This study sought to define 1) the risk of sudden death after operation for common
congenital heart defects; and 2) factors associated with an increased risk of sudden
death.
Although the prognosis for patients with congenital heart defects is improved by surgical
treatment, they remain at a well recognized but poorly defined risk of late sudden
death.
This population-based study evaluated all patients < 19 years old undergoing surgical
treatment of common forms of congenital heart disease in the state of Oregon between
1958 and 1996. Patients were identified retrospectively through 1958, with prospective
biannual follow-up beginning in 1982. The incidence and cause of late sudden death
were evaluated for 3,589 patients surviving operation for the following defects: atrial,
ventricular and atrioventricular septal defects; patent ductus arteriosus; pulmonary
stenosis; aortic stenosis; coarctation of the aorta; tetralogy of Fallot; and D-transposition
of the great arteries.
There were 41 unexpected late sudden deaths during 45,857 patient-years of follow-up,
an overall event rate of 1/1,118 patient-years. Thirty-seven of the 41 late sudden
deaths occurred in patients with aortic stenosis, coarctation, transposition of the
great arteries or tetralogy of Fallot, an event rate of 1/454 patients-years. In contrast,
only four sudden deaths occurred among the other defects, an event rate of 1/7,154
patient-years (p < 0.01). The risk of late sudden death increased incrementally 20
years after operation for tetralogy of Fallot, aortic stenosis and coarctation. However,
risk was not dependent on patient age at operation or surgical era. The causes of
sudden death were arrhythmia in 30 patients, circulatory (embolic or aneurysm rupture)
in 7 and acute heart failure in 4.
The risk of late sudden death for patients surviving operation for common congenital
heart defects is 25 to 100 times greater than an age-matched control population. This
increased risk is primarily represented by patients with cyanotic or left heart obstructive
lesions. The risk of sudden death appears to be time dependent, increasing primarily
after the second postoperative decade.