Epicardial ultrasound in a case of myocardial bridge and apical hypertrophic cardiomyopathy.

A 59-year-old male with a history of unstable angina was diagnosed with a myocardial bridge of the left anterior descending artery (LAD) and apical variant hypertrophic cardiomyopathy (AHCM). He underwent unroofing of the myocardial bridge and a left ventricular apical myectomy. Intraoperatively, epicardial ultrasound was used to identify the myocardial bridge with systolic compression of the LAD and confirm resolution of this compression postoperatively. Furthermore, epicardial ultrasound was used for guiding the degree of apical resection of the decompressed heart. This novel use of intraoperative epicardial ultrasound can help guide surgeons preoperatively and confirm results immediately after an operation.

Increased risk of atrial fibrillation among patients undergoing coronary artery bypass graft surgery while receiving nitrates and antiplatelet agents.

Background Postoperative atrial fibrillation (POAF) is a frequent complication of coronary artery bypass graft (CABG) surgery. This arrhythmia occurs more frequently among patients who receive perioperative inotropic therapy (PINOT). Administration of nitrates with antiplatelet agents reduces the conversion rate of cyclic guanosine monophosphate to guanosine monophosphate. This process is associated with increased concentrations of free radicals, catecholamines, and blood plasma volume. We hypothesized that patients undergoing CABG surgery who receive PINOT may be more susceptible to POAF when nitrates are administered with antiplatelet agents. Methods Clinical records were examined from a prospectively maintained cohort of 4,124 patients undergoing primary isolated CABG surgery to identify POAF-associated factors. Results POAF risk was increased among patients receiving PINOT, and the greatest effect was observed when nitrates were administered with antiplatelet therapy. Adjustment for comorbidities did not substantively change the study results. Conclusions Administration of nitrates with certain antiplatelet agents was associated with an increased POAF risk among patients undergoing CABG surgery. Additional studies are needed to determine whether preventive strategies such as administration of antioxidants will reduce this risk.

Perioperative Inotrope Therapy and Atrial Fibrillation Following Coronary Artery Bypass Graft Surgery: Evidence of a Racial Disparity.

BACKGROUND AND OBJECTIVE: Following coronary artery bypass graft (CABG) surgery, mortality rates are significantly higher among black patients who experience postoperative atrial fibrillation (POAF). Perioperative inotropic therapy (PINOT) was associated with POAF in previous reports, but the extent to which race influences this association is unknown. In the present study, the relationship between PINOT, race, and POAF was examined in patients undergoing CABG surgery. METHODS AND SETTING: Clinical records were examined from a prospectively maintained cohort of 11,855 patients (median age 64 yrs; 70% male; 16% black) undergoing primary isolated CABG at a large cardiovascular institute in the southeastern region of the United States. Relative risk (RR) and 95% confidence intervals (CIs) were computed using log-binomial regression. MAIN RESULTS: The association between PINOT and POAF was significantly increased among black patients (adjusted RR 1.7, CI 1.4-2.0) compared with white patients (adjusted RR 1.3, CI 1.2-1.4) (pinteraction  = 0.013). CONCLUSIONS: These findings suggest that PINOT may be disproportionately associated with POAF among black patients undergoing CABG surgery. Additional studies are needed to examine further the potential underlying mechanisms of this association.

Long-Term Survival after Cardiac Surgery in Patients with Chronic Obstructive Pulmonary Disease.

BACKGROUND: Although many patients with chronic obstructive pulmonary disease (COPD) require a prolonged length of stay (PLOS) following coronary artery bypass grafting (CABG), the impact of PLOS on long-term survival has not been examined in this population. OBJECTIVES: To determine the association between PLOS and long-term survival among COPD and non-COPD patients after CABG and to examine consequent policy and practice-based implications. METHODS: A retrospective cohort study of CABG patients was conducted between 2002 and 2011. Long-term survival was compared in patients with and without COPD and stratified by PLOS. Hazard ratios (HR) and 95% confidence intervals (CI) were computed using a Cox regression model. RESULTS: A total of 203 patients (4.2%) had PLOS after nonemergent CABG (N = 4801). PLOS was an important independent predictor of decreased long-term survival (no COPD, no PLOS: HR = 1.0; COPD, no PLOS: adjusted HR [95% CI], 1.8 [1.5-2.1]; no COPD, PLOS: 3.3 [2.5-4.4]; COPD, PLOS: 6.0 [4.4-8.2]; PTrend < .001). CONCLUSIONS: COPD and PLOS are 2 of many factors that affect long-term mortality in postoperative CABG patients. Aggressive treatment strategies aimed at early weaning off of mechanical ventilation and prevention of reintubation among COPD patients must be considered carefully as a means to reduce length of stay after CABG. Our results also have important implications for the long-term management of these patients and strategies for containing costs over the life course of the patient.

Seasonal Incidence of Emergent Coronary Artery Bypass Grafting Surgery.

BACKGROUND: Emergent coronary artery bypass grafting (CABG) surgery is often required in the case of severe coronary artery disease, which is refractory to traditional management. The objective of our study was to test the hypothesis that there is seasonal variation in the incidence of emergent CABG. METHODS: A sinusoidal logistic regression model was used to analyze operative data at our cardiovascular institute of 270 cases spanning 5939 calendar days. RESULTS: A cyclic peak risk for emergent CABG was observed for late winter (calendar day 66; P = .036). The odds ratios for the 1-, 2- and 3-month window surrounding this peak were 1.8 (95% CI = 0.94-3.5, P = .072), 1.6 (95% CI = 1.06-2.5, P = .024) and 1.4 (95% CI = 0.9-1.8, P = .066), respectively. CONCLUSION: Our results suggest that a seasonal variation may exist in the incidence of patients presenting with severe coronary artery disease requiring emergent CABG. This information is useful in the scheduling of hospital resources and staff. It also provides important etiology clues underlying coronary artery disease that may lead to future interventions or targeted therapies.

Operative Start Time Does Not Affect Post-Operative Infection Risk.

BACKGROUND: Surgical care is delivered 24 h a day at most institutions. Alarmingly, some authors have found that certain operative start times are associated with greater morbidity and mortality rates. This effect has been noted in both the public and private sector. Although some of these differences may be related to process, they may also be caused by the human circadian rhythm and corresponding changes in host defenses. We hypothesized that the time of day of an operation would impact the frequency of certain post-operative outcomes significantly. METHODS: Cases at a single tertiary-care center reported to the American College of Surgeons National Surgical Quality Improvement Program over a 10-year period were identified. Operative start times were divided into six-hour blocks, with 6 am to noon serving as the reference. Standard univariable techniques were applied. Multivariable logistic regression with mixed effects modeling then was used to determine the relation between operative start times and infectious outcomes, controlling for surgeon clustering. Statistical significance was set at p < 0.01. RESULTS: A total of 21,985 cases were identified, of which 2,764 (12.6%) were emergency procedures. Overall, 9.7% (n = 2,142) of patients experienced some post-operative infectious complication. Seventy percent of these infections (n = 1,506) were surgical site infections. On univariable analysis considering all cases, nighttime and evening operations had higher rates of post-operative infections than those in performed during the day (9.1% from 6 am to noon; 9.7% from noon to 6 pm; 14.8% from 6 pm to midnight; and 14.4% from midnight to 6 am; p < 0.001). On multivariable analysis, operative start time was not associated with the risk of post-operative infection, even when emergency cases were considered independently. CONCLUSION: Our data suggest that operative start times have no correlation with post-operative infectious complications. Further work is required to identify the source of the time-dependent outcome variability observed in previous studies.

Comparison of Risk of Atrial Fibrillation in Black Versus White Patients After Coronary Artery Bypass Grafting.

Obesity has been identified as a risk factor for postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG). However, no studies have addressed the influence of race on this association. A total of 13,594 patients undergoing first-time, isolated CABG without preoperative AF between 1992 and 2011 were included in our study. The association between body mass index and POAF was compared by race. Relative risk and 95% CIs were computed using maximum likelihood log-binomial regression. Increasing levels of body mass index were associated with higher POAF risk after CABG in black but not white patients (pinteraction = 0.0009).

Conditional long-term survival following minimally invasive robotic mitral valve repair: a health services perspective.

BACKGROUND: Conditional survival is defined as the probability of surviving an additional number of years beyond that already survived. The aim of this study was to compute conditional survival in patients who received a robotically assisted, minimally invasive mitral valve repair procedure (RMVP). METHODS: Patients who received RMVP with annuloplasty band from May 2000 through April 2011 were included. A 5- and 10-year conditional survival model was computed using a multivariable product-limit method. RESULTS: Non-smoking men (≤65 years) who presented in sinus rhythm had a 96% probability of surviving at least 10 years if they survived their first year following surgery. In contrast, recent female smokers (>65 years) with preoperative atrial fibrillation only had an 11% probability of surviving beyond 10 years if alive after one year post-surgery. CONCLUSIONS: In the context of an increasingly managed healthcare environment, conditional survival provides useful information for patients needing to make important treatment decisions, physicians seeking to select patients most likely to benefit long-term following RMVP, and hospital administrators needing to comparatively assess the life-course economic value of high-tech surgical procedures.

Increased Long-Term Mortality among Black CABG Patients Receiving Preoperative Inotropic Agents.

The aim of this study was to examine racial differences in long-term mortality after coronary artery bypass grafting (CABG), stratified by preoperative use of inotropic agents. Black and white patients who required preoperative inotropic support prior to undergoing CABG procedures between 1992 and 2011 were compared. Mortality probabilities were computed using the Kaplan-Meier product-limit method. Hazard ratios (HR) and 95% confidence intervals (CI) were computed using a Cox regression model. A total of 15,765 patients underwent CABG, of whom 211 received preoperative inotropic agents within 48 hours of surgery. Long-term mortality differed by race (black versus white) among preoperative inotropic category (inotropes: adjusted HR = 1.6, 95% CI = 1.009-2.4; no inotropes: adjusted HR = 1.15, 95% CI = 1.08-1.2; P(interaction) < 0.0001). Our study identified an independent preoperative risk-factor for long-term mortality among blacks receiving CABG. This outcome provides information that may be useful for surgeons, primary care providers, and their patients.

Temporal Trends in Blood Stream Infection Isolates from Surgical Patients.

BACKGROUND: Blood stream infections (BSIs) are a common source of morbidity and death in hospitalized patients. We hypothesized that the proportions of bacteremia from gram-positive and fungal pathogens have decreased over time, whereas rates of gram-negative bacteremia have increased as a result of better central venous catheter management. METHODS: All U.S. Centers for Disease Control and Prevention-defined BSIs in patients treated on the general surgery and trauma services at our institution between January 1, 1998, and December 31, 2009 were identified prospectively. These cases were analyzed on a yearly basis to compare rates of various infections over time. The Cochran-Armitage test for trend was used to evaluate categorical data, whereas the Jonckheere-Terpstra test for ordered values was used to analyze continuous data. RESULTS: A total of 1,040 patients had 1,441 episodes of BSI caused by 1,632 strains of bacteria or fungi. There was no difference over time in the proportion of BSI among overall infections. Rates of BSI for gram-negative and fungal pathogens increased over time (p=0.03 and<0.0001, respectively), whereas rates of gram-positive BSI decreased (p<0.0001). Positive changes in anaerobic BSI approached statistical significance. CONCLUSION: Although our hypothesis was only partly true, over the last 12 y, our institution clearly has witnessed a shift in the types of organisms causing BSIs. There was a decrease in the rates of BSI caused by gram-positive pathogens with an associated increase in the rates of BSI of infections by fungal and gram-negative pathogens. Interventions to reduce institutional rates of BSI should include targeted therapies based on historical institutional trends.

Hypoalbuminemia is disproportionately associated with adverse outcomes in obese elective surgical patients.

BACKGROUND: Protein deficiency (PD) is a known risk factor for surgical complications; however, the risks of PD by weight class have not been well described. It was hypothesized that the combination of obesity and PD is associated with increased surgical complications compared with normal weight and normoalbuminemic patients. METHODS: A total of 85,833 general surgery patients undergoing elective operations within the 2011 National Surgical Quality Improvement Program were analyzed. Patients with conditions that could potentially confound serum albumin (SA) were excluded. Patients were stratified by normal (>3.0 g/dL) versus low (<3.0 g/dL) SA. The relative impact of SA and body mass index (BMI) (as individual and as combined variables) on surgical morbidity and mortality were assessed. Multivariate analyses were performed to identify independent risk factors for morbidity and mortality. RESULTS: Overall, 2,088 (2.43%) patients had low preoperative SA. 587 (28.1%) patients with low preoperative SA were obese (BMI>30), versus 39,299 (46.9%) with normal preoperative SA. Importantly, the interaction of hypoalbuminemia and BMI was independently associated with all complications among hypoalbuminemic patients with BMI>40, and mortality for patients with BMI>30 after controlling for appropriate demographic characteristics, co-morbidities, surgical wound classification, operation type, and complexity (c-statistic: .803 and .874 respectively). CONCLUSION: PD and obesity appear to synergistically increase the risk of surgical complications. Paradoxically, malnutrition may be less easily recognized in obese individuals and surgeons may need to more carefully evaluate this population before surgery. Future studies should investigate therapy to correct PD specifically among obese patients before surgery.

Perioperative management of obese patients.

Obesity prevalence has quadrupled since the 1980s in the United States. It is estimated that 30% of the population is obese or has a body mass index of greater than or equal to 30 as defined by the World Health Organization. Surgeons are likely to engage in the care of obese patients and need to be adept in every aspect of the patients' care in order to have a successful hospital course. There is significant controversy in perioperative management of obese patients. This article discusses perioperative management of obese patients to provide guidelines, education, and discussion of current issues.

Lung protective ventilation (ARDSNet) versus airway pressure release ventilation: ventilatory management in a combined model of acute lung and brain injury.

BACKGROUND: Concomitant lung/brain traumatic injury results in significant morbidity and mortality. Lung protective ventilation (Acute Respiratory Distress Syndrome Network [ARDSNet]) has become the standard for managing adult respiratory distress syndrome; however, the resulting permissive hypercapnea may compound traumatic brain injury. Airway pressure release ventilation (APRV) offers an alternative strategy for the management of this patient population. APRV was hypothesized to retard the progression of acute lung/brain injury to a degree greater than ARDSNet in a swine model. METHODS: Yorkshire swine were randomized to ARDSNet, APRV, or sham. Ventilatory settings and pulmonary parameters, vitals, blood gases, quantitative histopathology, and cerebral microdialysis were compared between groups using χ2, Fisher's exact, Student's t test, Wilcoxon rank-sum, and mixed-effects repeated-measures modeling. RESULTS: Twenty-two swine (17 male, 5 female), weighing a mean (SD) of 25 (6.0) kg, were randomized to APRV (n = 9), ARDSNet (n = 12), or sham (n = 1). PaO2/FIO2 ratio dropped significantly, while intracranial pressure increased significantly for all three groups immediately following lung and brain injury. Over time, peak inspiratory pressure, mean airway pressure, and PaO2/FIO2 ratio significantly increased, while total respiratory rate significantly decreased within the APRV group compared with the ARDSNet group. Histopathology did not show significant differences between groups in overall brain or lung tissue injury; however, cerebral microdialysis trends suggested increased ischemia within the APRV group compared with ARDSNet over time. CONCLUSION: Previous studies have not evaluated the effects of APRV in this population. While our macroscopic parameters and histopathology did not observe a significant difference between groups, microdialysis data suggest a trend toward increased cerebral ischemia associated with APRV over time. Additional and future studies should focus on extending the time interval for observation to further delineate differences between groups.

Increased coronary artery disease severity in black women undergoing coronary bypass surgery.

Race and sex disparities are believed to play an important role in heart disease. The purpose of this study was to examine the association between race, sex, and number of diseased vessels at the time of coronary artery bypass grafting (CABG), and subsequent postoperative outcomes. The 13,774 patients undergoing first-time, isolated CABG between 1992 and 2011 were included. Trend in the number of diseased vessels between black and white patients, stratified by sex, were analyzed using a Cochran-Armitage trend test. Models were adjusted for age, procedural status (elective vs. nonelective), and payor type (private vs. nonprivate insurance). Black female CABG patients presented with an increasingly greater number of diseased vessels than white female CABG patients (adjusted P(trend) = 0.0021). A similar trend was not observed between black and white male CABG patients (adjusted P(trend) = 0.18). Black female CABG patients were also more likely to have longer intensive care unit and hospital lengths of stay than other race-sex groups.Our findings suggest that black female CABG patients have more advanced coronary artery disease than white female CABG patients. Further research is needed to determine the benefit of targeted preventive care and preoperative workup for this high-risk group.

Gastric bypass improves survival compared with propensity-matched controls: a cohort study with over 10-year follow-up.

BACKGROUND: The purpose of this study is to evaluate the long-term survival following gastric bypass using propensity-matched controls. METHODS: We identified all patients who either received a gastric bypass (GBP) or met criteria to receive a GBP between January 1, 2002 and December 31, 2003. Propensity matching was performed. Long-term, all-cause mortality data were collected and evaluated using Kaplan-Meier curves. RESULTS: Four hundred thirty GBP cases and 5,323 controls were identified from the enrollment period. Ultimately, 802 cases and controls (1:1 matching, 93.2% match rate) were identified using propensity matching. Median follow-up was similar between groups. Overall mortality was lower for the GBP group (odds ratio .48, 95% confidence interval .29 to .78). GBP demonstrated significantly increased survival when compared with controls (P = .002). Similar patterns were noted among diabetics. CONCLUSION: We have demonstrated that gastric bypass provides a clear long-term survival advantage compared with nonsurgical propensity-matched controls.

Twenty-first century weight loss: banding versus bypass.

BACKGROUND: The two most commonly performed procedures for bariatric surgery include Roux-en-Y gastric bypass (RYGB) and adjustable gastric banding (AGB). While many studies have commented on short-term, postoperative outcomes of these procedures, few have reported long-term data. The purpose of this study was to compare long-term, postoperative outcomes between RYGB and AGB. METHODS: This was a retrospective, cohort comparing all patients undergoing RYGB or AGB at our institution, from 01/1998 to 08/2012. Patients were followed at 1-, 3-, and 5-year intervals. Adjusted, Cox proportional hazard regression and mixed effects repeated measures modeling were performed to generate cure ratios (CR) and 95 % confidence intervals (CI). RESULTS: Two thousand four hundred twenty bariatric surgery patients (380 AGB, 2,040 RYGB) were identified by CPT code. Median (range) follow-up for patients was 3 (1-5) years. Preoperatively, RYGB patients were significantly younger, more obese, had higher hemoglobin A1c, and less often suffered from hypertension (HTN), dyslipidemia, and asthma as compared to AGB patients. Postoperatively, RYGB patients experienced significantly longer operating room times, higher incidences of intensive care unit admissions, longer hospital lengths of stay, and increased incidence of small bowel obstruction compared to AGB patients. After adjusting for statistically significant and clinically relevant factors [e.g., age, gender, body mass index, degenerative joint disease (DJD), diabetes, HTN, dyslipidemia, heart disease, apnea, and asthma], RYGB was independently associated with a significantly greater percentage of total body weight loss (p = 0.0065) and greater CR (95 % CI) regarding gastroesophageal reflux disease [2.1(1.4-3.0)], DJD [3.4(2.0-5.6)], diabetes [3.4(2.2-5.4)], apnea [3.1(1.9-5.3)], HTN [5.5(3.4-8.8)], and dyslipidemia [6.3(3.5-11)] compared to AGB. CONCLUSION: Our results support previous studies that have observed a greater weight loss associated with RYGB as compared to AGB and provide further evidence toward the long-term sustainability of this weight loss. Additionally, RYGB appears to result in a greater reduction of medical comorbidity.

Discharge ß-Blocker Use and Race after Coronary Artery Bypass Grafting.

INTRODUCTION: The use of discharge ß-blockers after cardiac surgery is associated with a long-term mortality benefit. ß-Blockers have been suggested to be less effective in black cardiovascular patients compared with whites. To date, racial differences in the long-term survival of coronary artery bypass grafting (CABG) patients who receive ß-blockers at discharge have not been examined. METHODS: A retrospective cohort study was conducted on patients undergoing CABG between 2002 and 2011. Long-term survival was compared in patients who were and who were not discharged with ß-blockers. Hazard ratios (HR) and 95% confidence intervals (CI) were computed using a Cox regression model. P-for-interaction between race and discharge ß-blocker use was computed using a likelihood ratio test. RESULTS: A total of 853 (88%) black (n = 970) and 3,038 (88%) white (n = 3,460) patients had a history of ß-blocker use at discharge (N = 4,430). Black patients who received ß-blockers survived longer than those not receiving ß-blockers and the survival advantage was comparable with white patients (black, adjusted HR = 0.33, 95% CI = 0.23-0.46; white, adjusted HR = 0.48, 95% CI = 0.39-0.58; p-for-interaction = 0.74). Among patients discharged on ß-blockers, we did not observe a long-term survival advantage for white compared with black patients (HR = 1.2, 95% CI = 0.95-1.5). CONCLUSION: ß-Blocker use at discharge was associated with a survival advantage among black patients after CABG and a similar association was observed in white patients.

Risk-adjusted survival after coronary artery bypass grafting: implications for quality improvement.

Mortality represents an important outcome measure following coronary artery bypass grafting. Shorter survival times may reflect poor surgical quality and an increased number of costly postoperative complications. Quality control efforts aimed at increasing survival times may be misleading if not properly adjusted for case-mix severity. This paper demonstrates how to construct and cross-validate efficiency-outcome plots for a specified time (e.g., 6-month and 1-year survival) after coronary artery bypass grafting, accounting for baseline cardiovascular risk factors. The application of this approach to regional centers allows for the localization of risk stratification rather than applying overly broad and non-specific models to their patient populations.

Characteristics of surgical patients receiving inappropriate empiric antimicrobial therapy.

BACKGROUND: Inappropriate antibiotics have been observed to result in an increased duration of antibiotic treatment and hospital length of stay, development of multidrug-resistant organisms, and mortality rate compared with appropriate antibiotic treatment. Few studies have evaluated independent risk factors associated with inappropriateness. The purpose of this study was to identify independent predictors of inappropriate, empiric antimicrobial therapy for the treatment of severe sepsis. METHODS: This was a retrospective analysis of a prospectively maintained database of all surgical/trauma patients admitted to a tertiary care center from 1996 to 2007 and treated for sepsis. "Appropriate" empiric antibiotic treatment was determined by sensitivity testing. Demographics and comorbidities, infection sites, infection organisms, and outcomes between strata were compared. Differences in outcome were estimated using relative risk and 95% confidence intervals for correlated data. RESULTS: A total of 2,855 patients (7,158 infections) were identified. Independent predictors of inappropriate, empiric antimicrobial therapy for the treatment of severe sepsis included site of infection and organism type. Severity of illness, age, medical conditions, and community versus health care-associated infections were not associated with inappropriate therapy. Although inappropriate empiric therapy was associated with a longer length of stay and duration of antimicrobial use, it did not result in higher mortality. CONCLUSION: Our study observed that inappropriate empiric antibiotic selection is related to site of infection and pathogen. Other clinical variables do not appear to predict inappropriateness of antibiotic treatment. Efforts should be focused on early broad-spectrum therapy and more rapid microbiologic methods. LEVEL OF EVIDENCE: Therapeutic/care management study, level II.