Objectives The study objective was to determine the impact of diabetes on radial artery and saphenous vein graft occlusion and clinical outcomes more than 5 years after coronary artery bypass surgery ...in the multicenter Radial Artery Patency Study (NCT00187356). Methods A total of 529 patients aged less than 80 years with triple-vessel disease undergoing coronary bypass surgery participated in this study. Angiographic follow-up occurred more than 5 years after surgery with annual clinical follow-up. The primary objective was to compare the proportion of complete graft occlusion between radial artery and saphenous vein grafts among diabetic and nondiabetic persons. Additional objectives included determining predictors of complete graft occlusion and comparison of major adverse cardiac events defined by cardiac death, late myocardial infarction, and reintervention. Results There were 148 of 529 patients (27.8%) with diabetes; 269 patients (83/269 30.9% diabetic) underwent late angiography at mean of 7.7 ± 1.5 years after surgery. In diabetic patients, the proportion of complete graft occlusion was significantly lower in the radial grafts (4/83 4.8%) than in the saphenous grafts (21/83 25.3%) ( P = .0004), and this was similar in nondiabetic patients ( P = .19). Multivariate modeling showed that the use of the radial artery and high-grade target vessel stenosis were protective against late graft occlusion, whereas female gender, smoking history, and elevated creatinine were associated with an increased risk; interaction between diabetic status and conduit type also was significant ( P = .02). Major adverse cardiac events were higher in diabetic patients (23/148 15.5% vs 35/381 9.2%, P = .04). Conclusions The use of the radial artery should be strongly considered in diabetic patients undergoing coronary bypass surgery, especially with high-grade target vessel stenosis.
Background Graft stenosis may be associated with future graft failure. The purpose of this investigation was to compare graft stenosis between radial artery (RA) grafts and saphenous vein grafts ...(SVGs) at least 5 years postoperatively using the multicenter Radial Artery Patency Study (RAPS) data. Methods Two hundred thirty-four patients underwent late invasive angiography after coronary artery bypass operations. The study population consists of 163 patients with thrombolysis in myocardial infarction (TIMI) 3 flow of both the RA graft and study SVGs. Angiograms were reviewed centrally and in a blinded fashion. Graft stenosis was recorded for the proximal anastomosis, graft body, and distal anastomosis; significant stenosis was defined as greater than or equal to 50%. Major adverse cardiac events (MACE) were reported in patients with and those without significant graft stenosis. Results There was no difference in significant graft stenosis of the patent RA grafts and SVGs (14 of 163 8.6% versus 19 of 163 11.7%) or in the proximal anastomosis (5 of 163 3.1% versus 5 of 163 3.1%), graft body (6 of 163 3.7% versus 13 of 163 8.0%), or distal anastomosis (4 of 163 2.5% versus 5 of 163 3.1%) considered separately. However, the overall burden of graft body disease was higher in SVGs ( p = 0.03). MACE was higher in patients with significant graft stenosis than in patients without stenosis (10 of 28 35.7% versus 7 of 135 5.2%; p < 0.0001). Conclusions There was no significant difference in the rates of significant stenosis of patent RA grafts and SVGs more than 5 years postoperatively. However, the burden of graft body stenosis was less in RA grafts compared with SVGs, suggesting that the RA grafts will continue to outperform the SVGs late after operation.
Background Increased cardiac troponin is observed after virtually every cardiac operation, indicating perioperative myocardial injury. The clinical significance of this elevation is controversial. ...This study aimed to correlate postoperative troponin levels with major adverse cardiac events (MACE). Methods The study included 1918 consecutive patients undergoing adult cardiac operations, including 1515 isolated coronary procedures, 229 valvular operations, and 174 combined coronary/valve procedures. Peak troponin T (normal value < 0.1 μg/L) was measured at less than 24 hours postoperatively. Excluded were 506 patients with a recent myocardial infarction (< 30-days of operation). The primary outcome was a composite of death, electrocardiogram-defined infarction, and low output syndrome (MACE). Results Mortality rates were 1.4%, 6.1%, and 7% in the coronary bypass, valve, and combined groups, respectively ( p < 0.001). The rates of MACE were 17%, 35%, and 44% ( p < 0.0001), and mean troponin T levels were 0.9 ± 1.5, 1.2 ± 2.9, and 1.3 ± 1.2 μg/L ( p < 0.001), in the coronary bypass, valve, and combined groups, respectively. All patients were divided into quintiles based on their peak postoperative troponin level (Q1, 0.0 to 0.39; Q2, 0.4 to 0.59; Q3, 0.6 to 0.79; Q4, 0.8 to 1.29; and Q5, > 1.3 μg/L). Adverse outcomes were similar and stable in the lower quintiles. A stepwise increase in adverse outcomes was observed in the higher quintiles. Receiver operating characteristic curve analysis revealed a troponin cutoff of 0.8 μg/L was the most discriminatory for MACE (area under the curve, 0.7). Multivariable analyses showed a troponin value of more than 0.8 μg/L was independently associated with MACE. Conclusions Moderate elevations in troponin are common after cardiac operations; troponin is a well-described predictor of outcomes. Troponin levels exceeding 0.8 μg/L are associated with increased MACE in patients without a history of preoperative myocardial infarction within 30 days of operation.
Introduction The popularity of surgical specialties is declining amongst Canadian medical students. Limited early exposure of students to surgery and minor involvement of surgeons in preclerkship ...education are barriers to creating interest in the field. Although many informal observerships and interest groups exist, there are no structured programs in Canada that offer preclerkship medical students a comprehensive exposure to surgery. Methods Twenty first-year medical students participated in the Surgical Exploration and Discovery (SEAD) Program. SEAD is a pilot project at the University of Toronto providing a unique combination of (1) observerships, (2) informal discussions on surgical careers, and (3) hands-on simulation workshops across all 7 direct-entry specialties within the Department of Surgery. All participants underwent pretraining and posttraining evaluation of learning through a paper-based knowledge test and all completed a structured survey on the benefit of the course. Results Comparison of test scores revealed an overall significant improvement in learning (p<0.0001). The improvement in test scores was seen in the knowledge of all 3 components of the course (p<0.0001). Qualitative evaluation revealed a positive student experience, with 100% of students indicating that SEAD helped them identify new interests in surgical subspecialties. Finally, 100% of students stated that they would recommend the program to incoming medical students. Conclusion The SEAD Program successfully improves preclerkship students' knowledge of surgical principles, understanding of a career in surgery, and basic surgical skills. Participation in the program also positively influenced their interest in pursuing a career in surgery. Programs such as SEAD may be offered to preclerkship medical students to improve their exposure to surgery at this level of training and to enhance perspectives toward surgical careers.
Objective This trial aimed to determine whether intraoperative graft assessment with criteria for graft revision would decrease the proportion of patients with 1 or more graft occlusions or stenoses ...or major adverse cardiac events 1 year after coronary artery bypass grafting. Methods A single-center, randomized, single-blinded, controlled clinical trial was designed. Patients were randomized to either of 2 groups: intraoperative graft patency assessment using indocyanine-green fluorescent angiography and transit-time flowmetry, with graft revision according to a priori criteria (imaging group), or standard intraoperative management (control group). Patients underwent follow-up angiography at 1 year. Results Between September 2005 and August 2008, 156 patients undergoing isolated coronary bypass grafting were enrolled (imaging, n = 78; control, n = 78). Demographic and angiographic characteristics were similar between groups. Operative, crossclamp, and cardiopulmonary bypass times were all nonsignificantly longer in the imaging arm. The number of grafts per patients was similar (imaging, 3.0 ± 0.7; control, 3.0 ± 0.7). The frequency of major adverse cardiac events (death, myocardial infarction, repeat revascularization) was not different between groups at 1 year postoperatively (imaging, 7.7%; control, 7.7%). One-year angiography was performed in 107 patients (imaging, 55 patients/160 grafts; control, 52 patients/152 grafts). The proportion of patients with 1 graft occlusion or more was comparable in the imaging (30.9%) and control (28.9%) groups (relative risk 95% confidence interval, 1.1 0.6–1.9; P = .82), as were other graft patency end points. The incidence of saphenous vein graft occlusion was high in both groups. Conclusions Routine intraoperative graft assessment is safe but does not lead to a marked reduction in graft occlusion 1-year after bypass grafting. The incidence of saphenous vein graft failure remains high despite contemporary practice and routine intraoperative graft surveillance.
Background Simulation-based programs allow trainees to be progressively challenged in a systematic, learner-centered and patient-focused fashion. The design of these programs requires an ...understanding of the individual steps that comprise the entire surgical procedure and our ability to assess the progress of the learner. We present the results of the design and validation of performance assessment checklists for a progressive simulation-based program in cardiac surgery. Methodology Using a case study design, we videotaped 10 off-pump coronary artery bypass procedures and applied a new methodological framework to deconstruct the procedure into teachable components for which 6 simulation scenarios were developed. Individual checklists were designed and validated using the Delphi technique. An expert panel of 11 cardiac surgeons rated each checklist item by using a 5-point Likert-type scale and provided comments on the rating choice. The consistency of the experts' ratings were interpreted as consensus achieved when 70% of experts rated 3.5 or greater on the 5-point Likert-type scale for each assessment item. Results An in vivo workflow diagram was developed, and 6 simulation modules with progressive difficulty were selected to design an off-pump coronary artery bypass simulation-based program. The corresponding 6 assessment checklists were designed and validated. After 2 Delphi rounds, the overall average score across all checklists was 4.0, and all items were greater 3.5. The final checklists comprise between 12 and 23 items. Conclusion We have demonstrated the feasibility of designing simulation-based program for complex operative procedures in a progressive fashion. The complexity at each level was given by the predefined training objectives and assessment checklists were designed and validated as content-specific assessment tools for each simulation scenario.
Abstract The goal of simulation-based medical education and training is to help trainees acquire and refine the technical and cognitive skills necessary to perform clinical procedures. When designers ...incorporate simulation into programs, their efforts should be in line with training needs, rather than technology. Designers of simulation-augmented surgical training programs, however, face particular problems related to identifying a framework that guides the curricular design activity to fulfill the particular requirements of such training programs. These problems include the lack of (1) an objective identification of training needs, (2) a systematic design methodology to match training objectives with simulation resources, (3) structured assessments of performance, and (4) a research-centered view to evaluate and validate systematically the educational effectiveness of the program. In this report, we present a process called “Aim – FineTune – FollowThrough” to enable the connection of the identified problems to solutions, using frameworks from psychology, motor learning, education and experimental design.
A 46-year-old man with polyarteritis nodosa and multiple myocardial infarctions treated with multiple percutaneous coronary interventions presented again with atypical angina. Coronary angiography ...revealed triple-vessel coronary artery disease. This patient underwent four-vessel coronary artery bypass graft and recovered uneventfully. A review of the literature and discussion of the surgical management of this patient is presented.
Objective The benefit of stentless valves remains in question. In 1999, a randomized trial comparing stentless and stented valves was unable to demonstrate any hemodynamic or clinical benefits at 1 ...year after implantation. This study reviews long-term outcomes of patients randomized in the aforementioned trial. Methods Between 1996 and 1999, 99 patients undergoing aortic valve replacement were randomized to receive either a stented Carpentier–Edwards pericardial valve (CE) (Edwards Lifesciences, Irvine, Calif) or a Toronto Stentless Porcine Valve (SPV) (St Jude Medical, Minneapolis, Minn). Among these, 38 patients were available for late echocardiographic follow-up (CE, n = 17; SPV, n = 21). Echocardiographic analysis was undertaken both at rest and with dobutamine stress, and functional status (Duke Activity Status Index) was compared at a mean of 9.3 years postoperatively (range, 7.5–11.1 years). Clinical follow-up was 82% complete at a mean of 10.3 years postoperatively (range, 7.5–12.2 years). Results Preoperative characteristics were similar between groups. Effective orifice areas increased in both groups over time. Although there were no differences in effective orifice areas at 1 year, at 9 years, effective orifice areas were significantly greater in the SPV group (CE, 1.49 ± 0.59 cm2 ; SPV, 2.00 ± 0.53 cm2 ; P = .011). Similarly, mean and peak gradients decreased in both groups over time; however, at 9 years, gradients were lower in the SPV group (mean: CE, 10.8 ± 3.8 mm Hg; SPV, 7.8 ± 4.8 mm Hg; P = .011; peak: CE, 20.4 ± 6.5 mm Hg; SPV, 14.6 ± 7.1 mm Hg; P = .022). Such differences were magnified with dobutamine stress (mean: CE, 22.7 ± 6.1 mm Hg; SPV, 15.3 ± 8.4 mm Hg; P = .008; peak: CE, 48.1 ± 11.8 mm Hg; SPV, 30.8 ± 17.7 mm Hg; P = .001). Ventricular mass regression occurred in both groups; however, no differences were demonstrated between groups either on echocardiographic, magnetic resonance imaging, or biochemical (plasma B-type brain natriuretic peptide) assessment ( P = .74). Similarly, Duke Activity Status Index scores of functional status improved in both groups over time; however, no differences were noted between groups (CE, 27.5 ± 19.1; SPV, 19.9 ± 12.0; P = .69). Freedom from reoperation at 12 years was 92% ± 5% in patients with CEs and 75% ± 5% in patients with SPVs ( P = .65). Freedom from valve-related morbidity at 12 years was 82% ± 7% in patients with CEs and 55% ± 7% in patients with SPVs ( P = .05). Finally, 12-year actuarial survival was 35% ± 7% in patients with CEs and 52% ± 7% in patients with SPVs ( P = .37). Conclusion Although offering improved hemodynamic outcomes, the SPV did not afford superior mass regression or improved clinical outcomes up to 12 years after implantation.
BackgroundCreatine kinase (CK) testing in the setting of suspected cardiac injury is commonly performed yet rarely provides clinical value beyond troponin testing. We sought to evaluate and reduce CK ...testing coupled with troponin testing by 50% or greater.MethodsWe performed root cause analysis to study prevailing processes and patterns of CK testing. We developed new institutional guidelines, removed CK from high-volume paper and electronic order bundles and conducted academic detailing for departments with highest ordering frequency. We evaluated consecutive patients at Sunnybrook Health Sciences Centre between 1 January 2018 and 31 March 2020 who had either a CK or troponin level measured. We prespecified successful implementation as a reduction of 50% in total CK orders and a decrease in the ratio of CK-to-troponin tests to one-third or less. We retained additional data beyond our study period to assess for sustained reductions in testing.ResultsTotal CK tests decreased over the study period from 3963 to 2111 per month, amounting to a 46.7% reduction (95% CI 33.2 to 60.2; p<0.001) equalling 61 fewer tests per hospital day. Troponin testing did not significantly change during the intervention. Ratio of CK-to-troponin tests decreased from 0.91 to 0.49 (p<0.001). The reduction coincided with changes to order-sets, was observed across all clinical units and was sustained during additional months beyond the study period. These reductions in testing resulted in a projected annual cost savings of C$28 446.ConclusionsWe demonstrate that a low-cost and feasible quality improvement initiative may lead to significant reduction in unnecessary CK testing and substantial savings in healthcare costs for patients with suspected cardiac injury.
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