Mackenzie Quantz

Monitoring brain oxygen saturation during coronary bypass surgery: a randomized, prospective study.

BACKGROUND:Cerebral deoxygenation is associated with various adverse systemic outcomes. We hypothesized, by using the brain as an index organ, that interventions to improve cerebral oxygenation would have systemic benefits in cardiac surgical patients. METHODS:Two-hundred coronary artery bypass patients were randomized to either intraoperative cerebral regional oxygen saturation (rSO2) monitoring with active display and treatment intervention protocol (intervention, n = 100), or underwent blinded rSO2 monitoring (control, n = 100). Predefined clinical outcomes were assessed by a blinded observer. RESULTS:Significantly more patients in the control group demonstrated prolonged cerebral desaturation (P = 0.014) and longer duration in the intensive care unit (P = 0.029) versus intervention patients. There was no difference in overall incidence of adverse complications, but significantly more control patients had major organ morbidity or mortality (death, ventilation >48 h, stroke, myocardial infarction, return for re-exploration) versus intervention group patients (P = 0.048). Patients experiencing major organ morbidity or mortality had lower baseline and mean rSO2, more cerebral desaturations and longer lengths of stay in the intensive care unit and postoperative hospitalization, than patients without such complications. There was a significant (r2 = 0.29) inverse correlation between intraoperative rSO2 and duration of postoperative hospitalization in patients requiring ≥10 days postoperative length of stay. CONCLUSION:Monitoring cerebral rSO2 in coronary artery bypass patients avoids profound cerebral desaturation and is associated with significantly fewer incidences of major organ dysfunction.

Does human leukocyte antigen matching influence the outcome of lung transplantation? an analysis of 3,549 lung transplantations

BACKGROUND AND OBJECTIVE Human leukocyte antigen (HLA) compatibility has been shown to improve the outcome of renal and cardiac transplantation. However, its impact on outcome following lung transplantation is not clear, with several single-center studies reporting inconsistent results. We studied the influence of HLA matching on survival and the development of rejection and obliterative bronchiolitis after lung transplantation, using data from the United Network for Organ Sharing/International Society for Heart and Lung Transplantation registry. METHODS The study population included adult patients who received cadaveric lung transplants between October 1987 and June 1997 for whom HLA data were available. Two cohorts were examined, depending on the era of transplantation: (1) October 1987 to June 1997 (n = 3,549): Differences in actuarial survival as stratified by either the total number of HLA mismatches or the number of mismatches at each HLA locus were determined using a log-rank test. Multivariate logistic regression models were developed to determine independent predictors of survival at 1, 3, and 5 years following lung transplantation. (2) April 1994 to June 1997 (n = 1,796): The association of HLA mismatching with acute rejection and obliterative bronchiolitis was determined using a chi-squared analysis. RESULTS Only 164 patients (4.6%) received lung grafts with 2 or fewer HLA mismatches. Univariate analyses demonstrated a significant difference in post-transplant survival by mismatch level, with the total number of HLA mismatches (p = 0.0008) and mismatching at the HLA-A locus (p = 0.002) associated with worse survival. Multivariate logistic regression demonstrated that the number of mismatches at the HLA-A and HLA-DR loci predicted 1-year mortality (incremental odds ratios 1.18, p = 0.01, and 1.15, p = 0. 03, respectively). The total number of HLA mismatches predicted 3- and 5-year mortality (incremental odds ratios 1.13 at 3 years, p = 0. 0004, and 1.14 at 5 years, p = 0.0002). However, other covariates such as repeat transplantation, transplantation for congenital heart disease, advanced recipient age, and an early era of transplantation were stronger predictors of mortality. We found no significant association between HLA mismatching and the development of obliterative bronchiolitis, although there was an association between mismatching at the HLA-A locus and acute rejection episodes requiring hospital admission (p = 0.008). We also found no association between mismatching at the HLA-B locus and rejection episodes requiring either hospitalization or the alteration of anti-rejection medications (p = 0.034). CONCLUSION Although the number of HLA mismatches at the HLA-A and HLA-DR loci predicted 1-year mortality and the total number of mismatches predicted 3- and 5-year mortality following lung transplantation, the effect of each covariate was small in this multicenter study of 3,549 patients. Further close follow-up of registry patients is necessary to determine the effect of HLA matching on long-term survival and freedom from obliterative bronchiolitis and rejection following lung transplantation. A prospective study of HLA matching for lung transplantation should not yet be considered in view of the small number of grafts with 2 or fewer mismatches and the modest effect of HLA matching on outcome.

Laser lead extraction: is there a learning curve?

Laser extraction of device leads offers an attractive alternative to countertraction and electrosurgical dissection sheath, potentially increasing efficacy and reducing complications. Wider adoption of this technology depends on relative ease of use. We report the experience of a new center to define the “learning curve.” We performed 76 laser lead extractions in 75 patients (age 63 ± 17 years, 59 male) from July 2001 to January 2004. Two experienced device implanters who were novice extractors underwent a 2‐day site visit to a high volume extraction center for training. Lead extractions were performed in the operating room with immediate surgical backup. The indication for extraction was infection in 39 (systemic in 15), erosion or pain in 11, and lead related or debulking in 25. Complete removal was achieved in 139 of 145 leads (14 ICD, 131 pacemaker). Partial removal (<4 cm retained) was achieved in five leads (4%), and one lead could not be extracted. Complete success was 95% in the first third of patients, 94% in the second third, and 100% in the latter third. Fluoroscopy time fell from 19 ± 22 minute in the first third of patients to 11 ± 8 minute in the second third to 8 ± 4 minute in the latter third (ANOVA P = 0.02). No major complications occurred. Local bleeding required minor left subclavian vein repair in two individuals. Symptomatic venous thrombosis occurred in 3 of the first 11 cases 1–21 days after extraction, but did not occur in the next 64 consecutive patients who received a 1‐month anticoagulation regimen (27% vs 0%, P < 0.001). One patient developed venous thrombosis 3 weeks following cessation of warfarin therapy. Practice guidelines reasonably recommend appropriate training prior to independent performance of lead extraction. The current study suggests that experienced device implanters with appropriate operative backup taking a limited, but intensive training program can be safe and effective at lead extraction in a short time, in part a reflection of the improved technology.

Effect of off-pump coronary artery bypass grafting on risk-adjusted and cumulative sum failure outcomes after coronary artery surgery.

Abstract Background and Aim: We have shown that cumulative sum (CUSUM) failure analysis may be more sensitive than standard statistical methods in detecting a cluster of adverse patient outcomes after cardiac surgical procedures. We therefore applied CUSUM, as well as standard statistical techniques, to analyze a surgeons experience with off‐pump coronary artery bypass grafting (OPCAB) and on‐pump procedures to determine whether the two techniques have similar or different outcomes. Methods: In 320 patients undergoing nonemergent, first time coronary artery bypass grafting, preoperative patient characteristics, rates of mortality and major complications, and ICU and hospital lengths of stay were compared between the on‐pump and OPCAB cohorts using Fishers exact tests and Wilcoxon two sample tests. Predicted mortality and length of stay were determined using previously validated models of the Cardiac Care Network of Ontario. Observed versus expected ratios of both variables were calculated for the two types of procedures. Furthermore, CUSUM curves were constructed for the on‐pump and OPCAB cohorts. A multivariable analysis of the predictors of hospital length of stay was also performed to determine whether the type of coronary artery bypass procedure had an independent impact on this variable. Results: The predicted mortality risk and predicted hospital length of stay were almost identical in the 208 on‐pump patients ( 2.2 ± 3.9% ; 8.2 ± 2.5 days) and the 112 OPCAB patients ( 2.0 ± 2.2% ; 7.8 ± 2.1 days). The incidence of hospital mortality and postoperative stroke were 2.9% and 2.4% in on‐pump patients versus zero in OPCAB patients (p= 0.09 and 0.17, respectively). Mechanical ventilation for greater than 48 hours was significantly less common in OPCAB (1.8%) than in on‐pump patients (7.7%, p= 0.04). The rate of 10 major complications was 14.9% in on‐pump versus 8.0% in OPCAB patients (p= 0.08). OPCAB patients experienced a hospital length of stay that was a median of 1.0 day shorter than on‐pump patients (p= 0.01). The observed versus expected ratio for length of stay was 0.78 in OPCAB patients versus 0.95 in on‐pump patients. On CUSUM analysis, the failure curve in OPCAB patients was negative and was flatter than that of on‐pump patients throughout the duration of the study. Furthermore, OPCAB was an independent predictor of a reduced hospital length of stay on multivariable analysis. Conclusions: OPCAB was associated with better outcomes than on‐pump coronary artery bypass despite a similar predicted risk. This robust finding was documented on sensitive CUSUM analysis, using standard statistical techniques and on a multivariable analysis of the independent predictors of hospital length of stay.(J Card Surg 2002;17:520‐528)

Monitoring brain oxygen saturation during coronary bypass surgery improves outcomes in diabetic patients: a post hoc analysis.

BACKGROUND Having previously demonstrated in a prospective study of 200 coronary artery bypass (CAB) patients that by using the brain as an index organ, interventions to improve cerebral oxygenation would have systemic outcome benefits, we undertook a post hoc analysis of the diabetic subset (n = 57) of the overall study group to determine whether the outcomes of these patients were similarly improved. METHODS Case-report forms for the 200 CAB patients study patients with a preoperative diagnosis of diabetes mellitus were stratified to intraoperative cerebral regional oxygen saturation (rSO2) monitoring with active display and a treatment intervention protocol (intervention group, n = 28) or to blinded rSO2 monitoring (control group, n = 29) and analyzed. RESULTS There were no significant differences between the 2 groups in overall risk factors, although there were trends toward a higher body mass index, a worse angina score, a worse grade of ventricle, and greater use of off-pump coronary revascularization in the control group of patients. The 2 groups were similar with respect to overall insulin dosage and perioperative blood glucose concentrations. Significantly more diabetic patients in the control group demonstrated profound cerebral desaturation, with an area under the curve of <50%/min (P = .043; d = 0.55), longer intensive care unit (ICU) stays (P = .045; d = 0.58), and longer overall postoperative hospital stays (P = .036; d = 0.47), compared with patients in the intervention group. Compared with the intervention group, the control group had a significantly higher incidence of sternal wound infection (P = .028; φ = 0.31) and a significantly greater number of diabetic patients with >2 postoperative complications (P = .006; φ = 0.37). An analysis after removing the patients who underwent off-pump surgery revealed that the control group had significantly more patients with sternal wound infections (5 versus 0; P = .047) and ≥2 postoperative complications (6 versus 0; P = .008) than the intervention group, as well as a trend toward longer ICU and postoperative hospitalization stays in the control group. CONCLUSION Monitoring and management of cerebral rSO2 in diabetic CAB patients avoid profound cerebral desaturation and are associated with significantly lower incidences of complications and shorter postoperative lengths of stay. IMPLICATION STATEMENT A post hoc analysis of the diabetic cohort of a prospective, randomized, and blinded study of CAB patients revealed that those in whom cerebral oxygen saturation was actively monitored and maintained demonstrated significantly lower incidences of complications, resulting in shorter ICU and postoperative hospital stays compared with an unmonitored control group.

Methylprednisolone does not reduce persistent pain after cardiac surgery

Background:Persistent incisional pain is common after cardiac surgery and is believed to be in part related to inflammation and poorly controlled acute pain. Methylprednisolone is a corticosteroid with substantial antiinflammatory and analgesic properties and is thus likely to ameliorate persistent surgical pain. Therefore, the authors tested the primary hypothesis that patients randomized to methylprednisolone have less persistent incisional pain than those given placebo. Methods:One thousand forty-three patients having cardiopulmonary bypass for cardiac surgery via a median sternotomy were included in this substudy of Steroids in Cardiac Surgery (SIRS) trial. Patients were randomized to 500 mg intraoperative methylprednisolone or placebo. Incisional pain was assessed at 30 days and 6 months after surgery, and the potential risk factors were also evaluated. Results:Methylprednisolone administration did not reduce pain at 30 days or persistent incisional pain at 6 months, which occurred in 78 of 520 patients (15.7%) in the methylprednisolone group and in 88 of 523 patients (17.8%) in the placebo group. The odds ratio for methylprednisolone was 0.93 (95% CI, 0.79 to 1.09, P = 0.37). Furthermore, there was no difference in worst pain and average pain in the last 24 h, pain interference with daily life, or use of pain medicine at 6 months. Younger age, female sex, and surgical infections were associated with the development of persistent incisional pain. Conclusions:Intraoperative methylprednisolone administration does not reduce persistent incisional pain at 6 months in patients recovering from cardiac surgery.

Postoperative atrial fibrillation is not pulmonary vein dependent: Results from a randomized trial

BACKGROUND Although often short-lived and self-limiting, postoperative atrial fibrillation (POAF) is a well-recognized postoperative complication of cardiac surgery and is associated with a 2-fold increase in cardiovascular mortality and morbidity. OBJECTIVE Our aim was to determine whether intraoperative bilateral pulmonary vein radiofrequency ablation decreases the incidence of POAF in patients undergoing coronary artery bypass grafting (CABG). METHODS A total of 175 patients undergoing CABG was prospectively randomized to undergo adjuvant bilateral radiofrequency pulmonary vein ablation in addition to CABG (group A; n = 89) or CABG alone (group B; n = 86). Intraoperative pulmonary vein isolation was confirmed by the inability to pace the heart via the pulmonary veins after ablation. All patients received postoperative β-blocker. RESULTS There was no difference in the incidence of POAF in the treatment group who underwent adjuvant pulmonary vein ablation (group A; 37.1%) compared with the control group who did not (group B; 36.1%) (P = .887). There were no differences in postoperative inotropic support, antiarrhythmic drug use, need for oral anticoagulation, and complication rates. The mean length of postoperative hospital stay was 8.2 ± 6.5 days in the ablation group and 6.7 ± 4.6 days in the control group (P < .001). CONCLUSION Adjuvant pulmonary vein isolation does not decrease the incidence of POAF or its clinical impact but increases the mean length of stay in the hospital. The mechanism of POAF does not appear to depend on the pulmonary veins.

Early and late outcomes after cardiac retransplantation.

BACKGROUND Cardiac retransplantation remains the most viable option for patients with allograft heart failure; however, careful patient selection is paramount considering limited allograft resources. We analyzed clinical outcomes following retransplantation in an academic, tertiary care institution. METHODS Between 1981 and 2011, 593 heart transplantations, including 22 retransplantations were performed at our institution. We analyzed the preoperative demographic characteristics, cause of allograft loss, short- and long-term surgical outcomes and cause of death among patients who had cardiac retransplantations. RESULTS Twenty-two patients underwent retransplantation: 10 for graft vascular disease, 7 for acute rejection and 5 for primary graft failure. Mean age at retransplantation was 43 (standard deviation [SD] 15) years; 6 patients were women. Thirteen patients were critically ill preoperatively, requiring inotropes and/or mechanical support. The median interval between primary and retransplantation was 2.2 (range 0-16) years. Thirty-day mortality was 31.8%, and conditional (> 30 d) 1-, 5- and 10-year survival after retransplantation were 93%, 79% and 59%, respectively. A diagnosis of allograft vasculopathy (p = 0.008) and an interval between primary and retransplantation greater than 1 year (p = 0.016) had a significantly favourable impact on 30-day mortality. The median and mean survival after retransplantation were 3.3 and 5 (SD 6, range 0-18) years, respectively; graft vascular disease and multiorgan failure were the most common causes of death. CONCLUSION Long-term outcomes for primary and retransplantation are similar if patients survive the 30-day postoperative period. Retransplantation within 1 year of the primary transplantation resulted in a high perioperative mortality and thus may be a contraindication to retransplantation.

Predictors of general surgical complications after heart transplantation

BACKGROUND Several studies have reported the incidence, morbidity, and mortality of general surgical conditions (GSCs) in orthotopic heart transplant (OHT) patients. The following is the largest reported series of such patients and the first study with sufficient patient numbers to formally evaluate peritransplant variables as risk factors for GSC development. STUDY DESIGN A GSC was defined as a condition for which a general surgeon had been consulted or as a general surgical condition recognized at the time of autopsy. The records of 453 consecutive patients who underwent OHT between 1981 and 1999 were reviewed to identify patients who developed a GSC. Kaplan-Meier actuarial analysis on this cohort, and univariate and multivariate logistic regression models applied to a subpopulation of 324 consecutive OHT patients between 1987 and 1997 were used to determine factors associated with and predictive of GSC after OHT. RESULTS Of 453 OHT patients, 371 (81.9%) were men, and the average age was 44.5 +/- 15 (standard deviation) years. Median followup was 2,086 days (range 1 to 6,642 days). Ninety-three patients (20.5%) developed 111 GSCs. Of these, 78 were men, and the average age was 49.9+/-10.2 years. There were 83 general surgical interventions. Actuarial analyses revealed that age greater than 50 years, pretransplant diagnosis of ischemic (PTDxI) versus nonischemic heart disease, and previous general surgical history were factors associated (p < 0.05) with a higher GSC incidence. Gender, more urgent transplant priority status, cardiopulmonary bypass time, total graft ischemic time, and intensive care unit length of stay were not associated with GSC. Factors associated with GSC on univariate analysis, with odds ratios (ORs) and 95% confidence intervals (CIs) included: age analyzed as a continuous variable (OR 1.04 per year; CI 1.01, 1.06 per year; p = 0.0021), PTDxI (OR 2.40; CI 1.39, 4.15; p = 0.0016), and pretransplant general surgical history (OR 3.35; CI 1.65, 6.82; p = 0.0008). Multivariate analysis revealed that only pretransplant general surgical history (OR 3.27; CI 1.58, 6.76; p = 0.0004) and PTDxI (OR 2.37; CI 1.35, 4.16; p = 0.0023) were associated with subsequent development of GSC. CONCLUSIONS A pretransplant diagnosis of ischemic heart disease and previous history of a general surgical procedure are two independent risk factors that predispose OHT patients to development of GSC. Because GSC may arise insidiously in immunosuppressed patients, identification of OHT patients at higher risk for GSC will permit timely intervention decisions, decreasing morbidity and mortality in this challenging group of patients.

Steroids In caRdiac Surgery (SIRS) trial: acute kidney injury substudy protocol of an international randomised controlled trial

Introduction Steroids In caRdiac Surgery trial (SIRS) is a large international randomised controlled trial of methylprednisolone or placebo in patients undergoing cardiac surgery with the use of a cardiopulmonary bypass pump. At the time of surgery, compared with placebo, methylprednisolone divided into two intravenous doses of 250 mg each may reduce the risk of postoperative acute kidney injury (AKI). Methods and analysis With respect to the study schedule, over 7000 substudy eligible patients from 81 centres in 18 countries were randomised in December 2013. The authors will use a logistic regression to estimate the adjusted OR of methylprednisolone versus placebo on the primary outcome of AKI in the 14 days following surgery (a postoperative increase in serum creatinine of ≥50%, or ≥26.5 μmol/L, from the preoperative value). The stage of AKI will also be considered, as will the outcome of AKI in those with and without preoperative chronic kidney disease. After receipt of grant funding, the authors began to record additional perioperative serum creatinine measurements in consecutive patients enrolled at substudy participating centres, and patients were invited to enroll in a 6-month serum creatinine collection. In these trial subpopulations, the authors will consider the outcome of AKI defined in alternate ways, and the outcome of a 6-month change in kidney function from the preoperative value. Ethics and dissemination The authors were competitively awarded a grant from the Canadian Institutes of Health Research for this SIRS AKI substudy. Ethics approval was obtained for additional serum creatinine recordings in consecutive patients enrolled at participating centres. The additional kidney data collection first began for patients enrolled after 1 March 2012. In patients who provided consent, the last 6-month kidney outcome data will be collected in 2014. The results will be reported no later than 2015. Clinical Trial Registration Number NCT00427388.