Abstract 11847: Remote Ischemic Conditioning by Single Cuff Inflation Improves Aortic Elastic Properties and Endothelial Glycocalyx Thickness in Acute Myocardial Infarction Patients

Background: Remote ischemic conditioning attenuates ischemia-reperfusion injury in patients with STEMI. However, its effects on vascular function and biochemical mechanisms are not fully defined. Methods: We examined 110 patients with STEMI and 30 healthy controls. Patients were randomised in 2 remote ischemic conditioning protocols after a baseline assessment of vascular function (T0), a) one with two ischemic conditioning stimuli by brachial cuff inflation of both arms at 200mmHg for 5 min, separated by 15min, and each followed by vascular assessment (T1,T2), and a final vascular assessment (T3), 25 min after 2nd cuff deflation (double cuff inlation,n=60 ) or b) a second with omission of the second cuff inflation (single cuff inflation-n=50).In both protocols we measured a) the carotid-femoral pulse wave velocity (PWV);b)perfusion boundary region (PBR- micrometers) of the sublingual arterial microvessels as a marker of endothelial glycocalyx thickness;c) plasma malondialdehyde (MDA),NOx, and IL-6 levels as biomarkers of oxidative stress and inflammation. Results: The single cuff inflation protocol resulted in a more uniform aortic elasticity improvement (PWV T0: 12.09m/s, T1:11.74m/s, T2:11.59m/s, T3:11.81m/s),with the greatest difference measured at the last vascular assessment (T3: PWV= 11.8 single cuff vs 13.8 m/s double cuff inflation,p<0.05).A greater glycocalyx integrity restoration was observed in patients with baseline PBR> 2.1 in both protocols (mean difference in PBR improvement=0.5 at T1, p<0.001).Conversely,in healthy controls, PWV and PBR remained unchanged throughout the study (p>0.05).MDA was significantly reduced at T3 compared to baseline in STEMI(2.1 ± 0.15 at T3 vs 2.59 ±0.15 at T0, p< 0.001) in both protocols while it remained unchanged in healthy controls. Additionally, the single cuff inflation protocol promoted a greater increase in NOx levels compared to the double inflation protocol (T0: 8.25± 1.18 to T3: 11.1 ± 2 μμ vs T0: 10.79± 1.18 to T3: 8.91±2 μμ, p< 0.05). IL-6 levels were unaffected. Conclusion: Remote ischemic conditioning by a single 5-min cuff inflation, confers acute short-term improvement of vascular function, likely through oxidative stress reduction and nitrate- nitrite- NO pathway activation.