aortic3
New member
Long time lurker, first time poster.
Quick background on me:
- Born with bicuspid aortic.
- Age 9: commissurotomy of aortic.
- Age 24: Ross Procedure.
- Age 46: Mechanical Aortic and Pulmonary.
- INR Range: 2.5-3.5
I have been on Warfarin for 10 years, check my INR 2-3 times a week with Coaguchek. My coaguchek has reliably been 15-20% higher than the lab. Basically the higher the INR, the bigger the variation. The variation is consistent. I keep a spreadsheet with statistics of every Lab vs coaguchek INR and can easily map what my INR is.
Question #1: Am I the only one whose coaguchek reports consistently higher than the lab every time? Does anyone have an explanation why?
For years I went to the same local hospital for an INR check. They used a Stago machine. Stago measures with viscosity based detection. It detects clot formation by measuring changes in the blood's viscosity rather than relying on optical methods.
One day that local hospital switched from Stago to Sysmex. Sysmex measure coagulation with a photo-optical detection method. The Sysmex measurement matches my coaguchek measurement (aka 15-20% higher than stago)
As an experiment one day I went to a hospital with Stago (INR=3.3), my local hospital with Sysmex(INR=.4.1). Both results were where I expected them. Sysmex was 20% higher than Stago. Both results were reported to my Warfarin provider which made for a fun day on them advising me on how to manage my warfarin that day.
FWIW, Labcorp uses Sysmex.
It's concerning that different machines used by hospitals and labs can give entirely different INR #'s. Sysmex being 15-20% higher than stago. I repeated this experiment a few times thinking maybe the Sysmex machine wasn't calibrated. But the Sysmex machine was consistently 15-20% higher than Stago. Which one do I believe?
I'm not sure what my question is here. Kinda wondering has anyone else had experiences like this? Or have detailed knowledge of Stago vs Sysmex?
Thanks.
Quick background on me:
- Born with bicuspid aortic.
- Age 9: commissurotomy of aortic.
- Age 24: Ross Procedure.
- Age 46: Mechanical Aortic and Pulmonary.
- INR Range: 2.5-3.5
I have been on Warfarin for 10 years, check my INR 2-3 times a week with Coaguchek. My coaguchek has reliably been 15-20% higher than the lab. Basically the higher the INR, the bigger the variation. The variation is consistent. I keep a spreadsheet with statistics of every Lab vs coaguchek INR and can easily map what my INR is.
Question #1: Am I the only one whose coaguchek reports consistently higher than the lab every time? Does anyone have an explanation why?
For years I went to the same local hospital for an INR check. They used a Stago machine. Stago measures with viscosity based detection. It detects clot formation by measuring changes in the blood's viscosity rather than relying on optical methods.
One day that local hospital switched from Stago to Sysmex. Sysmex measure coagulation with a photo-optical detection method. The Sysmex measurement matches my coaguchek measurement (aka 15-20% higher than stago)
As an experiment one day I went to a hospital with Stago (INR=3.3), my local hospital with Sysmex(INR=.4.1). Both results were where I expected them. Sysmex was 20% higher than Stago. Both results were reported to my Warfarin provider which made for a fun day on them advising me on how to manage my warfarin that day.
FWIW, Labcorp uses Sysmex.
It's concerning that different machines used by hospitals and labs can give entirely different INR #'s. Sysmex being 15-20% higher than stago. I repeated this experiment a few times thinking maybe the Sysmex machine wasn't calibrated. But the Sysmex machine was consistently 15-20% higher than Stago. Which one do I believe?
I'm not sure what my question is here. Kinda wondering has anyone else had experiences like this? Or have detailed knowledge of Stago vs Sysmex?
Thanks.
