COAG-SENSE PT/INR MONITORING METER
Report
- Report Number
- 3007507465-2026-00003
- Event Type
- Injury
- Date Received
- March 18, 2026
- Date of Event
- October 31, 2025
- Report Date
- February 8, 2026
- Manufacturer
- COAGUSENSE, INC.
- Product Code
- GJS
- PMA / PMN Number
- K212779
- Adverse Event
- Yes
- Report Source
- Manufacturer report
- Reporter Location
- NJ, US
- Reporter Occupation
- 003
Narratives
COAGUSENSE, INC. ACKNOWLEDGES MEDWATCH REPORT MW5183879, WHICH IS DATED F(B)(6) 2026, AND IDENTIFIED THROUGH THE FDA MAUDE DATABASE. WHILE THE REPORT IS DATED (B)(6) 2026, COAGUSENSE WAS NOT FORMALLY NOTIFIED OF THIS EVENT UNTIL (B)(6) 2026, UPON RECEIPT OF THE FDA NOTIFICATION LETTER (ATTACHED FOR REFERENCE). UPON BECOMING AWARE OF THIS EVENT, COAGUSENSE INITIATED ITS COMPLAINT HANDLING AND MDR EVALUATION PROCESSES IN A TIMELY MANNER. WE CONFIRM THAT WE ARE ACTIVELY ASSESSING THE REPORTABILITY OF THIS EVENT IN ACCORDANCE WITH 21 CFR PART 803 AND HAVE COMMENCED A THOROUGH INVESTIGATION. COAGUSENSE WILL ENSURE THAT ANY REQUIRED MEDICAL DEVICE REPORT IS SUBMITTED WITHIN THE APPLICABLE REGULATORY TIMEFRAME, CALCULATED FROM THE DATE THE FIRM BECAME AWARE OF THE EVENT. THE FOLLOWING TEXT IS THE SUMMARY OF THE MANUFACTURER'S (COAGUSENSE, INC.) INVESTIGATION AS A FOLLOW-UP TO THE INITIAL EMDR INFORMATION SUBMITTED ABOVE: COAGUSENSE, INC. INVESTIGATED MDR #MW5183879 CONCERNING REPORTED DISCREPANCIES BETWEEN THE COAG-SENSE® PT/INR METER AND LABORATORY INR RESULTS, ASSOCIATED WITH A SERIOUS ADVERSE EVENT (RETINAL ARTERIAL OCCLUSION AND VISION LOSS). A RETINAL ARTERY OCCLUSION (RAO) IS WHEN BLOOD FLOW TO THE EYE'S RETINA IS BLOCKED. YOUR EYES NEED A CONSTANT SUPPLY OF BLOOD TO SEE. THIS IS WHY AN RAO CAN CAUSE TEMPORARY[?]OR PERMANENT[?]LOSS OF VISION. BOTH LARGE AND SMALLER BLOOD VESSELS CALLED ARTERIES CARRY BLOOD FROM THE HEART TO THE EYE. SOMETIMES CHOLESTEROL, PLATELETS (WHICH CAUSE BLOOD TO CLOT), OR CALCIUM BUILDS UP INSIDE THESE BLOOD VESSELS. THIS BLOCKAGE[?]MUCH LIKE A KINK IN A HOSE STOPS THE FLOW OF WATER[?]STOPS THE FLOW OF BLOOD TO THE EYE. THIS IS WHAT CAUSES AN RAO. ACCORDING TO THE DESCRIPTION IN THE MDR, THE PATIENT CONDUCTED A SIDE-BY-SIDE COMPARISON IN THE HOSPITAL WITH THE COAG-SENSE METER. AS STATED, "THE RESULTS OF THE SIDE-BY-SIDE WERE 4.0 ON THE COAG-SENSE INR MACHINE AND 3.08 WITH THE BLOOD DRAW. THIS IS A .92 DIFFERENCE. IT WAS DETERMINED THAT MY HUSBAND BECAUSE OF THIS WAS NON-THERAPEUTIC FOR POSSIBLY 2 WEEKS WHICH CAUSED BLOOD CLOTS TO FORM, WHICH ONE BROKE OFF AND SHOT THROUGH IS PFO UP TO HIS LEFT EYE." AT THE TIME OF THIS COMPARISON, IT IS UNDERSTOOD THAT THE PATIENT'S THERAPEUTIC RANGE WAS 2.5 - 3.5 INR. IT IS ACKNOWLEDGED THAT THE PATIENT WAS SLIGHTLY OUTSIDE THEIR THERAPEUTIC RANGE WITH THE COAG-SENSE METER, BUT ON THE HIGH SIDE. THE HIGHER YOUR PT OR INR, THE LONGER YOUR BLOOD TAKES TO CLOT. AN ELEVATED PT OR INR MEANS YOUR BLOOD IS TAKING LONGER TO CLOT THAN YOUR HEALTHCARE PROVIDER BELIEVES IS HEALTHY FOR YOU. WHEN YOUR PT OR INR IS TOO HIGH, YOU HAVE AN INCREASED RISK OF BLEEDING. THEREFORE, THE RESULTS OBTAINED WERE NOT SUB-THERAPEUTIC (< TARGET RANGE) AND WOULD NOT HAVE CONTRIBUTED TO THE FORMATION OF BLOOD CLOTS. ALSO STATED IN THE DESCRIPTION, "WE REPORTED THIS TO COAG-SENSE, AND THEY REPLACED THE MACHINE IN (B)(6)." COAGUSENSE TECHNICAL SUPPORT RESEARCHED THE COMPANY'S DATABASES FOR ANY PREVIOUS COMPLAINTS RECORDED FOR THIS PATIENT, AND NONE WERE NOTED EITHER DIRECTLY BY THE PATIENT OR AS A COMPLAINT ESCALATION BY LINCARE. LINCARE IS ONE OF COAGUSENSE'S DISTRIBUTORS WHO OPERATES AS AN IDTF (INDEPENDENT DIAGNOSTIC TESTING FACILITY), PROVIDING DIAGNOSTIC TEST MATERIALS INDEPENDENT OF EITHER A PHYSICIAN'S OFFICE OR A HOSPITAL. UNDER MEDICARE THEY BILL FOR DIAGNOSTIC TESTS, NOT FOR TREATING PATIENTS, AND THEY ARE RESPONSIBLE FOR PROVIDING ALL TESTING SUPPLIES, TRAINING OF THE SELF-TESTER, AND COLLECTING TEST RESULTS TO CONVEY TO TREATING PHYSICIANS AT A FREQUENCY DECIDED PER THEIR PRESCRIPTION. THEY ARE THE OWNERS OF THE DEVICES SHIPPED TO THEM AND MUST COMPLY WITH TRACEABILITY AND OTHER STANDARDS UNDER MEDICARE REQUIREMENTS. LINCARE WOULD HAVE PROVIDED THE REPLACEMENT METER, AND THE ORIGINAL METER WAS NEVER RETURNED TO THE COAGUSENSE FOR INVESTIGATION. IN ADDITION, IT IS STATED THAT "WE GET THE COAG-SENSE THROUGH A SERVICE CALLED MDINR." THIS WEB APP IS OPERATED INDEPENDENTLY BY LINCARE AND IS NOT ASSOCIATED OR MANAGED BY COAGUSENSE. THERE IS NO ADDITIONAL INFORMATION AVAILABLE FROM THE PATIENT OR LINCARE. SHOULD THE ORIGINAL METER BE RETURNED OR IF THE IDENTIFICATION OF THE PATIENT TEST STRIPS BECOMES AVAILABLE, WE WILL REOPEN OUR INVESTIGATION TO DETERMINE IF ANY PRODUCT TRENDS ARE OF CONCERN.
COAGUSENSE, INC. ACKNOWLEDGES MEDWATCH REPORT MW5183879, WHICH IS DATED FEBRUARY 8, 2026, AND IDENTIFIED THROUGH THE FDA MAUDE DATABASE. WHILE THE REPORT IS DATED FEBRUARY 8, 2026, COAGUSENSE WAS NOT FORMALLY NOTIFIED OF THIS EVENT UNTIL (B)(6) 2026, UPON RECEIPT OF THE FDA NOTIFICATION LETTER (ATTACHED FOR REFERENCE). UPON BECOMING AWARE OF THIS EVENT, COAGUSENSE INITIATED ITS COMPLAINT HANDLING AND MDR EVALUATION PROCESSES IN A TIMELY MANNER. WE CONFIRM THAT WE ARE ACTIVELY ASSESSING THE REPORTABILITY OF THIS EVENT IN ACCORDANCE WITH 21 CFR PART 803 AND HAVE COMMENCED A THOROUGH INVESTIGATION. COAGUSENSE WILL ENSURE THAT ANY REQUIRED MEDICAL DEVICE REPORT IS SUBMITTED WITHIN THE APPLICABLE REGULATORY TIMEFRAME, CALCULATED FROM THE DATE THE FIRM BECAME AWARE OF THE EVENT.
MY HUSBAND, (B)(6), HAD AN RETINAL ARTERIAL OCCLUSION ON (B)(6) 2025. HE WAS HOSPITALIZED FOR A COUPLE OF DAYS FOR OBSERVATION. THEY FOLLOWED STROKE PROTOCOL AT THE HOSPITAL AND CALLED A RETINA SPECIALIST. OUR INTERNATIONAL NORMALISED RATIO (INR) MACHINE THAT WE USED AT HOME SEEMED TO BE GIVING INCONSISTENT RESULTS. AFTER VISITING THE CARDIOLOGIST, HE SUGGESTED WE SEE A HEMATOLOGIST. WE HAD A BLOOD WORKUP WITH THE HEMATOLOGIST AND A CONSULTATION WHERE WE BROUGHT OUR COAG-SENSE MONITOR WITH US. WE DID A SIDE BY SIDE AT THE HOSPITAL ON THAT DAY, (B)(6) 2025. THE RESULTS OF THE SIDE BY SIDE WERE 4.0 ON THE COAG-SENSE INR MACHINE AND 3.08 WITH THE BLOOD DRAW. THIS IS A .92 DIFFERENCE. IT WAS DETERMINED THAT MY HUSBAND BECAUSE OF THIS WAS NON-THERAPEUTIC FOR POSSIBLY 2 WEEKS WHICH CAUSED BLOOD CLOTS TO FORM, WHICH ONE BROKE OFF AND SHOT THOUGH HIS PFO (PATENT FORAMEN OVALE) UP TO HIS LEFT EYE. WE REPORTED THIS TO COAG-SENSE AND THEY REPLACED THE MACHINE IN (B)(6). WE HAVE BEEN USING THE NEW MACHINE AND INCREASE HIS THERAPEUTIC RANGE TO 3.0 - 3.7 (PREVIOUSLY 2.5 - 3.5, THE RANGE SUGGESTED FOR HIS CARBON COATED ONYX HEART VALVE). BY DOING THIS WE ARE TRYING TO AVOID A CLOT IN THE CASE THE MACHINE IS OFF. BECAUSE OF THE RETINAL ARTERY OCCLUSION, MY HUSBAND HAS PERMANENT VISION LOSS IN HIS LEFT EYE. FAST FORWARD TO (B)(6) 2026, (B)(6) HAD A HIP REPLACEMENT ON (B)(6) 2026. BEFORE LEAVING THE HOSPITAL, WE DECIDED TO DO A SIDE BY SIDE WITH THE NEW MACHINE TO ENSURE ACCURACY OF HIS AT HOME TESTING AS THIS IS VERY IMPORTANT FOR THE HIP AND HIS HEART VALVE. THE SIDE BY SIDE ONCE AGAIN HAD A BIG DISPARITY. WE DID THE SIDE BY SIDE ON (B)(6) 2026. THE SIDE BY SIDE WAS 2.3 ON THE COAG-SENSE INR MACHINE AND 1.46 WITH THE BLOOD DRAW. THIS IS A .84 DIFFERENCE. ACCORDING TO COAG-SENSE ONLY A .5 DIFFERENCE IS ACCEPTABLE. WE REACHED OUT TO THEM ON (B)(6) 2026, SENT THEM THE RESULTS AND HAVE YET TO HEAR BACK. I EXPECT THEY WILL CALL US SOON TO REPLACE THE MACHINE. THIS TYPE OF INACCURACY EFFECTS OUR DECISION AS TO HOW MUCH WARFARIN (B)(6) SHOULD TAKE. IN THE CASE OF (B)(6) 2025. HIS INR WAS 2.7 FOR THE 2 WEEKS PREVIOUS. IN THAT CASE WE THOUGHT HE WAS IN RANGE FOR THE WHOLE PERIOD OF TIME WHEN IN REALITY HE WAS NOT THERAPEUTIC IF IT WAS .84 OR .92 OFF GIVING PLENTY OF TIME FOR CLOTS TO FORM ON HIS VALVE. WE WERE NEVER NOTIFIED THAT THERE IS AN ACCEPTABLE AMOUNT IT COULD BE OFF SO THAT WE COULD ADJUST ACCORDINGLY. OBVIOUSLY NOW THAT WE KNOW THIS, WE ARE KEEPING HIS THERAPEUTIC RANGE HIGHER TO PROTECT HIM FROM THIS EVER HAPPENING TO HIM AGAIN. WE GET THE COAG- SENSE THOUGH A SERVICE CALLED MDINR THAT OUR CARDIOLOGIST SET UP FOR US. THE ADDRESS FOR COAG-SENSE IS: COAGUSENSE, INC (B)(6), (B)(6), (B) (6). INTERNATIONAL NORMALISED RATIO (INR) TEST BOTH DONE AT (B)(6) IN (B)(6). MY HUSBANDS RANGE IS 3.0 TO 3.7. THESE WERE THE BLOOD DRAWS. (B)(6) HAS TO BE THERAPEUTIC WITH HIS INR BECAUSE HE HAS A CARBON COATED ONYX TITANIUM HEAR VALVE. HIS THERAPEUTIC RANGE IS NOW 3 - 3.7.
MY HUSBAND, (B)(6), HAD AN RETINAL ARTERIAL OCCLUSION ON (B)(6) 2025. HE WAS HOSPITALIZED FOR A COUPLE OF DAYS FOR OBSERVATION. THEY FOLLOWED STROKE PROTOCOL AT THE HOSPITAL AND CALLED A RETINA SPECIALIST. OUR INTERNATIONAL NORMALISED RATIO (INR) MACHINE THAT WE USED AT HOME SEEMED TO BE GIVING INCONSISTENT RESULTS. AFTER VISITING THE CARDIOLOGIST, HE SUGGESTED WE SEE A HEMATOLOGIST. WE HAD A BLOOD WORKUP WITH THE HEMATOLOGIST AND A CONSULTATION WHERE WE BROUGHT OUR COAG-SENSE MONITOR WITH US. WE DID A SIDE BY SIDE AT THE HOSPITAL ON THAT DAY, (B)(6) 2025. THE RESULTS OF THE SIDE BY SIDE WERE 4.0 ON THE COAG-SENSE INR MACHINE AND 3.08 WITH THE BLOOD DRAW. THIS IS A .92 DIFFERENCE. IT WAS DETERMINED THAT MY HUSBAND BECAUSE OF THIS WAS NON-THERAPEUTIC FOR POSSIBLY 2 WEEKS WHICH CAUSED BLOOD CLOTS TO FORM, WHICH ONE BROKE OFF AND SHOT THOUGH HIS PFO (PATENT FORAMEN OVALE) UP TO HIS LEFT EYE. WE REPORTED THIS TO COAG-SENSE AND THEY REPLACED THE MACHINE IN NOVEMBER. WE HAVE BEEN USING THE NEW MACHINE AND INCREASE HIS THERAPEUTIC RANGE TO 3.0 - 3.7 (PREVIOUSLY 2.5 - 3.5, THE RANGE SUGGESTED FOR HIS CARBON COATED ONYX HEART VALVE). BY DOING THIS WE ARE TRYING TO AVOID A CLOT IN THE CASE THE MACHINE IS OFF. BECAUSE OF THE RETINAL ARTERY OCCLUSION, MY HUSBAND HAS PERMANENT VISION LOSS IN HIS LEFT EYE. FAST FORWARD TO (B)(6) 2026, (B)(6) HAD A HIP REPLACEMENT ON (B)(6) 2026. BEFORE LEAVING THE HOSPITAL, WE DECIDED TO DO A SIDE BY SIDE WITH THE NEW MACHINE TO ENSURE ACCURACY OF HIS AT HOME TESTING AS THIS IS VERY IMPORTANT FOR THE HIP AND HIS HEART VALVE. THE SIDE BY SIDE ONCE AGAIN HAD A BIG DISPARITY. WE DID THE SIDE BY SIDE ON (B)(6) 2026. THE SIDE BY SIDE WAS 2.3 ON THE COAG-SENSE INR MACHINE AND 1.46 WITH THE BLOOD DRAW. THIS IS A .84 DIFFERENCE. ACCORDING TO COAG-SENSE ONLY A .5 DIFFERENCE IS ACCEPTABLE. WE REACHED OUT TO THEM ON (B)(6) 2026, SENT THEM THE RESULTS AND HAVE YET TO HEAR BACK. I EXPECT THEY WILL CALL US SOON TO REPLACE THE MACHINE. THIS TYPE OF INACCURACY EFFECTS OUR DECISION AS TO HOW MUCH WARFARIN (B)(6) SHOULD TAKE. IN THE CASE OF (B)(6) 2025. HIS INR WAS 2.7 FOR THE 2 WEEKS PREVIOUS. IN THAT CASE WE THOUGHT HE WAS IN RANGE FOR THE WHOLE PERIOD OF TIME WHEN IN REALITY HE WAS NOT THERAPEUTIC IF IT WAS .84 OR .92 OFF GIVING PLENTY OF TIME FOR CLOTS TO FORM ON HIS VALVE. WE WERE NEVER NOTIFIED THAT THERE IS AN ACCEPTABLE AMOUNT IT COULD BE OFF SO THAT WE COULD ADJUST ACCORDINGLY. OBVIOUSLY NOW THAT WE KNOW THIS, WE ARE KEEPING HIS THERAPEUTIC RANGE HIGHER TO PROTECT HIM FROM THIS EVER HAPPENING TO HIM AGAIN. WE GET THE COAG- SENSE THOUGH A SERVICE CALLED MDINR THAT OUR CARDIOLOGIST SET UP FOR US. THE ADDRESS FOR COAG-SENSE IS: COAGUSENSE, INC (B)(6), (B)(6), (B) (6). INTERNATIONAL NORMALISED RATIO (INR) TEST BOTH DONE AT (B)(6) IN (B)(6). MY HUSBANDS RANGE IS 3.0 TO 3.7. THESE WERE THE BLOOD DRAWS. (B)(6) HAS TO BE THERAPEUTIC WITH HIS INR BECAUSE HE HAS A CARBON COATED ONYX TITANIUM HEAR VALVE. HIS THERAPEUTIC RANGE IS NOW 3 - 3.7.
Devices
| Seq | Brand | Generic | Product Code | Manufacturer | Model | Lot | UDI-DI |
|---|---|---|---|---|---|---|---|
| 695229 | COAG-SENSE PT/INR MONITORING METER | TEST, TIME, PROTHROMBIN | GJS | COAGUSENSE, INC. | 200107 |
Patients
| Seq | Age | Sex | Outcome | Treatment |
|---|---|---|---|---|
| 1 | 61 YR | Male | Other| H | B12 1000 MCG (1 TABLET).| B12 1000 MCG (1 TABLET).| COQ10 100 MG JUICE PLUS - QUAD.| COQ10 100 MG JUICE PLUS - QUAD.| HYDROCHLOROTHIAZIDE 12.5 MG.| HYDROCHLOROTHIAZIDE 12.5 MG.| IRON 325 MG (1 TABLET).| IRON 325 MG (1 TABLET).| NEBIVOLOL 2.5 MG.| NEBIVOLOL 2.5 MG.| NEBIVOLOL 2.5 MG.| NEBIVOLOL 2.5 MG.| OLMESARTEN 40 MG.| OLMESARTEN 40 MG.| PANTOPRAZOLE - 40 MG.| PANTOPRAZOLE - 40 MG.| VESCEPA 1 GRAM (4 CAPSULES).| VESCEPA 1 GRAM (4 CAPSULES).| VITAMIN C 1000 MG.| VITAMIN C 1000 MG.| VITAMIN D 2000 (2 CAPSULES).| VITAMIN D 2000 (2 CAPSULES).| WARFARIN - REGULAR SCHEDULE (3 - 3.7 INR GOAL).| WARFARIN - REGULAR SCHEDULE (3 - 3.7 INR GOAL). |