Human coronary collateral recruitment is facilitated by isometric exercise during acute coronary occlusion

Abstract

Objective: To determine whether isometric exercise increases collateral flow in remote ischaemic myocardium in acute coronary occlusion models of patients with coronary artery disease. Design: A randomized controlled study. Subjects: Sixty-five patients with 1-vessel coronary artery disease. Methods: Subjects were randomly assigned to either the isometric exercise group or non-exercise group. Patients in the exercise group performed isometric handgrip exercises (50% maximal voluntary contraction) during 1 min coronary balloon occlusion, while patients in the non-exercise group remained sedentary. The collateral flow index, heart rate, systolic blood pressure and diastolic blood pressure were determined prior to and following 1 min of coronary occlusion. Results: In the exercise group, difference values for collateral flow index (after coronary occlusion ? before coronary occlusion) were significantly higher than those in the non-exercise group (0. 04 standard deviation (SD) 0. 05 vs 0. 01 (SD 0. 03), p?<?0. 01). Differences in heart rate, systolic blood pressure and diastolic blood pressure were also significantly higher than controls (heart rate 7. 84 (SD 8. 20) vs 0. 88 (SD 3. 96), p<0. 01; systolic blood pressure: 3. 25 (SD 7. 17) vs ?1. 88 (SD 6. 21), p?<?0. 01; diastolic blood pressure 5. 88 (SD 6. 40) vs ?1. 5 (SD 6. 22), p?<?0. 01). Conclusion: Isometric exercise in patients with coronary artery disease induced an increase in coronary collateral flow during acute vessel occlusion, which was significantly different from control occlusion.