Family history, comorbidity and risk of thoracic aortic disease: a population-based case-control study

Objective To examine the risk of thoracic aortic disease (TAD) when one or more first-degree relatives are affected, and to relate the risk of family history to the risk of other cardiopulmonary comorbidity. Design Population-based, matched, case-control study. Setting Registry-based investigation. Patients All cases, nationwide, of TAD diagnosed 2001-2005 in individuals born 1932 or later (n=2436) were identified, and a random control-group (n=12 152) matched for age, sex and geography was generated. First-degree relatives were identified in the Multigeneration Registry. Family history of TAD was assessed by cross-linking nationwide health registries. Interventions None. Results Family history was present in 108 cases (4.4%), compared with 93 (0.77%) controls (p<0.0001). The risk of TAD increased with number of affected relatives: OR 5.8 (95% CI 4.3 to 7.7) vs OR 20 (2.2 to 179) with one versus two or more affected relatives. The relative risk of TAD was highest in the youngest (<= 49 years) age group and slightly more pronounced in women than in men (OR 7.2 (4.2 to 12) vs OR 5.5 (3.9 to 7.7)). Among cardiopulmonary comorbidities, heart failure conferred the highest relative risk, OR 6.3 (4.1 to 9.8). Conclusions Family history confers a significantly increased (sixfold to 20-fold) relative risk of TAD. The effect is more pronounced in women and in younger subjects, and is not conveyed by cardiopulmonary comorbidity. Knowledge of family history is important to counselling, treatment indications, surveillance and screening protocols.