Background: Women with SLE are at greater risk for cardiovascular events (CVE) even in the relative absence of cardiovascular risk factors. They also have more pregnancy complications. Pregnancy complications related to maternal-placental syndrome (MPS) are associated with an increased risk and accelerated development of CVE in parous women with SLE.
However, the role and relative contribution of pregnancy or MPS to the accelerated development of CVE is currently unknown.
Objectives: To determine if pregnancy and MPS were associated with accelerated development of CVE in women with SLE.
Methods: Utilizing linked Swedish population registries, women with SLE born between 1951-71 were included. MPS was defined as hypertensive disorders of pregnancy, small-for-gestational-age, stillbirth and placental abruption. SLE-related morbidity was defined as inpatient admissions, renal disease, malignancies and infections. A woman was classified as if she had a delivery > 22 weeks gestation. Outcome was CVE defined as coronary artery disease, stroke, peripheral vascular disease and/or death from these causes. Hazard was determined using Cox proportional-hazards adjusting for cardiovascular risk factors and SLE-related morbidity. The referent group was parous women without MPS.
Results: Among 3232 women with SLE, 2317 (72%) were parous. The non-parous women (n=915) had more SLE-related morbidity, cardiovascular risk factors and CVE compared to parous women (15.1 vs. 8.5 %). Amongst parous women 23.3% (n=539) had a history of MPS.
The incidence of CVE was highest amongst the non-parous group at 3.4/1,000 person-years followed by those who had pregnancies complicated by MPS (2.8/1,000 person-years). After adjustment, hazard of CVE was 1.6-fold higher in the non-parous group, compared to 1.5-fold increased in those with MPS. (Table 1) CVE-free survival was lowest in the non-parous group. (Figure 1)
Conclusions: Parous women with SLE with MPS had similar risk of CVE to non-parous women with SLE; but it was the non-parous women developed CVE earlier in life. The longest CVE-free survival in women with SLE was in those who had uncomplicated pregnancies.