Baseline demographics, cardiovascular risk factors, diagnosis characteristics, first von Willebrand laboratory results, and ET treatment in ExT and non-ExT patients
| . | Total . | Platelet count ≥1000 × 109/L . | P value . | |
|---|---|---|---|---|
| No . | Yes . | |||
| N = 451 (%) . | n = 323 (72) . | n = 128 (28) . | ||
| Demographics | ||||
| Institution | ||||
| DFCI | 412 (91) | 294 (91) | 118 (92) | .85∗ |
| MGH | 39 (9) | 29 (9) | 10 (8) | |
| Follow-up, median (95% CI) | 8 (6-9) | 6 (5-8) | 12 (10-15) | <.001† |
| Age at ET diagnosis, median (range) | 56 (10-96) | 57 (10-96) | 50 (12-84) | <.001‡ |
| Female sex | 260 (58) | 197 (61) | 63 (49) | .026∗ |
| Race | ||||
| White | 399 (88) | 285 (88) | 114 (89) | .59∗ |
| Black | 17 (4) | 11 (3) | 6 (5) | |
| Asian | 16 (4) | 11 (3) | 5 (4) | |
| Other/unknown | 19 (4) | 16 (5) | 3 (2) | |
| Cardiovascular risk factors at diagnosis | ||||
| Diabetes mellitus | 33 (7) | 24 (7) | 9 (7) | >.99∗ |
| Hypertension | 67 (15) | 56 (17) | 11 (9) | .019∗ |
| Hyperlipidemia | 67 (15) | 54 (17) | 13 (10) | .080∗ |
| Smoking | ||||
| Never | 205 (45) | 144 (45) | 61 (48) | .78∗ |
| Former | 120 (27) | 84 (26) | 36 (28) | |
| Current | 15 (3) | 12 (4) | 3 (2) | |
| Diagnosis characteristics | ||||
| Driver mutation | ||||
| CALR | 132 (29) | 71 (22) | 61 (48) | <.001∗ |
| JAK2 | 232 (51) | 192 (59) | 40 (31) | |
| MPL | 19 (4) | 13 (4) | 6 (5) | |
| Triple Neg | 50 (11) | 34 (11) | 16 (12) | |
| Platelet count at diagnosis, median (range), ×109/L | 775 (400-4055) | 661 (400-997) | 1196 (1000-4055) | <.001‡ |
| WBC count at diagnosis, median (range), ×109/L | 8.75 (3.60-61.52) | 8.41 (3.60-30.80) | 9.53 (3.70-61.52) | .031‡ |
| History of thrombosis before ET diagnosis | 49 (11) | 36 (11) | 13 (10) | .87∗ |
| R-IPSET thrombosis risk | ||||
| Very low risk | 118 (26) | 64 (20) | 54 (42) | <.001∗ |
| Low risk | 123 (27) | 99 (31) | 24 (19) | |
| Intermediate risk | 56 (12) | 39 (12) | 17 (13) | |
| High risk | 105 (23) | 89 (28) | 16 (12) | |
| First von Willebrand laboratory results in disease course | ||||
| First VWF antigen level, median (range) | 102 (36-297) | 114 (36-297) | 89 (44-187) | .028‡ |
| First VWF activity level, median (range) | 75 (16-90 648) | 89 (19-90 648) | 61 (16-168) | <.001‡ |
| First VWF activity level <50% | 19 (4) | 6 (2) | 13 (10) | .021∗ |
| ET treatment during disease course | ||||
| No treatment | 7 (2) | 3 (1) | 4 (3) | .10∗ |
| Aspirin alone | 114 (25) | 89 (28) | 25 (20) | .092∗ |
| Aspirin with cytoreductive agent | 282 (63) | 202 (63) | 80 (62) | >.99∗ |
| Any cytoreduction | 328 (73) | 230 (71) | 98 (77) | .29∗ |
| Cytoreduction start after diagnosis, median (range), y | 0.7 (0.0-61.8) | 1.0 (0.0-35.6) | 0.1 (0.0-61.8) | .0047‡ |
| Cytoreduction within 2 y after diagnosis | 285 (63) | 196 (61) | 89 (70) | .084∗ |
| . | Total . | Platelet count ≥1000 × 109/L . | P value . | |
|---|---|---|---|---|
| No . | Yes . | |||
| N = 451 (%) . | n = 323 (72) . | n = 128 (28) . | ||
| Demographics | ||||
| Institution | ||||
| DFCI | 412 (91) | 294 (91) | 118 (92) | .85∗ |
| MGH | 39 (9) | 29 (9) | 10 (8) | |
| Follow-up, median (95% CI) | 8 (6-9) | 6 (5-8) | 12 (10-15) | <.001† |
| Age at ET diagnosis, median (range) | 56 (10-96) | 57 (10-96) | 50 (12-84) | <.001‡ |
| Female sex | 260 (58) | 197 (61) | 63 (49) | .026∗ |
| Race | ||||
| White | 399 (88) | 285 (88) | 114 (89) | .59∗ |
| Black | 17 (4) | 11 (3) | 6 (5) | |
| Asian | 16 (4) | 11 (3) | 5 (4) | |
| Other/unknown | 19 (4) | 16 (5) | 3 (2) | |
| Cardiovascular risk factors at diagnosis | ||||
| Diabetes mellitus | 33 (7) | 24 (7) | 9 (7) | >.99∗ |
| Hypertension | 67 (15) | 56 (17) | 11 (9) | .019∗ |
| Hyperlipidemia | 67 (15) | 54 (17) | 13 (10) | .080∗ |
| Smoking | ||||
| Never | 205 (45) | 144 (45) | 61 (48) | .78∗ |
| Former | 120 (27) | 84 (26) | 36 (28) | |
| Current | 15 (3) | 12 (4) | 3 (2) | |
| Diagnosis characteristics | ||||
| Driver mutation | ||||
| CALR | 132 (29) | 71 (22) | 61 (48) | <.001∗ |
| JAK2 | 232 (51) | 192 (59) | 40 (31) | |
| MPL | 19 (4) | 13 (4) | 6 (5) | |
| Triple Neg | 50 (11) | 34 (11) | 16 (12) | |
| Platelet count at diagnosis, median (range), ×109/L | 775 (400-4055) | 661 (400-997) | 1196 (1000-4055) | <.001‡ |
| WBC count at diagnosis, median (range), ×109/L | 8.75 (3.60-61.52) | 8.41 (3.60-30.80) | 9.53 (3.70-61.52) | .031‡ |
| History of thrombosis before ET diagnosis | 49 (11) | 36 (11) | 13 (10) | .87∗ |
| R-IPSET thrombosis risk | ||||
| Very low risk | 118 (26) | 64 (20) | 54 (42) | <.001∗ |
| Low risk | 123 (27) | 99 (31) | 24 (19) | |
| Intermediate risk | 56 (12) | 39 (12) | 17 (13) | |
| High risk | 105 (23) | 89 (28) | 16 (12) | |
| First von Willebrand laboratory results in disease course | ||||
| First VWF antigen level, median (range) | 102 (36-297) | 114 (36-297) | 89 (44-187) | .028‡ |
| First VWF activity level, median (range) | 75 (16-90 648) | 89 (19-90 648) | 61 (16-168) | <.001‡ |
| First VWF activity level <50% | 19 (4) | 6 (2) | 13 (10) | .021∗ |
| ET treatment during disease course | ||||
| No treatment | 7 (2) | 3 (1) | 4 (3) | .10∗ |
| Aspirin alone | 114 (25) | 89 (28) | 25 (20) | .092∗ |
| Aspirin with cytoreductive agent | 282 (63) | 202 (63) | 80 (62) | >.99∗ |
| Any cytoreduction | 328 (73) | 230 (71) | 98 (77) | .29∗ |
| Cytoreduction start after diagnosis, median (range), y | 0.7 (0.0-61.8) | 1.0 (0.0-35.6) | 0.1 (0.0-61.8) | .0047‡ |
| Cytoreduction within 2 y after diagnosis | 285 (63) | 196 (61) | 89 (70) | .084∗ |