Prateek K. Gupta

Preoperative anemia is an independent predictor of postoperative mortality and adverse cardiac events in elderly patients undergoing elective vascular operations.

Objective: The objective of this study was to assess the impact of preoperative anemia (hematocrit <39%) on postoperative 30-day mortality and adverse cardiac events in patients 65 years or older undergoing elective vascular procedures. Background: Preoperative anemia is associated with adverse outcomes after cardiac surgery, but its association with postoperative outcomes after open and endovascular procedures is not well established. Elderly patients have a decreased tolerance to anemia and are at high risk for complications after vascular procedures. Methods: Patients (N = 31,857) were identified from the American College of Surgeons 2007–2009 National Surgical Quality Improvement Program—a prospective, multicenter (>250) database maintained across the United States. The primary and secondary outcomes of interest were 30-day mortality and a composite end point of death or cardiac event (cardiac arrest or myocardial infarction), respectively. Results: Forty-seven percent of the study population was anemic. Anemic patients had a postoperative mortality and cardiac event rate of 2.4% and 2.3% in contrast to the 1.2% and 1.2%, respectively, in patients with hematocrit within the normal range (P < 0.0001). On multivariate analysis, we found a 4.2% (95% confidence interval, 1.9–6.5) increase in the adjusted risk of 30-day postoperative mortality for every percentage point of hematocrit decrease from the normal range. Conclusions: The presence and degree of preoperative anemia are independently associated with 30-day death and adverse cardiac events in patients 65 years or older undergoing elective open and endovascular procedures. Identification and treatment of anemia should be important components of preoperative care for patients undergoing vascular operations.

Development and Validation of a Risk Calculator for Predicting Postoperative Pneumonia

OBJECTIVEnTo identify preoperative factors associated with an increased risk of postoperative pneumonia and subsequently develop and validate a risk calculator.nnnPATIENTS AND METHODSnThe American College of Surgeons National Surgical Quality Improvement Program, a multicenter, prospective data set (2007-2008) was used. Univariate and multivariate logistic regression analyses were performed. The 2007 data set (N=211,410) served as the training set, and the 2008 data set (N=257,385) served as the validation set.nnnRESULTSnIn the training set, 3825 patients (1.8%) experienced postoperative pneumonia. Patients who experienced postoperative pneumonia had a significantly higher 30-day mortality (17.0% vs 1.5%; P<.001). On multivariate logistic regression analysis, 7 preoperative predictors of postoperative pneumonia were identified: age, American Society of Anesthesiologists class, chronic obstructive pulmonary disease, dependent functional status, preoperative sepsis, smoking before operation, and type of operation. The risk model based on the training data set was subsequently validated on the validation data set, with model performance being very similar (C statistic: 0.860 and 0.855, respectively). The high C statistic indicates excellent predictive performance. The risk model was used to develop an interactive risk calculator.nnnCONCLUSIONnPreoperative variables associated with an increased risk of postoperative pneumonia include age, American Society of Anesthesiologists class, chronic obstructive pulmonary disease, dependent functional status, preoperative sepsis, smoking before operation, and type of operation. The validated risk calculator provides a risk estimate for postoperative pneumonia and is anticipated to aid in surgical decision making and informed patient consent.

Unplanned readmissions after vascular surgery

OBJECTIVEnExisting literature on readmission after vascular surgery is limited. The upcoming reduction in Medicare reimbursement for institutions with high readmission rates mandates an accurate understanding of this issue. In this study, we characterize the frequency and causes of 30-day unplanned readmissions after elective vascular surgery.nnnMETHODSnPatients who underwent elective carotid endarterectomy (CEA), endovascular aortic repair (EVAR), open abdominal aortic aneurysm (oAAA) repair, or infrainguinal bypass grafting (BPG) were identified from the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) 2011 database (n = 11,246). Multivariable logistic regression was used to determine variables that contributed to 30-day unplanned readmissions for each surgery type.nnnRESULTSnThe unadjusted unplanned readmission rates after the four vascular procedures ranged from 6.5% for CEA to 15.7% for BPG. In multivariable analyses, patient comorbidities were associated with unplanned readmission after BPG and CEA (P < .05), whereas postoperative complications were more consistently associated with unplanned readmission after EVAR and oAAA repair (P < .05). For all procedures, complications leading to readmission developed more frequently after discharge. Thirty-day mortality was significantly higher in readmitted patients after BPG (1.9% vs 0.3%), EVAR (3.9% vs 0.1%), and CEA (2.2% vs 0.2%; P < .001 for each), but not after oAAA repair.nnnCONCLUSIONSnSelect comorbidities and postoperative complications contribute to unplanned readmissions after vascular surgery. The characteristics of readmitted patients vary with the type of procedure. Interventions designed to mitigate these factors have the potential to reduce unplanned readmissions but likely need to vary with the type of vascular treatment.

A comparison of open surgery versus endovascular repair of unstable ruptured abdominal aortic aneurysms.

OBJECTIVEnTwo randomized trials to date have compared open surgery (OS) and endovascular (EVAR) repair for ruptured abdominal aortic aneurysm (rAAA); however, neither addressed optimal management of unstable patients. Single-center reports have produced conflicting data regarding the superiority of one vs the other, with the lack of statistical power due to low patient numbers. Furthermore, previous studies have not delineated between the outcomes of stable patients with a contained rupture vs those patients with instability. Our objective was to compare 30-day outcomes in patients undergoing OS vs EVAR for all rAAAs, focusing specifically on patients with instability.nnnMETHODSnPatients who underwent repair of rAAA were identified from the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database (2005 to 2010). Unstable patients with rupture were identified as those who were American Society of Anesthesiologists Physical Status Classification 4 or 5 requiring emergency repair with at least one of the following: preoperative shock, preoperative transfusion of >4 units, preoperative intubation, or preoperative coma or impaired sensorium. Univariable and multivariable logistic regression analyses were performed.nnnRESULTSnOf the 1447 patients with rAAA, 65.5% underwent OS and 34.5% EVAR. Forty-five percent were unstable, and for these patients, OS was performed in 71.3% and EVAR in 28.7%. The 30-day mortality rate was 47.9% (OS, 52.8%; EVAR, 35.6%; P < .0001) for unstable rAAAs and was 22.4% for stable rAAAs (OS, 26.3%; EVAR, 16.4%; P = .001). Amongst patients with unstable rAAA, 26% had a myocardial infarction or cardiac arrest ≤ 30 days (OS, 29.0%; EVAR, 19.1%; P = .006), and 17% needed postoperative dialysis (OS, 18.7%; EVAR, 12.8%; P = .04). Amongst patients with stable rAAA, 13.6% had a myocardial infarction or cardiac arrest ≤ 30 days (OS, 14.9%; EVAR, 11.6%; P = .20), and 11.5% needed postoperative dialysis (OS, 13.3%; EVAR, 8.7%; P = .047). Multivariable analyses showed OS was a predictor of 30-day mortality for unstable rAAA (odds ratio, 1.74; 95% confidence interval, 1.16-2.62) and stable rAAA (odds ratio, 1.64; 95% confidence interval, 1.10-2.43).nnnCONCLUSIONSnApproximately one-third of patients treated for rAAA undergo EVAR in NSQIP participating hospitals. Not surprisingly, unstable patients have less favorable outcomes. In both stable and unstable rAAA patients, EVAR is associated with a diminished 30-day mortality and morbidity.

Impact of COPD on Postoperative Outcomes: Results From a National Database

BACKGROUNDnAlthough COPD affects large sections of the population, its effects on postoperative outcomes have not been rigorously studied. The objectives of this study were to describe the prevalence of COPD in patients undergoing surgery and to analyze the associations between COPD and postoperative morbidity, mortality, and hospital length of stay.nnnMETHODSnPatients with COPD who underwent surgery were identified from the National Surgical Quality Improvement Program database (2007-2008). Univariate and multivariate analyses were performed on this multicenter, prospective data set (N = 468,795).nnnRESULTSnCOPD was present in 22,576 patients (4.82%). These patients were more likely to be older, men, white, smokers, and taking corticosteroids and had a lower BMI (P < .0001 for each). Median length of stay was 4 days for patients with COPD vs 1 day in those without COPD (P < .0001). Thirty-day morbidity rates were 25.8% and 10.2% for patients with and without COPD, respectively (P < .0001). Thirty-day death rates were 6.7% and 1.4% for patients with and without COPD, respectively (P < .0001). After controlling for > 50 comorbidities through logistic regression modeling, COPD was independently associated with higher postoperative morbidity (OR, 1.35; 95% CI, 1.30-1.40; P < .0001) and mortality (OR, 1.29; 95% CI, 1.19-1.39; P < .0001). Multivariate analyses with each individual postoperative complication as the outcome of interest showed that COPD was associated with increased risk for postoperative pneumonia, respiratory failure, myocardial infarction, cardiac arrest, sepsis, return to the operating room, and renal insufficiency or failure (P < .05 for each).nnnCONCLUSIONSnCOPD is common among patients undergoing surgery and is associated with increased morbidity, mortality, and length of stay.

Clinical characteristics associated with readmission among patients undergoing vascular surgery

OBJECTIVEnReadmission after a vascular surgery intervention is frequent, costly, and often considered preventable. Vascular surgery outcomes have recently been scrutinized by Medicare because of the high rates of readmission. We determined patient and clinical characteristics associated with readmission in a cohort of vascular surgery patients.nnnMETHODSnFrom 2009 to 2013, the medical records of all patients (n = 2505) undergoing interventions by the vascular surgery service at a single tertiary care institution were retrospectively reviewed. Sociodemographic and clinical characteristics were examined for association with 30-day readmission to the same institution.nnnRESULTSnThe 30-day readmission rate to the same institution was 9.7 % (n = 244). Procedures most likely to result in readmission were below-knee (25%), foot (22%), and toe amputations (19%), as well as lower extremity revascularization (22%). Patients covered by Medicaid (16.8%) and Medicare (10.0%) were most likely to be readmitted, followed by fee-for-service (9.5%), self-pay (8.0%), and health maintenance organizations (5.5%; P < .05). Patients urgently admitted were more likely to be readmitted (16.2%) than those electively admitted (9.1%; P < .01). Patient severity as rated using the All Patient Refined Diagnosis Related Groups software (3M Health Information Systems, Wallingford, Conn) predicted readmission (16.2% high vs 6.2% low severity; P < .01). Initial length of stay was longer for readmitted than nonreadmitted patients (8.5 vs 6.1 days, respectively; P < .01). Intensive care unit admission during the initial hospitalization was associated with higher readmission rates in univariable analysis (18.3% with vs 9.5% without intensive care unit stay; P < .05). Discharge destination was also a strong predictor of readmission (rehabilitation, 19.2%; skilled nursing facility, 16.2%; home, 6.2%; P < .01). The effects of urgent admission, proximity to hospital, length of stay, lower extremity open procedure or amputation, and discharge destination persisted in multivariable logistic regression (P < .05).nnnCONCLUSIONSnTo reduce readmission rates effectively, institutions must identify high-risk patients. Efforts should focus on subgroups undergoing selected interventions (amputations, lower extremity revascularization), those with urgent admissions, and patients with extended hospital stays. Patients in need of postacute care upon discharge are especially prone to readmission, requiring special attention to discharge planning and coordination of postdischarge care. By focusing on subgroups at risk for readmission, preventative resources can be efficiently targeted.

Risk index for predicting perioperative stroke, myocardial infarction, or death risk in asymptomatic patients undergoing carotid endarterectomy

OBJECTIVEnThe latest guidelines recommend performance of carotid endarterectomy (CEA) on asymptomatic patients with high-grade carotid stenosis, only if the combined perioperative stroke, myocardial infarction (MI), or death risk is ≤3%. Our objective was to develop and validate a risk index to estimate the combined risk of perioperative stroke, MI, or death in asymptomatic patients undergoing elective CEA.nnnMETHODSnAsymptomatic patients who underwent an elective CEA (nxa0= 17,692) were identified from the 2005-2010 National Surgical Quality Improvement Program, a multicenter, prospective database. Multivariable logistic regression analysis was performed with primary outcome of interest being the composite of any stroke, MI, or death during the 30-day periprocedural period. Bootstrapping was used for internal validation. A risk index was created by assigning weighted points to each predictor using the β-coefficients from the regression analysis.nnnRESULTSnFifty-eight percent of the patients were men with a median age of 72 years. Thirty-day incidences of stroke, MI, and death were 0.9% (nxa0= 167), 0.6% (nxa0= 108), and 0.4% (nxa0= 72), respectively. The combined 30-day stroke, MI, or death incidence was 1.8% (nxa0= 324). On multivariable analysis, six independent predictors were identified and a risk index created by assigning weighted points to each predictor using the β-coefficients from the regression analysis. The predictors included age in years (<60: 0 point; 60-69: -1 point; 70-79: -1 point; ≥80: 2 points), dyspnea (2 points), chronic obstructive pulmonary disease (3 points), previous peripheral revascularization or amputation (3 points), recent angina within 1 month (4 points), and dependent functional status (5 points). Patients were classified as low (<3%),xa0intermediate (3%-6%), or high (>6%) risk for combined 30-day stroke, MI, or death, based on a total point score ofxa0<4, 4-7, and >7, respectively. There were 15,249 patients (86.2%) in the low-risk category, 2233 (12.6%) in the intermediate-risk category, and 210 (1.2%) in the high-risk category.nnnCONCLUSIONSnThe validated risk index can help identify asymptomatic patients who are at greatest risk for 30-day stroke, MI, and death after CEA, thereby aiding patient selection.

Preoperative frailty Risk Analysis Index to stratify patients undergoing carotid endarterectomy.

OBJECTIVEnRapid and objective preoperative assessment of patients undergoing carotid endarterectomy (CEA) remains problematic. Preoperative variables correlate with increased morbidity and mortality, yet no easily implemented tool exists to stratify patients. We determined the relationship between our fully implemented frailty-based bedside Risk Analysis Index (RAI) and complications after CEA.nnnMETHODSnPatients undergoing CEA in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database from 2005 to 2011 were included. Variables of frailty RAI were matched to preoperative NSQIP variables, and outcomes including stroke, mortality, myocardial infarction (MI), and length of stay were analyzed. We further analyzed patients who were symptomatic and asymptomatic before CEA.nnnRESULTSnWith use of the NSQIP database, 44,832 patients undergoing CEA were analyzed (17,696 [39.5%] symptomatic; 27,136 [60.5%] asymptomatic). Increasing frailty RAI score correlated with increasing stroke, death, and MI (P < .0001) as well as with length of stay. RAI demonstrated increasing risk of stroke and death on the basis of risk stratification (low risk [0-10], 2.1%; high risk [>10], 5.0%). Among patients undergoing CEA, 88% scored low (<10) on the RAI. In symptomatic patients, the risk of stroke and death for patients with a score of ≤10 is 2.9%, whereas if the RAI score is 11 to 15, it is 5.0%; 16 to 20, 6.9%; and >21, 8.6%. In asymptomatic patients, the risk of stroke and death for patients with a score of ≤10 is 1.6%, whereas if the RAI score is 11 to 15, it is 2.9%; 16 to 20, 5.2%; and >21, 6.2%.nnnCONCLUSIONSnFrailty is a predictor of increased stroke, mortality, MI, and length of stay after CEA. An easily implemented RAI holds the potential to identify a limited subset of patients who are at higher risk for postoperative complications and may not benefit from CEA.

Development of a risk index for prediction of mortality after open aortic aneurysm repair

OBJECTIVEnOpen infrarenal abdominal aortic aneurysm (oAAA) repair is associated with significant morbidity and mortality. Although there has been a shift toward endovascular repair, many patients continue to undergo an open repair due to anatomic considerations. Tools currently existing for estimation of periprocedural risk in patients undergoing open aortic surgery have certain limitations. The objective of this study was to develop a risk index to estimate the risk of 30-day perioperative mortality after elective oAAA repair.nnnMETHODSnPatients who underwent elective oAAA repair (n = 2845) were identified from the American College of Surgeons 2007 to 2009 National Surgical Quality Improvement Program (NSQIP), a prospective database maintained at >250 centers. Univariable and multivariable analyses were performed to evaluate risk factors associated with 30-day mortality after oAAA repair and a risk index was developed.nnnRESULTSnThe 30-day mortality after oAAA repair was 3.3%. Multivariable analysis identified six preoperative predictors of mortality, and a risk index was created by assigning weighted points to each predictor using the β-coefficients from the regression analysis. The predictors included dyspnea (at rest: 8 points; on moderate exertion: 2 points; none: 0 points), history of peripheral arterial disease requiring revascularization or amputation (3 points), age >65 years (3 points), preoperative creatinine >1.5 mg/dL (2 points), female gender (2 points), and platelets <150,000/mm(3) or >350,000/mm(3) (2 points). Patients were classified as low (<7%), intermediate (7%-15%), and high (>15%) risk for 30-day mortality based on a total point score of <8, 8 to 11, and >11, respectively. There were 2508 patients (88.2%) patients in the low-risk category, 278 (9.8%) in the intermediate-risk category, and 59 (2.1%) in the high-risk category.nnnCONCLUSIONSnThis risk index has excellent predictive ability for mortality after oAAA repair and awaits validation in subsequent studies. It is anticipated to aid patients and surgeons in informed patient consent, preoperative risk assessment, and optimization.

In-hospital and postdischarge venous thromboembolism after vascular surgery

OBJECTIVEnRecent single-center reports demonstrate a high (up to 10%) incidence of postoperative venous thromboembolism (VTE) after major vascular surgery. Moreover, vascular patients rarely receive prolonged prophylaxis despite evidence that it reduces thromboembolic events after discharge. This study used a national, prospective, multicenter database to define the incidence of overall and postdischarge VTE after major vascular operations and assess risk factors associated with VTE development.nnnMETHODSnPatients with VTE who underwent elective vascular procedures (nxa0= 45,548) were identified from the 2007-2009 National Surgical Quality Improvement Program (NSQIP) database. The vascular procedures included carotid endarterectomy (CEA; nxa0= 20,785), open thoracoabdominal aortic aneurysm (TAAA) repair (nxa0= 361), thoracic endovascular aortic repair (TEVAR; nxa0= 732), open abdominal aortic (OAA) surgery (nxa0= 6195), endovascular aneurysm repair (EVAR; nxa0= 7361), and infrainguinal bypass graft (BPG; nxa0= 10,114). Univariable and multivariable analyses were performed to ascertain risk factors associated with VTE.nnnRESULTSnVTE was diagnosed in 187 patients (1.3 %) who underwent aortic surgery, with TAAA repair having the highest rate of VTE (4.2%), followed by TEVAR (2.2%), OAA surgery (1.7%), and EVAR (0.7%). In this subgroup, pulmonary embolisms (PE) were diagnosed in 52 (0.4%) and deep venous thrombosis (DVT) in 144 (1%). VTE rates were 1.0% and 0.2% for patients who underwent a BPG or CEA, respectively. Forty-one percent of all VTEs were diagnosed after discharge. The median (interquartile range) number of days from surgery to PE and DVT were 10 (5-15) and 10 (4-18), respectively. On multivariable analyses, type of surgical procedure, totally dependent functional status, disseminated cancer, postoperative organ space infection, postoperative cerebrovascular accident, failure to wean from ventilator ≤48 hours, and return to the operating room were significantly associated with development of VTE. In those experiencing a DVT or PE, overall mortality increased from 1.5% to 6.2% and from 1.5% to 5.7% respectively (Pxa0< .05 for both).nnnCONCLUSIONSnPostoperative VTE is associated with the type of vascular procedure and is highest after operations in the chest and abdomen/pelvis. About 40% of VTE events in elective vascular surgery patients were diagnosed after discharge, and the presence of VTE was associated with a quadrupled mortality rate. Future studies should evaluate the benefit of DVT screening and postdischarge VTE prophylaxis in high-risk patients.