Patients with rheumatoid arthritis (RA) die at a younger age than their peers in most hospital series [ 1 ], while an increase in standardized mortality rate (SMR) has not been a consistent feature in recent studies of RA patients from date of diagnosis (inception cohorts) The reasons for this apparent discrepancy are likely to be the presence of more severe disease in hospital-based series and the advent of earlier and more effective treatment in recent years. However, an increased mortality from vascular disease in RA has been consistently reported in both established and inception studies , and an increased SMR for respiratory disease and lymphoreticular cancers has also been recognized in most series.
A detailed study in this month’s issue addresses the important question of whether patients with RA treated early and actively with disease-modifying anti-rheumatic drugs (DMARDs) still have increased mortality rates . The study assesses the effect of modern out-patient intervention on all-cause mortality in a large inception cohort over the first 7 yrs of their disease, and examines whether this relates to disease severity or duration. Detailed assessment of the causes of death offers new insights into the relevance of both cardiovascular and respiratory contributions to mortality and attempts to identify risk factor profiles.
Although increasing age and male gender have been recognized as predictors for an earlier death in RA, few other clues as to an individual’s risk of premature death have been identified. However, recent work has shown direct links between rheumatoid disease activity, increased comorbidity and early death . The Early Rheumatoid Arthritis Study (ERAS) group reports on 1429 patients recruited within 2 yrs of diagnosis over the 11 yrs from 1986. Although 84% received therapy with DMARDs, the all-cause SMR was significantly raised. After increased age, the odds ratios for death were most elevated in those patients with extra-articular disease and in those with established comorbidity.
Early death was most often due to cardiovascular disease or interstitial pulmonary fibrosis, although other vascular and respiratory causes were also over-represented. Cardiovascular disease accounted for 31% of all deaths while pulmonary problems (including respiratory infection and lung cancer) were responsible for almost 29%.
Ischaemic heart disease (IHD) accounted for a quarter of all deaths and carried an SMR of 1.49. It was also the most common cause of death at a young age and had a worse prognosis than in patients without RA. There was a relationship between disease activity as assessed by erythrocyte sedimentation rate (ESR) and probability of death from IHD, a finding consistent with previous reports linking increased markers of inflammation with coronary artery disease . This suggests that DMARD therapy should protect RA patients from developing IHD, and reinforces the need for such therapy to be commenced early in the disease and used aggressively where possible, aiming for remission within the first year of disease.