Table 1.
Characteristics of definite and probable MI patients overall and by event year groups in the ARIC Community Surveillance Study, 1987-2008.
| Variable | Overall N=30986* | 1987-1991† N=7524 | 1992-1996 N=7730 | 1997-2001 N=7380 | 2002-2008 N=8352 |
|---|---|---|---|---|---|
| Age (mean, SD) | 60.4 (12.0%) | 61.1 (10.9%) | 60.6 (11.7%) | 60.5 (11.9%) | 59.6 (13.7%) |
| Male gender | 20360 (65.7%) | 4940 (65.7%) | 5207(67.4%) | 4813 (65.2%) | 5400 (64.7%) |
| Race-Center Classification | |||||
| Forsyth Black | 3273 (10.6%) | 616 (8.2%) | 777 (10.0%) | 832 (11.3%) | 1047 (12.5%) |
| Forsyth White | 8889 (28.7%) | 2103 (28.0%) | 2311 (29.9%) | 2130 (28.9%) | 2345 (28.1%) |
| Jackson Black | 3805 (12.3%) | 621 (8.3%) | 752 (9.7%) | 1005 (13.6%) | 1427 (17.1%) |
| Jackson White | 3276 (10.6%) | 1145 (15.2%) | 929 (12.0%) | 681 (9.2%) | 522 (6.3%) |
| Minnesota Whites | 6320 (20.4%) | 1584 (21.1%) | 1566 (20.3%) | 1407 (19.1%) | 1762 (21.1%) |
| Washington Whites | 5422 (17.5%) | 1454 (19.3%) | 1396 (18.1%) | 1324 (17.9%) | 1248 (15.0%) |
| Comorbidities | |||||
| Prior MI | 10085 (32.7%) | 2784 (37.2%) | 2672 (34.7%) | 2417 (33.0%) | 2211 (26.5%) |
| Hypertension | 19718 (63.9%) | 4285 (57.3%) | 4617 (59.9%) | 4855 (66.2%) | 5961 (71.6%) |
| Diabetes | 7743 (34.4%) | --- | 2034 (30.2%) | 2499 (34.1%) | 3188 (38.3%) |
| Stroke | 2873 (9.3%) | 583 (7.8%) | 796 (10.3%) | 741 (10.1%) | 753 (9.0%) |
| PREDICT score‡ (mean) | 9.5 (9.4, 9.5) | 9.6 (9.5, 9.6) | 9.5 (9.4, 9.5) | 9.5 (9.4, 9.5) | 9.3 (9.2, 9.4) |
| Length of stay in days (mean) | 7.9 (7.8, 8.1) | 10.1 (9.8, 10.5) | 8.4 (8.1, 8.6) | 7.0 (6.7, 7.3) | 6.4 (6.0, 6.8) |
| Length of stay in days | |||||
| (median) | 6.0 | 8.0 | 7.0 | 5.0 | 4.0 |
| EMS transport | 13048 (42.3%) | 2765 (36.9%) | 3171 (41.2%) | 3093 (42.1%) | 4019 (48.2%) |
| Prehospital delay § <2 hours | 8494 (27.4%) | 2102 (27.9%) | 2176 (28.2%) | 2085 (28.4%) | 2121 (25.4%) |
| Unknown | 3632 (11.7%) | 912 (12.1%) | 857 (11.1%) | 821 (11.1%) | 1043 (12.5%) |
| Event Classification** | |||||
| STEMI | 6106 (19.7%) | 1474 (19.6%) | 1926 (24.9%) | 1420 (19.3%) | 1284 (15.4%) |
| NSTEMI | 20302 (65.5%) | 4970 (66.1%) | 4439 (57.4%) | 4869 (66.0%) | 6023 (72.1%) |
*
Weighted number of definite or probable MI events
†
Chi-square test with Taylor Series variance estimation for independence of characteristics across study years (categorical variables) or one-way ANOVA (continuous variables) significant for all variables at p <0.001 ‡Modified PREDICT Score did not include data on kidney function
§
Prehospital delay was defined as the interval from earliest symptom onset time to hospital arrival time
**
STEMI defined as ST-elevation at any site on either the first or last ECG