Perioperative Myocardial Ischemia Research Articles

Blood group AB is associated with reduced blood loss but also elevated cardiovascular mortality in aortocoronary bypass surgery.

Patient blood group (BG) is predictive for von-Willebrand-factor (VWF) and Factor VIII variation. The clinical impact of this ABO-effect on blood loss, cardiovascular complications and outcome has been described for several patient cohorts. The aim of this study was to investigate the impact of patient BG on blood loss and outcome after coronary artery bypass surgery (CABG). Patient records, intraoperative data and perioperative transfusion records of 5713 patients receiving an on-pump CABG procedure between 05/2004 and 12/2018 were analyzed. A logistic regression model for death due to perioperative myocardial ischaemia (PMI) was developed from initially 24 variables by using an univariate and multivariate selection process. BG AB patients required less blood transfusions as compared to the other blood groups, especially in case of emergency operations. However, BG AB patients also had a higher mortality which was due to secondary cardiovascular complications. The impact of blood type on the rate of cardiovascular mortality was confirmed in the logistic regression model. BG AB patients have a worse outcome after CABG surgery due to an increased incidence of fatal cardiovascular complications. As perioperative myocardial ischemia due to graft occlusion appears to be the most likely explanation, stricter anticoagulation for BG AB patients should be discussed.

Introducing a free-breathing MRI method to assess peri-operative myocardial oxygenation and function: A volunteer cohort study.

Induction of general anaesthesia has many potential triggers for peri-operative myocardial ischaemia including the acute disturbance of blood gases that frequently follows alterations in breathing and ventilation patterns. Free-breathing oxygenation-sensitive cardiovascular magnetic resonance (OS-CMR) imaging may provide the opportunity to continuously quantify the impact of such triggers on myocardial oxygenation. To investigate the impact of breathing patterns that simulate induction of general anaesthesia on myocardial oxygenation in awake healthy adults using continuous OS-CMR imaging. Prospective observational study. Single-centre university hospital. Recruitment from August 2020 to January 2022. Thirty-two healthy volunteers younger than 45 years old were recruited. Data were analysed from n = 29 (69% male individuals). Participants performed a simulated induction breathing manoeuvre consisting of 2.5 min paced breathing with a respiration rate of 14 breaths per minute, followed by 5 deep breaths, then apnoea for up to 60s inside a magnetic resonance imaging scanner (MRI). Cardiac images were acquired with the traditional OS-CMR sequence (OS bh-cine ), which requires apnoea for acquisition and with two free-breathing OS-CMR sequences: a high-resolution single-shot sequence (OS fb-ss ) and a real-time cine sequence (OS fb-rtcine ). Myocardial oxygenation response at the end of the paced breathing period and at the 30 s timepoint during the subsequent apnoea, reflecting the time of successful intubation in a clinical setting. The paced breathing followed by five deep breaths significantly reduced myocardial oxygenation, which was observed with all three techniques (OS bh-cine -6.0 ± 2.6%, OS fb-ss -12.0 ± 5.9%, OS fb-rtcine -5.4 ± 7.0%, all P < 0.05). The subsequent vasodilating stimulus of apnoea then significantly increased myocardial oxygenation (OS bh-cine 6.8 ± 3.1%, OS fb-ss 8.4 ± 5.6%, OS fb-rtcine 15.7 ± 10.0%, all P < 0.01). The free-breathing sequences were reproducible and were not inferior to the original sequence for any stage. Breathing manoeuvres simulating induction of general anaesthesia cause dynamic alterations of myocardial oxygenation in young volunteers, which can be quantified continuously with free-breathing OS-CMR. Introducing these new imaging techniques into peri-operative studies may throw new light into the mechanisms of peri-operative perturbations of myocardial tissue oxygenation and ischaemia. http://links.lww.com/EJA/A922.

On-Pump Beating Heart Coronary Artery Bypass Grafting: A Safe Option for Severe Left Ventricular Dysfunction Coronary Artery Disease

Patients are increasingly presenting with advanced coronary artery disease after myocardial infarction with severe left ventricular dysfunction (LVEF <30%). Treating these patients is a separate problem: complete revascularisation along with minimum perioperative myocardial ischaemia is the most important goal in treating them. This study was from July 2013 to June 2021. A total of 107 patients had undergone CABG having LVEF <30%, and the incidence rate was 10.4%.

The Impact of Perioperative Morbidities, Lack of Discharge Aspirin, and Lack of Discharge Statin on Long Term Survival Following EVAR.

Adverse perioperative events and discharge medications both have the potential to impact survival following endovascular abdominal aortic aneurysm repair (EVAR). We hypothesize that variables such as blood loss, reoperation in the same hospital admission, and lack of discharge statin/aspirin have significant effect on long term survival following EVAR. Similarly, other perioperative morbidities, are hypothesized to affect long term mortality. Quantifying the mortality effect of perioperative events and treatment emphasizes to physicians the critical nature of preoperative optimization, case planning, operative execution and postoperative patient management. All EVAR in the Vascular Quality Initiative between 2003 and 2021 were queried. Exclusions were: ruptured/symptomatic aneurysm; concomitant renal artery or supra-renal intervention at the time of EVAR; conversion to open aneurysm repair at the time of initial operation; and undocumented mortality status at the 5 year mark postoperatively. 18,710 patients met inclusion criteria. Multivariable Cox regression time dependent analysis was performed to investigate the strength of mortality association of the exposure variables. Standard demographic variables and pre-existing major co-morbidities were included in the regression analysis to account for disproportionate, deleterious co-variables amongst those experiencing the various morbidities. Kaplan-Meier survival analysis was performed to provide survival curves for the key variables. Mean follow up was 5.99years and 5-year survival for included patients was 69.2%. Cox regression revealed increased long term mortality to be associated with the following perioperative events: reoperation during the index hospital admission (HR 1.21, P = .034), perioperative leg ischemia (HR 1.34, P = .014), perioperative acute renal insufficiency (HR 1.24, P = .013), perioperative myocardial infarction (HR 1.87, P < .001), perioperative intestinal ischemia (HR 2.13, P < .001), perioperative respiratory failure (HR 2.15, P < .001), lack of discharge aspirin (HR 1.26, P < .001), and lack of discharge statin (HR 1.26, P < .001). The following pre-existing co-morbidities correlated with increased long term mortality (P < .001 for all) : body mass index under 20kg/m2, hypertension, diabetes, coronary artery disease, reported history congestive heart failure, chronic obstructive pulmonary disease, peripheral artery disease, advancing age, baseline renal insufficiency and left ventricular ejection fraction less than 50%. Females were more likely to have EBL >300mL, reoperation, perioperative MI, limb ischemia and acute renal insufficiency than males (P < .01 for all). Female sex trended but was not associated with increased long term mortality risk (HR 1.06, 95% CI .995-1.14, P = .072). Survival after EVAR is improved with optimal operative planning to facilitate evading the need for reoperation and ensuring patients without contra-indication are discharged with aspirin and statin medications. Females and patients with pre-existing co-morbidity are at particularly higher risk for perioperative limb ischemia, renal insufficiency, intestinal ischemia and myocardial ischemia necessitating appropriate preparation and preventative measures.

Preoperative Assessment and Optimization of Cardiopulmonary Disease in Noncardiac Surgery.

More than 50 million surgical procedures are carried out every year in the United States with the estimated risk of major adverse cardiac events perioperatively between 1.4 and 3.9%. Given that the majority of surgeries are elective, this allows ample opportunity to identify patients at higher risk of perioperative adverse events and optimize them for surgery. Preexisting cardiopulmonary disease is a major risk factor for adverse events perioperatively and can lead to significant morbidity and mortality. It can predispose patients to perioperative myocardial ischemia and infarction, perioperative pulmonary complications, and perioperative stroke among other complications. This article details an approach to preoperative interview and examination, indications for preoperative testing, and strategies for optimization in patients with underlying cardiopulmonary disease. It also includes guidelines on optimal timing of elective surgery in certain clinical scenarios that can escalate perioperative risk. Through the use of thorough preoperative assessment, targeted preoperative testing, and multidisciplinary optimization of preexisting disease, perioperative risk can be decreased significantly and perioperative outcomes improved.

EFFECT OF ESMOLOL CARDIOPLEGIA ON INOTROPIC SUPPORT AND INOTROPIC SCORE AFTER CORONARY ARTERY BYPASS SURGERY

Coronary artery bypass surgery is associated with numerous complications as a result of perioperative myocardial ischemia. Administration of esmolol as an adjunct to cardioplegia is a pharmacological cardioprotective method to protect the myocardium in patients with coronary artery disease. The aim of this study was to determine whether the application of esmolol as an adjunct to cardioplegia itself would provide additional myocardial protection, reduce the need for inotropic and vasopressor support, and decrease the inotropic score. A total of 100 patients aged 40-80 years with coronary artery disease were included in this prospective, randomized, controlled study. Patients were grouped into two randomized groups according to whether they received esmolol in line with a well-defined protocol or placebo. In all patients, a vasoactive inotropic score was calculated by a formula. The inotropic score in the operating room was statistically insignificant (p=0.141), and the highest inotropic score in the first 24 hours was statistically significantly lower (p= 0.002) in patients receiving esmolol compared to others. Inotropic support in intensive care unit with statistical significance (p=0.0001) and vasopressor support with borderline significance (p=0.06) was applied in a lower percentage after 24 hours in patients given esmolol. A pharmacological cardioprotective method to protect the myocardium with esmolol in patients with coronary artery disease has a positive effect in reducing the inotropic score, respectively less use of inotropic and vasopressor support after coronary artery bypass surgery.

VALIDATING NOVEL FREE-BREATHING CARDIOVASCULAR MAGNETIC RESONANCE SEQUENCES FOR FUTURE APPLICATIONS OF PERI-OPERATIVE IMAGING OF INDUCIBLE MYOCARDIAL DEOXYGENATION

<h3>Background</h3> Perioperative myocardial ischemia is associated with increased morbidity and mortality. General anesthesia (GA) bears many possible triggers for myocardial ischemia including acute blood gas changes. While cardiovascular magnetic resonance (CMR) is not feasible in an everyday intra-operative setting, its ability to measure myocardial oxygenation using oxygen-sensitive (OS) imaging provides a novel possibility to quantify tissue ischemia during the induction of GA in a research setting. However, OS-CMR is acquired during a breath-hold to reduce chest motion and requires up to 10s per image, and hence is not ideal for continuous monitoring. Thus, we optimized two free breathing OS-CMR sequence variants that acquire images every heartbeat to measure rapid changes in myocardial oxygenation. We aimed to compare these new sequences in an awake healthy control population performing voluntary hyperventilation and apnea. The intent of this analysis is to develop and validate this new CMR sequence for future studies implementing OS-CMR to measure myocardial oxygenation during GA. <h3>Methods</h3> Twenty awake healthy participants underwent a CMR study and performed two breathing protocols. First a maneuver representing anesthesia pre-induction protocols was performed with paced breathing at 15bpm for 150s followed by 5 deep breaths and then apnea. Controls were then asked to perform a rapid paced maneuver consisting of 60s of deep hyperventilation at 30bpm for 60s, followed by a second apnea phase. During the procedure images were acquired with the original breath-hold (BH) OS-CMR sequence, the new free-breathing single shot (SS-FB) and real-time (RT-FB) sequences. The first is a single-shot variant that only acquires one image in diastole at a high resolution of 1.5mm2. The second is a real-time variant, that acquires 20 frames per second thus providing functional information throughout the cardiac cycle as well, but at a spatial resolution of 3mm2. Myocardial oxygenation was statistically compared at baseline, post hyperventilation which is a vasoconstricting stimulus, and at the 30s timepoint in apnea that is known to induce vasodilation. <h3>Results</h3> For the first breathing pacing protocol representing GA induction, hyperventilation significantly reduced myocardial oxygenation with all three sequences (SS-FB: -12.1±10.6%, p<0.001, RT-FB: -8.0 ±4.0% p<0.001, BH: -4.2±3.7% p<0.001) and apnea resulted in a rise in myocardial oxygenation (SS-FB: 6.2±7.3% p=0.002, RT-FB: 11.8±4.1% p<0.001, BH: 6.9±5.7% p<0.001). With the rapid pacing maneuver similar results were observed with hyperventilation (SS-FB: -4.4±8.2% p=0.047, RT-FB: -7.0±1.8% p<0.001, BH: -4.3±6.2% p=0.008) and apnea (SS-FB: 9.2±6.5% p=<0.001, RT-FB: 9.1±2.1% p<0.001, BH: 4.5±5.0% p=0.001). The new SS-FB and RT-FB sequences were not inferior to the known gold standard BH sequence for any stage. <h3>Conclusion</h3> In awake controls, alterations in myocardial oxygenation through hyperventilation and apnea can be observed with the novel free-breathing OS-CMR sequences. It is now warranted to implement these new techniques in future studies investigating peri-operative imaging of myocardial ischemia.

Perioperative infarction and myocardial injury: risk factors, mechanisms of development and clinical and epidemiological features

Тhe concept, risk factors, mechanisms, clinical and epidemiological, and angiographic features of perioperative ischemic injury and myocardial infarction were considered. Perioperative myocardial infarction is one of the most common complications (up to 3.6%) in non-cardiac surgical interventions and is characterized by high in-hospital mortality, reaching 25%. Most patients with this pathology (up to 65%) do not have typical symptoms of myocardial ischemia due to anesthesia and sedation. Pathogenetic mechanisms of perioperative myocardial infarction development continues to be actively studied. A critical increase in myocardial oxygen demand is indicated as the leading cause in some studies. Angiography reveals rupture of the coronary plaque and atherothrombosis in more than half of patients, according to other data. These contradictions point to the need for further epidemiological studies using coronary angiography with a focus on risk factors and triggers of this complication. In addition, the concept of perioperative myocardial injury in recent years has been formulated in the scientific literature. This is understood as ischemic damage that occurs in the first 30 days after surgery. Recent studies have shown that it can occur in 16% of surgical patients and is associated with a 6-fold increase in mortality within 1 month after surgery and a 2.5-fold increase within a year. It is important that perioperative myocardial injury does not include cases of non-ischemic etiology myocardial injury, for example, due to pulmonary embolism, sepsis, or electrical cardioversion. Thus, the assessment and understanding of risk factors for the development of perioperative myocardial ischemia is of great practical importance in optimizing the patient selection and preparation for surgical treatment.

Diagnosis and Management of Perioperative Myocardial Ischemia after Elective Aortic Aneurysm Surgery

Perioperative myocardial ischemia (PMI) is a serious postoperative complication. Aortic operations represent an especially high-risk surgery concerning cardiac complications. This aim of this study was to analyse the clinical features of PMI after elective aortic aneurysm surgery. This study is a retrospective analysis of 863 patients who underwent elective aortic aneurysm surgery between 2005 and 2012 in the Department of Vascular and Endovascular Surgery of Heidelberg University Hospital with regard to PMI. The PMI diagnosis was based on a positive serum troponin diagnostic test. We evaluated the clinical course, time point of the diagnosis and features of diagnostics to characterise PMI. Moreover, we analysed the treatment options and management of the patients' discharge. Thirty-one patients (3.6% of 863) with PMI after elective aortic aneurysm surgery were identified. Of these, 21 patients (67.7%) underwent open surgery and 10 patients (32.3%) received endovascular treatment. PMI was diagnosed in 24 patients (77%) during the first 3 days. More than half of these patients (16/31) were clinically asymptomatic. Electrocardiogram did not show pathological findings in 24 cases (77.4%). The first troponin measurement was not elevated in eight patients (25.8%). Drug therapy alone was used in 17 cases (54.8%) of PMI, coronary catheterisation was performed in 12 patients (38.7%) and two patients (6.5%) received aortocoronary bypass. Fourteen patients (45.1%) were discharged home and another 14 patients (44.1%) were transferred to another hospital or to a rehabilitation institution. Two patients died because of multi-organ failure. PMI is not a rare complication after elective aortic surgery. The diagnosis of PMI can be challenging because of occult symptoms especially in a perioperative setting. Due to the potentially serious consequences, cardiac enzyme diagnostics should be initiated immediately if there is suspicion of PMI or routinely in defined at-risk patients after aortic surgery.

Perioperative Supplemental Oxygen and Plasma Catecholamine Concentrations after Major Abdominal Surgery-Secondary Analysis of a Randomized Clinical Trial.

Perioperative stress is associated with increased sympathetic activity that leads to increases in heart rate and blood pressure, which are associated with the development of perioperative myocardial ischemia. In healthy volunteers, it was shown that the administration of supplemental oxygen attenuated sympathetic nerve activity and subsequently led to lower plasma catecholamine concentrations. We therefore tested the hypothesis that perioperative supplemental oxygen attenuates sympathetic nerve in patients at risk for cardiovascular complications undergoing major abdominal surgery. We randomly assigned 81 patients to receive either 80% or 30% inspired oxygen concentration throughout surgery and the first two postoperative hours. We assessed noradrenaline, adrenaline, and dopamine plasma concentrations before the induction of anesthesia, two hours after surgery and on the third postoperative day. There was no significant difference in postoperative noradrenaline (effect estimated: −41.5 ng·L−1, 95%CI −134.3, 51.2; p = 0.38), adrenaline (effect estimated: 11.2 ng·L−1, 95%CI −7.6, 30.1; p = 0.24), and dopamine (effect estimated: −1.61 ng·L−1, 95%CI −7.2, 3.9; p = 0.57) concentrations between both groups. Based on our results, it seems unlikely that supplemental oxygen influences endogenous catecholamine release in the perioperative setting.

Comparison of Perioperative High-Sensitive Troponin T and Troponin I Assays in Cardiac Surgery

Troponin measurements are among the standard parameters for monitoring perioperative myocardial ischaemia after cardiosurgical procedures. As high-sensitive assays continue to replace older analytic parameters with lower sensitivity, this study aimed to compare perioperative profiles of a high-sensitive troponin T assay (hsTnT, Roche Diagnostics, Mannheim, Germany) with a troponin I assay (sTnI, Siemens Healthcare Diagnostics, Eschborn, Germany). A total of 287 consecutive patients undergoing a typical spectrum of cardiac procedures from August 2017 to March 2018 monitored with the hsTnT assay were compared with a propensity-matched collective analysed with the sTnI assay. For side-by side comparison, the peak troponin (Tmax) values were scaled to a z-score distribution before comparison. Despite absolute postoperative hsTnT and sTnI values differing by an order of magnitude, parameters could be scaled to a common distribution with kernel density curves overlapping 92%. Both parameters showed equal behaviour in subgroup analyses regarding relevant perioperative factors, such as type of procedure, cross-clamping time, and type of cardioplegic solution. However, there were some differences regarding pre-existing renal impairment between both parameters. In both groups, renal failure patients with chronic kidney disease stages IV or V as well as patients on haemodialysis exhibited a marked Tmax increase of >100% compared with normal kidney function (hsTnT,+121%; 2,383.5 vs 1,078.8 ng/L; p=0.0006; and sTnI,+149%; 27.3 ng/mL vs 11.0 ng/mL; p=0.009). However, in patients with moderately impaired renal function, those in the hsTnT group, but not in the sTnI cohort, showed significantly increased Tmax values (CKD stages II or III, 1,233.5 ng/L [+14%] and 1,314.1 ng/L [+22%] vs 1,078.8 ng/L; p=0.01 and p=0.03). In these patients, the postoperative interval until Tmax was reached was also significantly increased (14.4 and 19.0 hrs vs 12.4 hrs for chronic kidney disease stages II and III; p=0.0038 and p<0.001), indicating a higher rate of accumulation in the hsTnT parameter. In the context of cardiac surgery, this study found that both parameters behaved in a similar manner under most relevant circumstances. Despite significant difference in the absolute serum concentration, hsTnT and sTnI can be scaled to virtually identical distributions. However, renal impairment did affect both parameters differently with troponin T but not troponin I, showing evidence of accumulation in moderately impaired renal disease.

Outcome Analysis and Risk Factors for Perioperative Myocardial Ischemia After Elective Aortic Surgery

Perioperative myocardial ischemia (PMI) after non-cardiac surgery remains a serious postoperative complication. This study analyzed the risk factors and outcomes of patients who suffered from PMI after elective aortic surgery. Data from 863 patients who underwent elective aortic surgery for aneurysms or Leriche syndrome were retrospectively analysed with regard to PMI. The diagnosis of PMI was based on a positive serum troponin diagnostic test. According to the clinical signs and symptoms, the patients with PMI were divided into two groups: symptomatic and asymptomatic patients. Comorbidities, preoperative medication, intraoperative parameters, postoperative complications, mortality, length of intensive care stay and hospitalisation, as well as the long-term follow-up, were compared in a matched-pair analysis (1:3) with patients without PMI. Logistic regression analyses were performed to identify independent risk factors for PMI. Thirty-two patients with PMI were identified. Cardiac comorbidities (previous myocardial ischemia, P=0.0099; left ventricular systolic dysfunction, P=0.0429), ASA score ≥III (P=0.0114) and preoperative elevated creatinine (P=0.0194) were more common in patients who suffered PMI. The regression analysis confirmed that peripheral artery disease and prolonged operative duration >180 min are significant predictors of PMI. Surgical complications (wound healing deficit, P=0.0027; rate of secondary interventions during primary admission, P=0.0057) and medical complications (pneumonia, P=0.0002; renal dysfunction, P=0.0041) were more common in patients with PMI compared to the control group. Patients who suffered PMI remained in intensive care for a significantly longer period (P=0.0001) and were also hospitalized for longer (P=0.0001) than the control group. The long-term survival of patients who suffered PMI after aortic surgery was significantly worse than the control group (P < 0.0001, median 53 vs. 84 months), independent of clinical ischemia-associated symptoms. PMI after aortic surgery not only affects long-term survival, but also correlates with worsening of surgical outcome. Thus, meticulous preoperative risk stratification is required for high-risk patients, together with routine postoperative monitoring of troponin levels after aortic surgery.

Perioperative cardioprotection - From bench to bedside : Current experimental evidence and possible reasons for the limited translation into the clinical setting

HintergrundZiel der perioperativen Kardioprotektion ist es, die Auswirkungen eines Ischämie- und Reperfusionsschadens zu minimieren. Aus anästhesiologischer Sicht spielt dieser Aspekt insbesondere in der Herzchirurgie bei Patienten mit Einsatz der Herz-Lungen-Maschine, aber auch allgemein bei längerfristigen hypotensiven Phasen oder perioperativen ischämischen Ereignissen im nichtkardiochirurgischen Setting eine wichtige Rolle. Im Laufe der letzten Jahre konnten diverse pharmakologische sowie nichtpharmakologische Strategien der Kardioprotektion identifiziert werden. Die Ergebnisse von Studien an isoliertem Gewebe sowie von tierexperimentellen In-vivo-Studien sind vielversprechend. Eine Translation dieser kardioprotektiven Strategien in die klinische Praxis ist bislang jedoch nicht gelungen. Große klinische Studien konnten keine signifikante Verbesserung des Outcome der Patienten zeigen.Ziel der ArbeitDieser Übersichtsartikel gibt einen Überblick über die aktuelle experimentelle Evidenz pharmakologischer und nichtpharmakologischer Kardioprotektion. Außerdem sollen mögliche Gründe für die limitierte Translation diskutiert werden. Schließlich werden Möglichkeiten aufgezeigt, wie der Schritt „from bench to bedside“ in Zukunft doch noch gelingen könnte.Material und MethodenNarrative Übersichtsarbeit.Ergebnisse und DiskussionTrotz der vielversprechenden präklinischen experimentellen Ansätze zum Thema Kardioprotektion besteht nach wie vor eine große Diskrepanz zu den Ergebnissen aus großen klinischen Studien in der perioperativen Phase. Mögliche Gründe für die limitierte Translation könnten insbesondere Komorbiditäten und Komedikationen, die Wahl des Anästhesieverfahrens, aber auch die Wahl des Studiendesigns sein. Eine sorgfältige Studienplanung mit Berücksichtigung der genannten Probleme sowie ein simultaner Einsatz mehrerer kardioprotektiver Strategien mit dem Ziel eines additiven bzw. synergistischen Effekts stellen mögliche Ansätze für die Zukunft dar.

Perioperative and Anesthetic Adverse Events in Thailand (PAAd Thai) Study: An Analysis of Suspected Myocardial Ischemia/Infarction

Background: Perioperative myocardial ischemia or infarction (PMI) is infrequent but is a life-threatening complication. The pathophysiology is complex, and the diagnosis can be difficult due to asymptomatic presentations. Objective: To investigate the patient, anesthetic, and surgical characteristics of the suspected PMI incidents, as well as the outcomes, and suggested corrective strategies to avoid the adverse events. Materials and Methods: The suspected PMI incident reports were extracted from the database of the Perioperative and Anesthetic Adverse Events in Thailand (PAAd Thai) study, conducted between January 1, and December 31, 2015. Surgical patients undergoing anesthesia with suspected PMI reported in 22 hospitals were included. Three anesthesiologists independently reviewed the reports. The patient, anesthetic, and surgical profiles, and other incident details were collected from the standardized report forms. Descriptive statistics were used. Results: Suspected PMI was reported in 29 non-cardiac surgical patients with the mortality rate of 20.7% (6/29 patients). PMI was confirmed in 24 patients (82.8%). Non-ST-elevation MI (NSTEMI) was the predominant diagnosis of all reports (15/29 patients, 51.7%). Most incidents occurred in the operating room and were asymptomatic at presentation. Patient factor was considered the most common predisposing factor (96.5%), followed by surgery (58.6%), and anesthesia (37.9%). Quality assurance activity was the most recommended corrective strategies. Conclusion: PMI is not common among non-cardiac surgical patients in Thailand but causes significant mortality. Understanding the pathophysiology and being aware of PMI are important for appropriate perioperative management. Furthermore, early detection, along with multidisciplinary assessment for optimization of the treatment are crucial for prognostic outcomes. Keywords: Perioperative, Adverse event, Anesthesia, Myocardial, Infarction, Ischemia, Complication

Myocardial Protection by Retrograde Application of HTK Solution Compare with Cold Blood Cardioplegic Solution during Heart Valve Surgery

Objective: Cardioplegic solution is one important principle for adequate myocardial protection in cardiac surgery. Bretschneider’s histidine-tryptophan-ketoglutarate (HTK) solution is an intracellular solution while blood cardioplegia solution is an extracellular solution. Both have been used to preserve the myocardium. The present study compared between the two cardioplegic solutions for incidence of ventricular fibrillation after aortic clamp removal in double valve replacement (DVR) and tricuspid annuloplasty (TVA) to assess the effectiveness for myocardial protection. Materials and Methods: A retrospective study was conducted among patients who underwent DVR with TVA operations between January 1, 2013 and June 30, 2017 and divided in two groups at Queen Sirikit Heart Center of the Northeast. The medical records were searched for detailed demographics, preoperative status, operative technique, and post-operative hospital course. Results: Thirty-six patients were included in the present study, 18 patients received HTK solution, the others received blood cardioplegia. The demographic data presented no statistical difference between the two groups. Incidence of ventricular fibrillation after aortic clamp removal occurred in 10 patients (55.6%) in the HTK group, which was more than the cold blood group [five patients (27.78%)]. Cardiopulmonary bypass (CPB) and aortic cross clamp time in the cold blood group was significantly longer than in the HTK group (p&lt;0.001). The peak of Trop-T and CK-MB within six hours after surgery tended to be downward after 24 hours and was not related to perioperative myocardial ischemia in the HTK group. No statistically difference was observed in postoperative outcome, ICU stay, or hospital stay. Conclusion: The use of HTK solution has no significant different outcome compared to conventional cold blood cardioplegia via retrograde route in DVR with TVA operation. There was no significantly different incidence of ventricular fibrillation and there was no evidence of postoperative myocardial infarction. CPB and aortic cross clamp time in the HTK group were shorter than in the cold blood cardioplegia significantly. Keywords: Cardioplegia, HTK, Custodiol, Ventricular fibrillation

Dexmedetomidine in modern anesthesiology and intensive care

Background. Sedation is a controlled medical depression of consciousness with the preservation of protective reflexes, independent effective breathing and response to physical stimulation and verbal commands. Sedation is indicated for patients in the intensive care unit in presence of agitation, delirium, withdrawal syndrome of alcohol, drugs or other potent medications and the need to protect the brain (blunt traumatic brain injury, posthypoxic encephalopathy). In addition, at the request of the patient, sedation can be used during invasive diagnostic and treatment procedures.&#x0D; Objective. To describe the role of dexmedetomidine in modern anesthesiology and intensive care.&#x0D; Materials and methods. Analysis of literature data on this issue.&#x0D; Results and discussion. When performing sedation, one should balance between the excessive sedation and its absence. Excessive sedation is accompanied by the lack of contact with the patient, inability to assess the neurological status of the patient, and respiratory depression. If the patient is optimally sedated, he is calm and able to cooperate; he is also adapted to mechanical lung ventilation and other procedures. The target level of sedation according to the Richmond excitation-sedation scale is from 0 to -1. Drugs such as benzodiazepines (diazepam, midazolam, lorazepam), barbiturates (sodium thiopental), propofol, ketamine, inhaled anesthetics (sevoflurane, dexflurane), dexmedetomidine, opioids (morphine, fentanyl, remifentanyl) are used for sedation. Dexmedetomidine is a highly selective α2-adrenoagonist, so it has anxiolytic, sedative, antinociceptive, sympatholytic, and hypothermic actions. In addition, this drug reduces heart rate, suppresses tremor and increases diuresis. The sedative effect of dexmedetomidine is due to the inhibition of neuronal activity in the locus coeruleus of the brain stem. The condition caused by dexmedetomidine is similar to the natural sleep. The use of dexmedetomidine allows to achieve the target level of sedation in a higher percentage of cases than the use of other drugs (propofol, midazolam) (Jacub S.M. et al., 2012). Cooperative sedation is a sedation with the possibility of interaction of the patient with the medical staff. Compared to other drugs, dexmedetomidine increases the patient’s ability to wake up and quickly orient, after which the patient can quickly return to a state of sedation. One of the major complications of critically serious diseases and their treatment is the deterioration of cognitive abilities. Dexmedetomidine has been shown to improve the patient’s cognitive performance by 6.8 points on the John Hopkins scale. In contrast, propofol reduces cognitive function by an average of 12.4 points (Mirski M.A. et al., 2010). Dexmedetomidine has no respiratory depressant effect. Patients on mechanical ventilation do not require discontinuation of dexmedetomidine prior to extubation. Importantly, dexmedetomidine increases coronary blood flow, reduces the incidence of perioperative myocardial ischemia and the risk of perioperative cardiac death. Dexmedetomidine reduces the intensity of pain in the postoperative period and the need for opioids, the incidence of delirium, and the duration of mechanical ventilation. The financial and economic reasonability of dexmedetomidine use has been proved.&#x0D; Conclusions. 1. Sedation is indicated for patients in the intensive care unit in presence of agitation, delirium, withdrawal syndrome and the need to protect the brain, as well as during invasive diagnostic and treatment procedures. 2. The target level of sedation is from 0 to -1 on the Richmond excitation-sedation scale. 3. Dexmedetomidine is a highly selective α2-adrenoagonist, which has anxiolytic, sedative, antinociceptive, sympatholytic, and hypothermic action. 4. Dexmedetomidine increases coronary blood flow and reduces the incidence of perioperative myocardial ischemia, the risk of perioperative cardiac death, pain, delirium incidence and the duration of mechanical ventilation.

Patients of risk groups in the perioperative period: the review of modern guidelines

Background. According to the Decree of the Ministry of Health of Ukraine № 275 issued on 11.09.2018, there is a list of measures to ensure surgical safety and patient’s safety. These measures can be divided into those that should be performed 1) before anesthesia; 2) before skin dissection; 3) before the patient leaves the operating room. Perioperative medicine (POM) is a patient-centered and interdisciplinary perioperative care for surgical patients.&#x0D; Objective. To describe the current recommendations for POM.&#x0D; Materials and methods. Review of available guidance documents.&#x0D; Results and discussion. The pathophysiology of postoperative complications (infectious processes, intestinal paralysis, respiratory failure, kidney damage, etc.) includes the following factors: triggers (anxiety, pain, surgical trauma), patient factors (age, comorbid conditions), the consequences of general operative stress (autonomous system imbalance, inflammation, coagulopathy, metabolic imbalance). Clinical evaluation or biomarkers should be used to identify high-risk patients in the perioperative period. Measures to improve postoperative rehabilitation should be carried out in the pre-, intra- and postoperative period. Thus, in the preoperative period it is necessary to examine the patient, to provide the carbohydrate load 2 hours before the intervention, to conduct antibiotic prophylaxis, to correct or stabilize the comorbid diseases (especially cardiovascular and renal diseases, diabetes, anemia). In the intraoperative period it is necessary to maintain normovolemia and normothermia, to use protective mechanical lung ventilation, to limit the use of opioids, to perform extubation immediately after the intervention. In the postoperative period early activation, early enteral nutrition and early removal of drainages and catheters should be used. The key components of POM include the identification of low-risk patients in order to save resources, the identification of high-risk patients with the possible use of alternative management strategies, and the frequent risk reassessment. The main components of the success of anesthesia include preoperative assessment of the patient’s somatic status and risk, use of controlled hypnotics and effective and predictable muscle relaxant, use of analgesics that break down quickly and have no ability to accumulate, control of the hemodynamics stability, blood gases and acid-base balance. To prevent the perioperative myocardial ischemia, it is advisable to use esmolol – a cardioselective β-blocker of ultrashort action. Preoperative anxiety, intubation and extubation, surgical manipulations lead to the excessive adrenergic response, which justifies the use of β-blockers. The pharmacological effects of esmolol (Biblok, “Yuria-Pharm”) include the reduction of myocardial oxygen consumption, increase of the diastole duration, limitation of the free radicals’ production, control of the activity of metalloproteinases, and the reduction of inflammation around atherosclerotic plaques. In addition, esmolol (Biblok) is able to reduce intra- and postoperative use of opioids, and therefore its use as a component of multimodal total intravenous anesthesia has been proposed. Preoperative administration of esmolol may also be an effective and safe method of myocardial protection in patients undergoing cardiac surgery. β-blockers are well tolerated in patients with acute hypovolaemia during anesthesia, however, episodes of hypercapnia should be avoided during their use.&#x0D; Conclusions. 1. For the optimal POM, the individual risk of perioperative complications should be determined. 2. POM includes a number of pre-, intra- and postoperative measures. 3. The use of ultrashort-acting β-blocker esmolol prevents intraoperative myocardial ischemia, has antioxidant and anti-inflammatory effects, reduces the need for opioids.

Combined Intravenous Sildenafil and l-Arginine Administration in a Porcine Animal Model: Hemodynamic Safety Profile and Effects on Coronary Blood Flow

BackgroundEndothelial dysfunction in the nitric oxide-cyclic guanosine monophosphate pathway is a potential contributor to perioperative myocardial ischemia. The nitric oxide precursor, l-arginine, and the cyclic guanosine monophosphate degradation blocker, sildenafil, have vasodilatory effects under high dosage.ObjectiveThis study examined the hemodynamic safety and effect profiles of the combined administration of l-arginine and sildenafil using an in-vivo pig model.MethodsHemodynamic safety including mean arterial pressure, central venous pressure, heart rate, coronary vascular resistance, and systemic vascular resistance, as well as effect profiles including cardiac output and left anterior descending blood flow were measured in ten female swine after administrations of l-arginine, sildenafil, as well as combined l-arginine and sildenafil. Measurements were compared using repeated-measures analysis of variance and linear mixed models.ResultsThe combination of l-arginine and sildenafil produced a significant dose-dependent increase in left anterior descending flow and cardiac output. In contrast, mean arterial pressure, heart rate, central venous pressure, coronary vascular resistance, and systemic vascular resistance did not show any significant changes. No significant change in serum osmolality was observed after administrations of l-arginine.ConclusionsThe combined intravenous administration of sildenafil and l-arginine in a porcine animal model was safe, well tolerated, and had at least additive effects on left anterior descending artery blood flow. Simultaneous application of both drugs might have dose-sparing effects leading to desired coronary effects at lower and safer sildenafil and l-arginine plasma concentrations. Hyperosmolality was only a minor factor in l-arginine hemodynamic effects.

Risk Factors for Postoperative Events in Patients on Antiplatelet Therapy Undergoing Off-Pump Coronary Artery Bypass Grafting Surgery.

This retrospective study assessed the risk factors for adverse events following off-pump coronary artery bypass graft (CABG) surgery with dual antiplatelet therapy (DAPT). Records (between 2013 and 2017) were reviewed for patients who discontinued DAPT (clopidogrel 75 mg and aspirin 100 mg) ≤5 days before off-pump CABG. The primary outcome was the incidence of a Bleeding Academic Research Consortium (BARC) type 4 major event. Factors associated with bleeding events and perioperative myocardial ischemia were evaluated using multivariable logistic regression. The incidence of major bleeding events was 17.6% in 2012 patients. Adjusted multiple logistic regression analysis showed that the risk of postoperative bleeding increased when DAPT was discontinued <3 days before surgery (day 2: adjusted odds ratio [OR]: 1.70, 95% confidence interval [CI]: 1.09-2.64; day 1: adjusted OR: 2.37, 95% CI: 1.49-3.77; day 0: adjusted OR: 2.45, 95% CI: 1.53-3.92). The adjusted risk of mortality (OR: 13.14, 95% CI: 4.55-37.94) was increased with bleeding complications. In subgroup analysis, perioperative myocardial ischemia was related to increased blood loss (adjusted OR: 1.10, 95% CI: 1.02-1.18). Aspirin and clopidogrel should optimally be discontinued >3 days before CABG to reduce the risk of bleeding complications, myocardial ischemia, and death.

High thoracic epidural decreases perioperative myocardial ischemia and improves left ventricle function in aortic valve replacement alone or in addition to cabg surgery even with increased left ventricle mass index.

Introduction:High thoracic epidural (HTE) may reduce perioperative tachyarrhythmias, respiratory complications and myocardial ischemia (MI) and it may increase coronary perfusion and myocardial oxygen balance through sympatholysis and pain control. The aim of this study is to investigate the benefit of HTE in patients undergoing aortic valve replacement (AVR) alone or in addition to coronary artery bypass graft (CABG).Methods:This prospective randomized controlled study was conducted on 80 patients (40 with increased left ventricular mass index (LVMI) and 40 with normal LVMI) who were equally randomised (n = 40) to receive either GA with HTE (HTE group) or GA alone (GA group). Heart rate (HR), mean arterial blood pressure (MAP) and the incidence of ischemic ECG changes were recorded. LV functions (preoperative and postoperative by transthoracic echocardiography and intraoperative by transoesophageal echocardiography) were measured preoperative, intraoperative and till 48 H postoperative.Results:There was no significant difference in the baseline values of all measurements. HR and MAP were lower, and LV functions were improved in HTE group intraoperatively and postoperatively. Ischemic ECG changes were significantly lower in HTE group; with 42.9% intraoperative risk reduction (95% CI: 0.195-0.943) and 46.6% postoperative risk reduction (95% CI 0.227-0.952) as compared to GA group. The risk of ischemia was significantly higher in patients with increased LVMI in GA group (2.25 times compared to normal LVMI patients with 95% CI: 1.195-4.236), but it wasn't increased in HTE group. LV functions were significantly improved from the induction to 48 H postoperative in HTE group as compared to GA group.Conclusion:HTE reduced the incidence of MI and improved the LV function, even with increased LVM, in patients undergoing AVR alone or in addition to CABG.