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), Balt imore VA Medical Center, Baltimore, Maryland. PARTICIPANTS: Ten older (59 +/- 8 years, mean +/- SD), highly conditioned ( maximal aerobic capacity (V)over dot o(2max) 50 +/- 5 mL/kg/min), aerobical ly 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 unde rwent physical examinations, metabolic testing, electrocardiogram at rest, exercise treadmill rests, exercise thallium scintigrams, and exercise multi gated acquisition scans. After 3 months of deconditioning, they had repeat maximal exercise stress tests. After 5 to 8 years of follow-up, they were r e-evaluated, including history and physical examination and measurement of their (V)over dot o(2max). RESULT: All 10 master athletes had normal studies at baseline. At the end o f 3 months of detraining, three of these athletes had exercise-induced sile nt ischemia, which disappeared after retraining in two subjects and persist ed at a higher heart rate in one subject. Over a 5- to 8-year period of obs ervation, two of these three athletes with silent ischemia experienced majo r cardiac events (sudden death, cardiac bypass surgery). The other seven at hletes did not have any cardiovascular events. CONCLUSIONS: Exercise-induced silent ischemia after a short period of detra ining in highly trained older athletes may be a predictor of future cardiac events. A study with a larger cohort is warranted.