Effect Of Ischemic Preconditioning Research Articles

Effect of distal ischemic preconditioning on cardiovascular events in adult patients with hip fracture one year after operation

To investigate the effect of remote ischemic preconditioning (RIPC) on major adverse cardiovascular events (MACE) in elderly patients with hip fracture 1 year after operation. Total of 314 elderly patients with hip fracture of gradeⅡand Ⅲ for American Society of Anesthesiologists (ASA) were treated by surgical operation from April 2015 to May 2020 including 116 males and 198 females, the age ranged from 60 to 76 years old. The subjects were divided into intervention group and control group according to whether received RIPC. Among them, 157 cases in intervention group included 56 males and 101 females with an average age of (68.12±7.13) years old and 157 cases in control group included 60 males and 97 females with an average age of (68.24±7.05) years old. Both groups were given routine anesthesia. The intervention group was treated with RIPC on the basis of routine anesthesia. The MACE events 1 year after operation in two groups were compared and analyzed. The OR values of RIPC for myocardial infarction, heart failure, stroke, nonfatal cardiac arrest, coronary revascularization, severe arrhythmia, peripheral artery thrombosis, readmission of cardiovascular disease, and all-cause death in patients with hip fracture one year after operation were 1.269, 1.304, 0.977, 1.089, 1.315, 1.335, 0.896, 0.774, 1.191, respectively, but there was no significant difference (P>0.05). RIPC did not significantly affect and change the occurrence of major cardiovascular adverse events within 1 year after hip fracture surgery. The long term impact of RIPC on clinical cardiovascular outcomes in non cardiac surgery needs to be confirmed in appropriate randomized clinical trials.

Does remote ischemic preconditioning affect the systemic inflammatory response by modulating presepsin levels?

We investigated the effect of Remote Ischemic Preconditioning (RIPC) on the inflammatory response during CPB by means of serum presepsin levels at preoperative and postoperative 1st and 24th h. In this prospective, randomized, cross-sectional study we included 81 patients undergoing coronary artery bypass graft surgery with cardiopulmonary bypass (CPB). Patients were randomized and RIPC was applied to 40 patients in the study group before anesthesia. The remaining 41 patients were determined as the control group. The relationships between RIPC and factors such as presepsin, C-reactive protein (CRP), and leukocyte levels were investigated. There was no significant difference between the groups in postoperative leukocyte and CRP values (p = 0.52, p = 0.13, respectively). When the preoperative and postoperative first hour presepsin values of the patients were compared, no significant difference was found in the control group (p = 0.17), but a significant difference was found in the study group (p < 0.05). When the presepsin values were compared between the groups, a significant difference was found only in the postoperative first hour value (p < 0.05). It was observed that RIPC application caused to increase the presepsin levels in the postoperative first hour significantly in the study group (p < 0.05).

Cardioprotective Effect of Remote Ischemic Preconditioning: From Bench to Bedside

Remote ischemic preconditioning (rIPC) refers to a cardioprotective phenomenon in which short episodes of ischemia, followed by reperfusion, in one organ or tissue might provide future protection against ischemia/reperfusion damage in other organs, namely the heart. The process involves the activation of humoral, neural, or systemic communication channels, which in turn induce various intracellular signals inside the heart. The primary objective of this review is to provide a concise overview of the potential processes implicated in rIPC cardioprotection, as well as to elucidate current clinical studies aimed at establishing the effectiveness of these techniques in safeguarding the heart from detrimental ischemia/reperfusion injury. In this context, many variables contribute to the attenuation of subcellular processes of rIPC in patients, including advanced age, presence of comorbidities, medication use, and variations in anaesthetic protocols. These factors may account for the observed variability in outcomes across different clinical studies. Additional research, meticulously planned, is needed in order to enhance our comprehension of the pathways and mechanisms associated with both early and late rIPC. A comprehensive understanding of the various routes is crucial in facilitating the translation of medical advancements to the benefit of patients. Keyword: Cardioprotection, Ischemic Preconditioning, Remote Ischemic Preconditioning.

Effect of Simultaneous Lower- and Upper-Body Ischemic Preconditioning on Lactate, Heart Rate, and Rowing Performance in Healthy Males and Females

The ergogenic effects of simultaneous lower- and upper-body ischemic preconditioning (IPC) are a factor that has not been investigated exhaustively. Therefore, this study aimed to investigate the effects of IPC on 500 m rowing performance (time, relative peak [RPP] and mean [MPP] power output, time to peak power [TPP], and blood lactate concentration [BLa]), as well as heart rate (HR) among forty-three physically active male (n = 24) and female (n = 19) subjects. In this cross-over randomized trial, either the IPC (220 mmHg) or SHAM (20 mmHg) protocol was applied to the upper and lower limbs simultaneously for 5 min. Then, after 5 min of reperfusion, the participants performed an all-out 500 m rowing trial. During rowing, HR was recorded, and after the completion of the rowing, the BLa concentration was determined. Wilcoxon’s signed-rank test showed a significantly shorter TPP in the SHAM condition compared to under the IPC condition for females (Z = 2.415, p = 0.017), but not for males (Z = 1.914, p = 0.056). Moreover, a significant main effect of the group was reported for rowing time, BLa, RPP, and RMP (p &lt; 0.001 for all dependent variables). No significant interactions nor a main effect of the condition were observed for rowing time, BLa, RPP, RMP, HRWP, HRMEAN, and HRMAX (p &gt; 0.05 for all dependent variables). Simultaneous lower- and upper-body IPC led to a significant decrease in the time to peak power during the 500 m ergometer rowing trial in females but not in males. Additionally, no significant effects on the time or other power output variables, HR, or BLa concentration were registered.

Targeted effect of ischemic preconditioning on the gas exchange threshold in healthy males and females.

Ischemic preconditioning (IPC) appears to improve exercise performance although there is uncertainty about the intensity dependence of this effect. The present study sought to clarify effects of IPC on physiological responses at and below peak oxygen uptake, including the gas exchange threshold (GET). Ten male and female participants completed five cycling ramp tests (10 W/min) to failure, with the final two tests preceded by either IPC (4 × 5min 220mmHg bilateral leg occlusions) or SHAM (20mmHg), in a randomised crossover design. The rates of O2 uptake ( O2), carbon dioxide output ( CO2), and expired ventilation ( E) were measured at rest and throughout exercise. Exercise data were fitted using several functions to identify GET, two ventilatory thresholds and peak O2. IPC increased O2 at GET by ~ 9% (IPC: 1.89 ± 0.51 L/min, SHAM: 1.73 ± 0.56 L/min; p = 0.055) and power output at GET by ~ 11% (IPC: 133 ± 36 W, SHAM: 120 ± 39 W; p = 0.022). In addition, peak power output increased by 2.4% following IPC (IPC: 217 ± 50 W, SHAM: 212 ± 51 W; p = 0.052), but there was no significant effect of IPC on peak O2 (IPC: 2.87 ± 0.68 L/min, SHAM: 2.84 ± 0.73 L/min; p = 0.60) or the ventilatory thresholds. The present results suggest that IPC improves GET and peak power output but not peak O2 during a maximal graded test.

Exploring the Potential Benefits of Interventions When Addressing Simulated Altitude Hypoxia during Male Cyclist Sports: A Systematic Review

Training in hypoxic environments enhances endurance, but the various influences of training protocols and supplementation for efficient performance are not yet clear. This systematic review explored the effects of different supplementations and interventions used to optimize the aerobic and anaerobic performance of cyclists. Data were collected from the following sources: PubMed, Google Scholar, EMBASE, WOS, Cochrane Central Register of Controlled Trials, and randomized controlled trials (RCTs). Studies that explored the effects of supplementation or intervention during cycling were selected for analysis. Five studies (67 male cyclists; mean age, 23.74–33.56 years) reported different outcomes from supplementation or intervention during the acute hypoxia of cyclists. Three studies (42 male cyclists; mean age, 25.88–36.22 years) listed the benefits of beetroot juice in preserving SpO2 (pulse oxygen saturation) and enhancing high-intensity endurance performance, effectively preventing the reduction in power output. This systematic review provided evidence that the different effects of ischemic preconditioning (IPC), sildenafil, and beetroot (BR) supplementation and intervention did not present a statistically greater benefit than for normoxia groups, but BR supplementation promoted the benefits of SpO2. Future research should evaluate the duration and higher FiO2 (simulated altitude, hypoxia) levels of hypoxia in training protocols for cyclists. This is important when determining the effectiveness of supplements or interventions in hypoxic conditions and their impact on sports performance, particularly in terms of power output.

Comparing the protective effects of local and remote ischemic preconditioning against ischemia-reperfusion injury in hepatectomy: a systematic review and network meta-analysis.

Local ischemic preconditioning (LIPC) has been proven to be a protective strategy against hepatic ischemia-reperfusion injury (HIRI) during hepatectomy. Growing evidence suggests remote ischemic preconditioning (RIPC) has the potential to reduce liver injury in hepatectomy. Few studies have directly compared the protective effects of these two mechanical preconditioning strategies. Therefore, we performed a network meta-analysis to compare the efficacy of LIPC and RIPC for hepatic injury during liver resection. We searched Cochrane, PubMed, Embase, and China National Knowledge Infrastructure (CNKI) from the database inception to January 2023. We included studies directly comparing the effectiveness of LIPC and RIPC and those comparing LIPC or RIPC with no-preconditioning in liver resection. Postoperative liver function and surgical events were analyzed. Data were expressed as standardized mean differences (SMDs) or odds ratios (ORs) and analyzed using network meta-analysis with random effects model. Following the screening of 268 citations, we identified 26 eligible randomized clinical trials (RCTs) involving 1,476 participants (LIPC arm: 789, RIPC arm: 859, no-preconditioning arm: 1,072). LIPC and RIPC were superior to no-preconditioning in reducing postoperative serum transaminase levels [aspartate aminotransferase (AST): SMD RIPC versus no-preconditioning: -2.05, 95% confidence interval (CI): -3.39, -0.71; SMD LIPC versus no-preconditioning: -1.10, 95% CI: -2.07, -0.12; alanine aminotransferase (ALT): SMD RIPC versus no-preconditioning: -2.24, 95% CI: -4.15, -0.32; SMD LIPC versus no-preconditioning: -1.32, 95% CI: -2.63, -0.01]. No significant difference was observed between RIPC and LIPC in postoperative liver function and surgical outcomes (AST: SMD RIPC versus LIPC: -0.95, 95% CI: -2.52, 0.62; ALT: SMD RIPC versus LIPC: -0.91, 95% CI: -3.11, 1.28). In addition, the subgroup analysis revealed the potential benefits of RIPC in improving liver function, especially in patients who diagnosed with cirrhosis or underwent major resection. RIPC and LIPC could serve as effective strategies in relieving HIRI during hepatectomy. No significant differences were observed between LIPC and RIPC, however, RIPC may be an easily applicable strategy to relieve liver injury in hepatectomy.

Active ischemic pre‐conditioning does not additively improve short‐term high‐intensity cycling performance when combined with caffeine ingestion in trained young men

AbstractWe investigated the effect of ischemic preconditioning (IPC) with and without caffeine supplementation on mean power output (MPO) during a 4‐min cycling time‐trial (TT). In a double‐blinded, randomized, crossover‐design, 11 trained men performed a TT on 4 days separated by ∼1 week. One hour before TT, participants ingested either caffeine (3 mg kg bw−1) or placebo pills, after which femoral blood‐flow was either restricted with occlusion cuffs inflated to ∼180 mmHg (IPC), or sham‐restricted (0–10 mmHg; Sham) during 3 × 2‐min low‐intensity cycling (10% of incremental peak power output). Then, participants performed a standardized warm‐up followed by the TT. Plasma lactate and K+ concentrations and ratings of perceived exertion (RPE) were measured throughout trials. TT MPO was 382 ± 17 W in Placebo + Sham and not different from Placebo + IPC (−1 W; 95% CI: −9 to 7; p = 0.848; d: 0.06), whereas MPO was higher with Caffeine + Sham (+6W; 95% CI: −2 to 14; p = 0.115; d: 0.49) and Caffeine + IPC (+8 W; 95% CI: 2–13; p = 0.019; d: 0.79) versus Placebo + Sham. MPO differences were attributed to caffeine (caffeine main‐effect: +7 W; 95% CI: 2–13; p = 0.015; d: 0.54. IPC main‐effect: 0 W; 95% CI: −6 to 7; p = 0.891; d: 0.03; caffeine × IPC interaction‐effect: p = 0.580; d: 0.17). TT RPE and plasma variables were not different between treatments. In conlcusion, IPC with co‐ingestion of placebo does not improve short‐term high‐intensity performance in trained men versus a double‐placebo control (Placebo + Sham) and does not additively enhance performance with caffeine. These data do not support IPC as a useful strategy for athletes prior to competition but confirms caffeine's performance‐enhancing effect.

Acute effect of Ischemic Preconditioning in different blood flow restriction compressions on the an-aerobic performance of trained individuals

Purpose: to analyze the acute effect of ischemic preconditioning in different compressions of blood flow restriction on the anaerobic performance of trained individuals. Material &amp; methods: the research has a quasi-experimental characteristic, crossed and randomized design, in which the subjects were their own controls and submitted to four experimental conditions before the RAST anaerobic power test: C1 = without IPC; C2 = IPC at 20 mmHg (SHAM); C3 = IPC at 220 mmHg and C4 = IPC at 100% of the auscultatory pulse (AP). The study included 21 trained individuals (21.0 ± 2.3 years), male, who performed the power test after 4 experimental conditions in a randomized manner. Result: Despite the IPC with 100% of the AP demonstrating a positive trend towards the improvement in the averages of Pmax (∆ = 2.6%), Pmed (∆ = 0.7%), Pmin (∆ = 1.8%) and running time in 35 m (∆ = 0.8%), none of the variables showed a significant effect between the experimental conditions. Conclusions: It is concluded that, even presenting a subtle improvement in the maximum, average and minimum powers in a 35-meter running test when using the compression of 100% of the AP, the IPC did not demonstrate a significant increase in performance. However, an increase of 2.6% in maximum power can represent the difference between first and second place in a high-performance test. Keywords: sports performance, anaerobic power, ischemic preconditioning, blood flow restriction, vascular occlusion.

Ischemic preconditioning affects phosphosites and accentuates myocardial stunning while reducing infarction size in rats.

Ischemic preconditioning (IPC), i.e., brief periods of ischemia, protect the heart from subsequent prolonged ischemic injury, and reduces infarction size. Myocardial stunning refers to transient loss of contractility in the heart after myocardial ischemia that recovers without permanent damage. The relationship between IPC and myocardial stunning remains incompletely understood. This study aimed primarily to examine the effects of IPC on the relationship between ischemia duration, stunning, and infarct size in an ischemia-reperfusion injury model. Secondarily, this study aimed to examine to which extent the phosphoproteomic changes induced by IPC relate to myocardial contractile function. Rats were subjected to different durations of left anterior descending artery (LAD) occlusion, with or without preceding IPC. Echocardiograms were acquired to assess cardiac contraction in the affected myocardial segment. Infarction size was evaluated using triphenyl tetrazolium chloride staining. Phosphoproteomic analysis was performed in heart tissue from preconditioned and non-preconditioned animals. In contrast to rats without IPC, reversible akinesia was observed in a majority of the rats that were subjected to IPC and subsequently exposed to ischemia of 13.5 or 15 min of ischemia. Phosphoproteomic analysis revealed significant differential regulation of 786 phosphopeptides between IPC and non-IPC groups, with significant associations with the sarcomere, Z-disc, and actin binding. IPC induces changes in phosphosites of proteins involved in myocardial contraction; and both accentuates post-ischemic myocardial stunning and reduces infarct size.

The effect of short-term remote ischemic preconditioning on endothelial function of patients with chronic kidney disease: A randomized pilot study.

Patients with chronic kidney disease (CKD) are more susceptible to endothelial dysfunction and cardiovascular disease (CV). Remote ischemic preconditioning (rIPC) has been proven efficient in improving endothelial function and lowering the risk of CV. However, the safety and effect of rIPC on endothelial function in patients with CKD have not been effectively assessed. 45 patients with CKD (average estimated glomerular filtration rate: 48.4 mL/min/1.73 m2 ) were randomly allocated to either 7-day daily upper-arm rIPC (4 × 5 min 200 mmHg, interspaced by 5-min reperfusion) or control (4 × 5 min 60 mmHg, interspaced by 5-min reperfusion). Vascular endothelial function was assessed by natural log-transformed reactive hyperemia index (LnRHI) before and after a 7-day intervention. Arterial elasticity was assessed by augmentation index (AI). The results showed that LnRHI could be improved by rIPC treatment (Pre = 0.57 ± 0.04 vs. Post = 0.67 ± 0.04, p = .001) with no changes relative to control (Pre = 0.68 ± 0.06 vs. Post = 0.64 ± 0.05, p = .470). Compared with the control group, the improvement of LnRHI was greater after rIPC treatment (rIPC vs. Control: 0.10 ± 0.03 vs. -0.04 ± 0.06, between-group mean difference, -0.15 [95% CI, -0.27 to -0.02], p = .027), while there was no significant difference in the change of AI@75 bpm (p = .312) between the two groups. RIPC is safe and well tolerated in patients with CKD. This pilot study suggests that rIPC seems to have the potential therapeutic effect to improve endothelial function. Of note, further larger trials are still warranted to confirm the efficacy of rIPC in improving endothelial function in CKD patients.

A Comparative Study: Cardioprotective Effects of High-Intensity Interval Training Versus Ischaemic Preconditioning in Rat Myocardial Ischaemia-Reperfusion.

(1) Background: Years of research have identified ischemic preconditioning (IPC) as a crucial endogenous protective mechanism against myocardial ischemia-reperfusion injury, enhancing the myocardial cell's tolerance to subsequent ischemic damage. High-intensity interval training (HIIT) is promoted by athletes because it reduces exercise duration and improves metabolic response and cardiopulmonary function. Our objective was to evaluate and compare whether HIIT and IPC could reduce myocardial ischemia and reperfusion injury in rats. (2) Methods: Male Sprague-Dawley rats were divided into four groups: sham surgery, coronary artery occlusion (CAO), high-intensity interval training (HIIT), and ischemic preconditioning (IPC). The CAO, HIIT, and IPC groups experienced 40 min of coronary artery occlusion followed by 3 h of reperfusion to induce myocardial ischemia-reperfusion injury. Subsequently, the rats were sacrificed, and blood samples along with cardiac tissues were examined. The HIIT group received 4 weeks of training before surgery, and the IPC group underwent preconditioning before the ischemia-reperfusion procedure. (3) Results: The HIIT and IPC interventions significantly reduced the extent of the myocardial infarction size and the levels of serum troponin I and lactate dehydrogenase. Through these two interventions, serum pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6, were significantly decreased, while the anti-inflammatory cytokine IL-10 was increased. Furthermore, the expression of pro-apoptotic proteins PTEN, caspase-3, TNF-α, and Bax in the myocardium was reduced, and the expression of anti-apoptotic B-cell lymphoma 2 (Bcl-2) was increased, ultimately reducing cellular apoptosis in the myocardium. In conclusion, both HIIT and IPC demonstrated effective strategies with potential for mitigating myocardial ischemia-reperfusion injury for the heart.

The Impact of Different Ischemic Preconditioning Pressures on Pain Sensitivity and Resistance Exercise Performance.

Kataoka, R, Song, JS, Yamada, Y, Hammert, WB, Seffrin, A, Spitz, RW, Wong, V, Kang, A, and Loenneke, JP. The impact of different ischemic preconditioning pressures on pain sensitivity and resistance exercise performance. J Strength Cond Res 38(5): 864-872, 2024-To determine (a) the impact of ischemic preconditioning pressures (applied as a % of arterial occlusion pressure [AOP]) on pressure pain threshold (PPT) and resistance exercise performance and (b) whether changes in performance could be explained by changes in PPT. Subjects ( n = 39) completed 4 protocols in a randomized order: (a) ischemic preconditioning (IPC) at 110% AOP (IPC 110%), (b) IPC at 150% AOP (IPC 150%), (c) IPC at 10% AOP (Sham), and (d) time-matched control (CON). Each protocol included 4 cycles of 5 minutes of occlusion followed by 5 minutes of reperfusion. Pressure pain threshold was taken before and after. Discomfort ratings were given at the end of each cycle. Every visit finished with 2 sets of 75-second maximal isokinetic unilateral elbow flexion or extension. Overall, IPC 110% and IPC 150% resulted in similar increases in PPT relative to CON [110%: difference of 0.36 (0.18, 0.54) kg·m -2 ; 150%: difference of 0.377 (0.15, 0.59) kg·m -2 ] and Sham. Both resulted in greater discomfort than Sham and CON, with IPC 150% inducing greater discomfort than IPC 110% (BF 10 : 14.74). There were no differences between the conditions for total work (BF 10 : 0.23), peak torque (BF 10 : 0.035), or average power (BF 10 : 0.159). We did not find evidence that PPT mediated performance. We did not detect changes in performance with 2 different relative pressures greater than AOP. Our mean applied pressures were lower than those used previously. There might be a minimal level of pressure (e.g., >150% of AOP) that is required to induce ergogenic effects of ischemic preconditioning.

Protective effect of remote ischemic preconditioning on blood pressure control in magnetic resonance-guided focused ultrasound operations

Backrgound. Magnetic resonance-guided focused ultrasound (MR-FUS) is a new non-invasive technology for the surgical treatment of extrapyramidal movement disorders for such pathologies as essential tremor, Parkinson’s disease, etc. In these cases, the brain is injured and a zone of ischemia is formed. Arterial hypertension (AH) is one of the most common pathologies, which is often accompanied by neurological diseases. Objective. To investigate the effect of the remote ischemic preconditioning (RIPC) on blood pressure (BP) during MR-FUS surgery. Design – blinded, randomized, controlled, 2-group study with sham preconditioning. Materials and Methods. Patients were randomized into the RIPC group (cuff systolic BP (SBP) &gt;50 mmHg, n=42) and the group with sham RIPC (cuff diastolic BP (DBP), n=39) before surgery in regime 3 cycles each 5 min with 5 min rest between cycles. Results. While there was a decrease in SBP and DBP before and after the operation in the RIPC group, there was an increase (p&lt;0.001) in the sham RIPC group. Using the Difference-in-Difference equation for SBP, SBP was 8.9 (5.9–11.9) mm Hg higher in the sham RIPC group than in the RIPC group (p&lt;0.01). Conclusion. As a result, MR-FUS operations showed a significant decrease in BP during RIPC compared to the imitation, which confirms the angioprotective effect of preconditioning.

Changes in excitatory amino acid transporters in response to remote ischaemic preconditioning and glutamate excitotoxicity

The successful implementation of remote ischaemic conditioning as a clinical neuroprotective strategy requires a thorough understanding of its basic principles, which can be modified for each patient. The mechanisms of glutamate homeostasis appear to be a key component. In the current study, we focused on the brain-to-blood glutamate shift mediated by glutamate transporters (excitatory amino acid transports [EAATs]) and the effect of remote ischaemic preconditioning (RIPC) as a mediator of ischaemic tolerance. We used model mimicking ischaemia-mediated excitotoxicity (intracerebroventricular administration of glutamate) to avoid the indirect effect of ischaemia-triggered mechanisms. We found quantitative changes in EAAT2 and EAAT3 and altered membrane trafficking of EAAT1 on the cells of the choroid plexus. These changes could underlie the beneficial effects of ischaemic tolerance. There was reduced oxidative stress and increased glutathione level after RIPC treatment. Moreover, we determined the stimulus-specific response on EAATs. While glutamate overdose stimulated EAAT2 and EAAT3 overexpression, RIPC induced membrane trafficking of EAAT1 and EAAT2 rather than a change in their expression. Taken together, mechanisms related to glutamate homeostasis, especially EAAT-mediated transport, represents a powerful tool of ischaemic tolerance and allow a certain amount of flexibility based on the stimulus used.

Effects of Ischemic Preconditioning on Lower Limb Isokinetic Muscle Function and Blood Lactate Concentration in College Baseball Players

Effects of Ischemic Preconditioning on Lower Limb Isokinetic Muscle Function and Blood Lactate Concentration in College Baseball Players

The Effect of Remote Ischemic Preconditioning on The Outcome of Elective Percutaneous Coronary Intervention

The Effect of Remote Ischemic Preconditioning on The Outcome of Elective Percutaneous Coronary Intervention

Ticagrelor enhances the cardioprotective effects of ischemic preconditioning in stable patients undergoing percutaneous coronary intervention: the TAPER-S randomized study.

Ticagrelor improves clinical outcomes in patients with acute coronary syndromes compared with clopidogrel. Ticagrelor also inhibits cell uptake of adenosine and has been associated with cardioprotective effects in animal models. We sought to investigate the potential cardioprotective effects of ticagrelor, as compared with clopidogrel, in stable patients undergoing percutaneous coronary intervention (PCI). This was a Prospective Randomized Open Blinded End-points (PROBE) trial enrolling stable patients with coronary artery disease (CAD) requiring fractional flow reserve-guided PCI of intermediate epicardial coronary lesions. ST-segment elevation at intracoronary electrocardiogram (IC-ECG) during a two-step sequential coronary balloon inflations in the reference vessel during PCI was used as an indirect marker of cardioprotection induced by ischemic preconditioning (IPC). The primary endpoint of the study was the comparison of the delta (Δ) (difference) ST-segment elevation measured by IC-ECG during two-step sequential coronary balloon inflations. Fifty-three patients were randomized to either clopidogrel or ticagrelor. The study was stopped earlier because the primary endpoint was met at a pre-specified interim analysis. ΔST-segment elevation was significantly higher in ticagrelor as compared to clopidogrel arms (P<0.0001). Ticagrelor was associated with lower angina score during coronary balloon inflations. There was no difference in coronary microvascular resistance between groups. Adenosine serum concentrations were increased in patients treated with ticagrelor as compared to those treated with clopidogrel. Ticagrelor enhances the cardioprotective effects of IPC compared with clopidogrel in stable patients with CAD undergoing PCI. Further studies are warranted to fully elucidate the mechanisms through which ticagrelor may exert cardioprotective effects in humans. http://www.clinicaltrials.gov. Unique Identifier: NCT02701140.

Remote ischemic preconditioning for reduction of ischemia-reperfusion injury after hepatectomy: A randomized sham-controlled trial

BackgroundRemote ischemic preconditioning reduces ischemia-reperfusion injury in patients undergoing hepatectomy. Moreover, there is evidence that the protective effects of remote ischemic preconditioning may be more pronounced in pre-damaged livers. The objective of this trial was to investigate the extent to which remote ischemic preconditioning can attenuate ischemia-reperfusion injury after hepatectomy and Pringle maneuver in patients with chronic liver disease. MethodsIn this randomized, controlled, triple-blind monocenter trial, a total of 102 patients with chronic liver disease and planned hepatectomy were enrolled between December 2019 and March 2022. Eligible patients were randomized to the remote ischemic preconditioning or sham arms. Remote ischemic preconditioning was induced through 3 10-minute cycles of alternating ischemia and reperfusion of the upper extremity. The study was prospectively registered in the German Clinical Trials Registry (DRKS00018931). ResultsA total of 102 patients were included in the study and were randomized (51 per arm). The median age was 69.5 years, approximately two-thirds of the patients were male (69/102, 67.7%), and the mean body mass index was 25.6 kg/m2. Most patients were classified as American Society of Anesthesiologists II (55/102, 53.9%) or III (45/102, 44.1%). The primary endpoint, the transaminases on the first postoperative day (alanine aminotransferase /aspartate aminotransferase: remote ischemic preconditioning arm: 250 (35–1721)/320 (42–1525) U/L versus sham control arm: 283 (32–792)/356 (20–1851) U/L, P = .820/0.639), clinical outcomes as well as remote ischemic preconditioning biomarker levels were comparable between both arms. ConclusionRemote ischemic preconditioning did not achieve a significant reduction in postoperative transaminase levels, nor did it affect clinical results and biomarkers.

Acute Effects of Ischemic Preconditioning at Different Occlusion Pressures on Athletic Performance Indicators in Male Soccer Players

Ischemic preconditioning (IPC) has been shown to improve exercise performance, but many factors related to IPC administration are unresolved. This study evaluated the effect of IPC performed with different pressures for exercise performance. Fifteen collegiate male soccer players completed five separate sessions in randomized order. For each session, blood pressure cuffs were placed on the thigh bilaterally, and IPC was administered in 2x5 minute cycles at cuff pressures of 0%, 25%, 50%, 75%, or 100% of each participant’s limb occlusion pressure (LOP), the pressure needed to occlude arterial flow of blood to the leg. Participants then completed vertical jump, soccer passing accuracy, and 1,600 meter run tests. Repeated-measures analysis of variance was used to assess differences in outcomes across the five trials. There were no significant differences in vertical jump or passing accuracy across the five trials. However, 1,600 meter run times were significantly faster for the 50-75% trials than the 0-25% trials (mean difference 7.1-8.4 seconds). In summary, IPC pressures below LOP improved running times while not negatively influencing jumping or passing accuracy in collegiate soccer players. Improved comfort and reduced risk from using cuff pressures below LOP may facilitate more effective IPC use in field-based settings.