Multicenter Study Of Perioperative Ischemia Research Articles

Predictive ability of perioperative atrial fibrillation risk indices in cardiac surgery patients: a retrospective cohort study.

The Multicenter Study of Perioperative Ischemia (McSPI) AFRisk index predicts postoperative atrial fibrillation (POAF) after cardiac surgery, but requires pre-, intra-, and postoperative data. Other more abbreviated risk indices exist, but there is no consensus on which risk index is optimal. We compared the discriminatory capacity of the McSPI AFRisk index with three indices containing only preoperative data (the CHA2DS2Vasc score, POAF score, and Kolek clinical risk prediction model), hypothesizing that the McSPI AFRisk index would have superior predictive capacity. We retrospectively evaluated 783 patients undergoing cardiac surgery using cardiopulmonary bypass. The predictive capacity of each index was assessed by comparing receiver-operating characteristic (ROC) curves, scaled Brier scores, net reclassification indices, and the integrated discrimination indices. The incidence of POAF was 32.6%. The area under the curve (AUC) of the ROC curve were 0.77, 0.58, 0.66, and 0.66 for the McSPI AFRisk index, CHA2DS2Vasc score, POAF score, and Kolek clinical risk prediction model, respectively. The McSPI AFRIsk index had the highest AUC (P < 0.0001). The scaled Brier scores for the McSPI AFRisk index, CHA2DS2Vasc score, POAF score, and Kolek clinical risk prediction model were 0.23, 0.02, 0.08, and 0.07, respectively. Both net reclassification indices and integrated discrimination indices showed that the McSPI AFRisk index more appropriately identified patients at high risk of POAF. The McSPI AFRisk index showed superior ability to predict POAF after cardiac surgery compared with three other indices. When clinicians and investigators wish to measure the risk of POAF after cardiac surgery, they should consider using the McSPI AFRisk index.

Postoperative red blood cell transfusion and morbid outcome in uncomplicated cardiac surgery patients

To evaluate postoperative red blood cell (RBC) transfusion and its association with postoperative cardiac events and multiorgan morbidity in uncomplicated cardiac surgery patients. A cohort of 945 patients from the 5,436 coronary artery bypass grafting patients enrolled in the international Multicenter Study of Perioperative Ischemia (McSPI) Epidemiology II (EPI II) study was investigated. Inclusion criteria were low to moderate risk profile, postoperative hemoglobin level ≥ 10 g/dl, minimal postoperative blood loss, and no evidence of any morbid event on the day of surgery. RBC transfusion was assessed during the first 24 postoperative hours and cardiac as well as multiorgan outcomes from postoperative day 2 to hospital discharge. Multivariate analysis was applied to assess the effect of RBC transfusion on multiorgan outcomes. A secondary propensity score analysis was performed in 4,465 patients without early postoperative morbid outcomes. Transfused patients (193/945, 20.4%) were more likely to suffer cardiac events (P = 0.03), harvest-site infection (P = 0.002), and composite morbidity outcome (P = 0.04). RBC transfusion was associated with cardiac events on multivariate as well as on propensity score analysis (adjusted odds ratio, 1.39; 95% confidence interval, 1.01-1.92; P = 0.04), and with harvest-site infection on multivariate analysis. Additionally, propensity score analysis suggested possible associations of RBC transfusion with increased risks for composite morbidity outcome and in-hospital mortality, renal morbidity, pneumonia, and mediastinitis. The data suggest a potential association between postoperative RBC transfusion and increased morbidity for cardiac surgery patients with low to moderate mortality risk profiles, adequate hemoglobin levels, and low bleeding rates.

Response to Letter Regarding Article, “Risk Index for Perioperative Renal Dysfunction/Failure: Critical Dependence on Pulse Pressure Hypertension”

HomeCirculationVol. 116, No. 5Response to Letter Regarding Article, “Risk Index for Perioperative Renal Dysfunction/Failure: Critical Dependence on Pulse Pressure Hypertension” Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBResponse to Letter Regarding Article, “Risk Index for Perioperative Renal Dysfunction/Failure: Critical Dependence on Pulse Pressure Hypertension” Solomon Aronson, MD Manuel L. Fontes, MD Yinghui Miao, MD, MPH Dennis T. Mangano, PhD, MD Solomon AronsonSolomon Aronson Duke University Medical Center, Durham, NC Search for more papers by this author Manuel L. FontesManuel L. Fontes Weill Medical College of Cornell University, Ithaca, NY Search for more papers by this author Yinghui MiaoYinghui Miao Ischemia Research and Education Foundation, San Bruno, Calif Search for more papers by this author Dennis T. ManganoDennis T. Mangano Multicenter Study of Perioperative Ischemia Research Group, San Bruno, Calif Search for more papers by this author Originally published31 Jul 2007https://doi.org/10.1161/CIRCULATIONAHA.107.709378Circulation. 2007;116:e120We thank Dr Augoustides for his interest regarding our study1 and are pleased to respond to his questions regarding the independent effects of use of perioperative aprotinin and preoperative ACE inhibitors (ACEI).To assess the effect of aprotinin on our findings, we must realize certain limitations: (1) the analysis is post hoc, for our formal design for this question (2001) did not include aprotinin; and (2) such analysis would include only one half of our cohort (the derivation cohort), reducing the sample size by 2420 patients, and further reduction for multiple drugs/incomplete information would further decrease power. Because of these considerations, we did not include in our report the post hoc analyses given below; however, we are pleased to address Dr Augoustides’ questions, given these limitations.Among 4801 patients in the study cohort, 29.4% received aprotinin, with no significant difference in aprotinin use found between the derivation and validation cohorts (28.2% and 30.6%, respectively, P=0.10). For the 2079 derivation cohort patients (2381 less 302 excluded for multiple drugs, etc), we found that aprotinin was an independent predictor for renal injury either without exposure to preoperative ACEI (OR, 2.94; 95% CI, 1.59 to 5.42; P<0.001) or with exposure (OR, 2.88; 95% CI, 1.56 to 5.32; P<0.001).To test the interaction between preoperative ACEI use and aprotinin use for renal events, we performed stratified data analyses, finding no interaction. For patients not taking ACEI, the OR (95% CI) for aprotinin versus control was 2.44 (1.52 to 3.90), and for patients taking ACEI, it was 2.33 (1.59 to 3.41). The crude OR equaled 2.52 (95% CI, 1.87 to 3.38; P<0.001; Cochran-Mantel-Haenszel statistic for general association, P<0.001), and the adjusted OR equaled 2.37 (95% CI, 1.76 to 3.19), with the Breslow-Day test for homogeneity of the ORs indicating P=0.878. We therefore conclude that preoperative ACEI use is neither a modifier nor a confounder for the association between aprotinin use and postoperative renal composite. Regarding ACEI as a predictor, it failed to meet the retention criterion of our multivariable logistic regression stepwise-selection procedure for renal risk.Finally, we note that our findings regarding the renal risk index are not inconsistent with the previously reported data referenced by Dr Augoustides2 and further demonstrate the critical role that preoperative pulse pressure plays in perioperative renal injury. We are grateful to have the opportunity to address Dr Augoustides’ valuable comments.Source of FundingThis work was supported by a grant from the Ischemia Research and Education Foundation.DisclosuresDr Aronson receives consultant fees from pharmaceutical and device companies, none of which are addressed in this study. Dr Fontes received a research grant from IREF and honoraria from the Medicine Co. Dr Mangano has intellectual rights to adenosine-regulating agents, none of which are addressed in this study. The other authors report no conflicts. References 1 Aronson S, Fontes ML, Miao Y, Mangano DT; for the Investigators of the Multicenter Study of Perioperative Ischemia Research Group and the Ischemia Research and Education Foundation. Risk index for perioperative renal dysfunction/failure: critical dependence on pulse pressure hypertension. Circulation. 2007; 115: 733–742.LinkGoogle Scholar2 Mangano DT, Tudor IC, Dietzel C; for the investigators of the Multicenter Study of Perioperative Ischemia and the Ischemia Research and Education Foundation. The risk associated with aprotinin in cardiac surgery. N Engl J Med. 2006; 354: 353–365.CrossrefMedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetails July 31, 2007Vol 116, Issue 5 Advertisement Article InformationMetrics https://doi.org/10.1161/CIRCULATIONAHA.107.709378 Originally publishedJuly 31, 2007 PDF download Advertisement SubjectsClinical StudiesPharmacologyVascular Biology

Impact of Preoperative Anemia on Outcome in Patients Undergoing Coronary Artery Bypass Graft Surgery

The risk of preoperative anemia in patients undergoing heart surgery has not been described precisely. Specifically, the impact of low hemoglobin per se or combined with other risk factors on postoperative outcome is unknown. Thus, we determined the effects of low preoperative hemoglobin and comorbidities on postoperative adverse outcomes in patients with coronary artery bypass graft in a large comprehensive multicenter study. The Multicenter Study of Perioperative Ischemia investigated 5065 patients with coronary artery bypass graft at 70 institutions worldwide, collecting approximately 7500 data points per patient. In 4804 patients who received no preoperative transfusions, we determined the association between lowest preoperative hemoglobin levels and in-hospital cardiac and noncardiac morbidity and mortality and the impact of concomitant risk factors, assessed by EuroSCORE, on this effect. In patients with EuroSCORE < 4 (n=2054), only noncardiac outcomes were increased, whereas patients with EuroSCORE > or = 4 (n=2750) showed an increased incidence of all postoperative events, starting at hemoglobin < 11 g/dL. Low preoperative hemoglobin was an independent predictor for noncardiac (renal > cerebral; P<0.001) outcomes, whereas the increase in cardiac events was due to other factors associated with preoperative anemia. Anemic patients undergoing cardiac surgery have an increased risk of postoperative adverse events. Importantly, the extent of preexisting comorbidities substantially affects perioperative anemia tolerance. Therefore, preoperative risk assessment and subsequent therapeutic strategies, such as blood transfusion, should take into account both the individual level of preoperative hemoglobin and the extent of concomitant risk factors.

Predictors of Diseased Ascending Aorta in Patients Undergoing Off-Pump Coronary Artery Bypass Surgery

To identify the preoperative risk factors associated with increased prevalence of atherosclerotic lesions of the ascending aorta among patients undergoing off-pump coronary artery bypass surgery (OPCAB). OPCAB was performed in 241 patients who were intraoperatively investigated by epiaortic ultrasound for the presence of atherosclerotic lesions of the ascending aorta. The Northern New England Cardiovascular Disease Study Group (NNECVDSG) and the Multicenter Study of Perioperative Ischemia (McSPI) stroke risk scores were retrospectively calculated. A diseased ascending aorta was detected by intraoperative epiaortic ultrasound in 74 patients (30.7%). Patient's age (P = .002, odds ratio [OR] 1.067, 95% confidence interval [CI] 1.025-1.110), diabetes (P = .023; OR, 2.211; 95% CI, 1.117-4.378), extracardiac arteriopathy (P = .014; OR, 2.567; 95% CI, 1.214-5.428) and urgent/emergency operation (P < .0001; OR, 3.066; 95% CI, 1.685-5.580) were independent preoperative predictors of a diseased ascending aorta. The area under the ROC curve of the NNECVDSG score in predicting a diseased ascending aorta was 0.710 (95% CI, 0.642-0.778), and that of the McSPI score was 0.722 (95% CI, 0.655-0.788). The prevalence of a diseased ascending aorta was 11.2%, 34.7%, and 49.4% among the NNECVDSG score tertiles (P < .0001), and 11.3%, 31.7%, and 49.4% among the McSPI score tertiles (P < .0001). These findings confirm the reported high incidence of a diseased ascending aorta in patients undergoing coronary artery bypass surgery. Current stroke risk scores, particularly the simple NNECVDSG score, are valuable predictors of increased prevalence of a diseased ascending aorta.

Preoperative statin therapy is associated with reduced cardiac mortality after coronary artery bypass graft surgery

Statin therapy in ambulatory populations is associated with a significant reduction in adverse cardiovascular events, including death and myocardial infarction. Much less is known about the beneficial effects of statins on acute perioperative cardiovascular events. The purpose of this study was to determine whether preoperative statin therapy is associated with a reduced risk of early cardiac death or nonfatal, in-hospital postoperative myocardial infarction after primary, elective coronary artery bypass graft surgery requiring cardiopulmonary bypass. The Multicenter Study of Perioperative Ischemia (McSPI) Epidemiology II Study was a prospective, longitudinal study of 5436 patients undergoing coronary artery bypass graft surgery between November 1996 and June 2000 at 70 centers in 17 countries. The present study consisted of a pre-specified subset of these subjects divided into patients receiving (n = 1352) and not receiving (n = 1314) preoperative statin therapy. To control for potential bias related to use of statin therapy, the study estimated propensity scores by logistic regression to determine the predicted probability of inclusion in the "statin" group. Multivariate, stepwise logistic regression was then performed, controlling for patient demographics, medical history, operative characteristics, and propensity score to determine whether preoperative statin therapy was independently associated with a reduction in the risk of early (DOS-POD3) cardiac death and/or nonfatal, in-hospital postoperative myocardial infarction. Preoperative statin therapy was independently associated with a significant reduction (adjusted odds ratio [OR] 0.25; 95% confidence intervals [CI] 0.07-0.87) in the risk of early cardiac death after primary, elective coronary bypass surgery (0.3% vs 1.4%; P < .03), but was not associated with a reduced risk of postoperative nonfatal, in-hospital myocardial infarction (7.9% vs 6.2%; P = not significant). Discontinuation of statin therapy after surgery was independently associated with a significant increase in late (POD4-discharge) all-cause mortality (adjusted OR 2.64; 95% CI 1.32-5.26) compared with continuation of statin therapy (2.64% vs 0.60%; P < .01). This was true even when controlling for the postoperative discontinuation of aspirin, beta-blocker, or angiotensin-converting enzyme inhibitor therapy. Discontinuation of statin therapy after surgery was also independently associated with a significant increase in late cardiac mortality (adjusted OR 2.95; 95% CI 1.31-6.66) compared with continuation of statin therapy (1.91% vs 0.45%; P < 0.01). Preoperative statin use is associated with reduced cardiac mortality after primary, elective coronary artery bypass grafting. Postoperative statin discontinuation is associated with increased in-hospital mortality. Although further randomized trials are needed to confirm these findings, these data suggest the importance of perioperative statin administration.

Parecoxib, Valdecoxib, and Cardiovascular Risk

Selective inhibitors of cyclooxygenase (COX)-21 depress prostacyclin (PGI2) but not COX-1–derived thromboxane A2. The effects of thromboxane A2 would be exaggerated during treatment with COX-2 inhibitors, potentially predisposing patients to heart attack and stroke.2 A randomized controlled trial in patients undergoing coronary artery bypass graft (CABG) surgery and receiving either placebo or 40 mg parecoxib (Dynastat; Pfizer), the intravenously administered prodrug of valdecoxib (Bextra; Pfizer), followed by oral valdecoxib 40 mg BID for 14 days, revealed a cluster of cardiovascular events.3 In a second study, one group received parecoxib/valdecoxib, another …

Reduction of neurologic complications by intra-aortic filtration in patients undergoing combined intracardiac and CABG procedures.

Patients undergoing combined intracardiac and coronary artery bypass grafting (CABG) procedures are at high risk for neurologic events. Previously the Multicenter Study of Perioperative Ischemia (McSPI) Study Group demonstrated that risk factors for neurologic complications in these patients related primarily to embolization. This study investigated risk factors and outcomes in 185 high-risk patients receiving intra-aortic filtration during combined intracardiac and CABG procedures. Seventeen European centers comprising the International Council of Emboli Management (ICEM) pooled data on patients receiving intra-aortic filtration (EMBOL-X, Mountain View, CA, USA) into a consecutive enrollment registry. Preoperative, intraoperative, and outcome variables were compared between ICEM patients undergoing combined CABG and intracardiac procedures and the corresponding McSPI subgroup. Type I outcomes (stroke, transient ischemic attack, coma, death due to neurologic causes) occurred in 2.2% (4/185) of ICEM patients compared to 8.4% (23/273) of McSPI patients. No ICEM patient suffered a fatal stroke compared with five in the McSPI study (1.8%). One nonfatal stroke was observed in the ICEM group (0.5%) and 16 were observed in the McSPI group (5.9%). Three patients (1.6%) were reported with transient ischemic attack in the ICEM group, compared to two in the McSPI study (0.7%). One of the reported patients in the ICEM group with transient ischemic attack also suffered a coma that was still evident at discharge. In all, four patients suffered Type I neurologic events in the ICEM group (2.2%), compared to 23 in the McSPI group (8.4%). In the ICEM study group, four patients (2.2%) died due to non-neurologic causes, compared to 18 in the McSPI group (6.6%). Even with a significantly worse preoperative profile, high-risk patients receiving intra-aortic filtration suffered Type I cerebral injury 74% less often than patients in the McSPI group.

Institutional variability in red blood cell conservation practices for coronary artery bypass graft surgery

Objective: To assess whether substantial institutional variability exists in red blood cell conservation practices associated with coronary artery bypass graft (CABG) surgery. Design: Prospective, randomized patient enrollment and data collection. Setting: Twenty-four U.S. academic institutions participating in the Multicenter Study of Perioperative Ischemia. Participants: A well-defined subset of primary CABG surgery patients (n = 713) expected to be at low risk for bleeding and exposure to allogeneic transfusion. Interventions: None (observational study). Measurements and Main Results: Frequency of use of red blood cell conservation techniques was determined among institutions. Correlation was determined between use of each technique and transfusion of allogeneic red blood cells and between use of each technique and median institutional blood loss. Significant variability ( p < 0.01) was detected in institutional transfusion practice with respect to the use of predonated autologous whole blood, normovolemic hemodilution, red cell salvage, and reinfusion of shed mediastinal blood. The frequency of institutional use of these techniques was not associated with allogeneic transfusion ( r 2 < 0.15) or blood loss ( r 2 < 0.10) in the low-risk population of patients examined. Conclusions: Institutions vary significantly in perioperative blood conservation practices for CABG surgery. Further study to determine the appropriate use of these techniques is warranted.

Improving Neurologic Outcome after Cardiac Surgery

Improving Neurologic Outcome after Cardiac Surgery

Effects of acadesine on myocardial infarction, stroke, and death following surgery. A meta-analysis of the 5 international randomized trials. The Multicenter Study of Perioperative Ischemia (McSPI) Research Group.

To determine the effects of a purine nucleoside, acadesine, on the incidence of fatal and nonfatal cardiovascular and cerebrovascular complications following coronary artery bypass graft (CABG) surgery. Individual patient data from 5 randomized, placebo-controlled, double-blind clinical trials, including 81 international medical centers of the United States, Canada, and Europe. All patients from all clinical trials were included: a total of 4043 patients undergoing CABG surgery, evaluable for efficacy, and randomized to receive either placebo (n= 2031) or acadesine (0.1 mg x kg(-1) x min(-1); n=2012) by intravenous infusion for 7 continuous hours and via the cardioplegia solution. Individual patient data were collected prospectively using standardized forms and methods and double-data entry. A general parametric approach and analysis-by-patient meta-analysis were used, including both fixed effects and random effects models. Inclusion and exclusion criteria, general methodology, and outcome assessment techniques were similar for all trials. Acadesine decreased the incidence of the primary outcome, perioperative myocardial infarction (MI) by 27% (odds ratio [OR], 0.69; 95% confidence interval [CI], 0.51-0.95; P=.02), decreased the incidence of cardiac death through postoperative day 4 by 50% (OR, 0.52; 95% Cl, 0.27-0.98; P=.04), and decreased the incidence of combined outcome (MI, stroke, or cardiac death) by 26% (OR, 0.73; 95% Cl, 0.57-0.93; P=.01). The random effects models for these outcomes also yielded significant results. The incidence of cerebrovascular accident was not significantly reduced by acadesine (OR, 0.69; 95% Cl, 0.44-1.08; P=.10). A secondary analysis of cardiac death following MI through postoperative day 4 demonstrated that acadesine decreased by 89% the number of deaths from 13.3% (13 deaths/98 MIs) in the placebo group to 1.4% (1 death/71 MIs) in acadesine-treated patients (P=.003). Acadesine also reduced the use of ventricular-assistance devices for severe postoperative heart failure by approximately one third (P=.05). Finally, regarding safety, the incidence of adverse events was similar in the acadesine vs placebo groups, with the exception of a transient increase in serum uric acid in the acadesine group. The results of this meta-analysis indicate that in patients undergoing CABG surgery, treatment with acadesine before and during surgery can reduce early cardiac death, MI, and combined adverse cardiovascular outcomes.

Atrial Fibrillation Following Coronary Artery Bypass Graft Surgery

To the Editor. —The pathophysiological mechanisms responsible for the high incidence of atrial fibrillation (AF) after coronary artery bypass surgery remain rather unclear. Consequently, identification of clinical predictors remains the most practical approach, as Dr Mathew and colleagues 1 demonstrated. Among the predictors of postoperative AF, they listed advanced age and male sex. In a similar study published almost simultaneously, Aranki and colleagues 2 also found advanced age and male sex to be significant predictors. In addition, they found the need for an intraoperative intraaortic balloon pump (IABP) to be an independent predictor. I wonder if the MultiCenter Study of Perioperative Ischemia (McSPI) Research Group, which Mathew and colleagues represented, also found this. Another noteworthy difference between these 2 studies was in the estimation of utilization of hospital resources resulting from this complication. Whereas Mathew et al 1 found the occurrence of postoperative AF was associated with an increase of

Atrial Fibrillation Following Coronary Artery Bypass Graft Surgery

To determine the incidence, predictors, and cost of atrial fibrillation and flutter (AFIB) following coronary artery bypass graft (CABG) surgery. Prospective observational study (MultiCenter Study of Perioperative Ischemia). Twenty-four university-affiliated hospitals in the United States from 1991 to 1993. A total of 2417 patients undergoing CABG with or without concurrent valvular surgery selected using a systematic sampling interval. Detailed preoperative, intraoperative, and postoperative data collected on standardized reporting forms. The overall incidence of postoperative AFIB was 27 percent. Independent predictors of postoperative AFIB included advanced age (odds ratio [OR], 1.24 per 5-year increase; 95 percent confidence interval [CI], 1.18-1.31); male sex (OR, 1.41; 95 percent CI, 1.09-1.81); a history of AFIB (OR, 2.28; 95 percent CI, 1.74-3.00); a history of congestive heart failure (OR, 1.31; 95 percent CI, 1.04-1.64); and a precardiopulmonary bypass heart rate of more than 100 beats per minute (OR, 1.59; 95 percent CI, 1.00-2.55). Surgical practices such as pulmonary vein venting (OR, 1.44; 95 percent CI, 1.13-1.83); bicaval venous cannulation (OR, 1.40; 95 percent CI, 1.04-1.89); postoperative atrial pacing (OR, 1.27; 95 percent CI, 1.00-1.62); and longer cross-clamp times (OR, 1.06 per 15 minutes; 95 percent CI, 1.00-1.11) also were identified as independent predictors of postoperative AFIB. Patients with postoperative AFIB remained an average of 13 hours longer in the intensive care unit and 2.0 days longer in the ward when compared with patients without AFIB. Postoperative AFIB is common after CABG surgery and has a significant effect on both intensive care unit and overall hospital length of stay. In addition to expected demographic factors, certain surgical practices increase the risk of postoperative AFIB. Randomized controlled trials are necessary to determine if modification of these surgical practices, especially in patients at high risk, would decrease the incidence of postoperative AFIB.

Ischemia--a coagulation problem?

The causes of perioperative ischemia and myocardial infarction (MI) in coronary artery bypass graft (CABG) patients are almost certainly multifactorial, although not well understood. Ultimately, outcome after CABG is dependent on myocardial preservation and prevention of further myocardial ischemia. The largest number of ST-T-wave events come immediately after protamine is given, suggesting that re-establishment of coagulation function after cardiopulmonary bypass (CPB) may be an important event. CPB induces an inflammatory state that involves platelet-endothelial-cell interactions and vasospastic responses that result in low flow states in the coronary vasculature. The fibrinolytic system is activated during CPB, with raised tissue plasminogen activator (tPA) levels and related falls in plasminogen activator inhibitor (PAI-1). PAI-1 levels rise during the postoperative period. There is a huge variability in human response. However, the patients with the highest tPA surge are not the same patients who have the highest PAI surge. It could be postulated that patients with high PAI-1 levels are at highest risk for early ischemia. New data just being evaluated from the Multicenter Study of Perioperative Ischemia (McSPI) Research Groups' database in San Francisco may support the hypothesis that coagulation influences perioperative ischemia. The study of approximately 2,400 patients undergoing CABG surgery at 24 major institutions in the United States revealed that intensive care unit (ICU) entry hematocrit was significantly related to the risk for postoperative MI. Patients entering the ICU with hematocrits below 24% had the lowest MI rate (3.7%), whereas those with hematocrits greater than 34% had the highest rate (8.1%). Patients with ICU entry hematocrits below 18% had a zero incidence of perioperative MI. One possible explanation for these findings is that platelets are involved. As red cells stream down vessels, they marginate the smaller formed elements of the blood. As hematocrit is increased, the number of platelets moved to the outer sides of the vessels increases. Therefore, the number of endothelial-platelet interactions would increase over time with higher hematocrits.

Introduction to the Third Annual Workshop on Frontiers in Perioperative Myocardial Management

Journal of Cardiac SurgeryVolume 9, Issue 3S p. 379-381 Introduction Introduction to the Third Annual Workshop on Frontiers in Perioperative Myocardial Management Andrew S. Wechsler M.D., Andrew S. Wechsler M.D. Guest Editor Department of Surgery, Medical College of Virginia, Richmond, VirginiaSearch for more papers by this authorDennis T. Mangano Ph.D., M.D., Dennis T. Mangano Ph.D., M.D. Guest Editor Department of Anesthesiology, University of California, San Francisco, VA Medical Center, and the Multicenter Study of Perioperative Ischemia (McSPI), San Francisco, CaliforniaSearch for more papers by this author Andrew S. Wechsler M.D., Andrew S. Wechsler M.D. Guest Editor Department of Surgery, Medical College of Virginia, Richmond, VirginiaSearch for more papers by this authorDennis T. Mangano Ph.D., M.D., Dennis T. Mangano Ph.D., M.D. Guest Editor Department of Anesthesiology, University of California, San Francisco, VA Medical Center, and the Multicenter Study of Perioperative Ischemia (McSPI), San Francisco, CaliforniaSearch for more papers by this author First published: May 1994 https://doi.org/10.1111/jocs.1994.9.3s.379 Address for correspondence: Andrew Wechsler, M.D., Chairman, Department of Surgery, Medical College of Virginia, P.O. Box 0645, MCV Station, Richmond, VA 23298-0645. Fax: (804) 371-7830. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume9, Issue3SMay 1994Pages 379-381 RelatedInformation