Baseline characteristics and risk factors for myocardial infarction (MI) in patients with and without SLE (for detailed descriptions of variables see table 1)
| MI-SLE | MI-non-SLE | Non-MI-SLE | P value* | Post hoc analysis* | |
| N=34 | N=34 | N=34 | |||
| Women, n (%) | 30 (88) | 30 (88) | 30 (88) | ||
| Age, median (IQR) years | 61 (49–68) | 61 (49–69) | 61 (49–68) | ||
| Age at SLE onset, median (IQR) years | 36 (22–47) | 42 (27–53) | 0.08 | ||
| CVD and VTE combined, n (%) | 4 (12) | 0 (0) | 1 (2.9) | 0.07 | |
| Venous thromboembolism (VTE), n (%) | 9 (26) | 0 (0) | 5 (15) | 0.004 | P=0.29†† |
| Cardiovascular disease (CVD, MI excluded), n (%) | 15 (44) | 2 (5.9) | 4 (12) | <0.001 | P=0.007†† |
| Coronary artery disease (MI excluded), n (%) | 11 (32) | 1 (2.9) | 0 (0) | <0.001 | P=0.002‡‡ |
| Ischaemic stroke, n (%) | 6 (18) | 1 (2.9) | 2 (5.9) | 0.10 | |
| Peripheral arterial diseases, n (%) | 6 (18) | 2 (5.9) | 2 (5.9) | 0.17 | |
| Diabetes, n (%) | 4 (12) | 3 (8.8) | 0 (0) | 0.16 | |
| Antiphospholipid syndrome, n (%) | 7 (21) | 0 (0) | 4 (12) | 0.04 | P=0.55†† |
| Smoking status, n (%) | |||||
| - Never smoker | 6 (18) | 15 (44) | 12 (35) | ||
| - Previous smoker | 18 (53) | 8 (24) | 18 (53) | 0.18 | P=0.34§§ |
| - Current smoker | 8 (24) | 11 (32) | 4 (12) | §§ | |
| - Missing | 2 (5.9) | 0 (0.0) | 0 (0.0) | ||
| Prednisolone equivalents, median (IQR) mg/24 hours | 5.0 (0.0–7.5) | 0.0 (0.0–0.0) | 2.5 (0.0–7.5) | <0.001† | P=0.97†† |
| Hydroxychloroquine at MI/inclusion, n (%) | 7 (23) | 18 (53) | 0.06‡ | ||
| Low-dose acetylsalicylic acid at MI/inclusion, n (%) | 11 (36) | 3 (10) | 0.04§ | ||
| Creatinine, median (IQR) mmol/L | 81 (68–100) | 70 (59–79) | 72 (58–88) | 0.09¶ | |
| Creatinine-based eGFR, median (IQR) mL/min/1.73 m2 | 67 (48–77) | 79 (67–92) | 72 (60–106) | 0.08¶ | |
| Current/previous renal involvement, n (%) | 15 (44) | 11 (32) | 0.42 | ||
| Albumin levels in blood, median (IQR) g/L | 35 (29–37) | 40 (37–42) | 0.002** |
*P values are derived from comparing matched triplets using the Cochran’s Q and the Friedman’s test for binominal or ordinal and continuous data, respectively. For comparison between matched pairs, the McNemar’s and the Wilcoxon signed-rank tests were used for binominal and continuous data, respectively.
†Data were available in 34/34 MI-SLE, 33/34 MI-non-SLE and 34/34 non-MI-SLE patients.
‡Data were available in 31/34 MI-SLE and 34/34 non-MI-SLE patients.
§Data were available in 31/34 and 31/34 non-MI-SLE patients.
¶Data were available in 32/34 MI-SLE, 28/34 MI-non-SLE and 34/34 non-MI-SLE patients.
**Data were available in 16/34 MI-SLE and 34/34 non-MI-SLE patients.
††A post hoc comparison between MI-SLE and non-MI-SLE.
‡‡A post hoc comparison between MI-SLE and MI-non-SLE.
§§A post hoc comparison between the frequency of currently smoking MI-SLE patients and the frequency of currently smoking non-MI-SLE patients.
CAD, coronary artery disease (MI excluded); CVD, cardiovascular disease; eGFR, estimated glomerular filtration rate; PADs, peripheral arterial diseases; VTE, venous thromboembolism.