While some published research has hinted at the connection between the sickle cell trait and sudden cardiac death among young, athletic African-American males, which was initially observed in black military recruits 25 years ago, a new study with the first sizeable patient series definitively confirms this risk for these individuals during competitive sports.
The sickle cell trait, for which all U.S. African Americans are tested at birth, affects approximately 8 percent of the population. The Minneapolis Heart Institute Foundation maintains a 32-year-old forensic database, the U.S. Sudden Death in Athletes Registry, which researchers interrogated to determine the frequency, epidemiology and clinical profile of sickle cell trait-related deaths in a large population of competitive athletes for the purposes of this study.
The findings from this registry show there is "convincing evidence of a causal relationship between the sickle cell trait and the deaths of young, black competitive athletes, especially football players," says the study's senior author Barry J. Maron, MD, director of the Hypertrophic Cardiomyopathy Center at the Minneapolis Heart Institute Foundation. The study will be published in the October edition of the American Journal of Cardiology, but currently is available online.
Prior to this registry study, a lawsuit and previous research prompted the National Collegiate Athletic Association (NCAA) to conduct mandatory screening for the sickle cell trait in all division I athletes prior to their participation in college athletics. As of yet, the NCAA has not expanded to the screening program to division II or III athletes, nor has the association shared its data with the medical community.
Of the 2,462 athlete deaths in the U.S. Sudden Death in Athletes Registry, which provides the first and largest published record of athletes who died of sudden cardiac death on an athletic field, 23 occurred in association with the sickle cell trait (ages 12 to 22 years): 21 were male and all were African Americans. The deaths most often occurred in college-aged athletes (19-23 years) during football conditioning drills early in the season, and with those exposed to high environmental temperatures.
"The registry was initially started by Dr. Maron to help the medical community understand why any athlete would collapse on a field," explains the study's lead author Kevin M. Harris, MD, co-director of the Acute Aortic Dissection Program and director of the echocardiography laboratory at the Minneapolis Heart Institute- at Abbott Northwestern Hospital in Minneapolis.