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

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.