Abstract 16951: Long term Incidence and 30-mortality of Myocardial Infarction in Congenital Heart Disease Survivors Compared With the General Population: A Nationwide Cohort Study

Abstract

The population of adults with congenital heart disease (CHD) is growing and aging. Some adult CHD survivors have an increased risk of myocardial infarction (MI) due to the specific CHD, and the presence of CHD may impair prognosis following MI depending on CHD severity. Few data exist on the incidence and prognosis of MI in the adult CHD population. We aimed to compare the incidence and mortality of MI in adult survivors of CHD with the general population with attention to the impact of CHD severity. Methods: In this cohort study we used two nationwide population based medical databases to identify individuals diagnosed with CHD in Denmark between 1963 and 1974 (before 15 years of age) and from 1977 to 2012 (at any age). Patients were followed from 1977 to 2012 for first time MI using data from the Danish National Registry of Patients (DNRP). The DNRP is a nationwide hospital discharge registry covering all Danish hospitals. For each CHD subject we identified 10 controls from the general population, matched by sex and birth year. A unique personal identifier assigned at birth and used in all Danish public registries enabled virtually complete follow-up for migration, death or MI. We computed cumulative incidences and hazard ratios (HR) of MI. Subsequently, we computed 30 day-mortality following MI for CHD subjects and controls, as well as the corresponding HR adjusted for age and sex. Results: We identified 14,038 CHD subjects. By 70 years of age, the cumulative incidence of MI was 10% among CHD subjects. The HR of MI among CHD subjects compared with controls was 3.5 (95% CI: 2.9-4.3) below 50 years of age, and 1.9 (95% CI: 1.7-2.2) > 50 years. The 30-day mortality was 16% for the 322 CHD subjects experiencing an MI during follow-up; the corresponding HR comparing 30-day post-MI mortality between CHD subjects and controls was 1.9 (95% CI: 1.4-2.6). Patients with severe CHD had a 30-day post-MI mortality HR of 4.1 (95% CI: 2.2-7.5), somewhat higher than among those with mild and moderate CHD (HR 1.5; 95% CI: 1.1-2.3). Conclusion: Both incidence of MI and post MI 30-day mortality were increased in individuals with CHD compared with the general population. This should be an important consideration for optimizing preventive and acute cardiovascular care for the high-risk adult CHD population.