A one-point increase in the Damage Index for Antiphospholipid Syndrome (DIAPS) predicts mortality in thrombotic antiphospholipid syndrome

OBJECTIVES: To determine whether early damage and its kinetics measured by the Damage Index for Antiphospholipid Syndrome (DIAPS) predicts mortality. METHODS: We carried out a single-centre retrospective analysis of thrombotic APS patients (2006 Sydney criteria), using the DIAPS for damage assessment. Early damage was considered to be at six months after disease onset; early damage increase (delta-DIAPS) was deemed to be at least a one-point rise in DIAPS within the first five years of illness. Groups were compared using appropriate statistical tests. Survival was analysed by the Kaplan-Meier method. Cox regression analysis was performed to investigate predictors of mortality. RESULTS: A total of 197 patients (71.1% female; 65.9% primary APS; 72.4% Caucasian) were followed for up to 43 years (median 10). Damage developed in 143 (73.6%) patients. Twenty-three patients (12%) died. Secondary APS (HR 3.07, 95%CI 1.32-7.12, p=0.009), male sex (HR 3.14, 95%CI 1.35-7.33, p=0.008) and age at APS onset ≥40 years (HR 5.34, 95%CI 1.96-14.53, p=0.001) were risk factors for death. Early damage (n=69, 35.0%) was not associated with death (p=0.231). Having a first arterial event was associated with early damage (p<0.001), but not with delta-DIAPS (p=0.539) nor with the risk of death (p=0.151). Delta-DIAPS (n=53/181, 29.3%) predicted mortality (HR 5.40, 95%CI 2.33-12.52, p<0.001), even after adjusting individually for APS category (secondary), sex (male), early damage and age at APS onset (≥40 years) (all p