Long-term outcome of patients with rheumatoid arthritis and systemic lupus erythematosus with special reference to cardiovascular disease

Abstract

The aim of this thesis was to assess the long-term prognosis in terms of mortality, especially from cardiovascular disease, in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). By using the population based Swedish health care registries, large cohorts with patients with RA and SLE were identified in the nationwide Hospital Discharge Register from 1964 to 1994.

In a cohort of 46,917 RA patients followed until the end of 1995, overall mortality was increased 2fold compared with the expected. Cardiovascular disease comprised 49% of all deaths. Coronary artery disease was the major cause of death and the relative risk was increased by 80 %. Young patients with RA had a more than 5-fold increased risk of coronary death.

In a cohort of 4,737 SLE patients followed until the end of 1995. mortality was 3-fold increased compared with the expected. Cardiovascular disease comprised 42% of all deaths. The relative risk of death from coronary heart disease was 3-fold and persisted increased even 20 years after the first discharge. SLE patients diagnosed at young age were at an additional increased risk for death due to coronary heart disease, which was 16-fold compared with the expected.

There was a decline in overall mortality during the two last decades in patients with RA and SLE. This decline was most prominent in the patients youngest at first discharge. In SLE patients, this decrease was entirely due to causes attributed to SLE. Despite this decrease in overall mortality, the risk for cardiovascular death still remained unchanged for RA and SLE patients.

The risk for cardiovascular death is increased in RA patients, but we did not know the impact of a familial history of cardiovascular disease, and whether it is due to common genetic and/or environmental factors shared in a family. Through the national Multi Generation Register, we identified a cohort of 14,390 patients with RA and their 57,350 first-degree relatives. RA patients whose parent(s) died from cardiovascular disease had themselves a 70% higher risk of cardiovascular death. than patients without such parental history. whereas patients whose relative(s) also had RA were not at higher risk of death than other patients. The parents and siblings of RA patients had a barely increased overall mortality, but a 10% and 30%, respectively, increased risk from cardiovascular death. The data suggest that the increased cardiovascular morbidity in RA patients is mainly related to the phenotype of the disease, possibly disease activity, and thus preventable.

In a cohort of 5.715 SLE patients. 443 cancers were registered during 1964-1995. The overall incidence of cancer overall was increased by 25% to the expected, mainly due to lymphomas, lung cancer and nonmelanoma skin cancer (SCC). The inciderce of non-Hodgkin's lymphoma (NHL) was nearly 3-fold increased compared with the expected.