the steering mechanism on your car is found to have a manufacturing or design defect, the National Highway Transportation Safety Administration directs the manufactuer to send a letter to all owners of the model (a registry is kept for this purpose) with instructions concerning replacement or repair. Owners are thus warned about the problem and given information about what to do about it, and manufacturers are prepared to make the necessary adjustments. This arrangement assumes that owners have a right to know about relevant defects, manufacturers have an obligation to inform and repair, and the government has the responsibility to oversee this process. While this arrangement is not perfect, it acknowledges the vulnerability of consumers and the corresponding obligations of the manufacturer and the government to protect them. What happens if a similar situation arises with your implanted artificial heart valve? Is there a similar system to warn recipients and provide information about what to do? The recent failure of hundreds of Bjork-Shiley Convexo-Concave (C/C) mechanical heart valves provides a case study on how information about the risk of failure was communicated to patients and the medical community. Unlike automobile recalls, the arrangements for dealing with defective heart valves were--until recently--indirect, ineffective, and marked by serious conflicts of interest. None of the three groups responsible for protecting patients with artificial heart valves--the Food and Drug Administration, the physicians and surgeons whose patients received the device, or the manufacturer (Shiley, Inc., of Irvine, California)--adequately responded to the discovery that the C/C valves were susceptible to strut fracture. The system placed commercial and professional interests over the rights of patients. Mechanical Heart Valves The development of mechanical heart valves is one of the success stories of contemporary medicine. Many persons with diseased heart valves become seriously disabled and soon die unless a prosthetic valve can be installed. The first mechanical heart valves were implanted in 1960, and since then their use has grown rapidly. Today about 40,000 American receive artificial heart valves each year.[1] Shiley, Inc., has been a pioneer in the development of mechanical heart valves. In 1974 they developed their radial spherical (R/S) valve, consisting of a disk attached to two wire struts that allow it to swing open and shut in response to blood flow. The struts are welded to a metal ring that is covered with a teflon sewing ring for attachment to the heart. In 1979 Shiley introduced a similar valve, the 60[degrees] Convexo-Concave (C/C), which they believed would improve blood flow through the valve. A C/C valve that opened to 70[degrees] was also manufactured, but it was not approved for sale in the United States. Blood clots (thromboses) caused by the presence of artificial implants are a serious problem and are responsible for the greatest percentage of complications that occur. Because the movement of blood is obstructed by the valve, there are areas of relatively stagnant flow where clots can form. They may form on the valve, preventing it from fully opening or closing, or they may break free and cause strokes, heart attacks, and other serious complications. Drugs to "thin" the patient's blood and reduce clotting are an essential part of the treatment after implantation, but there is a limit to their ability to reduce the incidence of thromboembolism--blood clots that break free and lodge in an artery, cutting off blood flow to tissues or organs. Shiley's 60[degrees] C/C valve, which appeared to allow better blood flow and promised a lower incidence of thromboembolism, was regarded as a significant improvement in heart valve technology. …