Trends in Sudden Cardiovascular Death in Young Competitive Athletes

Trends in Sudden Cardiovascular Death in Young Competitive Athletes after Implementation of a Preparticipation Screening Program

Date: Oct. 4, 2006

Why it’s important: The deaths of young athletes is a tragedy that could be avoided in many cases if the athletes, their coaches and physicians knew of heart problems before the youngsters began strenuous physical activity. Understanding the value of screening programs to identify such problems could lead to more systematic screening in nations around the world.

What’s already known: Most young athletes who die suddenly are found to have a previously unknown heart defect with which they were born. A condition called hypertrophic cardiomyopathy is most common cause of sudden death in young athletes in the United States, accounting for one-third of all mortalities. In Italy, one-fourth of such deaths are caused by arrhythmogenic right ventricular cardiomyopathy. Cardiomyopathy is a weakening of the heart muscle or a change in heart muscle structure such that the heart no longer pumps blood well.

Screening young athletes before they begin competition can identify potentially deadly heart problems. By preventing these youths from participating in such activities, authorities can reduce sudden death. Under Italian law passed in 1982, all youths who take part in competitive sports must undergo a screening evaluation by a physician before they are deemed eligible. In 1982, Italy instituted a nationwide systematic screening program. The screening included a sophisticated electrocardiogram to measure the electrical activity of the heart called a 12-lead ECG or electrocardiogram.

How this study was done: The researchers analyzed the trends in sudden cardiovascular death rates in competitive athletes 12 to 35 years old in the Veneto region of Italy between 1979 and 2004. Sudden cardiovascular death rates were analyzed in the non-athletic unscreened population of the same age range as the control. All deaths among athletes and nonathletes were investigated medically by a local pathologist or medical examiner, who determined whether the death was heart-related. If it was, then the heart was sent to the Institute for Pathological Anatomy for detailed assessment. The medical history, athletic activity and circumstances surrounding the heart stoppage were all investigated. The investigators looked at three periods: prescreening (1979-81), early screening (1982-92) and late screening (1993-2004). The screening consisted of family and personal medical history, a physical examination and a 12-lead ECG. If the athletes had positive findings, more tests were done. The researchers also looked at the causes of disqualification of young athletes in the early and late screening period.

What was found: Over the entire period of the study, 55 cases of sudden cardiovascular death occurred in the screened population of athletes 12 to 35 in the Veneto region. Fifty were male and five were female. Fifty of the cases occurred during the sports activity or immediately after.

They found that the number and rates of sudden cardiovascular death decreased in the population over the 26 years of the study. Between 1979-80, the annual death rate was 3.6 per 100,000 per-years (eight deaths). In 1981-82, there were nine sudden deaths for a 4.0 per 100,000 person-years death rate. The death rate decreased steadily after that. In 2001-04 there was one sudden death per period for a rate of 0.43 per 100,000 person-years — about one-tenth that recorded 1980-81.

During the period of the study, the annual incidence of sudden death from heart-related problems decreased 89 percent in screened athletes. By contrast, the death rate did not change in the unscreened nonathletes.

The authors, led by Domenico Corrado, M.D., Ph.D., of the University of Padua Medical School in Italy, noted that there were 14 deaths during the prescreening period. Twelve of those occurred during sports activity. In the early screening period, there were 29 deaths, 27 of them sports related. In the late screening period, there 12 deaths, 11 of which were sports related. By contrast, there was no difference in the death rates in the unscreened population that did not take part in competitive sports. A total of 265 sudden deaths occurred in this population. Two percent of athletes were disqualified from taking part in competitive sport for heart problems during the period of the screening.

“Our trend analysis showed that the incidence of sudden death from arrhythmogenic right ventricular cardiomyopathy decreased dramatically over the 26-year period and accounted for much of the change in mortality from cardiomyopathy," the authors wrote. "The downward trend of fatal events from this cardiomyopathy paralleled the concomitant increase in the number of athletes with cardiomyopathies successfully identified and hence disqualified from competition over the screening periods. All these findings suggest that screening athletes for cardiomyopathies is a life-saving strategy and that 12-lead ECG is a sensitive and powerful tool for identification and risk stratification of athletes with cardiomyopathies…These data demonstrate the benefit of the current Italian screening program and have important implications for implementing screening strategies for prevention of sudden death in athletes in other countries.”

In an accompanying editorial, Paul D. Thompson, M.D., of Hartford Hospital and the University of Connecticut, Hartford, and Benjamin D. Levine, M.D., of Presbyterian Hospital and the University of Texas Southwestern Medical Center in Dallas, wrote: “The study by Corrado et al provides the best evidence to date supporting the preparticipation screening of athletes and provocative evidence for including ECGs in this process. However, cardiologists and other physicians involved in the evaluation of athletes can take a valuable lesson from Corrado et al, and collaborate to develop a rigorous, comprehensive regional or national registry to study the preparticipation screening process prospectively and directly, and to determine how to implement such programs most effectively and how to manage asymptomatic athletes with cardiac abnormalities detected by the screening process.”

The bottom line: Screening young athletes for heart problems provides the best way to identify those for whom competitive sports could prove deadly. A systematic method of insuring that all young athletes receive such screening could save many young lives.