Silent ischemia during voluntary detraining and future cardiac events in master athletes.

OBJECTIVES

To determine whether exercise-induced silent ischemia in older master athletes following a 3-month period of deconditioning is a predictor of future cardiovascular events.

DESIGN

A longitudinal study of a cohort of master athletes.

SETTING

The Geriatric Research Education and Clinical Center (GRECC), Baltimore VA Medical Center, Baltimore, Maryland.

PARTICIPANTS

Ten older (59 +/- 8 years, mean +/- SD), highly conditioned (maximal aerobic capacity VO2max 50 +/- 5 mL/kg/min), aerobically trained athletes.

INTERVENTION: Five to eight years of longitudinal follow-up of athletes who had previously participated in a 3-month-long detraining intervention.

MEASUREMENTS: At baseline, all 10 athletes had their history taken and underwent physical examinations, metabolic testing, electrocardiogram at rest, exercise treadmill tests, exercise thallium scintigrams, and exercise multigated acquisition scans. After 3 months of deconditioning, they had repeat maximal exercise stress tests. After 5 to 8 years of follow-up, they were re-evaluated, including history and physical examination and measurement of their VO2max.

RESULT: All 10 master athletes had normal studies at baseline. At the end of 3 months of detraining, three of these athletes had exercise-induced silent ischemia, which disappeared after retraining in two subjects and persisted at a higher heart rate in one subject. Over a 5- to 8-year period of observation, two of these three athletes with silent ischemia experienced major cardiac events (sudden death, cardiac bypass surgery). The other seven athletes did not have any cardiovascular events.

CONCLUSIONS

Exercise-induced silent ischemia after a short period of detraining in highly trained older athletes may be a predictor of future cardiac events. A study with a larger cohort is warranted.