Objectives: The incidence of late mortality and morbidity of aortic dissection remained unchanged during the past 20 years. The present study was to analyze the risk factors of late events for patients with aortic dissection.
Methods: A total of 5654 cases of aortic dissection (3871 males) were collected from the National Health Insurance Databases from 1996 to 2001. Age, gender, Marfan syndrome, and initial treatment modality were the main factors to be investigated. Corrective group was defined by surgical operation with cardiopulmonary bypass and palliative group for the remaining. Late aortic events were defined by late aneurysmal evolution of diseased aorta needing surgical intervention or death of aortic causes from 6 months to 6 years.
Results: The incidence of aortic dissection was 43 per 1000000 population in our country. Corrective group accounted for 19.3% of them and palliative group for 80.7%. Marfan syndrome accounted for 1.5% of all cases (4.3% of corrective surgery group). The rate of freedom from mortality at 1, 6 months, and 6 years was 80.4+/-1.3, 69.0+/-1.5, and 56.5+/-2.9% for corrective group and 89.5+/-0.5, 78.4+/-0.6, and 46.1+/-1.35% for palliative group. Nearly half of the late mortalities were attributed to atherosclerosis-related conditions (cardiac, stroke, or aortic causes). The incidence of late aortic events was 2.48% per year on an average, comparable between corrective and palliative groups. This incidence increased since the fourth year after their initial episode. For corrective group, young age was a risk factor of late aortic events (relative risk of 0.60-0.82 per decade, P = 0.037). For palliative group, Marfan syndrome and male gender were risk factors of late aortic events (relative risk of 4.08-10.7, P < 0.001 in the former; relative risk of 1.46-2.1, P = 0.002 in the latter).
Conclusions: Late aortic events were not uncommon for both corrective and palliative groups, and its incidence increased since the fourth year after their initial episodes. Young age for corrective group, Marfan syndrome and male gender for palliative group were risk factors of late aortic events.