Pos0537 mortality in Rheumatoid Arthritis: Changing Causes and Predictive Factors. Study of a Cohort Followed Prospectively

Abstract

BackgroundPatients with Rheumatoid Arthritis (RA) present an increased risk of mortality. In the last decades, mortality rates tended to decrease but cardiovascular (CV) events remained as the leading cause of death in most series (1).ObjectivesTo assess mortality rates and leading causes of death, as well as predictors of mortality related to disease activity in a prospectively followed-up cohort of RA patients.MethodsWe conducted a prospective longitudinal study that included 673 RA patients from a single tertiary center. Univariate and multivariate Cox proportional hazards regression were used to identify predictors of mortality.ResultsWe studied 673 patients with RA (75% women), mean age 61±13 years. The main general characteristics, CV risk factors, RA disease activity data and current treatment are summarized in the Table 1.Table 1.Baseline characteristics of 673 RA patientsAge, years, (mean±sd)61 ± 13Female/Male, n (%)505 (75) /168 (25)Past or Current smoker, n (%)338 (50)Obesity, n (%)226 (34)Hypertension, n (%)310 (46)Diabetes Mellitus, n (%)85 (13)Dyslipidemia, n (%)310 (46)BMI, kg/m2 (mean±sd)28 ± 6Abdominal circumference, cm (mean±sd)97 ± 15Total/HDL/LDL cholesterol, mg/dl (mean±sd)204±38/62±18/120 ± 31Disease duration, years (median, [IQR])13 [10-20]CRP, mg/l (median, [IQR])3.0 [0.8-7.0]ESR, mm/ 1º hour (median, [IQR])12 [5-21]Rheumatoid factor/ ACPA, n (%)376 (56) / 314 (48)DAS28-ESR/ DAS28-PCR (mean±sd)3.18 ± 1.41/3.00 ± 1.23NSAIDs / Prednisone, n (%)265 (39) /341 (51)Prednisone dose, mg/day (median, [IQR])5 (2.5-5)c-DMARDS: Metotrexate/ Leflunomide/ Hydroxychloroquine/ Salazopyrin, n (%)406 (60) /52 (8) / 178 (26) / 10 (1)b-DMARDS: TNFi/ Tocilizumab/ Rituximab/ Abatacept, n (%)88 (13) / 43 (6) / 13 (2) / 8 (1)JAK inhibitors, n (%)12 (2)After a follow-up of 4,367 person-years (mean 6.4±1.4), 67 deaths were recorded. Considering all causes of mortality, the cumulative incidence was 14% (95% CI 11-18) with a mortality incidence rate of 0.015 (95% CI 0.012-0.020) patient/year. The main causes of mortality in decreasing order of frequency were infections (N=23) (34%), incidence rate-IR: 0.005 [95% CI 0.003-0.008]), cancer (N=18) (27%), IR: 0.004 [95% CI 0.002-0.007]), CV events (N= 12) (18%), IR: 0.003 [95% CI 0.001-0.005]), respiratory diseases (N=2) (3%), IR: 0.0005 [95% CI 0.00007-0.002] and other causes (N=12) (18%), IR: 0.003 [95% CI 0.001-0.005I].The statistically significant predictive factors of mortality in the univariate analysis were male gender (HR 1.97[95%CI 1.20-3.21, p=0.007), abdominal circumference (HR 1.03 [95% CI 1.01-1.05], p=0,0006), diabetes (HR 2.85 [95%CI 1.68-4.86], p<0.001) and hypertension (HR 2.92 [95%CI 1.73-4.94], p<0.001). Also, baseline data of variables associated with disease activity such as increased CRP, ESR, DAS28-CRP, DAS28-ESR were predictors of mortality (Figure 1). Disease related parameters were adjusted by CV risk factors in a multivariate analysis. Following this procedure, the predictive factors that reached statistical significance; (Hazard Ratio [95%CI]), were an increased in DAS28-VSG (1.40 [1.07-1.83], p=0.016), DAS- 28-PCR (1.40 [1.07-1.83], p=0.016), CRP (1.02 [1.01-1.05] p=0.002), and ESR (1.03 [1.01- 1.05], p=<0.001) (Figure 1).Figure 1.Forest Plot of mortality (Univariate and multivariate analysis).Results expressed in logarithmic scale. Multivariate analysis: Disease activity related parameters adjusted by age, gender, disease duration, smoker, diabetes, hypertension and abdominal circumference. CDAI, ESR and CPR expressed value/10. (*) p<0.05.ConclusionIn a cohort of patients with RA followed prospectively in a tertiary hospital, infections and malignancies are the main cause of mortality rather than CV events. Disease activity parameters are associated with an increased risk of mortality in these patients with RA.References[1]Avina-Zubieta JA et al. Risk of cardiovascular mortality in patients with rheumatoid arthritis: a meta-analysis of observational studies. Arthritis Rheum 2008,59:1690–97.Disclosure of InterestsNone declared.