Background: Long-term outcomes and life expectancy for children with a previous history of Kawasaki disease (KD), particularly those with coronary artery aneurysms (CAA), remain to be determined.
Methods: An inception cohort of all patients with KD assessed at The Hospital for Sick Children in Toronto between 1978 and 2013 was assembled. Patient outcomes were obtained throughout their pediatric and adult clinical follow-up as long as available. Prevalence of outcomes over time was modelled with Kaplan-Meier survival curves. Life tables from Statistics Canada were used to obtain age/gender specific cumulative mortality for the general population.
Results: The cohort included 2,623 KD patients, of whom 410 (16%) had coronary artery involvement (215 dilatation, 57 non-giant CAA and 138 giant CAA). Average follow-up for patients with coronary artery involvement was 6.7 years (13.3 years for giant CAA); 57 and 34 patients had at least 15 and 25 years of follow-up, respectively. No patients with coronary artery dilatation or non-giant CAA had revascularization or a myocardial infarct. Freedom from revascularization (14 events) for patients with giant CAA was 90±6%, 87±7% and 80±13% at 10, 20 and 40 years of follow-up. Freedom from myocardial infarct (11 events) was 94±4%, 92±5% and 89±7% at 5, 20 and 40 years. For patients without coronary artery involvement, 3 (0.1%) deaths were recorded, one secondary to complications of macrophage activation syndrome during the acute phase of KD and 2 from cancer. No deaths were noted for patients with coronary artery dilatation or non-giant CAA, although clinical follow-up was more limited. For patients with giant CAA, 3 deaths (2.2%) were noted, 2 related to CAA complications and 1 from non-medical cause. Cumulative mortality for patients with giant CAA was 1.5% at 10 years of age (expected mortality 0.7%, HR: 2.2 (0.3-11.5), p=0.08) and 3.1% at 40 years of age (expected 2.3%, HR: 1.3 (0.4-4.0), p=0.37).
Conclusions: Despite risks of myocardial infarction and revascularization, patients with giant CAA had life-expectancy similar to that of the general population up to the fourth decade of life. Additional follow-up will be necessary to determine if these trends continue into later decades.