Clinical diagnostics market sectors that continue to attract investment by suppliers include the hospital-based point-of-care (POC) market, self-testing products and products for the physician's office laboratory (POL). The POC hemostasis testing products segment is advancing on two fronts. There is growing interest in platelet function testing at the point of care, as well as in tests that can help identify patients who are at risk for conditions such as heparininduced thrombocytopenia, a condition affecting patients who have had prior surgery and which can lead to life-threatening disorders such as pulmonary embolism, gangrene and thromboembolism. In addition, coagulation self-testing is expected to increase in popularity later this year as reimbursement becomes available through Medicare for heart valve patients.

Up to half of all cardiac surgery patients may have antibodies to heparin as a result of a prior treatment, and in 1 to 2 per cent of those patients thrombocytopenia occurs due to formation of immune complexes when they receive another heparin dose. About 51 per cent of patients experiencing heparin-induced thrombocytopenia develop thromboembolism, and 37 per cent die. To prevent such adverse events, Santrach uses the Ecarin Clotting Time (ECT) assay manufactured by Pharmanetics (Morrisville, North Carolina) and marketed exclusively by Bayer Diagnostics on the RapidPoint Coag POC testing system. The test is approved under humanitarian device exemption regulations, and thus must be provided under institutional review board control and informed consent.

However, it can play an important role in avoiding adverse events in cardiac surgery patients who are typically at high risk. When a patient scheduled for cardiac surgery tests positive with the ECT assay, the physician can either delay the procedure until the antibodies disappear or switch to an alternative anticoagulant.

Platelet function testing is gaining increased importance as a result of the growing use of anti-platelet agents such as clopidogrel, ticlopidine, aspirin, and GP IIb/IIIa inhibitors in cardiology. As discussed by Steven Steinhubl, MD, of the University of North Carolina (Chapel Hill, North Carolina) during the AACC meeting in the sprawling Orange County Convention Center, there is a high degree of variability among patients in their response to such agents, but most are treated with a standardized dose, at present. Systems now available for platelet function testing include the PFA-100 from Dade Behring, the Ultegra from Radiometer Medical (Copenhagen, Denmark) and the Platelet-works from Helena Laboratories (Beaumont, Texas). By using POC platelet function testing to optimize the dose of anti-platelet agents, physicians can minimize concerns that arise, for example, when patients from the cath lab must undergo emergency CABG procedures. Since an increasing number of patients undergoing angioplasty and stent procedures are being treated with anti-platelet agents, particularly clopidogrel, those who are high responders are at risk of excessive bleeding if they must be switched to surgical treatment and have received a standardized dose. Tests are now available for POC use on systems such as the Ultegra, for example, to monitor not only anti-platelet agents such as abciximab but also aspirin and other agents to ensure that the dosage is optimized for each patient.

The market for coagulation self-testing products is likely to be stimulated later this year by the availability of reimbursement, as well as by the introduction of additional products tailored for that application. Reimbursement under Medicare will be available in three categories, including 1) a physician reimbursement for training of patients in the use of the test system; 2) an additional reimbursement to physicians for oversight of ongoing testing (paid in four-test increments); and 3) reimbursement for the cost of the test. Reimbursement is being provided under a Diagnostic Service Model, with payment made to the agency that is managing the patient. At least one private insurer, Aetna (Hartford, Connecticut), has indicated that coverage will be added, according to LifeScan (Milpitas, California), although a different reimbursement model will be used.

However, as reimbursement becomes available in October of this year, there may be renewed interest in the market. The LifeScan Harmony system will be available for shipment at the end of the year, with pricing for the instrument expected to be between $1,295 and $1,500. There is potentially a large market for home prothrombin time or INR testing. Data from the Center for Medicare & Medicaid Services (Baltimore, Maryland) indicates that there are more than 1 million patients in the U.S. alone who have conditions such as atrial fibrillation or who have suffered a stroke who could benefit from anti-coagulation therapy but do not receive it, and that for 80% of the patients who are receiving therapy the frequency of testing is probably too low, as indicated by increased rates of adverse events. Home testing, now employed by less than 5% of all patients, is a potential solution to the problem of underutilization of therapy and of testing, since physicians are often reluctant to subject patient s, particularly older ones, to a potentially dangerous treatment with adverse event rates in excess of 15%. Since home monitoring has been shown to provide the lowest adverse event rates, it may become the preferred method in the future, and could also result in increased utilization of anticoagulation therapy.

- (Courtesy: BBI Group)