Abstract 18419: Remote Ischemic Preconditioning Does Not Improve Coronary Hemodynamics
Introduction: Remote ischemic preconditioning (RIPC) reportedly reduces the risk of myocardial injury after coronary artery bypass grafting and percutaneous coronary intervention. Limb ischemia produces nitric oxide (NO), which leads to increased blood flow.
Hypothesis: We assessed the hypothesis that RIPC might improve coronary hemodynamics.
Methods: In 27 patients with angiographically normal coronary arteries (% diameter stenosis < 50%), the average peak velocity (APV), coronary blood flow (CBF), and hyperemic microvascular resistance (HMR) were simultaneously measured using a Doppler guide-wire during RIPC. A cuff applied to the upper left arm was inflated to a blood pressure of 200mmHg and was maintained for 5 minutes, followed by 5 minutes of deflation. All the patients received 3 cycles of RIPC, and the APV, CBF, and HMR measurements were obtained for each cycle.
Results: The mean parameter values during RIPC changed as follows (baseline, first, second, and third measurements; compared using a one-way ANOVA): for APV, 25.0, 22.9, 22.4, and 23.0 cm/s, P = 0.96; for CBF, 53.6, 44.3, 43.0, and 42.6 mL/min, P = 0.92; and for HMR, 3.23, 3.47, 3.99, and 3.69, P = 0.87.
Conclusions: Although a recent study showed that RIPC generates NO and transfers it to the heart, we were unable to demonstrate an increase in coronary blood flow during RIPC. These findings suggest that the cardioprotective effect of RIPC would not be provided by the improvement of coronary hemodynamics, suggesting that NO generated by RIPC would not activate the adenosine triphosphate-sensitive potassium channels.
Author Disclosures: T. Ashida: None. H. Takahashi: None. S. Tani: None. K. Kikushima: None. S. Furuya: None. T. Washio: None. S. Niizuma: None. K. Kawauchi: None. M. Kobori: None. M. Matsuzaki: None. N. Matsumoto: None.
- © 2016 by American Heart Association, Inc.