Mandatory public reporting of cardiac surgery outcomes: The 2003 to 2014 Massachusetts experience.

OBJECTIVES: Beginning in 2002, all 14 Massachusetts nonfederal cardiac surgery programs submitted Society of Thoracic Surgeons (STS) National Database data to the Massachusetts Data Analysis Center for mandatory state-based analysis and reporting, and to STS for nationally benchmarked analyses. We sought to determine whether longitudinal prevalences and trends in risk factors and observed and expected mortality differed between Massachusetts and the nation. METHODS: We analyzed 2003 to 2014 expected (STS predicted risk of operative [in-hospital + 30-day] mortality), observed, and risk-standardized isolated coronary artery bypass graft mortality using Massachusetts STS data (N = 39,400 cases) and national STS data (N = 1,815,234 cases). Analyses included percentage shares of total Massachusetts coronary artery bypass graft volume and expected mortality rates of 2 hospitals before and after outlier designation. RESULTS: Massachusetts patients had significantly higher odds of diabetes, peripheral vascular disease, low ejection fraction, and age ≥75 years relative to national data and lower odds of shock (odds ratio, 0.66; 99% confidence interval, 0.53-0.83), emergency (odds ratio, 0.57, 99% confidence interval, 0.52-0.61), reoperation, chronic lung disease, dialysis, obesity, and female sex. STS predicted risk of operative [in-hospital + 30-day] mortality for Massachusetts patients was higher than national rates during 2003 to 2007 (P < .001) and no different during 2008 to 2014 (P = .135). Adjusting for STS predicted risk of operative [in-hospital + 30-day] mortality, Massachusetts patients had significantly lower odds (odds ratio, 0.79; 99% confidence interval, 0.66-0.96) of 30-day mortality relative to national data. Outlier programs experienced inconsistent, transient influences on expected mortality and their percentage shares of Massachusetts coronary artery bypass graft cases. CONCLUSIONS: During 12 years of mandatory public reporting, Massachusetts risk-standardized coronary artery bypass graft mortality was consistently and significantly lower than national rates, expected rates were comparable or higher, and evidence for risk aversion was conflicting and inconclusive.

Protein Intake, Nutritional Status and Outcomes in ICU Survivors: A Single Center Cohort Study.

BACKGROUND: We hypothesized that protein delivery during hospitalization in patients who survived critical care would be associated with outcomes following hospital discharge. METHODS: We studied 801 patients, age ≥ 18 years, who received critical care between 2004 and 2012 and survived hospitalization. All patients underwent a registered dietitian formal assessment within 48 h of ICU admission. The exposure of interest, grams of protein per kilogram body weight delivered per day, was determined from all oral, enteral and parenteral sources for up to 28 days. Adjusted odds ratios for all cause 90-day post-discharge mortality were estimated by mixed- effects logistic regression models. RESULTS: The 90-day post-discharge mortality was 13.9%. The mean nutrition delivery days recorded was 15. In a mixed-effect logistic regression model adjusted for age, gender, race, Deyo-Charlson comorbidity index, acute organ failures, sepsis and percent energy needs met, the 90-day post-discharge mortality rate was 17% (95% CI: 6⁻26) lower for each 1 g/kg increase in daily protein delivery (OR = 0.83 (95% CI 0.74⁻0.94; p = 0.002)). CONCLUSIONS: Adult medical ICU patients with improvements in daily protein intake during hospitalization who survive hospitalization have decreased odds of mortality in the 3 months following hospital discharge.

Decreased preoperative functional status is associated with increased mortality following coronary artery bypass graft surgery.

OBJECTIVES: Functional status prior to coronary artery bypass graft surgery may be a risk factor for post-operative adverse events. We sought to examine the association between functional status in the 3 months prior to coronary artery bypass graft surgery and subsequent 180 day mortality. DESIGN, SETTING, AND PARTICIPANTS: We performed a single center retrospective cohort study in 718 adults who received coronary artery bypass graft surgery from 2002 to 2014. EXPOSURES: The exposure of interest was functional status determined within the 3 months preceding coronary artery bypass graft surgery. Functional status was measured and rated by a licensed physical therapist based on qualitative categories adapted from the Functional Independence Measure. MAIN OUTCOMES AND MEASURES: The main outcome was 180-day all-cause mortality. A categorical risk prediction score was derived based on a logistic regression model of the function grades for each assessment. RESULTS: In a logistic regression model adjusted for age, gender, New York Heart Association Class III/IV, chronic lung disease, hypertension, diabetes, cerebrovascular disease, and the Society of Thoracic Surgeons score, the lowest quartile of functional status was associated with an increased odds of 180-day mortality compared to patients with highest quartile of functional status [OR = 4.45 (95%CI 1.35, 14.69; P = 0.014)]. CONCLUSIONS: Lower functional status prior to coronary artery bypass graft surgery is associated with increased 180-day all-cause mortality.

Malnutrition, Critical Illness Survivors, and Postdischarge Outcomes: A Cohort Study.

BACKGROUND: We hypothesized that preexisting malnutrition in patients who survived critical care would be associated with adverse outcomes following hospital discharge. METHODS: We performed an observational cohort study in 1 academic medical center in Boston. We studied 23,575 patients, aged ≥18 years, who received critical care between 2004 and 2011 and survived hospitalization. RESULTS: The exposure of interest was malnutrition determined at intensive care unit (ICU) admission by a registered dietitian using clinical judgment and on data related to unintentional weight loss, inadequate nutrient intake, and wasting of muscle mass and/or subcutaneous fat. The primary outcome was 90-day postdischarge mortality. Secondary outcome was unplanned 30-day hospital readmission. Adjusted odds ratios were estimated by logistic regression models adjusted for age, race, sex, Deyo-Charlson Index, surgical ICU, sepsis, and acute organ failure. In the cohort, the absolute risk of 90-day postdischarge mortality was 5.9%, 11.7%, 15.8%, and 21.9% in patients without malnutrition, those at risk of malnutrition, nonspecific malnutrition, and protein-energy malnutrition, respectively. The odds of 90-day postdischarge mortality in patients at risk of malnutrition, nonspecific malnutrition, and protein-energy malnutrition fully adjusted were 1.77 (95% confidence interval [CI], 1.23-2.54), 2.51 (95% CI, 1.36-4.62), and 3.72 (95% CI, 2.16-6.39), respectively, relative to patients without malnutrition. Furthermore, the presence of malnutrition is a significant predictor of the odds of unplanned 30-day hospital readmission. CONCLUSIONS: In patients treated with critical care who survive hospitalization, preexisting malnutrition is a robust predictor of subsequent mortality and unplanned hospital readmission.

Malnutrition at Intensive Care Unit Admission Predicts Mortality in Emergency General Surgery Patients.

BACKGROUND: Emergency general surgery (EGS) patients are at an increased risk for morbidity and mortality compared with non-EGS patients. Limited information exists regarding the contribution of malnutrition to the outcome of critically ill patients who undergo EGS. We hypothesized that malnutrition would be associated with increased risk of 90-day all-cause mortality following intensive care unit (ICU) admission in EGS patients. MATERIALS AND METHODS: We performed an observational study of patients treated in medical and surgical ICUs at a single institution in Boston. We included patients who underwent an EGS procedure and received critical care between 2005 and 2011. The exposure of interest, malnutrition, was determined by a registered dietitian's formal assessment within 48 hours of ICU admission. The primary outcome was all-cause 90-day mortality. Adjusted odds ratios were estimated by multivariable logistic regression models. RESULTS: The cohort consisted of 1361 patients. Sixty percent had nonspecific malnutrition, 8% had protein-energy malnutrition, and 32% were without malnutrition. The 30-day readmission rate was 18.9%. Mortality in-hospital and at 90 days was 10.1% and 17.9%, respectively. Patients with nonspecific malnutrition had a 1.5-fold increased odds of 90-day mortality (adjusted odds ratio [OR], 1.51; 95% confidence interval [CI], 1.09-5.04; P = .009) and patients with protein-energy malnutrition had a 3.1-fold increased odds of 90-day mortality (adjusted OR, 3.06; 95% CI, 1.89-4.92; P < .001) compared with patients without malnutrition. CONCLUSION: In critically ill patients who undergo EGS, malnutrition at ICU admission is predictive of adverse outcomes. In survivors of hospitalization, malnutrition at ICU admission is associated with increases in readmission and mortality.

Severity of tricuspid regurgitation is associated with long-term mortality.

OBJECTIVES: To determine the association between intraoperative/presurgical grade of tricuspid regurgitation (TR) and mortality, and to determine whether surgical correction of TR correlated with an increased chance of survival compared with patients with uncorrected TR. METHODS: The grade of TR assessed by intraoperative transesophageal echocardiography (TEE) before surgical intervention was reviewed for 23,685 cardiac surgery patients between 1990 and 2014. Cox proportional hazard regression models were used to determine association between grade of TR and the primary endpoint of all-cause mortality. Association between tricuspid valve (TV) surgery and survival was determined with Cox proportional hazard regression models after matching for grade of TR. RESULTS: Kaplan-Meier survival curves demonstrated a relationship between all grades of TR. Multivariable analysis of the entire cohort demonstrated significantly increased mortality for moderate (hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.1-1.4; P < .0001) and severe TR (HR, 2.02; 95% CI, 1.57-2.6; P < .0001). Mild TR displayed a trend for mortality (HR, 1.07; 95% CI, 0.99-1.16; P = .075). After matching for grade of TR and additional confounders, patients who underwent TV surgery had a statistically significant increased likelihood of survival (HR, 0.74; 95% CI, 0.61-0.91; P = .004). CONCLUSIONS: Our study of more than 20,000 patients demonstrates that grade of TR is associated with increased risk of mortality after cardiac surgery. In addition, all patients who underwent TV surgery had a statistically significantly increased likelihood of survival compared with those with the same degree of TR who did not undergo TV surgery.

Aortic Atheroma Increases the Risk of Long-Term Mortality in 20,000 Patients.

BACKGROUND: The association between long-term survival and aortic atheroma in cardiac surgical patients has not been comprehensively investigated. In this study we determine the relation between grade of atheroma and the risk of long-term mortality in a retrospective cohort of more than 20,000 patients undergoing cardiac operation during a 20-year period. METHODS: We included 22,304 consecutive intraoperative transesophageal and epiaortic ultrasound examinations performed at Brigham and Women's Hospital between 1995 and 2014, with long-term follow-up. The extent of atheromatous disease recorded in each examination was used for analysis. Mortality data were obtained from our institution's data registry. Mortality analyses were done using Cox proportional hazard regression models with follow-up as a time scale. We repeated the analysis in a subgroup of 14,728 patients with more detailed demographic characteristics, including postoperative stroke, queried from the institutional Society of Thoracic Surgeons database. RESULTS: A total of 7,722 mortality events and 872 stroke events occurred. Patients with atheromatous disease demonstrated a significant increase in mortality across all grades of severity, both for the ascending and descending aorta. This relation remained unchanged after adjusting for additional covariates. Adjustments for postoperative stroke resulted in only minimal attenuation in the risk of postoperative mortality related to aortic atheroma. CONCLUSIONS: Aortic atheromatous disease of any grade in the ascending and descending aorta is a significant long-term risk of long-term, all-cause mortality in cardiac operation patients. This association remains independent of other conventional risk factors and is not related to postoperative cerebrovascular accidents.

Surgical outcomes of infective endocarditis among intravenous drug users.

BACKGROUND: With increasing prevalence of injected drug use in the United States, a growing number of intravenous drug users (IVDUs) are at risk for infective endocarditis (IE) that may require surgical intervention; however, few data exist about clinical outcomes of these individuals. METHODS: We evaluated consecutive adult patients undergoing surgery for active IE between 2002 and 2014 pooled from 2 prospective institutional databases. Death and valve-related events, including reinfection or heart valve reoperation, thromboembolism, and anticoagulation-related hemorrhage were evaluated. RESULTS: Of the 436 patients identified, 78 (17.9%) were current IVDUs. The proportion of IVDUs increased from 14.8% in 2002 to 2004 to 26.1% in 2012 to 2014. IVDUs were younger (aged 35.9 ± 9.9 years vs 59.3 ± 14.1 years) and had fewer cardiovascular risk factors than non-IVDUs. During follow-up (median, 29.4 months; quartile 1-3, 4.7-72.6 months), adverse events among all patients included death in 92, reinfection in 42, valve-reoperation in 35, thromboembolism in 17, and hemorrhage in 16. Operative mortality was lower among IVDUs (odds ratio, 0.25; 95% confidence interval [CI], 0.06-0.71), but overall mortality was not significantly different (hazard ratio [HR], 0.78; 95% CI, 0.44-1.37). When baseline profiles were adjusted by propensity score, IVDUs had higher risk of valve-related complications (HR, 3.82; 95% CI, 1.95-7.49; P < .001) principally attributable to higher rates of reinfection (HR, 6.20; 95% CI, 2.56-15.00; P < .001). CONCLUSIONS: The proportion of IVDUs among surgically treated IE patients is increasing. Although IVDUs have lower operative risk, long-term outcomes are compromised by reinfection.

Are homografts superior to conventional prosthetic valves in the setting of infective endocarditis involving the aortic valve?

BACKGROUND: Surgical dogma suggests that homografts should be used preferentially, compared with conventional xenograft or mechanical prostheses, in the setting of infective endocarditis (IE), because they have greater resistance to infection. However, comparative data that support this notion are limited. METHODS: From the prospective databases of 2 tertiary academic centers, we identified 304 consecutive adult patients (age ≥17 years) who underwent surgery for active IE involving the aortic valve (AV), in the period 2002 to 2014. Short- and long-term outcomes were evaluated using propensity scores and inverse-probability weighting to adjust for selection bias. RESULTS: Homografts, and xenograft and mechanical prostheses, were used in 86 (28.3%), 139 (45.7%), and 79 (26.0%) patients, respectively. Homografts were more often used in the setting of prosthetic valve endocarditis (58.1% vs 28.8%, P = .002) and methicillin-resistant Staphylococcus (25.6% vs 12.1%, P = .002), compared with conventional prostheses. Early mortality occurred in 17 (19.8%) in the homograft group, and 20 (9.2%) in the conventional group (P = .019). During follow-up (median: 29.4 months; interquartile-range: 4.7-72.6 months), 60 (19.7%) patients died, and 23 (7.7%) experienced reinfection, with no significant differences in survival (P = .23) or freedom from reinfection rates (P = .65) according to the types of prostheses implanted. After adjustments for baseline characteristics, using propensity-score analyses, use of a homograft did not significantly affect early death (odds ratio 1.61; 95% confidence interval [CI], 0.73-3.40, P = .23), overall death (hazard ratio 1.10; 95% CI, 0.62-1.94, P = .75), or reinfection (hazard ratio 1.04; 95% CI, 0.49-2.18, P = .93). CONCLUSIONS: No significant benefit to use of homografts was demonstrable with regard to resistance to reinfection in the setting of IE. The choice among prosthetic options should be based on technical and patient-specific factors. Lack of availability of homografts should not impede appropriate surgical intervention.

Nutritional Status and Mortality in the Critically Ill.

OBJECTIVES: The association between nutritional status and mortality in critically ill patients is unclear based on the current literature. To clarify this relation, we analyzed the association between nutrition and mortality in a large population of critically ill patients and hypothesized that mortality would be impacted by nutritional status. DESIGN: Retrospective observational study. SETTING: Single academic medical center. PATIENTS: Six thousand five hundred eighteen adults treated in medical and surgical ICUs between 2004 and 2011. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: All cohort patients received a formal, in-person, standardized evaluation by a registered dietitian. The exposure of interest, malnutrition, was categorized as nonspecific malnutrition, protein-energy malnutrition, or well nourished and determined by data related to anthropometric measurements, biochemical indicators, clinical signs of malnutrition, malnutrition risk factors, and metabolic stress. The primary outcome was all-cause 30-day mortality determined by the Social Security Death Master File. Associations between nutrition groups and mortality were estimated by bivariable and multivariable logistic regression models. Adjusted odds ratios were estimated with inclusion of covariate terms thought to plausibly interact with both nutrition status and mortality. We used propensity score matching on baseline characteristics to reduce residual confounding of the nutrition status category assignment. In the cohort, nonspecific malnutrition was present in 56%, protein-energy malnutrition was present in 12%, and 32% were well nourished. The 30-day and 90-day mortality rates for the cohort were 19.1% and 26.6%, respectively. Nutritional status is a significant predictor of 30-day mortality following adjustment for age, gender, race, medical versus surgical patient type, Deyo-Charlson index, acute organ failure, vasopressor use, and sepsis: nonspecific malnutrition 30-day mortality odds ratio, 1.17 (95% CI, 1.01-1.37); protein-energy malnutrition 30-day mortality odds ratio, 2.10 (95% CI, 1.70-2.59), all relative to patients without malnutrition. In the matched cohort, the adjusted odds of 30-day mortality in the group of propensity score-matched patients with protein-energy malnutrition was two-fold greater than that of patients without malnutrition. CONCLUSION: In a large population of critically ill adults, an association exists between nutrition status and mortality.

Influence of experience and the surgical learning curve on long-term patient outcomes in cardiac surgery.

OBJECTIVE: We hypothesized that increased postgraduate surgical experience correlates with improved operative efficiency and long-term survival in standard cardiac surgery procedures. METHODS: Utilizing a prospectively collected retrospective database, we identified patients who underwent isolated coronary artery bypass grafting (CABG) (n = 3726), aortic valve replacement (AVR) (n = 1626), mitral valve repair (n = 731), mitral valve replacement (MVR) (n = 324), and MVR + AVR (n = 184) from January 2002 through June 2012. After adjusting for patient risk and surgeon variability, we evaluated the influence of surgeon experience on cardiopulmonary bypass and crossclamp times, and long-term survival. RESULTS: Mean surgeon experience after fellowship graduation was 16.0 ± 11.7 years (range, 1.0-35.2 years). After adjusting for patient risk and surgeon-level fixed effects, learning curve analyses demonstrated improvements in cardiopulmonary bypass and crossclamp times with increased surgeon experience. There was marginal improvement in the predictability (R(2) value) of cardiopulmonary bypass and crossclamp time for CABG with the addition of surgeon experience; however, all other procedures had marked increases in the R(2) following addition of surgeon experience. Cox proportional hazard models revealed that increased surgeon experience was associated with improved long-term survival in AVR (hazard ratio [HR], 0.85; P < .0001), mitral valve repair (HR, 0.73; P < .0001), and MVR + AVR (HR, 0.95; P = .006) but not in CABG (HR, 0.80; P = .15), and a trend toward significance in MVR (HR, 0.87; P = .09). CONCLUSIONS: In cardiac surgery, not including CABG, surgeon experience is an important determinant of operative efficiency and of long-term survival.

Surgical Embolectomy for Acute Massive and Submassive Pulmonary Embolism in a Series of 115 Patients.

BACKGROUND: Pulmonary embolectomy is often indicated for central pulmonary embolism (PE) with hemodynamic instability, but remains controversial for hemodynamically stable patients with signs of right ventricular dysfunction. Because thrombolytic therapy is often contraindicated postoperatively, we reviewed risk factors and outcomes of pulmonary embolectomy for stable and unstable central PE, particularly in the early postoperative period. METHODS: Between October 1999 and September 2013, 115 patients underwent pulmonary embolectomy for central, hemodynamically unstable PE (49 of 115, 43%) or hemodynamically stable PE (56 of 115, 49%). Ten operations for alternate indications (right atrial mass, endocarditis) were excluded for comparison analysis, leaving 105 patients. RESULTS: Mean age was 59 ± 13 years; 46 of 105 patients (44%) had recent surgery (within 5 weeks): orthopedic (12 of 46, 25%), neurosurgery (11 of 46, 24%), or general surgery (10 of 46, 22%). Preoperative demographics did not differ between groups, except for the frequency of cardiopulmonary resuscitation among unstable patients (11 of 49, 22%) versus stable patients (0 of 56, 0%; p < 0.001). Operative mortality for the combined groups was 6.6% (7 of 105): unstable 10.2% (5 of 49) versus stable 3.6% (2 of 56; p = 0.247). Of 11 patients requiring preoperative cardiopulmonary resuscitation, 4 died. Six-month, 1-year, and 3-year survival rates were, respectively, 75%, 68.4%, and 65.8% for unstable PE, and 92.6%, 86.7%, and 80.4% for stable PE (p = 0.018). CONCLUSIONS: This large series of pulmonary embolectomies demonstrates excellent early and late survival rates for patients with stable PE and unstable PE. These findings confirm pulmonary embolectomy as a beneficial therapeutic option for central PE, especially during the postoperative period when thrombolytic therapy is often contraindicated.

Increased plasma catalytic iron in patients may mediate acute kidney injury and death following cardiac surgery.

Catalytic iron, the chemical form of iron capable of participating in redox cycling, is a key mediator of acute kidney injury (AKI) in multiple animal models, but its role in human AKI has not been studied. Here we tested in a prospective cohort of 250 patients undergoing cardiac surgery whether plasma catalytic iron levels are elevated and associated with the composite outcome of AKI requiring renal replacement therapy or in-hospital mortality. Plasma catalytic iron, free hemoglobin, and other iron parameters were measured preoperatively, at the end of cardiopulmonary bypass, and on postoperative days 1 and 3. Plasma catalytic iron levels, but not other iron parameters, rose significantly at the end of cardiopulmonary bypass and were directly associated with bypass time and number of packed red blood cell transfusions. In multivariate analyses adjusting for age and preoperative eGFR, patients in the highest compared with the lowest quartile of catalytic iron on postoperative day 1 had a 6.71 greater odds of experiencing the primary outcome, and also had greater odds of AKI, hospital mortality, and postoperative myocardial injury. Thus, our data are consistent with and expand on findings from animal models demonstrating a pathologic role of catalytic iron in mediating adverse postoperative outcomes. Interventions aimed at reducing plasma catalytic iron levels as a strategy for preventing AKI in humans are warranted.

The relationship among obesity, nutritional status, and mortality in the critically ill.

INTRODUCTION: The association between obesity and mortality in critically ill patients is unclear based on the current literature. To clarify this relationship, we analyzed the association between obesity and mortality in a large population of critically ill patients and hypothesized that mortality would be impacted by nutritional status. METHODS: We performed a single-center observational study of 6,518 adult patients treated in medical and surgical ICUs between 2004 and 2011. All patients received a formal, in-person, and standardized evaluation by a registered dietitian. Body mass index was determined at the time of dietitian consultation from the estimated dry weight or hospital admission weight and categorized a priori as less than 18.5 kg/m (underweight), 18.5-24.9 kg/m (normal/referent), 25-29.9 kg/m (overweight), 30-39.9 kg/m (obesity class I and II), and more than or equal to 40.0 kg/m (obesity class III). Malnutrition diagnoses were categorized as nonspecific malnutrition, protein-energy malnutrition, or well nourished. The primary outcome was all-cause 30-day mortality determined by the Social Security Death Master File. Associations between body mass index groups and mortality were estimated by bivariable and multivariable logistic regression models. Adjusted odds ratios were estimated with inclusion of covariate terms thought to plausibly interact with both body mass index and mortality. We utilized propensity score matching on baseline characteristics and nutrition status to reduce residual confounding of the body mass index category assignment. RESULTS: In the cohort, 5% were underweight, 36% were normal weight, 31% were overweight, 23% had class I/II obesity, and 5% had class III obesity. Nonspecific malnutrition was present in 56%, protein-energy malnutrition was present in 12%, and 32% were well nourished. The 30-day and 90-day mortality rate for the cohort was 19.1 and 26.6%, respectively. Obesity is a significant predictor of improved 30-day mortality following adjustment for age, gender, race, medical versus surgical patient type, Deyo-Charlson index, acute organ failure, vasopressor use, and sepsis: underweight odds ratio 30-day mortality is 1.09 (95% CI, 0.80-1.48), overweight 30-day mortality odds ratio is 0.93 (95% CI, 0.80-1.09), class I/II obesity 30-day mortality odds ratio is 0.80 (95% CI, 0.67-0.96), and class III obesity 30-day mortality odds ratio is 0.69 (95% CI, 0.49-0.97), all relative to patients with body mass index 18.5-24.9 kg/m. Importantly, there is confounding of the obesity-mortality association on the basis of malnutrition. Adjustment for only nutrition status attenuates the obesity-30-day mortality association: underweight odds ratio is 0.74 (95% CI, 0.54-1.00), overweight odds ratio is 1.05 (95% CI, 0.90-1.23), class I/II obesity odds ratio is 0.96 (95% CI, 0.81-1.15), and class III obesity odds ratio is 0.81 (95% CI, 0.59-1.12), all relative to patients with body mass index 18.5-24.9 kg/m. In a subset of patients with body mass index more than or equal to 30.0 kg/m (n = 1,799), those with either nonspecific or protein-energy malnutrition have increased mortality relative to well-nourished patients with body mass index more than or equal to 30.0 kg/m: odds ratio of 90-day mortality is 1.67 (95% CI, 1.29-2.15; p < 0.0001), fully adjusted. In a cohort of propensity score matched patients (n = 3,554), the body mass index-mortality association was not statistically significant, likely from matching on nutrition status. CONCLUSIONS: In a large population of critically ill adults, the association between improved mortality and obesity is confounded by malnutrition status. Critically ill obese patients with malnutrition have worse outcomes than obese patients without malnutrition.

Mitral valve repair versus replacement in the elderly: short-term and long-term outcomes.

OBJECTIVE: To compare the short-term and long-term outcomes of mitral valve repair (MVP) versus mitral valve replacement (MVR) in elderly patients. METHODS: All patients, age 70 years or greater, with mitral regurgitation who underwent MVP or MVR with or without coronary artery bypass graft (CABG), tricuspid valve surgery, or a maze procedure between 2002 and 2011 were retrospectively identified. Patients with a rheumatic cause or who underwent concomitant aortic valve or ventricular-assist device procedures were excluded. RESULTS: Overall, 556 patients underwent MVP and 102 patients underwent MVR. The mean age of the patients in the MVR group was 78 years versus 77 years for those in the MVP group (P<.02). The patients in the MVR group had a better mean left ventricular ejection fraction than those in the MVP group (60% vs 55%, P=.04). The incidence of concomitant CABG, tricuspid valve operations, and atrial fibrillation ablation procedures was similar in both groups, but perfusion time was significantly longer for the MVR group (median 177 minutes vs 146 minutes for MVP, P=.001). Postoperatively, patients in the MVR group had a higher incidence of stroke (6% vs 2%, P<.10) and significantly longer intensive care unit stay (median 86 hours vs 55 hours, P=.001) and hospital stay (9 days vs 8 days, P<.01). Operative mortality of patients was significantly higher for the MVR group (8.8% vs 3.6%, P=.03) and remained significant long-term on Kaplan-Meier analysis. Cox regression analysis of all 658 patients and propensity-matched analysis of 96 patients also confirmed these results. CONCLUSIONS: Elderly patients with mitral regurgitation who undergo MVP have better postoperative outcomes, lower operative mortality, and improved long-term survival than those undergoing MVR. MVP is a safe and more effective option for the elderly with mitral regurgitation.

Usefulness of preoperative cardiac dimensions to predict success of reverse cardiac remodeling in patients undergoing repair for mitral valve prolapse.

Mitral valve repair for mitral regurgitation (MR) is currently recommended based on the degree of MR and left ventricular (LV) function. The present study examines predictors of reverse remodeling after repair for degenerative disease. We retrospectively identified 439 patients who underwent repair for myxomatous mitral valve degeneration and had both pre- and postoperative echocardiographic data available. Patients were categorized based on left atrial (LA) diameter and LV diameter standards of the American Society of Echocardiography. The outcome of interest was the degree of reverse remodeling on all heart dimensions at follow-up. Mean age was 57 ± 12 years, and 37% of patients were women. Mean preoperative LV end-diastolic diameter was 5.8 ± 0.7 cm, LV end-systolic diameter 3.5 ± 0.6 cm, LA 4.7 ± 0.7 cm, and median ejection fraction 60%. Median observation time was 81 months, and time to postoperative echocardiography was 38 months. Overall, 95% of patients had normal LV diastolic dimensions postoperatively, 93% normal LV systolic dimensions, and 37% normal LA dimensions. A Cox regression analysis showed that moderate (odds ratio [OR] 2.1, 95% confidence interval [CI] 1.3 to 3.4) or severe preoperative LA dilatation (OR 2.7, 95% CI 1.7 to 4.4), abnormal preoperative LV end-systolic dimensions (OR 1.3, 95% CI 1.1 to 1.5), and age in years (OR 1.02, 95% CI 1.01 to 1.03) were predictive of less reverse remodeling on follow-up. In conclusion, preoperative LV end-systolic dimensions and LA dilatation substantially affect the likelihood of successful LA remodeling and normalization of all heart dimensions after mitral valve repair for MR. These findings support early operation for MR before the increase in heart dimensions is nonreversible.

Cumulative team experience matters more than individual surgeon experience in cardiac surgery.

OBJECTIVES: Individual surgeon experience and the cumulative experience of the surgical team have both been implicated as factors that influence surgical efficiency. We sought to quantitatively evaluate the effects of both individual surgeon experience and the cumulative experience of attending surgeon-cardiothoracic fellow collaborations in isolated coronary artery bypass graft (CABG) procedures. METHODS: Using a prospectively collected retrospective database, we analyzed all medical records of patients undergoing isolated CABG procedure at our institution. We used multivariate generalized estimating equation regression models to adjust for patient mix and subsequently evaluated the effect of both attending cardiac surgeon experience (since fellowship graduation) and the number of previous collaborations between attending cardiac surgeons and cardiothoracic fellow pairs on cardiopulmonary bypass and crossclamp times. RESULTS: From 2001 to 2010, 4068 consecutive patients underwent isolated CABG procedure at our institution performed by 11 attending cardiac surgeons and 73 cardiothoracic fellows. Mean attending experience after fellowship graduation was 10.9 ± 8.0 years and mean number of cases between unique pairs of attending cardiac surgeons and cardiothoracic fellows was 10.0 ± 10.0 cases. After patient risk adjustment, both attending surgical experience since fellowship graduation and the number of previous collaborations between attending surgeons and cardiothoracic fellows were significantly associated with a reduction in cardiopulmonary bypass and crossclamp times (P < .001). The influence of attending-fellow pair experience far exceeded the influence of surgical experience with beta estimates for attending-fellow pair experience nearly three times that of attending surgeon experience. CONCLUSIONS: Cumulative experience of attending cardiac surgeons and cardiothoracic fellows has a dramatic effect on both cardiopulmonary bypass and crossclamp times, whereas attending cardiac surgeon learning curves following fellowship graduation are clinically insignificant. Taken together, these findings suggest that the primary driver of operative efficiency in CABG procedure is the collaborative experience of the attending surgeon-cardiothoracic fellow operative team, rather than the individual experience of the attending surgeon.

Predictors of hyperglycemia after cardiac surgery in nondiabetic patients.

OBJECTIVE: Postoperative hyperglycemia is associated with poor clinical outcomes in patients undergoing cardiac surgery. However, some experts consider hyperglycemia to be an epiphenomenon related to acute stress. We investigated whether preoperative patient characteristics can predict hyperglycemia after cardiac surgery in nondiabetic patients. METHODS: This is a retrospective study of nondiabetic patients undergoing cardiac surgery at a single center during the years 2004 to 2009. Hyperglycemia was defined as 2 consecutive blood glucose readings of 150 mg/dL or greater during the 72 hours after cardiac surgery. RESULTS: This study included 1453 patients with hyperglycemia and 2205 patients without hyperglycemia. Hyperglycemic patients were older, were more likely to be men, had higher body mass index, were more likely to be hypertensive and hypercholesterolemic, and had lower left ventricular ejection fractions; in addition, a greater proportion had a history of cardiovascular disease and renal failure. Multivariate logistic regression analysis showed age, gender, body mass index, preoperative serum creatinine, left ventricular ejection fraction, previous cardiac surgery, and preoperative cardiogenic shock to be independently associated with hyperglycemia (P < .05 for all). Hyperglycemic patients had more intraoperative and postoperative complications. CONCLUSIONS: Preoperative patient characteristics are associated with hyperglycemia after cardiac surgery.

The "no-dissection" technique is safe for reoperative aortic valve replacement with a patent left internal thoracic artery graft.

OBJECTIVE: Management of a patent left internal thoracic artery graft during reoperation is controversial. The "no-dissection" technique avoids dissection and clamping of the left internal thoracic artery graft, and myocardial protection is achieved using adjunctive systemic hypothermia and hyperkalemia. We compared the postoperative outcomes after isolated reoperative aortic valve replacement in patients with previous coronary artery bypass grafting with a patent left internal thoracic artery graft using a no-dissection technique with the outcomes of patients with previous coronary artery bypass grafting without a left internal thoracic artery graft. METHODS: The outcomes were analyzed for patients who underwent isolated reoperative aortic valve replacement with previous coronary artery bypass grafting from January 1, 2002, to June, 30, 2011. Patency of the left internal thoracic artery was confirmed using either coronary angiography or computed tomography angiography. The patent left internal thoracic artery group did not undergo dissection or clamping of the left internal thoracic artery graft, and myocardial protection was obtained using systemic hypothermia and hyperkalemia. The no left internal thoracic artery group underwent isolated aortic valve replacement with previous coronary artery bypass grafting but had no left internal thoracic artery graft. RESULTS: A total 174 patients were identified for the patent left internal thoracic artery group and 26 for the no left internal thoracic artery group. The perfusion and crossclamp times were similar. No differences were seen between the 2 groups in operative mortality (6.9% vs 7.7%, P = 1.00). The complication rates were similar, and the peak creatine kinase-MB values within 24 hours of surgery were not significantly different between the 2 groups (median, 27.4 vs 29 µ/mL; P = .72). CONCLUSIONS: Reoperative aortic valve replacement in patients with previous coronary artery bypass grafting and a patent left internal thoracic artery graft can be performed safely without dissection or clamping of the left internal thoracic artery using systemic hyperkalemia and hypothermia. We believe this method prevents unnecessary injury during dissection of the left internal thoracic artery graft.