Influence of dietary intervention on microvascular endothelial function in coronary patients and atherothrombotic risk of recurrence

Endothelial dysfunction is a key player in both the onset and development of atherosclerosis. No study has examined whether healthy dietary patterns can improve microvascular endothelial function in patients with coronary heart disease (CHD) in the long-term and whether this relationship can affect patient’s risk of CHD recurrence. In the CORDIOPREV study, a randomized, double-blind, controlled trial, dietary intervention with either the Mediterranean diet or a low-fat diet was implemented in 1,002 CHD patients. A laser-doppler flowmetry was performed at baseline and after 6 years of follow up in 664 patients, evaluating the effects of this dietary intervention on microvascular basal flow and reactive hyperaemia area, as well as on the risk of CHD recurrence, based on the TRS2P risk score. Basal flow (97.78 ± 2.79 vs. 179.31 ± 5.06 arbitrary perfusion units, 83.38% increase, p < 0.001) and reactive hyperaemia area (4233.3 ± 127.73 vs. 9695.9 ± 205.23 arbitrary perfusion units per time, 129.04% increase, p < 0.001) improved after the dietary intervention in the cohort, without finding differences due to the diet (p > 0.05 for the diet-effect). When patients were stratified to low, moderate or high-risk of recurrence, basal flow was similarly increased in all three groups. However, reactive hyperaemia area was improved to a greater extent in patients at the low-risk group compared with those at moderate or high-risk. No differences were observed between diets. Healthy dietary patterns can improve microvascular endothelial function and this improvement persists in the long-term. Patients with a low-risk of CHD recurrence show a greater improvement in reactive vasodilation to ischemia than patients in the moderate or high-risk groups.

Hyperspectral Imaging to Study Dynamic Skin Perfusion after Injection of Articaine-4% with and without Epinephrine—Clinical Implications on Local Vasoconstriction

This study aimed to investigate the dynamic skin perfusion via hyperspectral imaging (HSI) after application of Articaine-4% ± epinephrine as well as epinephrine only. After the subcutaneous injection of (A100) Articaine-4% with epinephrine 1:100,000, (A200) Articaine-4% with epinephrine 1:200,000, (Aw/o) Articaine-4% without epinephrine, and (EPI200) epinephrine 1:200,000, into the flexor side of the forearm in a split-arm design, dynamic skin perfusion measurement was performed over 120 min by determining tissue oxygen saturation (StO2) using HSI. After injection, all groups experienced a reactive hyperaemia. With A200, it took about three min for StO2 to drop below baseline. For Aw/o and EPI200, perfusion reduction when compared to baseline was seen at 30 min with vasoconstriction >120 min. A100 caused vasodilation with hyperaemia >60 min. After three minutes, the perfusion pattern differed significantly (p < 0.001) between all groups except Aw/o and EPI200. The vasoactive effect of epinephrine-containing local anaesthetics can be visualised and dynamically quantified via StO2 using HSI. Aw/o + epinephrine 1:100,000 and 1:200,000 leads to perfusion reduction and tissue ischaemia after 30 min, which lasts over 120 min with no significant difference between both formulations. When using Aw/o containing epinephrine in terms of haemostasis for surgical procedures, a prolonged waiting time before incision of 30 or more min can be recommended.

MO164NOVEL PARAMETERS TO ASSESS ENDOTHELIAL DYSFUNCTION BY PULSE WAVE ANALYSIS

Background and Aims Pulse wave morphology changes under the high flow condition of reactive hyperaemia. We hypothesized, that those alterations may be able to indicate endothelial dysfunction. Method We recorded digitized pulse waves measured tonometrically with the SphygmoCor® device of 64 persons, 41 kidney transplant recipients and 23 healthy individuals, under normal conditions (NC) and under reactive hyperaemia (RH). Using matlab®, we calculated novel parameters, which had a temporal relationship with 3 charactereristic points (PO) of the normalized pulse wave, namely the maximum of the antegrade wave (1), the diacrotic notch (2) and the first diastolic inflection point (3). The following parameters were calculated: Mean slope between PO 1 and 2 (λ2), area under the curve (AUC) in the systole (Asys), AUC between PO 1 and 3 (A13), AUC between PO 1 and 2 (A12) and AUC between PO 2 and 3 (A23). Parameters were analyzed as their difference under reactive hyperaemia and under normal conditions. Also the maximum of the instantaneous difference of normalized pulse waves under NC und RH (Dmax) was analyzed. Endothelial function was evaluated by duplex sonography using ROC-analysis of peak systolic and end-diastolic flow difference under NC and RH. Results ROC-assessment of endothelial dysfunction as indicated by systolic peak flows demonstrated AUCs of 0.733 for λ2 (p=0.002), 0.751 for Dmax (p&lt; 0.001), 0.698 for Asys (p=0.006), 0.648 for A13 (p=0.077), 0.678 for A12 (p=0.027) and 0.732 for A23 (p=0.001). For the diastole the values were 0.753 for λ2 (p=0.003), 0.733 for Dmax (p=0.002) 0.670 for Asys (p=0.038), 0.566 for A13 (p=0.495), 0.664 for A12 (p=0.091) and 0.722 for A23 (p=0.015) respectively. Conclusion Pulse wave analysis under the condition of reactive hyperaemia probably is useful to assess endothelial function in kidney transplant recipients.

P1333PULSE WAVE ANALYSIS UNDER THE CONDITIONS OF HIGH ARTERIAL FLOW: ASSESSMENT OF SHUNT FUNCTION AND REACTIVE HYPEREMIA

Background and Aims Fistula-creation as well as reactive hyperaemia increase local arterial blood flow. We wanted to analyse the impact of these haemodynamic changes on pulse wave (PW) morphology to assess fistula- and endothelial function. Method We conducted a clinical pilot study including 56 patients with functioning forearm fistula. PW morphology in the A. brachialis was assessed tonometrically at the non-fistula and fistula arm using the SpygmoCor® device. We also performed a PW analysis on the non-fistula arm under the condition of reactive hyperaemia (possible in 43 patients). Duplex-sonography was used as a complementary and reference method. Results In comparison to measurements under physiologic conditions, both the fistula arm (a) and the non-fistula arm with reactive hyperemia (b) showed marked differences in the pulse wave morphology (figure). The changes in PW morphology were most prominent in the area of the diacrotic notch and could be assessed as the differences of the sum of the mean slope (Δλ in mmHg/ms) between the diacrotic notch and the main preceding and subsequent inflexion point. Measurement with duplex-sonography confirmed increased peak blood flow velocity in the arteria brachialis (ΔVmax in cm/s) under both conditions. Statistical significance could be proved for Δλ and for ΔVmax (table). Finally, bivariate regression analysis revealed a correlation of Δλ with ΔVmax (figure; c: p=0.001 and r=-0,483 for interarm-differences of the fistula and non-fistula arm; d: p= 0.030 and r=-0.343 for the differences between the physiologic state and reactive hyperaemia at the non-fistula arm). Conclusion PW analysis under high flow conditions has the potential to be a new useful clinical tool in nephrology to monitor fistula- as well as endothelial function assessed by reactive hyperaemia. The findings should be verified in a trial with clinical endpoints.