The incidence of sudden cardiac arrest in athletes varies according to age, race and ethnic group, sex, sport, and social determinants of health. The common causes of sudden cardiac arrest include cardiomyopathies, electrical disorders, coronary-artery anomalies, and other cardiac structural abnormalities. There has not been an increase in the incidence of sudden cardiac arrest in athletes during the time frame of the coronavirus disease 2019 (Covid-19) pandemic. Primary prevention is based on cardiovascular screening before participation, and secondary prevention on implementation of emergency action plans. Diagnostic evaluation of athletes who survive sudden cardiac arrest should mirror that of age-matched nonathletes, with additional sport-specific considerations, and should be performed by medical professionals with expertise in the interpretation of test results in the context of athletic adaptation. An increasing body of evidence indicates that many athletes can return to play after disease-specific treatment, without an increase in risk, and professional societies now consider return to participation in sports to be reasonable or appropriate through shared decision making for numerous cardiac conditions.

In patients with autoimmune hemolytic anemia (AIHA), the risk of relapse is high owing to persistent autoreactive B-cell activity. Multirefractory AIHA is a more advanced stage of disease that is defined by a lack of response to at least three lines of therapy. CD19-directed chimeric antigen receptor (CAR) T-cell therapy results in profound B-cell depletion and may be a useful approach to achieving drug-free remission in multirefractory AIHA.

Fremanezumab, a humanized monoclonal antibody that selectively targets calcitonin gene-related peptide, is approved for the prevention of migraine in adults. Evidence from randomized, controlled trials in children and adolescents is needed.