National Screening Slows Sudden Cardiac Deaths Among Athletes

PADUA, Italy, Oct. 3 -- Sudden cardiac deaths among athletes in the Veneto region of Italy dropped by 89% since initiation of a pre-participation screening program a quarter-century ago for those in competitive athletics.

Most of the dramatic decline in sudden cardiac deaths over time among athletes was due to fewer sudden cardiac deaths caused by cardiomyopathies, a drop that paralleled an increase in cardiomyopathies identified by the screening program, according to findings reported in the October 4 issue of the Journal of the American Medical Association.

But a similar screening program may not work in the United States because the cause of sudden cardiac death for American athletes is usually hypertrophic cardiomyopathy, while in Italy the usual suspect is arrhythmogenic right ventricular cardiomyopathy, according to an editorial that appeared in the same issue of JAMA.

Domenico Corrado, M.D., Ph.D., of the University of Padua, and colleagues, conducted a population-based study of sudden cardiovascular death rates among athletes and nonathletes ages 12 to 35 who were residents of the Veneto region of Italy from 1979 to 2004.

In 1982 Italy initiated a nationwide preparticipation cardiovascular screening program that included physical examination, family history. and 12-lead ECG study.

They also conducted a parallel study of trends in cardiovascular causes of disqualification from competitive sports for 42,386 athletes who underwent preparticipation screening at the Center for Sports Medicine in Padua.

There were 55 sudden cardiovascular deaths in the screened athletes during the study period (1.9 deaths/100,000 person-years) and 265 sudden deaths among unscreened non-athletes (0.79/100,000 person-years).

The rate of sudden cardiac deaths among athletes was 3.6 per 100,000 during the years before the screening program (1979-1981) versus 0.4 deaths per 100,000 two decades after the screening was initiated (P for trend <0.001).

During the pre-screening period (1979 to 1981) there were 14 sudden cardiac deaths among athletes of which 12 were sports related. During the first decade of screening (1982 to 1992) there were 29 deaths and 27 were sports related, while during the second decade of screening (1993-2004) there were 12 deaths of which 11 were sports related.

Compared with the pre-screening period, the relative risk of sudden cardiac death among athletes was 0.56 in the early screening period (95% confidence interval 0.29-1.15; P=0.04), which declined to 0.21 in the late screening period (95% CI 0.09-0.48; P=0.001).

During that same period there was no significant change in the rate of sudden cardiac death among unscreened, non-athletes.

Nine percent (3,914) of the 42,386 athletes screened at the Center for Sports Medicine in Padua were referred for additional tests because of positive findings on initial screening. Of these, 879 were ultimately disqualified from sports, including 39% who had rhythm and conduction abnormalities that worsened with exercise, 23% had systemic hypertension, 21% had evidence of valvular heart disease, 6.8% had cardiomyopathies, and 1.3% had atherosclerosis. Another 8.4% had a variety of conditions including rheumatic heart disease, pericarditis, and congenital heart diseases.

The authors concluded that their data demonstrate the benefits of a preparticipation screening program such as the one initiated in Italy.

But Paul D. Thompson, M.D., of the University of Connecticut and Benjamin D. Levine, M.D., of University of Texas Southwestern in Dallas, said that data from the Italian study don't make a persuasive case for similar screening in the U.S.

They pointed out that the study was not a controlled comparison of the screening versus nonscreening of athletes, but rather is a population-based observational study which cannot prove causality.

In addition, not only did the study fail to compare the utility of ECGs versus screening based on history and physical, but while hypertrophic cardiomyopathy is the predominant cause of exercise-related sudden death in the U.S., the predominant cause in Italy is arrhythmogenic right ventricular cardiomyopathy, they wrote.

Moreover, Drs. Thompson and Levine said that the lowest death rate achieved by the screening program was roughly equivalent to the death rate for U.S. athletes without a screening program.

That said, the editorialists said they don't flatly oppose screening programs adding that the Corrado "findings support a screening process, which should at a minimum follow established guidelines."

But they added that screening programs should be tailored to the evaluation of symptomatic athletes. Such a program, Drs. Thompson and Levine wrote, "may be one of the most effective sudden death preventive strategies."