Risk Factor For Myocardial Ischemia Research Articles

Prevalence and associated risk factors of myocardial ischemia in children living with sickle cell anemia in Lagos, Nigeria.

Myocardial ischemia (MI) in children living with sickle cell anemia (SCA) is rarely reported. MI among children living with this disease could portend untoward outcomes on their quality of life and survival. This study evaluated the prevalence and associated risk factors of MI in children living with SCA during a vaso-occlusive crisis (VOC) compared with those with SCA who had no symptoms nor an MI in the past (those in "steady state") in Lagos, Nigeria. This comparative cross-sectional study was conducted over 10 months (between March and December 2019) among 250 children living with SCA aged 6 months-18 years (125 in VOC and 125 age and sex-matched controls in steady state). The assessment of MI was determined by measuring cardiac troponin T (cTnT) and electrocardiography (ECG). The prevalence of MI measuring cTnT alone in children with SCA during VOC and steady state was 42.4% and 23.2%, respectively. Comparatively, measuring ECG alone, the prevalence of MI in VOC and steady state was 40.8% and 20.8%, respectively. The prevalence of MI measuring cTnT and ECG in children with SCA in VOC and steady state was 38.4% and 20%, respectively. Older age, severity of pain, longer duration of illness, frequent crises per year, elevated white blood cells, and platelet count were significantly associated with MI in participants with SCA. However, with multivariate analysis, age, severity of pain, and elevated platelet counts remained significantly associated with the occurrence of MI. This study affirms the high prevalence of MI in children with SCA irrespective of the diagnostic criteria. Routine evaluation should be done in this cohort to avert MI-associated sequelae.

The Correlation between Region-specific Epicardial Adipose Tissue and Myocardial Ischemia Defined by CT-FFR in Type 2 Diabetes Mellitus Patients.

Epicardial Adipose Tissue (EAT) accumulation is closely associated with the presence and severity of coronary artery disease (CAD), myocardial ischemia, plaque vulnerability, and major adverse cardiovascular events. The aim of this study was to investigate the correlation between myocardial ischemia defined by computed tomography-derived fractional flow reserve (CT-FFR) and region-specific EAT in patients with type 2 diabetes mellitus (T2DM). Between January 2022 and May 2023, 200 T2DM patients were randomly selected from the Department of Endocrinology in The Central Hospital of Wuhan. These patients were divided into two groups based on myocardial ischemia defined by CT-FFR: myocardial ischemia group (152 cases) and control group (48 cases). Both groups of patients used a post-treatment workstation to measure the thickness of region-specific EAT. Receiver operating characteristic (ROC) curve analysis and binary logistic regression were used to evaluate the correlation between various parameters and myocardial ischemia. Patients in the myocardial ischemia group had significantly higher values of age, male gender, systolic blood pressure, total cholesterol, triglycerides, LDL, HDL, fasting blood glucose, fasting insulin, HOMA-IR, EAT thickness in right ventricular wall, left atrioventricular groove, and superior and inferior interventricular groove. ROC curve analysis results showed that EAT thickness in the left atrioventricular groove had the largest area under the ROC curve for diagnosing myocardial ischemia (0.837 [95% CI 0.766-0.865]; P < 0.001). Binary logistic regression analysis showed that EAT thickness in the left atrioventricular groove was an independent risk factor for myocardial ischemia in patients with T2DM (P < 0.05). The EAT thickness in the left atrioventricular groove is an independent risk factor for myocardial ischemia in patients with T2DM. Adipose tissue in the left atrioventricular groove region plays a major role in EAT-mediated CAD.

Exaggerated Systolic Blood Pressure Increase with Exercise and Myocardial Ischemia on Exercise Stress Echocardiography.

Central Illustration : Exaggerated Systolic Blood Pressure Increase with Exercise and Myocardial Ischemia on Exercise Stress Echocardiography ESBPRE: exaggerated systolic blood pressure response to exercise; HR: heart rate; SBP: systolic blood pressure. The association between exaggerated systolic blood pressure response to exercise (ESBPRE) and myocardial ischemia is controversial and little studied in patients with established or suspected chronic coronary syndrome. To verify the relationship between myocardial ischemia and ESBPRE in patients undergoing exercise stress echocardiography (ESE). This is a cross-sectional study with 14,367 patients undergoing ESE, from January 2000 to January 2022, divided into the following 2 groups: G1, composed of patients whose peak systolic pressure increased ≥ 90 mmHg (value corresponding to the 95th percentile of the study population), and G2, patients who did not demonstrate an exaggerated hypertensive response. The groups were compared using Student's t and chi-square tests. P values < 0.05 were considered significant. Logistic regression was also performed to identify independent risk factors for myocardial ischemia, ESBPRE, complaints of typical chest pain prior to the exam, and angina during the test. Of the 14,367 patients, 1,500 (10.4%) developed ESBPRE, and 7,471 (52.0%) were female. The percentages of previous complaints of typical chest pain, angina during the test, and myocardial ischemia in patients with ESBPRE were 5.8%, 2.4% and 18.1%, compared to 7.4%, 3.9%, and 24.2%, in patients without ESBPRE, respectively (p = 0.021,p = 0.004, p < 0.001). In multivariate analysis, ESBPRE was independently associated with a lower probability of myocardial ischemia (odds ratio: 0.73; 95% confidence interval: 0.58 to 0.93; p = 0.009). Exaggerated increase in systolic blood pressure during ESE may be a marker for excluding myocardial ischemia.

Computational Evidence for Laboratory Diagnostic Pathways: Extracting Predictive Analytes for Myocardial Ischemia from Routine Hospital Data.

Background: Laboratory parameters are critical parts of many diagnostic pathways, mortality scores, patient follow-ups, and overall patient care, and should therefore have underlying standardized, evidence-based recommendations. Currently, laboratory parameters and their significance are treated differently depending on expert opinions, clinical environment, and varying hospital guidelines. In our study, we aimed to demonstrate the capability of a set of algorithms to identify predictive analytes for a specific diagnosis. As an illustration of our proposed methodology, we examined the analytes associated with myocardial ischemia; it was a well-researched diagnosis and provides a substrate for comparison. We intend to present a toolset that will boost the evolution of evidence-based laboratory diagnostics and, therefore, improve patient care. Methods: The data we used consisted of preexisting, anonymized recordings from the emergency ward involving all patient cases with a measured value for troponin T. We used multiple imputation technique, orthogonal data augmentation, and Bayesian Model Averaging to create predictive models for myocardial ischemia. Each model incorporated different analytes as cofactors. In examining these models further, we could then conclude the predictive importance of each analyte in question. Results: The used algorithms extracted troponin T as a highly predictive analyte for myocardial ischemia. As this is a known relationship, we saw the predictive importance of troponin T as a proof of concept, suggesting a functioning method. Additionally, we could demonstrate the algorithm's capabilities to extract known risk factors of myocardial ischemia from the data. Conclusion: In this pilot study, we chose an assembly of algorithms to analyze the value of analytes in predicting myocardial ischemia. By providing reliable correlations between the analytes and the diagnosis of myocardial ischemia, we demonstrated the possibilities to create unbiased computational-based guidelines for laboratory diagnostics by using computational power in today's era of digitalization.

Diagnostic efficacy of CCTA and CT-FFR based on risk factors for myocardial ischemia

BackgroundCoronary artery coronary computed tomography angiography (CCTA) can observe the degree of coronary artery stenosis and fractional flow reserve (FFR) can diagnose hemodynamic abnormalities caused by coronary artery stenosis. However, noninvasive imaging examination that can both observe the above two methods at the same time has not yet been elucidated.ObjectiveTo investigate the diagnostic efficacy of CCTA and computed tomography-derived fractional flow reserve (CT-FFR) based on different risk factors for myocardial ischemia.MethodsPatients undergoing CCTA in our hospital from August 18, 2020 to April 28, 2021 were randomly selected, and the data were subjected to CT-FFR analysis. Vascular characteristics were measured, including total plaque volume, calcified plaque volume, non-calcified plaque volume, plaque length, and lumen stenosis, and the patients were categorized into a non-ischemia group (FFR > 0.8) and an ischemia group (FFR ≤ 0.8). Plaque characteristics were compared between the two groups, and logistic regression analysis was employed to explore the correlations between plaque characteristics and ischemic lesions.ResultsFrom a total of 122 patients enrolled in the study, there were 218 vascular branches with FFR > 0.8 and 174 vascular branches with FFR ≤ 0.8. There were significant group differences in total plaque volume, calcified plaque volume, plaque length, and lumen stenosis > 50% (n). The obtained data were as follows: non-ischemic group 10.57 (4.80, 259.65), ischemic group 14.87 (3.39, 424.45), Z = 9.772, p = 0.002, non-ischemic group 10.57 (0, 168.77), ischemic group 14.87 (0, 191.00), Z = 2.503, p ≤ 0.001), non-ischemic group 8.17 (37.05, 40.53), ischemic group 8.38 (56.66, 86.47), Z = 5.923, p = 0.016, and lumen stenosis > 50%, non-ischemic group 46, ischemic group 90, x2 = 14.77, p ≤ 0.001. The regression analysis results indicated that total plaque volume, calcified plaque volume, plaque length and lumen stenosis > 50% were risk factors for myocardial ischemia, with ORs and p values of (2.311, p = 0.002), (1.021, p = 0.004), (2.159, p < 0.001), and (0.181, p < 0.001), respectively.ConclusionTotal plaque volume, calcified plaque volume, plaque length and lumen stenosis > 50% are predictors for myocardial ischemia. Coronary artery CCTA combined with CT-FFR could simultaneously observe the anatomical stenosis and evaluate myocardial blood supply at the functional level. Thus, myocardial ischemia could be better diagnosed.

Vitamin D Deficiency as a Risk Factor for Myocardial Ischemia

Background and Objectives: Vitamin D (Vit D) deficiency has been implicated in various conditions, including cardiovascular disease. The purpose of this retrospective study was to investigate the incidence of patients with myocardial ischemia in relation to their serum levels of vitamin D. Materials and Methods: A 64-month search (January 2016 to April 2021) in our database of the Nuclear Medicine Laboratory revealed 113 patients who had both myocardial perfusion imaging with single photon emission computed tomography (MPI SPECT) and Vit D measurements. MPI SPECT obtained myocardial images during both stress (summed stress score, SSS) and rest (summed rest score, SRS). Abnormal MPI SPECT was when the SSS was ≥4. Vit D was determined by radioimmunoassay (RIA). Patients with Vit D values <10 ng/mL, 10–29 ng/mL and ≥30 ng/mL were defined as having a deficiency, insufficiency and sufficiency, respectively. Results: Among patients, 46/113 (40.7%) were male and 67/113 (59.3%) were female. Abnormal MPI was found in 58/113 (51.3%) patients. Vit D deficiency was noted in 20/113 (17.7%) patients, insufficiency in 86/113 (76.1%) patients, and normal Vit D was noted in only 7/113 (6.2%) patients. Sixteen of the 20 patients (80%) with Vit D deficiency, and 38/86 (44.2%) with insufficiency had an abnormal MPI SPECT. In contrast, only 1/7 (14.3%) patients with sufficient Vit D levels had an abnormal MPI SPECT. The Mann-Whitney U-test showed that ischemia reduced the values of Vit D. Correlation analysis showed a negative association of Vit D levels with SSS (rho = −0.232, p = 0.014) and SRS (rho = −0.250, p = 0.008). Further evaluation with a Vit D cut off 20 ng/mL retrieved no statistical significance. Finally, Vit D and gender were independently associated with myocardial ischemia. Conclusions: Low Vit D levels may represent a risk factor for myocardial ischemia.

Evaluation of Coronary Artery Disease in Patients with Atrial Fibrillation by Cardiac Computed Tomography for Catheter Ablation: CADAF-CT Trial 2.

Objective We recently reported that routine cardiac computed tomography (CT) scans for radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) could steadily detect coronary artery lesions (CALs) and could accurately detect myocardial ischemia in 9% of patients with AF who underwent RFCA of AF. The aim of this study was to identify the independent risk factor (s) of myocardial ischemia in those patients. Methods Patient characteristics, blood test, CALs, Ordinal coronary calcium scoring (OCCS), and myocardial Ischemia (MI) were evaluated in 757 consecutive patients who underwent RFCA of AF. Results There were 685 and 72 patients without and with myocardial ischemia, respectively. A univariate analysis and multivariate statistical analysis revealed that a male gender (Odds ratio 2.11), a high number of co-existing coronary risk factors (NCCRF ≥3) (Odds ratio 2.03), an elevated brain natriuretic peptide level (BNP ≥100 pg/mL) (Odds ratio 3.37), an enlarged left atrial volume (≥90 mL) (Odds ratio 2.91), and a high OCCS (≥4) (Odds ratio 13.0) were independent risk factors of myocardial ischemia in patients undergoing RFCA of AF. Conclusion The high OCCS (≥4) by cardiac CT was the strongest independent risk factor of myocardial ischemia in those patients. However, physicians may be able to find the high risk patients of myocardial ischemia by evaluating a male gender, in the presence of a high NCCRF (≥3) and elevated BNP (≥100 pg/mL) without OCCS by cardiac CT in patients undergoing RFCA of AF.

Abstract 444: The Phase of Third Harmonic of Radial Pulse Predicts Cardiac Risk in Asymptomatic Patients With Type 2 Diabetes

Patients with type 2 diabetes (T2DM) have a significantly increased risk of heart disease and adverse cardiac events(ACE). Many of asymptomatic patients with T2DM have myocardial perfusion defects or coronary artery disease and are not recognized by traditional risk factors. The third harmonic of radial pulse has been proved a risk factor for myocardial ischemia. We sought to further investigate if the third harmonic phase of the radial pulse(P3) could be an independent predictor of ACE and cardiac dysfunction in asymptomatic T2DM patients. The study consisted of 1968 asymptomatic T2DM patients who had no history of angina and cardiovascular disease. We conducted the pulse wave measurement at baseline and dived the enrolled patients into quartile groups based on P3 value(&gt;3.2, 3.0 to 3.2, 2.7 to 3.0, and &lt;2.7). Participated patients received an average of 1.8 years of follow-up. To assess the risk of ACE , the primary outcomes were the composite of myocardial infarction, heart failure, and cardiovascular death. To measure the risk of cardiac dysfunction, the secondary outcomes were composed of newly discovered single or multi coronary stenosis, myocardial ischemia, and left ventricular dysfunciton. Cox proportional hazards model were used. Reference to patients with P3&gt;3.2, the hazard ratios(HR) of patients with P3&lt;2.7 were as follows: (1) myocardial infarction(HR, 1.98; 95% CI, 1.32-2.98), heart failure(HR, 1.64; 95% CI, 0.88-3.06), and cardiovascular death(HR, 3.51; 95% CI, 0.73-16.9); (2) Single coronary stenosis(HR, 10.1; 95% CI, 1.29-78.7), multi coronary stenosis(HR, 9.06; 95% CI, 1.15-71.5), myocardial ischemia(HR, 3.05; 95% CI, 1.37-6.80), and low left ventricular ejection fraction(HR, 2.09; 95% CI, 1.13-38.7). The trend analysis further demonstrated that the reducing P3 leads to higher incidence of both primary and secondary composite outcomes(P&lt;0.001). After adjusting for age, gender, smoking, systolic blood pressure, dyslipidemia, duration of diabetes, and Hba1c, P3 was still an independent predictor of ACE and cardiac dysfunction (P trend &lt;0.005). Conclusively, this report suggested that P3 provides independent predictive value for risk assessment of ACE and cardiac dysfunction in asymptomatic patients with T2DM.

Effects of Nicorandil Versus Nitroglycerin on Arterial Oxygenation During Two-Lung Ventilation and One-Lung Ventilation in Patients With Risk Factors for Myocardial Ischemia: A Prospective, Randomized, Double-Blind Study

To compare the effects of nicorandil and nitroglycerin on arterial oxygenation during two-lung ventilation (TLV) and one-lung ventilation (OLV) in patients with risk factors for myocardial ischemia. A prospective, randomized, double-blind study. A tertiary care hospital. Fifty-six patients scheduled for elective video-assisted thoracic surgery were assigned randomly to either the nicorandil group or the nitroglycerin group. Patients in the nicorandil group received a bolus dose of nicorandil, 0.08 mg/kg during induction of anesthesia, followed by a continuous infusion at a rate of 0.08 mg/kg/h. Patients in the nitroglycerin group received a continuous infusion of nitroglycerin at a rate of 1 µg/kg/min from the induction of anesthesia. Arterial blood gas analysis was performed at the following points: before induction of anesthesia; during TLV; at 5, 10, 20, and 30 minutes after the initiation of OLV. PaO2 at TLV (479.7 ± 57.1 v 408.2 ± 70.9 mmHg, p < 0.001); and at 5 minutes (344.8 ± 85.1 v 282.6 ± 85.8 mmHg, p = 0.012), 20 minutes (215.7 ± 103.0 v 158.2 ± 74.5 mmHg, p = 0.027), and 30 minutes (198.8 ± 103.5 v 147.5 ± 64.1 mmHg, p = 0.039) after OLV was significantly higher in the nicorandil group than in the nitroglycerin group. This study demonstrated that oxygenation during TLV and OLV was significantly higher in patients receiving nicorandil than in those receiving nitroglycerin.

Low to Moderate Alcohol Consumption and Myocardial Ischemia on Exercise Stress Echocardiography

Abstract Background: The impact of alcohol consumption on the development of myocardial ischemia remains uncertain. Studies diverge whether low to moderate alcohol consumption provides cardioprotection or whether it is a risk factor for myocardial ischemia. Objective: To study the relationship between low to moderate alcohol consumption and myocardial ischemia on exercise stress echocardiography (ESE). Methods: Cross-sectional study with 6,632 patients with known or suspected coronary artery disease undergoing ESE between January/2000 and December/2015. The patients were divided into two groups: [...]

Pharmacological postconditioning with atorvastatin calcium attenuates myocardial ischemia/reperfusion injury in diabetic rats by phosphorylating GSK3β.

Diabetes is an independent risk factor for myocardial ischemia, and many epidemiological data and laboratory studies have revealed that diabetes significantly exacerbated myocardial ischemia/reperfusion injury and ameliorated protective effects. The present study aimed to determine whether pharmacological postconditioning with atorvastatin calcium lessened diabetic myocardial ischemia/reperfusion injury, and investigated the role of glycogen synthase kinase (GSK3β) in this. A total of 72 streptozotocin-induced diabetic rats were randomly divided into six groups, and 24 age-matched male non-diabetic Sprague-Dawley rats were randomly divided into two groups. Rats all received 40 min myocardial ischemia followed by 180 min reperfusion, except sham-operated groups. Compared with the non-diabetic ischemia/reperfusion model group, the diabetic ischemia/reperfusion group had a comparable myocardial infarct size, but a higher level of serum cardiac troponin I (cTnI) and morphological alterations to their myocardial cells. Compared with the diabetic ischemia/reperfusion group, the group that received pharmacological postconditioning with atorvastatin calcium had smaller myocardial infarct sizes, lower levels of cTnI, reduced morphological alterations to myocardial cells, higher levels of p-GSK3β, heat shock factor (HSF)-1 and heat shock protein (HSP)70. The cardioprotective effect conferred by atorvastatin calcium did not attenuate myocardial ischemia/reperfusion injury following application of TDZD-8, which phosphorylates and inactivates GSK3β. Pharmacological postconditioning with atorvastatin calcium may attenuate diabetic heart ischemia/reperfusion injury in the current context. The phosphorylation of GSK3β serves a critical role during the cardioprotection in diabetic rats, and p-GSK3β may accelerate HSP70 production partially by activating HSF-1 during myocardial ischemic/reperfusion injury.

Influence of two anesthetic methods on postoperative cardiac function in elderly patients with coronary artery disease

Objective To explore the influence of inhalation anesthesia versus intravenous anesthesia on postoperative cardiac function in elderly patients with coronary artery disease, and to assess the effect of the two anesthesia schemes on controlling the incidence rate of postoperative adverse cardiovascular events in patients with versus without heart surgery. Methods 224 elderly patients with coronary artery disease admitted to our hospital were chosen from Jan. 2013 to Sep. 2015. Patients were randomly divided into the inhalation anesthesia group and the intravenous anesthesia group (n=112, each). The perioperative adverse cardiovascular events were considered as a primary endpoint, and the postoperative adverse cardiovascular events within 3 days after operation as a secondary endpoint in all patients. The univariate analysis and multivariate Logistic regression analysis were used to evaluate the risk factors for the adverse cardiovascular events after surgery. The influence of the two anesthesia methods on the incidence rate of postoperative adverse cardiovascular events was compared. Results Among 224 patients, 31 cases (13.8%) showed the perioperative adverse cardiovascular events, including 4 cases (1.8%) during surgery, 27 cases (12.1%) after surgery; 16 cases (14.3%) in inhalation group and 15 cases (13.4%) in intravenous group (16, 14.3% vs. 15, 13.4%, P>0.05). The independent risk factors for myocardial ischemia shown at the day of surgery were New York Heart Association (NYHA) class Ⅲ and intraoperative hypotension, those shown at second day after surgery were intraoperative hypotension, intravenous anesthesia, NYHA class Ⅲ, and those shown at third day after surgery were intraoperative hypertension and intravenous anesthesia (all P<0.05). Among 224 cases, 7 patients (3.1%) died after surgery, of which 2 cases had cardiac death and 5 cases had non-cardiac death. Conclusions The inhalation anesthesia effectively reduces the incidence of myocardial ischemic events in elderly patients within 3 days after surgery, but it does not improve the incidence of perioperative cardiac events and mortality. The inhalation anesthesia has a certain protective effect on myocardium, which is worthy of promotion. Key words: Anesthetic, inhalation; Anesthesia, intravenous; Coronary artery disease

Early diagnosis, prevention and treatment of myocardial ischemia during endoscopic retrograde cholangiopancreatography in elderly patients

Objective To investigate the risk factors and biomarkers for early diagnosis and treatment for myocardial ischemia during endoscopic retrograde cholangiopancreatography (ERCP) in patients aged ≥75 years, in order to improve the effectiveness and security of ERCP. Methods A total of 82 patients undergoing ERCP in our hospital from Jan. 2013 to Dec. 2014 were divided into the elderly group (n = 42, aged≥75 years) and the non-elderly group (n = 40, aged <75 years). The pre- and post-operative ECG findings, laboratory serological indexes, ERCP operating parameters and post-operative complications were compared between two groups. Results ASA grade was increased in elderly patients as compared with the non-elderly group. The intraoperative hypothermia, preoperative infection and jaundice, and hypertension were risk factors for myocardial ischemia during ERCP. The biochemical indexes including myeloperoxidase, creatine kinase and cardiac troponin I were the biomarkers for early diagnosis of myocardial ischemia in patients with non-specific changes of ST-T wave. The indications of anesthesia meeting operation, the consecutive and close anesthesia monitoring, application of nitroglycerin, thermal insulation during operation, oxygen inhalation can effectively relieve myocardial ischemia during ERCP operation. Conclusions The early discovering and effectively treating myocardial ischemia during ERCP can ensure the safe and effectiveness of ERCP in elderly patients aged ≥75 years. Key words: Myocardial ischemia; Endoscopic retrograde cholangiopancreatography; Complication

Antioxidant and cardioprotective effects of Danshensu (3-(3, 4-dihydroxyphenyl)-2-hydroxy-propanoic acid from Salvia miltiorrhiza) on isoproterenol-induced myocardial hypertrophy in rats

Myocardial hypertrophy has been linked to the development of a variety of cardiovascular diseases, and is a risk factor for myocardial ischemia, arrhythmias, and sudden cardiac death. The objective of the present study was to evaluate the cardioprotective effects of Danshensu (DSS), a water-soluble active component of Danshen, on cardiac hypertrophy in rats. We are the first to report that DSS reversed Cx43 down-regulation in ventricular tissue. Cardiomyopathy in rats was produced using isoproterenol (Iso) treatment (2.5 mg/kg/d, s.c.) for seven days. DSS (3 and 10 mg/kg/d, i.p.) and Valsartan (Val) (10 mg/kg, i.g.) were administered on days 4-7 of Iso-treatment. Heart weight index, hemodynamic parameters, and ECG II parameters were monitored and recorded; protein expression of left ventricular connexin 43 (Cx43) and the activity of the redox system were assayed, and arrhythmias were produced using a coronary ligation/reperfusion procedure. The results demonstrated that DSS treatment significantly decreased heart weight/body weight (HW/BW) and left ventricular weight/body weight (LVW/BW) ratios. The protective role of DSS against Iso-induced myocardial hypertrophy was further confirmed using ECG. The incidences of ventricular tachycardia and ventricular fibrillation (VT, VF) and arrhythmic scores were higher in the model group and were suppressed by DSS. DSS decreased the serum and myocardium levels of creatine kinase, lactate dehydrogenase, and malondialdehyde (CK, LDH, and MDA) and increased serum activity of superoxide dismutase (SOD) in a dose-dependent manner. Cx43 expression in the left ventricle was down-regulated, and there was significant oxidative stress in this model of cardiomyopathy. DSS reversed the down-regulated Cx43 protein levels and showed potent anti-oxidative activities and cellular protection. These data demonstrate that DSS can prevent cardiac I/R injury and improve cardiac function in a rat model of hypertrophy, the effects partially resulting from antioxidants and the protection from Cx43 expression.

Myocardial ischemia during endoscopic retrograde cholangiopancreatography: An overlooked issue with significant clinical impact

The occurrence of peri-procedural myocardial ischemia with endoscopic retrograde cholangiopancreatography (ERCP) has been documented, but its significance remains controversial. This study aimed to investigate the incidence and risk factors of myocardial ischemia during ERCP procedures and to analyze the potential association between myocardial ischemia and post-ERCP complications. Ambulatory 24-h ST-segment monitoring from 30 min prior to 24 h after ERCP was obtained on 71 patients from September 2006 to August 2007. Changes in vital signs during ERCP, post-ERCP complications, and their outcomes were recorded and analyzed. Cardiac ischemia occurred in 13 patients (18.3%) during ERCP and one patient developed myocardial infarction. More patients in the ischemic group (38.5%) than in the non-ischemic group (5.2%) had ST-T changes in pre-ERCP resting electrocardiography (P < 0.01). Hypotension during ERCP was found only in the ischemic group (15.4% vs 0%; P = 0.03). Patients with cardiac ischemia during ERCP had a significantly higher rate of elevated serum amylase and lipase levels (53.8% vs 15.5%; P < 0.01) and post-ERCP pancreatitis (30.8% vs 6.9%; P = 0.03). Multivariable logistic regression analysis revealed that cardiac ischemia during ERCP (OR: 5.21, P = 0.050) and pancreatic duct cannulation (OR: 5.7, P = 0.036) were independent predictors for post-ERCP pancreatitis. ST-T changes on resting electrocardiography and intra-procedural hypotension are risk factors of myocardial ischemia during ERCP. Post-ERCP hyperamylasemia, hyperlipasemia, and pancreatitis were associated with myocardial ischemia during ERCP.

Anesthesia management for retrograde aortic valve replacement

To the Editor, We read with great interest the article, ‘‘Case series: Anesthesia for retrograde percutaneous aortic valve replacement—experience with the first 40 patients’’. Ree et al. report their experiences with the retrograde aortic valve replacement procedure, and the preliminary results of the two new valve application techniques, the transfemoral and transapical approaches, are encouraging. Since anesthesiologists must deal with the added co-morbidities associated with elderly patients, this article is of utmost interest, because the number of minimally invasive aortic valve replacement procedures is increasing worldwide. Whereas this procedure is performed under general anesthesia in 90% of cases, other groups prefer and propagate regional anesthesia and conscious sedation for the retrograde approach. Ree et al. performed the procedures in the cardiac catheterization laboratory, and, unfortunately, it was not possible to deliver the prosthetic valve in five patients, and, in two patients, the valve was malpositioned. These results dictate the operating room setup for minimally invasive aortic valve replacement. Anesthesiologists must be prepared for sudden hemodynamic deterioration which may require inotropic support, ventricular pacing, or emergency cardiopulmonary bypass; thus, the setup of the room must lend itself to the possibility of an emergency cardiopulmonary bypass. The authors reported that the most common procedural complications were myocardial ischemia and arrhythmia following rapid ventricular pacing. Did they maintain a specific mean arterial pressure before commencing the rapid ventricular pacing? Also, the authors treated intraoperative hypotension (systolic arterial pressure \90 mmHg) with intravenous crystalloid infusion as well as inotropic agents. We routinely experience a significant decline in the mean arterial pressure for both balloon valvuloplasty and valve implantation after rapid ventricular pacing. In our experience, it is important to increase the mean arterial pressure (MAP [ 75 mmHg) before starting rapid ventricular pacing, especially if the procedure is performed under general anesthesia. If the ‘‘starting point’’ of the mean arterial pressure is higher before initiating rapid ventricular pacing, the necessary time to stabilize the patient is shorter. A prolonged period of hypotension after rapid ventricular pacing may be the risk factor for myocardial ischemia after rapid ventricular pacing. These initial experiences necessitate a thorough understanding of anesthesia management and the hemodynamic effects of retrograde valve replacement in order to ensure successful outcomes with this new approach for percutaneous retrograde replacement of the aortic valve for high risk patients.

Predictors of Electrocardiographic Change, Cardiac Troponin Elevation, and Survival after Major Vascular Surgery: A Community Hospital Experience

Cardiovascular disease is the leading cause of perioperative morbidity and mortality after vascular surgery. The purpose of this study was to identify risk factors for myocardial ischemia after vascular surgery and to investigate a potential association of ischemia with mortality in a community hospital setting. A retrospective review was conducted after 190 major vascular procedures. Electrocardiogram (ECG) results and troponin I levels were obtained serially during the first 24 postoperative hours. Outcomes analyzed were ischemic ECG changes, troponin I level more than 2 ng/mL, 6-month mortality, and overall survival. The authors investigated any association of these outcomes with each other and the type of operation, history of coronary artery disease, diabetes, recent coronary intervention, age older than 70 years, or postoperative symptoms. Twenty-seven (14%) patients experienced ischemic ECG changes. Twenty-one (11%) patients experienced troponin I elevation. Univariate analysis revealed a history of coronary artery disease, diabetes, concerning symptoms, and troponin elevation to be predictive of ECG change (P < 0.05). ECG change and symptoms were predictive of troponin elevation (P < 0.01). Cox multivariate analysis revealed only infrainguinal bypass to predict 6-month mortality (odds ratio = 2.92, P = 0.02). Diabetes was the sole predictor of overall mortality (odds ratio = 1.94, P = 0.001). Nonsustained ischemic postoperative ECG changes during the first 24 postoperative hours do not independently influence 6-month or overall mortality after major vascular surgery. Postoperative troponin elevation likely conveys a mortality risk in the subsequent 6 months. In the community hospital setting, midterm survival rates after vascular surgery equivalent to those in higher volume centers can be achieved. Patients undergoing infrainguinal bypass and diabetics continue to be the most moribund vasculopaths.

Silent myocardial ischemia in coronary artery disease patients under aspirin therapy presenting with upper gastrointestinal hemorrhage

To identify the risk factors for myocardial ischemia in patients undergoing aspirin therapy for coronary artery disease (CAD) presenting with upper gastrointestinal hemorrhage and to ascertain the impacts on mortality and length of hospital stay. Adults with CAD under aspirin therapy (100 mg once daily) presenting to the emergency department with upper gastrointestinal hemorrhage were retrospectively recruited and divided into group A (ischemia) and group B (non-ischemia). Charts were reviewed for various demographic, laboratory and outcome data. Electrocardiograms were interpreted blindly by a senior cardiologist. A total of 152 patients, 72.4% men and 27.6% women, were analyzed. Of these, 31 patients had ischemia and were placed in group A and 121 patients did not have ischemia and were in group B. Independent multivariate predictors of myocardial ischemia were history of triple vessel disease (odds ratio [OR], 9.24; 95% confidence interval [CI], 2.00-42.72), lower diastolic blood pressure (OR, 1.09; 95% CI, 1.02-1.16), lower hematocrit (OR, 1.41; 95% CI, 1.16-1.70), and higher blood urea nitrogen (OR, 0.94; 95% CI, 0.89-0.98). Patients with myocardial ischemia had significantly longer hospital length of stay (8.7 +/- 4.0 days vs 5.4 +/- 1.7 days; P < 0.001) and higher in-hospital mortality (16.1%vs 2.5%; P < 0.01) than did those without myocardial ischemia. Myocardial ischemia is a relatively common complication in CAD patients under aspirin therapy presenting with upper gastrointestinal hemorrhage. A history of CAD with triple vessel disease, higher blood urea nitrogen, lower diastolic blood pressure and lower hematocrit may help identify patients who are at increased risk of myocardial ischemia, which tends to be associated with higher in-hospital mortality and increased length of hospital stay.

ROLE OF CARDIOMYOCYTE APOPTOSIS IN TRAUMA-INDUCED SENSITIZATION TO MI INJURY

Previous epidemiological studies have demonstrated that trauma exposure is linked to adverse health outcomes. Moreover, recent clinical observation suggests that trauma patients who later develop myocardial ischemia (MI) have a much higher mortality rate than age-matched controls. These results highly suggest that traumatic injury may increase the risk for cardiovascular diseases. We have recently demonstrated that nonfatal mechanical trauma results in significant cardiomyocyte apoptosis. The current study was designed to determine whether trauma-induced cardiomyocyte apoptosis may "prime" the heart to be more susceptible to MI injury. Adult male Swiss Webster mice were anesthetized and subjected to nonfatal trauma (Noble-Collip drum, 200 revolutions at 40 rpm). Sham traumatic mice were subjected to the same number of revolutions without trauma. One week after trauma, mice were subjected to 30 min MI followed by 1 week of reperfusion (R). Cardiac function assessed by echocardiography before ischemia was normal, and there was no difference between trauma mice and non-trauma mice. However, ischemic cardiac dysfunction assessed by both non-invasive and invasive techniques was significantly aggravated in those animals subjected to a nonfatal trauma (P < 0.01). Moreover, infarct size (fraction of the infarcted left ventricle as the percentage of length of circumference) was significantly enlarged in those animals exposed to a mild trauma 1 week before (74 ± 4.6% vs. 56 ± 3.9% in sham trauma plus MI, n = 10/group, P < 0.01). Treatment with Z-VAD-FMK, a broad-spectrum caspase inhibitor (4 mg/kg, i.p.), given immediately after trauma, blocked trauma-induced apoptosis and abolished traumainduced sensitization to MI/R injury. These results suggest that traumatic injury might be a "silent" risk factor for ischemic MI and that cardiomyocyte apoptosis contributes to trauma-induced sensitization to MI/R injury.Figure

Repair of Thoracic Aneurysms, with Special Emphasis on the Preoperative Work-Up

The anesthetic approach to the patient with a thoracic aortic aneurysm depends on the urgency of repair. Symptomatic patients with leaking aneurysms require urgent intervention, and there is generally little time to perform more than the most basic preoperative assessment. For elective repair, however, one must consider nearly every organ system. Many of the specific issues are inherent to the underlying pathophysiology that has resulted in aneurysm formation, and some stem from the requirements of the surgical procedure itself. A thorough knowledge of the extent and location of the aneurysm, the functional status of the heart, and the coronary artery anatomy are critical. Most patients aged older than 40 years undergo coronary angiography preoperatively, as do younger patients with specific risk factors for myocardial ischemia. Respiratory failure is one of the most common sequelae of these procedures, and a thorough preoperative pulmonary work-up is mandatory. Neurologic deficits are not uncommon postoperatively, and pre-existing deficits in the central nervous system must be sought. Coagulopathy is common in the immediate postoperative period, and preoperative assurance of hemostatic competence is important. Computed tomography scans and magnetic resonance imaging are the mainstay of diagnosis, although the adjunctive use of echocardiography provides important information. Routine preoperative laboratory studies include complete blood count, chemistries, coagulation profile, and indices of renal function; an electrocardiogram, and chest radiograph. Close communication with the surgeon regarding the operative procedure, cannulation strategy (where applicable), and planned evoked potential monitoring is necessary to ensure appropriate perioperative management. Prophylactic antibiotics and antifibrinolytics are routine.