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CORONARY CALCIFICATION BY COMPUTED TOMOGRAPHY(CT).Since the last version of these guidelines, the widespread dissemination of noninvasive techniques such as EBCT, or even more recently, multi-slice gated CT, has markedly increased the number of individuals, including competitive athletes, who may be diagnosed with atherosclerotic CAD. Although exceedingly rare in young persons (6% of men and 3% of women 20 to 29 years of age), the presence of coronary calcium increases substantially with age, such that for master’s athletes, age 40 to 49 years, approximately 41% of men and 13% of women may have measurable coronary calcium (13). Among individuals age 50 to 59 years, 68% of men and 27% of women have documented coronary calcium (13). There is compelling evidence that the presence of any coronary calcium indicates underlying atherosclerosis (14) and that increasing coronary calcium scores are associated with increased CAD risk (15). The coronary calcium score that warrants additional evaluation in asymptomatic competitive athletes is unknown, although scores of more than 100 (15) have been associated with increased risk for coronary events (16) in the general population compared to patients with no coronary calcium. It is unknown whether the risk of coronary events during intense exercise is increased in the presence of this or lesser amounts of coronary calcium. Nevertheless, for the purpose of the present document, athletes with coronary artery calcification scores more than 100 should undergo the same evaluation as those with more clinically evident CAD. RISK ASSESSMENT.A paucity of data exists in competitive athletes directly relating the presence and severity of CAD to the risk of athletic participation. This requires that these recommendations for athletes with CAD be based in part on observations obtained from non-athletes with CAD. Nevertheless, it is likely that risk is increased to some degree whenever coronary atherosclerosis is present. It is also likely that the risk of exercise-related events increases with the extent of disease, LV dysfunction, inducible ischemia, and electrical instability, and that the risk increases with the intensity of the competitive sport and the intensity of the participant’s effort. Evaluation. 1. Athletes with CAD diagnosed by any method including coronary artery classification scoring more than 100, coronary angiography, evidence of inducible ischemia, or prior coronary event, and who are undergoing evaluation for competitive athletics, should have their LV function assessed. 2. These athletes should undergo maximal treadmill (or bicycle) exercise testing to assess their exercise capacity and the presence or absence of provocable myocardial ischemia. Exercise testing should approximate as closely as possible the cardiovascular and metabolic demands of the planned competitive event and its training regimen. Despite such simulation, graded exercise testing cannot replicate the cardiovascular stress produced by the sudden bursts of activity, the combination of high dynamic and static exercise, such as rowing, or the sustained bouts of exercise required by athletic training and competition. Therefore, standard clinical exercise tests may not be appropriate for the evaluation of athletes with coronary heart disease. RISK STRATIFICATION.Two levels of risk can be defined on the basis of testing. Mildly increased risk. Athletes with CAD diagnosed by any method are judged to be at mildly increased risk if they demonstrate all of the following: 1. Preserved LV systolic function at rest (i.e., ejection fraction greater than 50%). 2. Normal exercise tolerance for age, demonstrated during treadmill or cycle ergometer exercise testing: greater than 10 metabolic equivalents (METS), or greater than 35 O2/kg-min if less than 50 years old; greater than 9 METS, or greater than 31 ml O2/kg-min for 50 to 59 years old; greater than 8 METS, or greater than 28 ml 1349 JACC Vol. 45, No. 8, 2005 Thompson et al. April 19, 2005:1348–53 Task Force 6: Coronary Artery Disease O2/kg-min, if 60 to 69 years old; and greater than 7 METS, or greater than 24 ml O2/kg-min, if greater than or equal to 70 years old. It should be noted that young, highly competitive endurance athletes should have maximal oxygen uptakes far in excess of ranges regarded as normal, which in fact may represent substantial functional impairment in this population. 3. Absence of exercise-induced ischemia and exerciseinduced or post-exercise complex ventricular arrhythmias, including frequent premature ventricular contractions (greater than 10% of beats/min), couplets, or ventricular tachycardia. 4. Absence of hemodynamically significant stenosis (generally regarded as 50% or more luminal diameter narrowing) in any major coronary artery by coronary angiography. 5. Successful myocardial revascularization by surgical or percutaneous techniques if such revascularization was performed. Substantially increased risk. Athletes with CAD identified by noninvasive or invasive testing are judged to be at substantially increased risk if they demonstrate any of the following: 1. Impaired LV systolic function at rest (i.e., ejection fraction less than 50%). 2. Evidence of exercise-induced myocardial ischemia or complex ventricular arrhythmias. 3. Hemodynamically significant stenosis of a major coronary artery (generally regarded as 50% or more lumen diameter narrowing) if coronary angiography was performed. The American College of Cardiology/AHA guidelines on exercise testing note that it is not necessary to stop beta-blockers before routine exercise testing, although this practice may reduce the diagnostic and prognostic value of the test (17). The decision whether or not to stop betablocker therapy before exercise testing of athletes should be made on an individual basis. Stopping beta-blockers and other anti-ischemic mediations before testing may be useful to more closely approximate the probable risk if the athlete either intentionally or unintentionally does not take these medications before competition, or when certain athletic regulatory bodies prohibit beta-blockers. If anti-ischemic medications are stopped, this should be done carefully to avoid a potential hemodynamic rebound effect, which could lead to accelerated angina or hypertension. Coronary arteriography is not required to determine eligibility for competition in patients with known CAD, and no evidence of inducible ischemia, but is recommended in athletes with exercise-induced ischemia who choose to participate in sports against medical advice. Such studies may identify coronary lesions that may be better managed by percutaneous or surgical myocardial revascularization procedures to relieve exercise-induced ischemia and potentially to reduce exercise-related risk. The panel wishes to emphasize that the following recommendations are prepared as a guidelines for permitting participation in competitive sports. Restrictions in the following recommendations, therefore, should not be misinterpreted as an injunction against regular physical activity as opposed to athletic competition. Indeed, regular and recreational physical activity and moderate-intensity exercise training are recommended for patients with CAD for its general cardiovascular benefits (1). Recommendations: Date: 2016-03-03; view: 789
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