Table 4. Comparison of case patients with first myocardial infarction (MI) after breast cancer vs case patients with MI before and after breast cancer.
| Case patients with first MI after breast cancer (n=134) | Cases with MI before and after breast cancer (n=35) | ||
|---|---|---|---|
| Characteristic | N (%) | N (%) | P |
| Year of breast cancer diagnosis | 0.18 | ||
| 1980–1984 | 40 (29.9) | 5 (14.3) | |
| 1985–1989 | 49 (36.6) | 12 (34.3) | |
| 1990–1994 | 27 (20.2) | 11 (31.4) | |
| 1995–1998 | 18 (13.4) | 7 (20.0) | |
| Years between initial breast cancer and post-breast cancer MI diagnosis | 0.011 | ||
| <1 | 22 (16.4) | 11 (31.4) | |
| 1–3 | 34 (25.4) | 11 (31.4) | |
| 4–6 | 26 (19.4) | 7 (20.0) | |
| 7–9 | 17 (12.7) | 6 (17.1) | |
| ⩾10 | 35 (26.1) | 0 (0.0) | |
| MI classification | 0.62 | ||
| Definite | 72 (53.7) | 18 (51.4) | |
| Probable | 22 (16.4) | 4 (11.4) | |
| Immediate fatalitya | 40 (29.9) | 13 (37.1) | |
| Age at breast cancer diagnosis (years) | 0.13 | ||
| <50 | 10 (7.5) | 1 (2.9) | |
| 50–59 | 23 (17.2) | 1 (2.9) | |
| 60–69 | 46 (34.3) | 13 (37.1) | |
| 70–79 | 42 (31.3) | 14 (40.0) | |
| >80 | 13 (9.7) | 6 (17.1) | |
| Race/ethnicity | 0.072 | ||
| Black | 19 (14.2) | 6 (17.1) | |
| White | 97 (72.4) | 29 (82.9) | |
| Other/unknown | 18 (13.4) | 0 (0.0) | |
| Oral contraceptive use ever | 0.12 | ||
| No | 93 (69.4) | 21 (60.0) | |
| Yes | 25 (18.7) | 5 (14.3) | |
| Unknown | 16 (11.9) | 9 (25.7) | |
| Use of oestrogen and/or hormone replacement therapy ever | 0.83 | ||
| No | 60 (44.8) | 14 (40.0) | |
| Yes | 69 (51.5) | 20 (57.1) | |
| Unknown | 5 (3.7) | 1 (2.9) | |
| Smoking status at MI | 0.004 | ||
| Never | 70 (52.2) | 9 (25.7) | |
| Ever | 59 (44.0) | 21 (60.0) | |
| Unknown | 5 (3.7) | 5 (14.3) | |
| History of hypertension | 0.091 | ||
| No | 34 (25.4) | 3 (8.6) | |
| Yes, no medication | 7 (5.2) | 3 (8.6) | |
| Yes, medication | 93 (69.4) | 29 (82.9) | |
| History of diabetes | 0.18 | ||
| No | 88 (65.7) | 1 (48.6) | |
| Yes, no medication | 8 (6.0) | 3 (8.6) | |
| Yes, medication | 38 (28.4) | 15 (42.9) | |
| History of hypocholesterolemia | 0.82 | ||
| No | 68 (50.8) | 16 (45.7) | |
| Yes, no medication | 34 (25.4) | 9 (25.7) | |
| Yes, medication | 32 (23.9) | 10 (28.6) | |
| Stage at diagnosis | 0.99 | ||
| Localised | 89 (66.4) | 23 (65.7) | |
| Regional | 38 (28.4) | 10 (28.6) | |
| Distant/unstageable | 7 (5.2) | 2 (5.7) | |
| Oestrogen receptor status | 0.26 | ||
| Negative | 20 (14.9) | 2 (5.7) | |
| Positive or borderline | 86 (64.2) | 27 (77.1) | |
| Not done | 28 (20.9) | 6 (17.1) | |
| Progesterone receptor status | 0.17 | ||
| Negative | 33 (24.6) | 5 (14.3) | |
| Positive or borderline | 61 (45.5) | 22 (62.9) | |
| Not done | 40 (29.9) | 8 (22.9) | |
| Tamoxifen and radiation therapy | 0.15 | ||
| Neither | 52 (38.8) | 8 (22.9) | |
| Radiation therapy only | 13 (9.7) | 2 (5.7) | |
| Tamoxifen only | 49 (36.6) | 20 (57.1) | |
| Both | 20 (14.9) | 5 (14.3) |
a
Cases identified from death certificate only; no diagnostic work-up to permit classification.