Cardiac Screening for Conditions Associated With Sudden Cardiac Death: Yield, Interventions, and SCA/SCD Incidence in 104,369 Young Individuals.

BACKGROUND

Efforts to prevent sudden cardiac death (SCD), including cardiac screening, have focused on young athletes. There is limited data on the impact of population screening for conditions associated with SCD in the young general population.

OBJECTIVES

The objective of this study was to determine the diagnostic yield of cardiac screening, subsequent cardiac diagnoses after initial clearance, and incidence of sudden cardiac arrest (SCA) and SCD in young individuals after a single screening.

METHODS

Between 2008 and 2018, 104,369 consecutive individuals aged 14 to 35 years (62% male, 89% White, 9% athletes) underwent a single screening with a questionnaire, electrocardiogram (ECG), and selective echocardiography. All individuals had a consultation with an attending cardiologist who reviewed the results and recommended secondary cardiac evaluation when appropriate. Outcomes were obtained from national databases and a follow-up questionnaire.

RESULTS

Of the 104,369 individuals screened, 2,619 (2.5%) were referred for secondary evaluation, 937 (0.9%) because of symptoms or family history of clinical concern, 1,361 (1.3%) because of an abnormal ECG, and 321 (0.3%) because of both. Screening identified 280 (0.3%) individuals with conditions associated with SCA/SCD, of whom 115 (41%) received risk-modifying interventions, including 10 prophylactic implantable cardioverter defibrillators and 2 cardiac transplants. Over a mean follow-up of 6.0 ± 2.5 years, 86 (0.08%) additional individuals were diagnosed with conditions associated with SCA/SCD, including 35 who experienced SCA (n = 15) or SCD (n = 20). The incidence of SCA/SCD was 5.6 of 100,000 person-years. Median age of presentation was 23.8 years (IQR: 10.5), and events occurred a median of 3.6 years (range: 0.2-11.7) after screening. The sensitivity of the ECG and the questionnaire for detecting conditions associated with SCA/SCD was 75.4% and 32.5%, respectively.

CONCLUSIONS

A single cardiac screening identified a condition associated with SCA/SCD in 0.3% of young individuals of whom 41% received risk-modifying interventions beyond lifestyle and medication. Over a 6-year follow-up, 0.08% of individuals cleared at screening were diagnosed with conditions associated with SCA/SCD or presented with SCA/SCD. The incidence of SCA/SCD was 5.6 of 100,000 person-years, underscoring the need to strengthen strategies for the prevention of SCD in young individuals. Serial evaluations may mitigate the challenge of age-related penetrance.