Abstract 13855: Effect of Preconditioning on Post-Ischemic Left Ventricular Diastolic Stunning in Patients with Coronary Artery Disease Undergoing Percutaneous Coronary Intervention

Abstract

Background) Ischemic preconditioning has been demonstrated in animal models to significantly reduce the extent of myocardial necrosis. Recently, post-ischemic left ventricular (LV) diastolic stunning is shown to persist for more than 24 hours despite complete systolic functional recovery. Considering that limited data are available for preconditioning effect in human beings, we sought to examine whether preconditioning may protect post-ischemic diastolic stunning during percutaneous coronary intervention (PCI) in patients with coronary artery disease.

Methods) Twenty-six patients who were planned to undergo PCI and had no left ventricular wall motion abnormalities were enrolled in this study. They were randomly assigned to either a control (n = 12) or preconditioning group (n = 14). Control subjects underwent only 2-minute inflation of the angioplasty balloon and subsequent direct stenting at the target vessel. In contrast, preconditioning was preformed by 4 episodes of 1-minute inflation and 1-minute deflation of the angioplasty balloon followed by 2-minute inflation of the balloon and direct stenting at the target vessel in preconditioning group. Regional LV transverse strain and strain changes during the first one-third of diastole duration (diastolic index) were measured in at-risk segments after PCI. Strain data in the at-risk segments were compared with values derived from remote non-ischemic segments in both groups.

Results) In both groups, coronary occlusion induced a marked reduction in the systolic strain and diastolic index at-risk segments. Upon reperfusion, systolic strain returned to normal values, however, diastolic index decreased 10 minutes after reperfusion in control and preconditioning group (-31 ± 10% vs. 15 ± 28%, respectively, p < 0.01). Twenty-four hours after reperfusion, although diastolic index recovered to normal pre-occlusion values in preconditioning group (58 ± 12%), those with control group still remained lower values (17 ± 15%).

Conclusions) Decreased diastolic index persisted even 24 hours after PCI only in control group. This suggests that preconditioning protects post-ischemic diastolic stunning after PCI.