['To establish whether the adaptation to ischemia observed in humans during percutaneous transluminal coronary angioplasty (PTCA) after repeated balloon inflations, i.e. a clinical correlate of ischemic preconditioning, is preserved in elderly patients.', 'We studied 53 consecutive patients undergoing successful angioplasty for an isolated stenosis of a major epicardial coronary artery. On the basis of age, patients were separated into terciles: patients in the lower and middle terciles were grouped together (Group 1, adult patients, n = 24, mean age 50 +/- 6 years) and compared with those in the upper tercile (Group 2, elderly patients, n = 29, mean age 68 +/- 3 years). Intracoronary electrocardiogram was obtained at the end of the first two balloon inflations. Collateral recruitment during repeated balloon inflations was assessed by using an intracoronary Doppler guide wire (23 patients) or by using an intracoronary pressure guide wire (30 patients).', 'In Group 1, ST-segment changes during the second inflation were significantly less than those at the end of the first inflation (6 +/- 3 vs 13 +/- 5 mm, p < 0.001). Similarly, in Group 2, ST-segment changes during the second inflation were significantly less than those at the end of the first inflation (6 +/- 4 vs 13 +/- 6 mm, p < 0.001). In both groups, collateral recruitment did not change from the first inflation to the second inflation (p = 0.1).'] Is ischemic preconditioning during coronary angioplasty preserved in elderly patients?