Exercise training following myocardial infarction improves myocardial perfusion assessed by thallium-201 scintigraphy

Aim: We assessed the effects of a 6-week exercise programme on the thallium-201 myocardial perfusion characteristics of patients following myocardial infarction. Methods: Twenty-five patients presenting with a first acute myocardial infarction were randomised into two groups: (i) those undergoing a supervised exercise training programme over 6 weeks (n=15) and (ii) a control group who did not attend the exercise programme (n=10). All underwent three sequential stress thallium myocardial perfusion scans at 10 days, 6 weeks and 3 months after infarction. The stress conditions were identical on each occasion. The images were analysed using a polar plot with a computer assisted algorithm comparing stress and redistribution data. Values for extent, severity and percentage redistribution of the thallium images were generated. Results: A total of 29 perfusion defects were identified, 18 in the exercise group and 11 in the control group. Over 3 months in the exercise group the mean extent of the stress image defect fell from 109 64 to 95 51 pixels (P<0.05) while in the control group there was an increase from 133+/-57 to 144+/-57 pixels (P=ns). Stress defect severity fell in the exercise group from 581+/-417 to 494+/-346 S.D. (P<0.05) but increased in the control group from 765+/-494 to 877+/-543 S.D. (P=ns). On redistribution imaging in the exercise group a significant decrease was observed in both extent (94+/-56 to 76+/-43 pixels (P<0.05)) and severity (541 387 to 438 291 S.D. (P<0.05)) of the defects. However in the control group no significant change was observed for extent (125 54 to 125 52 pixels) or severity (745 485 to 820 503 S.D.) of the redistribution defects (P=ns). Reversibility of the defects increased slightly in both the exercise group (from 14.6+/-17 to 17.5+/-20%) and the control group (5.2+/-5 to 9.6+/-10%) (P=ns). Conclusion: Following myocardial infarction a 6-week exercise programme improves myocardial perfusion characteristics. An exercise programme should be integrated into cardiac rehabilitation protocols for patients after infarction. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.