Ischemic preconditioning lowered ischemic burden in adults (≤55 years) but not in elderly patients (≥65 years), though this impaired responsiveness was reversed by nicorandil or prolonged ischemia.
RCT (n=56)
randomly allocated
Does ischemic preconditioning or nicorandil reduce ischemic burden in elderly patients undergoing coronary angioplasty compared to adult patients?
Elderly patients have impaired ischemic preconditioning during angioplasty due to attenuated K(ATP) channel activation, which can be reversed by nicorandil or prolonged ischemia.
BACKGROUND: The ischemic preconditioning response among elderly patients is known to be lower than in adult patients. Since mitochondrial ATP-sensitive potassium (K(ATP)) channels exert preconditioning effects, we undertook this study to determine whether this attenuated activation of K(ATP) channels influences the reduced responsiveness of elderly patients to ischemic preconditioning. METHODS AND RESULTS: Fifty-six patients undergoing angioplasty for a major epicardial coronary artery were randomly allocated to either an ischemic preconditioning group, a nicorandil (an agonist of K(ATP) channels) group, or a glibenclamide (an antagonist of K(ATP) channels), group based on their age: adult groups (n=26; age, /=65 years; mean age, 71+/-3 years). Ischemic preconditioning with a 120-second coronary occlusion significantly lowered the ischemic burden assessed by ST-segment shift, chest pain score, and myocardial lactate extraction ratios in the adult group. This did not occur in the elderly group. The impaired preconditioning responsiveness in the elderly patients was reversed by nicorandil administration or an ischemic period lengthened to 180 seconds. However, nicorandil-induced cardioprotection was abolished by administering glibenclamide in both the adult and elderly groups. CONCLUSIONS: The present study demonstrates that preconditioning significantly enhances the tolerance of the heart to subsequent ischemia in adults but not in senescent patients. Since prolonged ischemia and nicorandil are able to mimic preconditioning and can reverse impaired responsiveness, impaired preconditioning of the aged heart appears to be due to an attenuated activation of K(ATP) channels.
Lee et al. (Tue,) conducted a rct in undergoing angioplasty for a major epicardial coronary artery (n=56). Ischemic preconditioning, nicorandil, or glibenclamide vs. Adult vs elderly groups was evaluated on Ischemic burden assessed by ST-segment shift, chest pain score, and myocardial lactate extraction ratios. Ischemic preconditioning lowered ischemic burden in adults (≤55 years) but not in elderly patients (≥65 years), though this impaired responsiveness was reversed by nicorandil or prolonged ischemia.