Tetralogy of Fallot. A population-based study of epidemiology, associated malformations and survival in western Denmark 1984-1992.

The study describes the epidemiology and mortality of tetralogy of Fallot (TOF) in a population-based study in Western Denmark. Ninety-two infants with TOF were born during 1984-1992. Prevalence was 3.01 per 10,000 livebirths. Karyotype anomalies were present in 12 (13%) and extracardiac malformations in 16 (17%) of the infants. Down syndrome, cleft palate, cleft lip and palate and combined skeletal, gastrointestinal and renal lesions (VACTERL association) were prevalent. Twenty-four infants died (26% of total), 13 (54%) of the deaths occurring during the first year of life. Mortality was significantly increased in infants with extracardiac malformations (50% vs 19%, p < 0.05). Eighteen deaths (75% of total deaths) occurred before corrective surgery and 7 of these deaths were sudden. Extracardiac malformation(s) in infants with TOF is a significant risk factor for death. The study stresses the importance of population-based studies for the assessment of mortality from congenital heart malformations. Overall mortality may be very different from mortality related to cardiac surgery.