Serological and clinical outcomes of 20 heparin reexposures performed for cardiac or vascular surgery
| Patient . | Age (y) . | Sex . | Interval (wk) . | UFH rechallenge . | Postoperative AC . | SRA . | EIA . | Seroconversion by . | Recurrent HIT . | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| IgG . | IgA . | IgM . | SRA . | EIA . | ||||||||||||
| EIA-IgG negative at heparin reexposure baseline (n = 10) | Pre | Post | Pre | Post | Pre | Post | Pre | Post | ||||||||
| 3 | 60 | M | 132 | CPB | DS | − | +++ | − | +++ | − | ++ | − | + | Yes | Yes | No |
| 4 | 48 | M | 8 | Vasc | DS | − | − | − | − | − | − | − | − | No | No | No |
| 5 | 60 | F | 8 | CPB | Nil | − | − | − | − | − | − | − | − | No | No | No |
| 6 | 65 | M | 307 | Vasc | DS | − | − | − | − | − | − | − | − | No | No | No |
| 8 | 51 | M | 180 | CPB | DS | − | +++ | − | +++ | − | ++ | − | + | Yes | Yes | No |
| 10 | 73 | M | 37 | CPB | DS | − | ++ | − | +++ | − | ++ | − | − | Yes | Yes | No |
| 12 | 74 | F | 62 | Vasc | DS | − | − | − | − | − | − | − | − | No | No | No |
| 17 | 68 | M | 597 | CPB | Fx | − | +++ | − | +++ | − | − | − | +* | Yes | Yes† | Yes |
| 18a | 48 | M | 414 | Vasc | Fx | − | − | − | − | − | − | − | + | No | Yes | No |
| 18b | — | +132 | Vasc | Fx | − | − | − | − | − | − | − | + | No | Yes | No | |
| EIA-IgG positive at heparin reexposure baseline (n = 10) | ||||||||||||||||
| 9 | 77 | F | 21 | Vasc | Clopid/asp | − | − | + | + | − | − | − | − | No | No | No |
| 11 | 72 | M | 47 | Vasc | Clopid/asp | − | +++ | +* | +++* | − | − | − | − | Yes | Yes† | No |
| 13 | 48 | F | 22 | CPB | DS | − | − | ++ | ++ | − | +* | − | − | No | Yes† | No |
| 14 | 66 | M | 22 | Vasc | Nil | − | +++ | + | +++ | − | +++ | − | − | Yes | Yes | No |
| 15 | 57 | M | 515 | CPB | DS | − | +++ | ++ | +++ | − | + | +* | ++* | Yes | Yes | No |
| 16 | 61 | M | 422 | Vasc | DS | − | +++ | + | +++ | − | − | − | + | Yes | Yes | No |
| 19 | 62 | M | 166 | CPB | Warf | − | − | ++ | ++ | − | − | − | − | No | No | No |
| 20 | 54 | M | 20 | CPB | Fx | − | − | ++ | +++ | − | + | − | − | No | Yes | No |
| 21 | 76 | F | 12 | CPB | Fx PLEX preoperative | − | − | ++ | ++ | − | − | − | − | No | No | No |
| 22 | 56 | F | 28 | CPB | DS | − | +++ | + | +++ | − | + | − | − | Yes | Yes | No |
| Patient . | Age (y) . | Sex . | Interval (wk) . | UFH rechallenge . | Postoperative AC . | SRA . | EIA . | Seroconversion by . | Recurrent HIT . | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| IgG . | IgA . | IgM . | SRA . | EIA . | ||||||||||||
| EIA-IgG negative at heparin reexposure baseline (n = 10) | Pre | Post | Pre | Post | Pre | Post | Pre | Post | ||||||||
| 3 | 60 | M | 132 | CPB | DS | − | +++ | − | +++ | − | ++ | − | + | Yes | Yes | No |
| 4 | 48 | M | 8 | Vasc | DS | − | − | − | − | − | − | − | − | No | No | No |
| 5 | 60 | F | 8 | CPB | Nil | − | − | − | − | − | − | − | − | No | No | No |
| 6 | 65 | M | 307 | Vasc | DS | − | − | − | − | − | − | − | − | No | No | No |
| 8 | 51 | M | 180 | CPB | DS | − | +++ | − | +++ | − | ++ | − | + | Yes | Yes | No |
| 10 | 73 | M | 37 | CPB | DS | − | ++ | − | +++ | − | ++ | − | − | Yes | Yes | No |
| 12 | 74 | F | 62 | Vasc | DS | − | − | − | − | − | − | − | − | No | No | No |
| 17 | 68 | M | 597 | CPB | Fx | − | +++ | − | +++ | − | − | − | +* | Yes | Yes† | Yes |
| 18a | 48 | M | 414 | Vasc | Fx | − | − | − | − | − | − | − | + | No | Yes | No |
| 18b | — | +132 | Vasc | Fx | − | − | − | − | − | − | − | + | No | Yes | No | |
| EIA-IgG positive at heparin reexposure baseline (n = 10) | ||||||||||||||||
| 9 | 77 | F | 21 | Vasc | Clopid/asp | − | − | + | + | − | − | − | − | No | No | No |
| 11 | 72 | M | 47 | Vasc | Clopid/asp | − | +++ | +* | +++* | − | − | − | − | Yes | Yes† | No |
| 13 | 48 | F | 22 | CPB | DS | − | − | ++ | ++ | − | +* | − | − | No | Yes† | No |
| 14 | 66 | M | 22 | Vasc | Nil | − | +++ | + | +++ | − | +++ | − | − | Yes | Yes | No |
| 15 | 57 | M | 515 | CPB | DS | − | +++ | ++ | +++ | − | + | +* | ++* | Yes | Yes | No |
| 16 | 61 | M | 422 | Vasc | DS | − | +++ | + | +++ | − | − | − | + | Yes | Yes | No |
| 19 | 62 | M | 166 | CPB | Warf | − | − | ++ | ++ | − | − | − | − | No | No | No |
| 20 | 54 | M | 20 | CPB | Fx | − | − | ++ | +++ | − | + | − | − | No | Yes | No |
| 21 | 76 | F | 12 | CPB | Fx PLEX preoperative | − | − | ++ | ++ | − | − | − | − | No | No | No |
| 22 | 56 | F | 28 | CPB | DS | − | +++ | + | +++ | − | + | − | − | Yes | Yes | No |
Patient age is at the previous episode of HIT. Patient numbers are from Warkentin and Sheppard18 with patient 21 reported subsequently32 and patient 22 representing the most recent heparin exposure (December 2015) discussed in detail in this article (case 2). Note that for patient 11, the positive EIA-IgG at reexposure baseline was not inhibited >30% by high heparin. Note also that the data shown for patient 10 differs from that presented previously,18 because repeat studies showed that the baseline EIA reactivity before reexposure was consistently negative upon retesting. Strength of assay results: EIA: −, negative; +, weakly positive (0.40 [or 0.45] to 0.99 OD units; ++, moderately positive (1.00 to 1.99 OD units); +++, strongly positive (≥2.00 OD units). SRA: −, negative (<20% serotonin release); +, weakly positive (20.0% to 49.9% release); ++, moderately positive (50.0% to 79.9% release); +++, strongly positive (≥80% release).
AC, anticoagulation; Clopid/asp, clopidogrel/aspirin; DS, danaparoid sodium; F, female; Fx, fondaparinux; M, male; PLEX preoperative, plasma exchange administered preoperatively (pre-heparin reexposure); Vasc, vascular surgery; warf, warfarin.
Positive anti-PF4/heparin EIA was not inhibited by >30% in the presence of high heparin.
Any/all EIA seroconversions for that patient were not inhibited >30% by high heparin.