Multidrug-Resistant Organism Infections in Patients with Left Ventricular Assist Devices

Left ventricular assist devices improve survival prospects in patients with end-stage heart failure; however, infection complicates up to 59% of implantation cases. How many of these infections are caused by multidrug-resistant organisms is unknown. We sought to identify the incidence, risk factors, and outcomes of multidrug-resistant organism infection in patients who have left ventricular assist devices. We retrospectively evaluated the incidence of multidrug-resistant organisms and the independent risk factors associated with them in 57 patients who had permanent left ventricular assist devices implanted at our institution from May 2007 through October 2011. Outcomes included death, transplantation, device explantation, number of subsequent hospital admissions, and number of subsequent admissions related to infection. Infections were categorized in accordance with criteria from the Infectious Diseases Council of the International Society for Heart and Lung Transplantation. Multidrug-resistant organism infections developed in 18 of 57 patients (31.6%)-a high incidence. We found 3 independent risk factors: therapeutic goal (destination therapy vs bridging), P=0.01; body mass index, P=0.04; and exposed velour at driveline exit sites, P=0.004. We found no significant differences in mortality, transplantation, or device explantation rates; however, there was a statistically significant increase in postimplantation hospital admissions in patients with multidrug-resistant organism infection. To our knowledge, this is the first report in the medical literature concerning multidrug-resistant organism infection in patients who have permanent left ventricular assist devices.

Prospective Evaluation of Weight-Based Prophylactic Enoxaparin Dosing in Critically Ill Trauma Patients: Adequacy of AntiXa Levels Is Improved

Venous thromboembolism (VTE) is a leading cause of death in multisystem trauma patients; the importance of VTE prevention is well recognized. Presently, standard dose enoxaparin (30 mg BID) is used as chemical prophylaxis, regardless of weight or physiologic status. However, evidence suggests decreased bioavailability of enoxaparin in critically ill patients. Therefore, we hypothesized that a weight-based enoxaparin dosing regimen would provide more adequate prophylaxis (as indicated by antifactor Xa levels) for patients in our trauma intensive care unit (TICU).These data were prospectively collected in TICU patients admitted over a 5-month period given twice daily 0.6 mg/kg enoxaparin (actual body weight). Patients were compared with a historical cohort receiving standard dosing. Anti-Xa levels were collected at 11.5 hours (trough, goal ≥ 0.1 IU/mL) after each evening administration. Patient demographics, admission weight, dose, and daily anti-Xa levels were recorded. Patients with renal insufficiency or brain, spine, or spinal cord injury were excluded. Data were collected from 26 patients in the standard-dose group and 37 in the weight-based group. Sixty-four trough anti-Xa measurements were taken in the standard dose group and 74 collected in the weight-based group. Evaluating only levels measured after the third dose, the change in dosing of enoxaparin from 30 to 0.6 mg/kg resulted in an increased percentage of patients with goal antifactor Xa levels from 8 per cent to 61 per cent (P < 0.0001). Examining all troughs, the change in dose resulted in an increase in patients with a goal anti-Xa level from 19 to 59 per cent (P < 0.0001). Weight-based dosing of enoxaparin in trauma ICU patients yields superior results with respect to adequate anti-Xa levels when compared with standard dosing. These findings suggest that weight-based dosing may provide superior VTE prophylaxis in TICU patients. Evaluation of the effects of this dosing paradigm on actual VTE rate is ongoing at our institution.

Prospective Evaluation of Weight-Based Prophylactic Enoxaparin Dosing in Critically Ill Trauma Patients: Adequacy of AntiXa Levels is Improved

Venous thromboembolism (VTE) is a leading cause of death in multisystem trauma patients; the importance of VTE prevention is well recognized. Presently, standard dose enoxaparin (30 mg BID) is used as chemical prophylaxis, regardless of weight or physiologic status. However, evidence suggests decreased bioavailability of enoxaparin in critically ill patients. Therefore, we hypothesized that a weight-based enoxaparin dosing regimen would provide more adequate prophylaxis (as indicated by antifactor Xa levels) for patients in our trauma intensive care unit (TICU).These data were prospectively collected in TICU patients admitted over a 5-month period given twice daily 0.6 mg/kg enoxaparin (actual body weight). Patients were compared with a historical cohort receiving standard dosing. Anti-Xa levels were collected at 11.5 hours (trough, goal ≥0.1 IU/mL) after each evening administration. Patient demographics, admission weight, dose, and daily anti-Xa levels were recorded. Patients with renal insufficiency or brain, spine, or spinal cord injury were excluded. Data were collected from 26 patients in the standard-dose group and 37 in the weight-based group. Sixty-four trough anti-Xa measurements were taken in the standard dose group and 74 collected in the weight-based group. Evaluating only levels measured after the third dose, the change in dosing of enoxaparin from 30 to 0.6 mg/kg resulted in an increased percentage of patients with goal antifactor Xa levels from 8 per cent to 61 per cent ( P < 0.0001). Examining all troughs, the change in dose resulted in an increase in patients with a goal anti-Xa level from 19 to 59 per cent ( P < 0.0001). Weight-based dosing of enoxaparin in trauma ICU patients yields superior results with respect to adequate anti-Xa levels when compared with standard dosing. These findings suggest that weight-based dosing may provide superior VTE prophylaxis in TICU patients. Evaluation of the effects of this dosing paradigm on actual VTE rate is ongoing at our institution.

Avoiding aortic clamping during coronary artery bypass grafting reduces postoperative stroke

OBJECTIVE

The purpose of this study was to determine whether the incidence of postoperative stroke could be reduced by eliminating aortic clamping during coronary artery bypass grafting.

METHODS

From 2002 to 2013, 12,079 patients underwent primary, isolated coronary artery bypass grafting at a single US academic institution. Aortic manipulation was completely avoided by using in situ internal thoracic arteries for inflow in 1552 patients (12.9%) (no-touch), a clampless facilitating device for proximal anastomoses in 1548 patients (12.8%), and aortic clamping in 8979 patients (74.3%). These strategies were assessed in a logistic regression model controlling for relevant variables.

RESULTS

The overall incidence of postoperative stroke was 1.4% (n = 165), with an unadjusted incidence of 0.6% (n = 10) in the no-touch group, 1.2% (n = 18) in the clampless facilitating device group, and 1.5% (n = 137) in the clamp group (P < .01 for no-touch vs clamp). The ratio of observed to expected stroke rate increased as the degree of aortic manipulation increased, from 0.48 in the no-touch group, to 0.61 in the clampless facilitating device group, and to 0.95 in the clamp group. Aortic clamping was independently associated with an increase in postoperative stroke compared with a no-touch technique (adjusted odds ratio, 2.50; P < .01). When separated by cardiopulmonary bypass use, both the off-pump partial clamp and the on-pump crossclamp techniques increased the risk of postoperative stroke compared with no-touch (adjusted odds ratio, 2.52, P < .01; and adjusted odds ratio, 4.25, P < .001, respectively).

CONCLUSIONS

A no-aortic touch technique has the lowest risk for postoperative stroke for patients undergoing coronary artery bypass grafting. Clamping the aorta during coronary artery bypass grafting increases the risk of postoperative stroke, regardless of the severity of aortic disease.

The impact of clopidogrel therapy on postoperative bleeding after robotic-assisted coronary artery bypass surgery

OBJECTIVES

The purpose of this study was to determine whether patients undergoing robotic-assisted coronary artery bypass graft surgery (CABG) on clopidogrel had an increased risk of bleeding complications compared with those not on clopidogrel.

METHODS

From 2008 to 2011, 322 patients underwent robotic-assisted CABG either as an isolated procedure or as part of a hybrid coronary revascularization procedure (HCR). Patients were classified according to whether they received clopidogrel within 5 days of surgery or intraoperatively (n = 64) compared with those who never received or who had discontinued clopidogrel therapy >5 days before surgery (n = 258). A propensity analysis using 31 preoperative variables was used to control for confounding variables. In a subgroup analysis, patients undergoing one-stage HCR (clopidogrel load 600 mg in odds ratio (OR) prior to stenting) were compared with patients in the clopidogrel group who underwent two-stage HCR.

RESULTS

In the Clopidogrel group, the mean interval between surgery and last dose of clopidogrel was 2.1 ± 1.5 days. Compared with the No Clopidogrel group, the Clopidogrel group had greater 24-h chest tube drainage (1003 ± 572 vs 782 ± 530 ml, P = 0.004) and more blood transfusions (35.9%, 23 of 64 patients vs 20.9%, 54 of 258 patients, P = 0.01). On logistic regression analysis, there was greater 24-h chest tube drainage in the Clopidogrel group (+198 ml, P = 0.02) and a significantly higher incidence of blood transfusion (OR = 2.30, P = 0.01). In the subgroup analysis, patients undergoing one-stage HCR (n = 17) had greater 24-h chest tube drainage compared with patients undergoing two-stage HCR (1262 vs 909 ml, P = 0.03).

CONCLUSIONS

Patients undergoing robotic-assisted CABG on clopidogrel had more postoperative bleeding and a higher incidence of blood transfusion. Therefore, despite a less invasive approach, surgery should be delayed in these patients when possible.

Postoperative warfarin following mitral valve repair or bioprosthetic valve replacement

BACKGROUND AND AIM OF THE STUDY

Short-term postoperative warfarin therapy has been used to decrease neurologic events following mitral valve repair or bioprosthetic replacement (MVR). The study aim was to compare the short- and long-term outcomes of patients undergoing mitral valve surgery with or without short-term postoperative warfarin.

METHODS

A single academic US institution retrospective review was performed on discharged patients who underwent MVR between January 1996 and March 2010. Patients were allocated to two groups: MVR with four to six weeks of postoperative warfarin (n = 315; Warfarin group) or MVR without postoperative warfarin (n = 257; No warfarin group). Patients who required either preoperative or postoperative warfarin for any disease process (e.g., atrial fibrillation, mechanical valve, deep venous thrombosis) were excluded. Logistic and Cox proportional hazards regression models were constructed to evaluate the effects of warfarin on short- and long-term outcomes, respectively. Adjusted odds ratios (AOR) and adjusted hazard ratios (AHR), with 95% confidence intervals (CI) were constructed for each outcome. To reduce selection bias, propensity scoring methods were employed to balance the groups with respect to 54 preoperative variables.

RESULTS

Mean age was not significantly different between groups (No warfarin group = 56.8 +/- 14.5 years versus Warfarin group 55.9 +/- 12.9 years; p = 0.46). The average length of hospital stay was 9.8 +/- 8.4 days and 7.3 +/- 4.5 days in the No warfarin and Warfarin groups, respectively (p < 0.001). At the six-week follow up the incidences of stroke (p = 0.74), pleural effusions (p = 0.88), pericardial effusions (p = 0.75), and bleeding complications (p = 0.30) were similar between the two groups. In an unadjusted Kaplan-Meier analysis, the No warfarin group had a poorer long-term survival than the Warfarin group (p < 0.001). However, after propensity adjustment, the benefit of warfarin was not statistically significant (AHR = 0.66, 95% CI 0.40-1.08, p = 0.098).

CONCLUSION

The use of postoperative warfarin following MVR does not reduce the incidence of stroke at early follow up. However, there remains a trend for improved long-term outcomes in those patients receiving postoperative warfarin therapy.

Use of transaortic, transapical, and transcarotid transcatheter aortic valve replacement in inoperable patients

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is an effective treatment in patients with severe aortic stenosis unsuitable for surgical aortic valve replacement (SAVR). This study evaluated the early experience with the posttrial application of TAVR, with specific focus on non-transfemoral (TF) access.

METHODS

All patients who underwent posttrial TAVR at Emory University from November 2011 to April 2012 were reviewed. During this time, 44 posttrial TAVRs were performed: TF in 18, transapical in 11, transaortic in 12, and transcarotid in 3.

RESULTS

A total of 40.9% of all patients were candidates for TF implantation. Mean age was 78.2 ± 11.3 years, and 34.1% were women. Mean ejection fraction was 0.463 ± 0.164, and 90.2% had New York Heart Association class III to IV heart failure. Fifty percent were diabetic, 27.3% had moderate to severe chronic obstructive pulmonary disease, and 20.5% had a prior stroke. The mean creatinine was 1.63 ± 1.74 mg/dL, 9.1% required preoperative dialysis, and 61.4% had undergone prior cardiac operations. No patients had postoperative myocardial infarction, stroke, or required new dialysis. Intraoperative vascular complications occurred in 11.4%. No patient had more than mild perivalvular leak by transthoracic echocardiography at discharge. Mean postoperative ventilator time was 17.8 ± 40.1 hours. Intensive care unit length of stay was 58.0 ± 67.0 hours. Postoperative hospital length of stay was 6.1 ± 4.7 days. The 30-day mortality was 6.8% (3 of 44) for all patients, despite a mean The Society of Thoracic Surgeons Predicted Risk of Mortality score of 12.6.

CONCLUSIONS

Less than half of patients deemed appropriate for posttrial TAVR were candidates for TF implantation. The use of all available access routes leads to excellent outcomes in patients deemed inoperable.

Trends in aortic clamp use during coronary artery bypass surgery: effect of aortic clamping strategies on neurologic outcomes

OBJECTIVE

The purpose of the present study was to determine the effect of different clamping strategies during coronary artery bypass grafting on the incidence of postoperative stroke.

METHODS

In the present case-control study, all patients at Emory hospitals from 2002 to 2009 with postoperative stroke after isolated coronary artery bypass grafting (n = 141) were matched 1:4 to a contemporaneous cohort of patients without postoperative stroke (n = 565). The patients were matched according to the Society of Thoracic Surgeons' predicted risk of postoperative stroke score, which is based on 26 variables. The patients who received on-pump and off-pump coronary artery bypass grafting were matched separately. Multiple logistic regression analysis with adjusted odds ratios was performed to identify the operative variables associated with postoperative stroke.

RESULTS

Among the on-pump cohort, the single crossclamp technique was associated with a decreased risk of stroke compared with the double clamp (crossclamp plus partial clamp) technique (odds ratio, 0.385; P = .044). Within the on-pump cohort, no significant difference was seen in the incidence of stroke according to clamp use. Epiaortic ultrasound of the ascending aorta increased from 45.3% in 2002 to 89.4% in 2009. From 2002 to 2009, clamp use decreased from 97.7% of cases to 72.7%.

CONCLUSIONS

During on-pump coronary artery bypass grafting, the use of a single crossclamp compared with the double clamp technique decreased the risk of postoperative stroke. The use of any aortic clamp decreased and epiaortic ultrasound use increased from 2002 to 2009, indicating a change in the operative technique and surgeon awareness of the potential complications associated with manipulation of the aorta.

Avoiding the clamp during off-pump coronary artery bypass reduces cerebral embolic events: results of a prospective randomized trial

The purpose of this study was to determine whether a clampless facilitating device (CFD) to perform proximal aortocoronary anastomoses would result in a lower incidence of cerebral embolic events compared with a partial clamping strategy during off-pump coronary artery bypass (OPCAB). After epiaortic ultrasound confirmed the mild aortic disease (Grades I and II), 57 patients were randomly assigned to have proximal anastomoses using a partial-occluding clamp (CL, n = 28) or a CFD [Heartstring (HS), n = 29] (Maquet Cardiovascular LLC, San Jose, CA). Solid and gaseous emboli in the middle cerebral arteries were detected using transcranial Doppler ultrasonography. The mean number of proximal anastomoses was similar between groups 1.93 ± 0.72 (CL) and 1.72 ± 0.70 (HS) (P = 0.28). The mean number of gaseous plus solid emboli was greater in the CL group than the HS group (90.0 ± 64.0 vs. 50.8 ± 36.6, P = 0.01). Emboli were fewest in patients undergoing HS anastomoses using the suction device. The number of intraoperative cerebral emboli was proportional to the number of proximal anastomoses in the HS groups, but independent of the number of proximal anastomoses in the CL groups. Among patients with a low burden of aortic atherosclerosis, partial clamping of the ascending aorta during OPCAB was associated with more cerebral embolic events compared with an anastomosis with a CFD.

A novel technology to screen for cognitive impairment in the elderly

BACKGROUND

Traditional evaluation of mild cognitive impairment (MCI) can be costly, time consuming, and impractical for widespread screening. DETECT is a portable device developed to rapidly perform cognitive testing in diverse settings. This study compares DETECT with formal clinical assessment.

METHODS

A prospective cross-sectional comparison of the DETECT device versus an expert neuropsychologist's assessment (NPA). A total of 405 participants ≥65 years old, recruited from geriatric clinics and retirement facilities, completed both DETECT and NPA. Multivariable logistic regression methods were used to evaluate the degree of correlation between DETECT testing and the NPA diagnosis.

RESULTS

Predictive modeling demonstrated very good ability to discriminate between normal, MCI, and dementia per the NPA reference standard using DETECT subtests (c = 0.85 for any impairment; c = 0.99 for dementia).

CONCLUSION

DETECT scores closely correlate with NPA. DETECT can identify and discriminate between normal, MCI, and dementia and could be incorporated as a screener for MCI.

Impact of preoperative renal dysfunction in patients undergoing off-pump versus on-pump coronary artery bypass

BACKGROUND

The impact of the degree of renal dysfunction (RD) in patients undergoing coronary artery bypass grafting (CABG) ranging from normal to dialysis-dependence is not well defined.

METHODS

A retrospective review of 14,199 patients undergoing isolated, primary CABG from January 1996 to May 2009 at Emory Healthcare was performed. The estimated glomerular filtration rate (eGFR) was estimated by the Modification of Diet in Renal Disease formula: mild RD (eGFR 60 to 90 mL/min/1.73 m2), moderate RD (eGFR 30 to 59), severe RD (eGFR<30). A propensity scoring was used to balance the groups with 46 preoperative covariates. Multivariable logistic and Cox regression methods were used to determine the independent association of eGFR with mortality. Adjusted odds ratios were calculated for outcomes using the normal eGFR group as the reference. Kaplan-Meier curves were created to estimate long-term survival.

RESULTS

A total of 8,086 patients (57.0%) underwent off-pump coronary artery bypass (OPCAB) while 6,113 (43.0%) underwent on-pump CAB. Preoperative RD was common: Normal eGFR (n=3,503/14,199 [24.7%]); mild RD (7,236/14199 [51.0%]); moderate RD (2,860/14,199 [20.1%]); severe RD (283/14,199 [2.0%]); and preoperative dialysis (317/14,199 [2.2%]). Moderate to severe RD or preoperative dialysis was associated with worse adjusted in-hospital mortality: mild RD (odds ratio [OR] 1.42; 95% confidence interval [CI] 0.93 to 2.16; p=not significant); moderate RD (OR 3.55; 95% CI 2.32 to 5.43; p<0.05]; severe RD (OR 8.84; 95% CI 4.92 to 15.9; p<0.05); and dialysis-dependent (OR 9.64; 95% CI 5.45 to 17.0; p<0.05). Adjusted long-term survival was worse across levels of RD. The OPCAB patients with moderate to severe RD had worse long-term survival than on-pump CAB patients; however, the surgery types were similar among normal, mild, and dialysis patients.

CONCLUSIONS

Preoperative RD is common in the CABG population and is associated with diminished long-term survival. Improved early outcomes in patients with RD undergoing OPCAB diminished with worsening RD.

Impact of off-pump coronary artery bypass graft surgery on postoperative pulmonary complications in patients with chronic lung disease

BACKGROUND

Off-pump coronary artery bypass graft surgery (OPCAB) has proven to be beneficial in many high-risk subgroups. This study aims to determine whether OPCAB lowers the incidence of pulmonary complications among patients with chronic lung disease (CLD) when compared with on-pump coronary artery bypass graft surgery (ONCAB).

METHODS

From 2002 to 2007, 7,060 patients underwent isolated coronary artery bypass graft surgery in an academic center. Patients were classified according to surgery type (ONCAB or OPCAB) and presence or absence of CLD. A propensity score was produced to estimate each patient's likelihood of being assigned to OPCAB on the basis of 39 preoperative risk factors. Multiple logistic regression models and adjusted odds ratios with 95% confidence intervals were used to evaluate the effect of surgery type, CLD, and their interaction on pulmonary-related complications and mortality.

RESULTS

Among OPCAB patients, 15.3% (720 of 4,693) had CLD compared with 11.2% (264 of 2,367) for ONCAB. Off-pump coronary artery bypass graft surgery was performed in 73.2% of CLD patients compared with 66.5% in those without CLD (p<0.0001). Chronic lung disease was associated with a greater incidence of prolonged ventilation, reintubation, pneumonia, intensive care unit hours, and non-home discharge. After propensity score adjustment, OPCAB was associated with a significantly reduced incidence of prolonged ventilation, pneumonia, intensive care unit stay, and mortality. No significant interactions existed between surgery type and CLD status, suggesting that OPCAB was equally beneficial to patients with and without CLD.

CONCLUSIONS

In this series, patients with CLD were more likely to undergo OPCAB. Patients with CLD are at significantly greater risk of pulmonary-related complications than patients without CLD. Off-pump coronary artery bypass graft surgery reduced the incidence of pulmonary complications and mortality in all patients. Importantly, this benefit was seen similarly for patients with and without CLD.

Use of a novel technology for presenting screening measures to detect mild cognitive impairment in elderly patients

BACKGROUND

Available screening tools for mild cognitive impairment (MCI), often a precursor to Alzheimer's disease, are insensitive or not feasible for administration in a busy primary care setting. Display Enhanced TEsting for Cognitive impairment and Traumatic brain injury (DETECT) addresses these issues by creating an immersive environment for the brief administration of neuropsychological (NP) measures.

OBJECTIVE

The aim of this study was to determine if the DETECT cognitive subtests can identify MCI patients as accurately as standard pen and paper NP tests.

METHODS

Twenty patients with MCI recruited from a memory disorders clinic and 20 age-matched controls were given both a full battery of NP tests (standard NP) and the DETECT screen. Logistic regression models were used to determine whether individual tests were predictive of group membership (MCI or control). Demographic variables including age, race, education and gender were adjusted as covariates. Selection methods were used to identify subset models that exhibited maximum discrimination between MCI patients and controls for both testing methods.

RESULTS

Both the standard NP model (C-index = 0.836) and the DETECT model (C-index = 0.865) showed very good discrimination and were not significantly different (p = 0.7323).

CONCLUSION

The DETECT system shows good agreement with standard NP tests and is capable of identifying elderly patients with cognitive impairment.

New-onset atrial fibrillation predicts long-term mortality after coronary artery bypass graft

OBJECTIVES

We sought to investigate the association between new-onset atrial fibrillation after coronary artery bypass graft (CABG) (post-operative atrial fibrillation [POAF]) and long-term mortality in patients with no history of atrial fibrillation.

BACKGROUND

POAF predicts longer hospital stay and greater post-operative mortality.

METHODS

A total of 16,169 consecutive patients with no history of AF who underwent isolated CABG at our institution between January 1, 1996, and December 31, 2007, were included in the study. All-cause mortality data were obtained from Social Security Administration death records. A multivariable Cox proportional hazards regression model was constructed to determine the independent impact of new-onset POAF on long-term survival after adjusting for several covariates. The covariates included age, sex, race, pre-operative risk factors (ejection fraction, New York Heart Association functional class, history of myocardial infarction, index myocardial infarction, stroke, chronic obstructive pulmonary disease, peripheral arterial disease, smoking, diabetes, renal failure, hypertension, dyslipidemia, creatinine level, dialysis, redo surgery, elective versus emergent CABG, any valvular disorder) and post-operative adverse events (stroke, myocardial infarction, acute respiratory distress syndrome, and renal failure), and discharge cardiac medications known to affect survival in patients with coronary disease.

RESULTS

New-onset AF occurred in 2,985 (18.5%) patients undergoing CABG. POAF independently predicted long-term mortality (hazard ratio: 1.21; 95% confidence interval: 1.12 to 1.32) during a mean follow-up of 6 years (range 0 to 12.5 years). This association remained true after excluding from the analysis those patients who died in-hospital after surgery (hazard ratio: 1.21; 95% confidence interval: 1.11 to 1.32). Patients with POAF discharged on warfarin experienced reduced mortality during follow-up.

CONCLUSIONS

In this large cohort of patients, POAF predicted long-term mortality. Warfarin anticoagulation may improve survival in POAF.

Racial Disparity Persists After On-Pump and Off-Pump Coronary Artery Bypass Grafting

Background— Race has been shown to be an independent risk factor for operative mortality after coronary artery bypass grafting (CABG). This study sought to determine the extent to which race is a risk factor for adverse events, long-term mortality, and whether off-pump surgery (OPCAB) modifies that risk.

Methods and Results— The Society of Thoracic Surgeons Adult Cardiac Database at Emory Healthcare affiliated hospitals was queried for all primary isolated CABG records from 1997 to 2007. A propensity score was formulated to balance the patient groups with respect to treatment assignment (OPCAB or CABG on cardiopulmonary bypass). Multivariable logistic regression was used to assess the impact of black race and OPCAB on in-hospital outcomes (death, stroke, myocardial infarction, and their composite, major adverse cardiac events). Cox proportional hazards regression model and Kaplan–Meier curves determined whether black race affected long-term all-cause mortality. Interaction terms were constructed to test whether OPCAB surgery influences surgical results differently in black patients than in white patients. There were 12 874 consecutive CABG patients, including 2033 (15.8%) blacks and 10 841 (84.2%) whites. Survival at 3, 5, and 10 years for blacks (87.5%, 81.4%, 63.8%) was significantly lower than for whites (90.7%, 85.2%, 67.1%, P <0.001). Blacks (adjusted odds ratio, 0.77; 95% CI, 0.44 to 1.36) and whites (adjusted odds ratio, 0.72; 95% CI, 0.53 to 0.99) who had OPCAB had lower risk-adjusted odds of major adverse cardiac events than their racial counterparts who had CABG on cardiopulmonary bypass.

Conclusions— Short- and long-term outcomes are significantly worse in black than in white patients undergoing primary isolated CABG. OPCAB does not narrow the disparity in outcomes between blacks and whites.

Long-term outcomes after isolated aortic valve replacement in octogenarians: a modern perspective

BACKGROUND

With the recent advent of percutaneous valve therapy, an increased need for the evaluation of outcomes after open aortic valve replacement (AVR) in elderly patients is warranted. This study compares the short- and long-term survival outcomes of octogenarians after AVR with younger age groups in the modern surgical era.

METHODS

A retrospective review was performed on patients who underwent isolated, primary AVR from 1996 to 2006 at the Emory Healthcare Hospitals. Five-hundred fifteen patients were divided into three age groups: 60 to 69 (n = 206), 70 to 79 (n = 221), and 80 to 89 years of age (n = 88). Outcomes were compared among the age groups using logistic regression and analysis of variance techniques. Long-term survival between age groups was compared using the Cox proportional hazards model. Kaplan-Meier plots were used to determine survival rates.

RESULTS

The groups were similar with respect to in-hospital mortality (p = 0.66) and hospital length of stay (p = 0.08). Preoperative predictors of in-hospital mortality included stroke (odds ratio [OR] 5.36), chronic lung disease (OR 4.51), and renal failure (OR 1.39). As expected, age significantly impacted long-term survival (hazard ratio [HR] 1.06). Other predictors of long-term survival included stroke (HR 2.15), current smoker (HR 2.03), diabetes (HR 1.53), and renal failure (HR 1.4). The Kaplan-Meier estimate of median survival for octogenarians was 7.4 years.

CONCLUSIONS

In the modern era, octogenarians have acceptable short- and long-term results after open AVR. Comparisons of less invasive techniques for AVR should rely on outcomes based in the modern era and decisions regarding surgical intervention in patients requiring AVR should not be based on age alone.

Elevated preoperative hemoglobin A1c level is associated with reduced long-term survival after coronary artery bypass surgery

BACKGROUND

The predictive role of hemoglobin A1c (HbA1c) on long-term outcomes after coronary artery bypass surgery has not been evaluated.

METHODS

Preoperative HbA1c levels were obtained in 3,201 patients undergoing primary, elective coronary artery bypass surgery at Emory Healthcare Hospitals from January 2002 to December 2006 and entered prospectively into a computerized database. Long-term survival status was determined by cross-referencing patient records with the Social Security Death Index. Log-rank (unadjusted) and Cox proportional hazards regression models (adjusted) were employed to determine whether HbA1c and diabetes mellitus were independent risk factors for reduced long-term survival, adjusted for 29 covariates. Hazard ratios for each unit increase in continuous HbA1c were calculated.

RESULTS

Patients with HbA1c of 7% or greater had lower unadjusted 5-year survival compared with patients with HbA1c less than 7% (p = 0.001). Similarly, patients with diabetes mellitus had lower unadjusted 5-year survival compared with patients without diabetes (p < 0.001). After multivariable adjustment, higher HbA1c (measured as a continuous variable) was associated with reduced long-term survival for each unit increase in HbA1c (hazard ratio 1.15, p < 0.001), but preoperative diagnosis of diabetes was not associated with reduced long-term survival after coronary artery bypass surgery (p = 0.41). Other multivariable predictors of reduced long-term survival included age, cerebrovascular disease, elevated serum creatinine, renal insufficiency, congestive heart failure, previous myocardial infarction, chronic lung disease, and peripheral vascular disease.

CONCLUSIONS

Poor preoperative glycemic control, as measured by an elevated HbA1c, is associated with reduced long-term survival after coronary artery bypass surgery. Optimizing glucose control in these patients may improve long-term survival.

Elevated preoperative hemoglobin A1c level is predictive of adverse events after coronary artery bypass surgery

OBJECTIVE

Diabetes mellitus has been associated with an increased risk of adverse outcomes after coronary artery bypass grafting. Hemoglobin A1c is a reliable measure of long-term glucose control. It is unknown whether adequacy of diabetic control, measured by hemoglobin A1c, is a predictor of adverse outcomes after coronary artery bypass grafting.

METHODS

Of 3555 consecutive patients who underwent primary, elective coronary artery bypass grafting at a single academic center from April 1, 2002, to June 30, 2006, 3089 (86.9%) had preoperative hemoglobin A1c levels obtained and entered prospectively into a computerized database. All patients were treated with a perioperative intravenous insulin protocol. A multivariable logistic regression model was used to determine whether hemoglobin A1c, as a continuous variable, was associated with in-hospital mortality, renal failure, cerebrovascular accident, myocardial infarction, and deep sternal wound infection after coronary artery bypass grafting. Receiver operating characteristic curve analysis identified the hemoglobin A1c value that maximally discriminated outcome dichotomies.

RESULTS

In-hospital mortality for all patients was 1.0% (31/3089). An elevated hemoglobin A1c level predicted in-hospital mortality after coronary artery bypass grafting (odds ratio 1.40 per unit increase, P = .019). Receiver operating characteristic curve analysis revealed that hemoglobin A1c greater than 8.6% was associated with a 4-fold increase in mortality. For each unit increase in hemoglobin A1c, there was a significantly increased risk of myocardial infarction and deep sternal wound infection. By using receiver operating characteristic value thresholds, renal failure (threshold 6.7, odds ratio 2.1), cerebrovascular accident (threshold 7.6, odds ratio 2.24), and deep sternal wound infection (threshold 7.8, odds ratio 5.29) occurred more commonly in patients with elevated hemoglobin A1c.

CONCLUSION

Elevated hemoglobin A1c level was strongly associated with adverse events after coronary artery bypass grafting. Preoperative hemoglobin A1c testing may allow for more accurate risk stratification in patients undergoing coronary artery bypass grafting.

American Association for the Surgery of Trauma Organ Injury Scale I: spleen, liver, and kidney, validation based on the National Trauma Data Bank

BACKGROUND

This study attempts to validate the American Association for the Surgery of Trauma (AAST) Organ Injury Scale (OIS) for spleen, liver, and kidney injuries using the National Trauma Data Bank (NTDB).

STUDY DESIGN

All NTDB entries with Abbreviated Injury Scale codes for spleen, liver, and kidney were classified by OIS grade. Injuries were stratified either as an isolated intraabdominal organ injury or in combination with other abdominal injuries. Isolated abdominal solid organ injuries were additionally stratified by presence of severe head injury and survival past 24 hours. The patients in each grading category were analyzed for mortality, operative rate, hospital length of stay, ICU length of stay, and charges incurred.

RESULTS

There were 54,148 NTDB entries (2.7%) with Abbreviated Injury Scale-coded injuries to the spleen, liver, or kidney. In 35,897, this was an isolated abdominal solid organ injury. For patients in which the solid organ in question was not the sole abdominal injury, a statistically significant increase (p < or = 0.05) in mortality, organ-specific operative rate, and hospital charges was associated with increasing OIS grade; the exception was grade VI hepatic injuries. Hospital and ICU lengths of stay did not show substantial increase with increasing OIS grade. When isolated organ injuries were examined, there were statistically significant increases (p < or = 0.05) in all outcomes variables corresponding with increasing OIS grade. Severe head injury appears to influence mortality, but none of the other outcomes variables. Patients with other intraabdominal injuries had comparable quantitative outcomes results with the isolated abdominal organ injury groups for all OIS grades.

CONCLUSIONS

This study validates and quantifies outcomes reflective of increasing injury severity associated with increasing OIS grades for specific solid organ injuries alone, and in combination with other abdominal injuries.

A population-based comparison of CIREN and NASS cases using similarity scoring

The Crash Injury Research and Engineering Network (CIREN) provides significant details on injuries, and data on patient outcomes that is unavailable in the National Automotive Sampling System (NASS). However, CIREN cases are selected from specific Level I trauma centers with different inclusion criteria than those used for NASS, and the assertion that a given case is similar to the population of NASS cases is often made qualitatively. A robust, quantitative method is needed to compare CIREN to weighted NASS populations. This would greatly improve the usefulness and applicability of research conducted with data from the CIREN database. Our objective is to outline and demonstrate the utility of such a system to compare CIREN and NASS cases. This study applies the Mahalanobis distance metric methodology to determine similarity between CIREN and NASS/CDS cases. The Mahalanobis distance method is a multivariate technique for population comparison. Independent variables considered were total delta V, age, weight, height, maximum AIS, ISS, model year, gender, maximum intrusion, number of lower and upper extremity injuries, and number of head and chest injuries. The technique provides a unit-independent quantitative score which can be used to identify similarity of CIREN and NASS cases. Weighted NASS data and CIREN data were obtained for the years 2001-2005. NASS cases with Maximum AIS 3 resulted in a subset of 1,869 NASS cases, and 2,819 CIREN cases.

Improving outcomes in a regional trauma system: impact of a level III trauma center

BACKGROUND

Trauma systems decrease morbidity and mortality of injured populations, and each component contributes to the final outcome. This study evaluated the association between a referring hospital's trauma designation and the survival and resource utilization of patients transferred to a level I trauma center.

METHODS

Data from the Registry of the American College of Surgeons on patients transferred to a level I trauma center during a 7-year period were subdivided into 3 categories: group 1 = level III-designated trauma center; group 2 = potential level III trauma centers; and group 3 = other transferring hospitals. Trauma and Injury Severity Score methodology was used to provide a probability estimate of survival adjusted for the effect related to injury severity, physiologic host factors, and age. A W statistic was calculated for each type of referring hospital so that comparisons between observed survival and predicted survival could be measured. Differences in W, length of stay, intensive care unit days, and ventilator days were examined using general linear models.

RESULTS

Patients transferred to a level I from a level III trauma center (group 1) were more seriously injured (P < .0001) and had improved survival (P < .0018) compared with those transferred from nondesignated hospitals (groups 2 and 3). Patients transferred from large nondesignated hospitals (group 2) had outcomes similar to patients transferred from all other hospitals (group 3). Level I hospital resource utilization did not show significant differences based on referring hospital type.

COMMENTS

Outcomes of patients in a trauma system are associated with trauma-center designation of the referring hospitals.

Effect of etanercept (Enbrel) on interleukin 6, tumor necrosis factor alpha, and markers of immune activation in HIV-infected subjects receiving interleukin 2

The effect of etanercept, a soluble p75 tumor necrosis factor (TNF) receptor:Fc fusion protein (Enbrel; Immunex, Seattle, WA) on plasma cytokines was evaluated in 11 HIV-infected subjects receiving highly active antiretroviral therapy (HAART) for 28 weeks with or without subcutaneous or intravenous recombinant human interleukin 2 (rhIL-2). Plasma IL-6 and C-reactive protein (CRP) levels increased after rhIL-2 treatment. Etanercept pretreatment attenuated these increases. Median plasma IL-6 levels were 20.29 pg/ml 4 days after rhIL-2 and 7.87 pg/ml 4 days after etanercept and rhIL-2 (p = 0.22); median CRP levels were 78.73 and 46.16 microg/ml, respectively (p = 0.03). An effect on TNF bioactivity could not be assessed as all measurements were below limits of detection. No significant changes were seen in temperature or plasma levels of IL-4, IL-10, IL-12, interferon gamma, or HIV-1 RNA levels. All subjects had undetectable or low-level HIV-1 RNA levels before etanercept dosing. One subject died; however, her death was thought to be unrelated to etanercept. Pretreatment with etanercept may blunt activation of IL-6 and CRP expression induced by rhIL-2. The safety and utility of etanercept in HIV-infected persons should be explored further.

Effect of therapeutic immunization with HIV type 1 recombinant glycoprotein 160 ImmunoAG vaccine in HIV-infected individuals with CD4+ T cell counts of >or=500 and 200-400/mm3 (AIDS Clinical Trials Group Study 246/946)

AIDS Clinical Trials Group (ACTG) 246/946 was a double-blinded, randomized, controlled trial of HIV-1 MN rgp160 ImmunoAG vaccine in HIV-infected patients with CD4(+) T cell counts >or=500 and 200-400/mm(3). The main objectives were to study the safety and immunogenicity of this vaccine and to study the persistence of the immune responses after vaccination over a longer period of time. Fifteen patients with CD4(+) T cell counts of >or=500/mm(3) were enrolled in the ACTG 246 study. ACTG 246 patients received a monthly injection of vaccine or control for 6 months and then injections every 2 months. After completion of this study, seven new patients with CD4(+) T cell counts of 200-400/mm(3) entered into the ACTG 946 study. These study patients received highly active antiretroviral therapy (HAART) (ritonavir, didanosine, and stavudine) for 9 weeks to stabilize their viral load and then each patient received a monthly injection of vaccine or control substance for 6 months with HAART. The study of these two relatively small populations showed that the vaccine was safe without any adverse effect both in the patients with CD4(+) T cell counts of >or=500 and 200-400/mm(3). The vaccine was also immunogenic in patients with CD4(+) T cell counts of >or=500/mm(3) as measured by gp160-specific lymphocyte proliferative responses, and it persisted after they had received more than six vaccine injections, for a longer period of time.