Roche Diagnostics Announces Nationwide Recall on Medical Device Used to Determine Blood Clotting Time

Roche Diagnostics Announces Nationwide Recall on Medical Device Used to Determine Blood Clotting Time

Contact:
Roche Diagnostics' Point-of-Care Technical Service Center 1-800-820-0995

FOR IMMEDIATE RELEASE -- October 19, 2006 -- Roche Diagnostics is notifying users of an important recall of all CoaguChek PT test strips currently in the market, due to a potential for a test strip defect that may cause falsely elevated test results. The company has identified the root cause and is instituting corrective action with highest priority. To date, the company has confirmed one incident and its internal investigation suggests that a small percentage of strips may be affected. To date, no deaths, illnesses or injuries have been reported due to this issue.

CoaguChek PT test strips are used by patients in the home and by professionals in medical settings to determine blood clotting time of patients taking anti-coagulants, also known as blood thinners. Blood thinners are used to treat patients with a potential for blood clots, for example, patients with heart valve replacements, certain types of heart disease or blood clots in their legs. Incorrect results may have serious or life threatening consequences because patients may be improperly treated.

Roche Diagnostics has determined the potential for a test strip defect when insufficient active ingredient (thromboplastin) is applied to the test strip, possibly causing falsely elevated results. As a result of the unpredictable positive bias, patient test results may be falsely elevated. This can result in an incorrect dose of anti-coagulant or unnecessary corrective measures to reduce the effect of circulating anti-coagulants. Both incorrect treatment choices could put patients at risk for blood clots.

Roche Diagnostics is notifying all home users of the CoaguChek PT test strip to immediately discontinue use of and discard the product as well as to consult with their health care provider to determine alternate testing methodologies and clinical implications. U.S. customers with questions or concerns should call Roche Diagnostics' Point-of-Care Technical Service at 1-800-820-0995.

Roche Diagnostics is notifying all health care professionals who use the CoaguChek PT test strip to institute 'duplicate testing' - or two strips on each patient - using different lot numbers to reduce the risk of bias. If health care professionals require another lot to enable duplicate testing, they are encouraged to call their medical supply distributor. For general questions, health care professionals should call the company's Point-of-Care Technical Service Center at 1-800-820-0995. These actions must remain in place until the issue has been resolved and health care professionals are supplied with unaffected replacement product.

Letters are being sent to customers, providers and physicians - including additional information regarding this voluntary action. Roche Diagnostics is working with its affiliates worldwide to coordinate appropriate activities. Any adverse reactions experienced with the use of this product, and/or quality problems should also be reported to the FDA's MedWatch Adverse Event Reporting program online http://www.fda.gov/medwatch/report.htm by phone 1-800-FDA-1088, or by returning the postage-paid FDA form 3500 [which may be downloaded from http://www.fda.gov/medwatch/getforms.htm by mail to MedWatch, 5600 Fishers Lane, Rockville, MD 20852-9787 or fax 1-800-FDA-0178. This action is being taken by Roche Diagnostics with the knowledge of the U.S. Food and Drug Administration.

http://www.fda.gov/Medwatch/safety/2006/safety06.htm#CoaguChek

http://www.fda.gov/oc/po/firmrecalls/roche10_06.html

Home INR Machines and Antiphospholipid Antibodies

Finally - someone has spoken up and said these machines do not work with us patients....that you are really playing Russian Roulette!

http://www.fvleiden.org/ask/94.html

Q."I bought a home Coaguchek® INR machine. My insurance company refused to pay for it, so I paid for it out of my own money, close to $ 2000. I have antiphospholipid antibodies and am on warfarin. Initially, I did many comparisons between the machine and hospital-testing INRs, before I and my doctor accepted the machine's numbers. Things were initially working fine. But recently I noticed that there was a discrepancy between my home INR machine (which read an INR of 7.8) and a hospital INR (which was 3.5). I ran all the controls for the machine (liquid and electronic) and they all ran fine. I called the company. They said their machine was fine. I bought a new box of test strips and the discrepancies were still there. I am done using the machine. I will deal with the hassle of going to the lab. At least I know those INR's are correct. I am really disgusted at what a waste of money the machine was."

A. Home INR machines do not give accurate readings in about 1/3 rd of patients with antiphospholipid antibodies who are on warfarin. This is not due to the machine malfunctioning, but likely due to antibodies interfering with the test method of the home INR machines

In one third of patients with antiphospholipid antibodies the INRs read by the home INR machines are unreliable: (a) they either read too high, compared to INRs tested in a laboratory from an i.v. stick (reference 2), or (b) the instruments flash up an error message (reference 1). This inaccuracy is likely caused by the presence of the antiphospholipid antibodies. Since antibody levels can fluctuate over time, the instrument may give accurate readings at times when the antibody levels are low, but inaccurate ones at times when the levels are higher. This is a phenomenon not unique to the Coaguchek® instrument, but is also seen with the ProTime® and the INRatio® instruments (reference 1,2). In patients who do not have antiphospholipid antibodies the home INR machines give reliable readings and are a good way to monitor warfarin therapy (ref. 3).

Personal Comment:
Because of the potential inaccuracies of home INR machines in patients with antiphospholipid antibodies, I prefer to see these patients not use home INR machines, but have their warfarin monitored with i.v. blood draws through an office or hospital laboratory. However, if a patient with antiphospholipid antibodies decides to use a home INR machine, I recommend that initially and every so often thereafter, such as every 6 months, the INR of the machine be compared to the INR obtained at a laboratory. If the machine gives unreliable readings, the patient should switch to i.v. stick INR measurements through a laboratory. Alternatively, the patient could correlate the INRs obtained with the home INR machine to the laboratory INR, and thus determine his/her unique therapeutic range with the machine. The patient could then continue using the machine.

References:

Perry SL, Samsa GP, Ortel TL: Point-of-care testing of the international normalized ratio in patients with antiphospholipid antibodies. Thromb Haemost 2005 Dec;94(6):1196-202.
Moll S, Wobbleton DL, Misita CP, Bryant B, Malone R, Musty M: INR Determination by plasma-based methods versus point-of-care instruments in patients with antiphospholipid antibody syndrome on anticoagulants. Int Soc Thromb Haemost meeting; Sydney, Australia, Aug 2005. J Thromb Haemost. 2005 Aug;3(suppl 1);abstract.
Yang DT, Robetorye RS, Rodgers GM: Home prothrombin time monitoring: a literature analysis. Am J Hematol 2004;77:177-186.

Finally - someone has spoken up and said these machines do not work with us patients....that you are really playing Russian Roulette!

http://www.fvleiden.org/ask/94.html

Q."I bought a home Coaguchek® INR machine. My insurance company refused to pay for it, so I paid for it out of my own money, close to $ 2000. I have antiphospholipid antibodies and am on warfarin. Initially, I did many comparisons between the machine and hospital-testing INRs, before I and my doctor accepted the machine's numbers. Things were initially working fine. But recently I noticed that there was a discrepancy between my home INR machine (which read an INR of 7.8) and a hospital INR (which was 3.5). I ran all the controls for the machine (liquid and electronic) and they all ran fine. I called the company. They said their machine was fine. I bought a new box of test strips and the discrepancies were still there. I am done using the machine. I will deal with the hassle of going to the lab. At least I know those INR's are correct. I am really disgusted at what a waste of money the machine was."

A. Home INR machines do not give accurate readings in about 1/3 rd of patients with antiphospholipid antibodies who are on warfarin. This is not due to the machine malfunctioning, but likely due to antibodies interfering with the test method of the home INR machines

In one third of patients with antiphospholipid antibodies the INRs read by the home INR machines are unreliable: (a) they either read too high, compared to INRs tested in a laboratory from an i.v. stick (reference 2), or (b) the instruments flash up an error message (reference 1). This inaccuracy is likely caused by the presence of the antiphospholipid antibodies. Since antibody levels can fluctuate over time, the instrument may give accurate readings at times when the antibody levels are low, but inaccurate ones at times when the levels are higher. This is a phenomenon not unique to the Coaguchek® instrument, but is also seen with the ProTime® and the INRatio® instruments (reference 1,2). In patients who do not have antiphospholipid antibodies the home INR machines give reliable readings and are a good way to monitor warfarin therapy (ref. 3).

Personal Comment:
Because of the potential inaccuracies of home INR machines in patients with antiphospholipid antibodies, I prefer to see these patients not use home INR machines, but have their warfarin monitored with i.v. blood draws through an office or hospital laboratory. However, if a patient with antiphospholipid antibodies decides to use a home INR machine, I recommend that initially and every so often thereafter, such as every 6 months, the INR of the machine be compared to the INR obtained at a laboratory. If the machine gives unreliable readings, the patient should switch to i.v. stick INR measurements through a laboratory. Alternatively, the patient could correlate the INRs obtained with the home INR machine to the laboratory INR, and thus determine his/her unique therapeutic range with the machine. The patient could then continue using the machine.

References:

Perry SL, Samsa GP, Ortel TL: Point-of-care testing of the international normalized ratio in patients with antiphospholipid antibodies. Thromb Haemost 2005 Dec;94(6):1196-202.
Moll S, Wobbleton DL, Misita CP, Bryant B, Malone R, Musty M: INR Determination by plasma-based methods versus point-of-care instruments in patients with antiphospholipid antibody syndrome on anticoagulants. Int Soc Thromb Haemost meeting; Sydney, Australia, Aug 2005. J Thromb Haemost. 2005 Aug;3(suppl 1);abstract.
Yang DT, Robetorye RS, Rodgers GM: Home prothrombin time monitoring: a literature analysis. Am J Hematol 2004;77:177-186.