Trends and In-Hospital Mortality for Perioperative Myocardial Infarction After the Introduction of a Diagnostic Code for Type 2 Myocardial Infarction in the United States Between 2016 and 2018.

BACKGROUND: The frequency of perioperative myocardial infarction has been declining; however, previous studies have only described type 1 myocardial infarctions. Here, we evaluate the overall frequency of myocardial infarction with the addition of an International Classification of Diseases 10th revision (ICD-10-CM) code for type 2 myocardial infarction and the independent association with in-hospital mortality. METHODS: A longitudinal cohort study spanning the introduction of the ICD-10-CM diagnostic code for type 2 myocardial infarction using the National Inpatient Sample (NIS) from 2016 to 2018. Hospital discharges that included a primary surgical procedure code for intrathoracic, intraabdominal, or suprainguinal vascular surgery were included. Type 1 and type 2 myocardial infarctions were identified using ICD-10-CM codes. We used segmented logistic regression to estimate change in frequency of myocardial infarctions and multivariable logistic regression to determine the association with in-hospital mortality. RESULTS: A total of 360,264 unweighted discharges were included, representing 1,801,239 weighted discharges, with median age 59 and 56% female. The overall incidence of myocardial infarction was 0.76% (13,605/1,801,239). Before the introduction of type 2 myocardial infarction code, there was a small baseline decrease in the monthly frequency of perioperative myocardial infarctions (odds ratio [OR], 0.992; 95% confidence interval [CI], 0.984-1.000; P = .042), but no change in the trend after the introduction of the diagnostic code (OR, 0.998; 95% CI, 0.991-1.005; P = .50). In 2018, where there was an entire year where type 2 myocardial infarction was officially a diagnosis, the distribution of myocardial infarction type 1 was 8.8% (405/4580) ST elevation myocardial infarction (STEMI), 45.6% (2090/4580) non-ST elevation myocardial infarction (NSTEMI), and 45.5% (2085/4580) type 2 myocardial infarction. STEMI and NSTEMI were associated with increased in-hospital mortality (OR, 8.96; 95% CI, 6.20-12.96; P < .001 and OR, 1.59; 95% CI, 1.34-1.89; P < .001). A diagnosis of type 2 myocardial infarction was not associated with increased odds of in-hospital mortality (OR, 1.11; 95% CI, 0.81-1.53; P = .50) when accounting for surgical procedure, medical comorbidities, patient demographics, and hospital characteristics. CONCLUSIONS: The frequency of perioperative myocardial infarctions did not increase after the introduction of a new diagnostic code for type 2 myocardial infarctions. A diagnosis of type 2 myocardial infarction was not associated with increased in-patient mortality; however, few patients received invasive management that may have confirmed the diagnosis. Further research is needed to identify what type of intervention, if any, may improve outcomes in this patient population.

Preoperative ß-Blocker Therapy and Stroke or Major Adverse Cardiac Events in Major Abdominal Surgery: A Retrospective Cohort Study.

BACKGROUND: Perioperative ß-blocker therapy has been associated with increased risk of stroke. However, the association between ß-blocker initiation before the day of surgery and the risk of stroke is unknown. The authors hypothesized there would be no association between preoperative ß-blocker initiation within 60 days of surgery or chronic ß-blockade (more than 60 days) and the risk of stroke in patients undergoing major abdominal surgery. METHODS: Data on elective major abdominal surgery were obtained from the IBM (USA) Truven Health MarketScan 2005 to 2015 Commercial and Medicare Supplemental Databases. Patients were stratified by ß-blocker dispensing exposure: (1) ß-blocker-naïve, (2) preoperative ß-blocker initiation within 60 days of surgery, and (3) chronic ß-blocker dispensing (more than 60 days). The authors compared in-hospital stroke and major adverse cardiac events between the different ß-blocker therapy exposures. RESULTS: There were 204,981 patients who underwent major abdominal surgery. ß-Blocker exposure was as follows: perioperative initiation within 60 days of surgery for 4,026 (2.0%) patients, chronic ß-blocker therapy for 45,424 (22.2%) patients, and ß-blocker-naïve for 155,531 (75.9%) patients. The unadjusted frequency of stroke for patients with ß-blocker initiation (0.4%, 17 of 4,026) and chronic ß-blocker therapy (0.4%, 171 of 45,424) was greater than in ß-blocker-naïve patients (0.2%, 235 of 155,531; P < 0.001). After propensity score weighting, patients initiated on a ß-blocker within 60 days of surgery (odds ratio, 0.90; 95% CI, 0.31 to 2.04; P = 0.757) or on chronic ß-blocker therapy (odds ratio, 0.86; 95% CI, 0.65 to 1.15; P = 0.901) demonstrated similar stroke risk compared to ß-blocker-naïve patients. Patients on chronic ß-blocker therapy demonstrated lower adjusted risk of major adverse cardiac events compared to ß-blocker-naïve patients (odds ratio, 0.81; 95% CI, 0.72 to 0.91; P = 0.007), despite higher unadjusted absolute event rate (2.6% [1,173 of 45,424] vs. 0.6% [872 of 155,531]). CONCLUSIONS: Among patients undergoing elective major abdominal surgery, the authors observed no association between preoperative ß-blocker initiation within 60 days of surgery or chronic ß-blocker therapy and stroke.

Perioperative Ischemic Optic Neuropathy after Cardiac Surgery: Development and Validation of a Preoperative Risk Prediction Model.

OBJECTIVE: Previous studies identified risk factors for ischemic optic neuropathy (ION) after cardiac surgery; however, there is no easy-to-use risk calculator for the physician to identify high-risk patients for ION before cardiac surgery. The authors sought to develop and validate a simple-to-use predictive model and calculator to assist with preoperative identification of risk and informed consent for this rare but serious complication. DESIGN: Retrospective case-control study. SETTING: Hospital discharge records. PATIENTS: A total of 5,561,177 discharges in the National Inpatient Sample >18 years of age, with procedure codes for coronary artery bypass grafting, heart valve repair/replacement, or left ventricular assist device insertion. INTERVENTIONS: All patients had undergone cardiac surgery. MEASUREMENTS AND MAIN RESULTS: Known preoperative risk factors for ION after cardiac surgery were assessed to develop a risk score and prediction model. This model was validated internally using the split-sample method. There were 771 cases of ION among 5,561,177 patients in the National Inpatient Sample. The risk factors for ION used in the model were carotid artery stenosis, cataract, diabetic retinopathy, macular degeneration, glaucoma, male sex, and prior stroke; whereas uncomplicated diabetes decreased risk. With the internal validation, the predictive model had an area under the receiver operating characteristic curve of 0.66. A risk score cutoff ≥3 had 98.4% specificity. CONCLUSIONS: This predictive model, based on previously identified preoperative factors, predicted risk of perioperative ION with a fair area under the receiver operating characteristic curve. This predictive model could enable screening to provide a more accurate risk assessment for ION, and consent process for cardiac surgery.

Evaluation of Appropriate Use of Preoperative Echocardiography before Major Abdominal Surgery: A Retrospective Cohort Study.

BACKGROUND: Preoperative resting echocardiography is often performed before noncardiac surgery, but indications for preoperative resting echocardiography are limited. This study aimed to investigate appropriateness of preoperative resting echocardiography using the Appropriate Use Criteria for Echocardiography, which encompass indications from the guidelines on perioperative cardiovascular evaluation and management and nonperioperative indications independent of the perioperative period. The authors hypothesized that patients are frequently tested without an appropriate indication. METHODS: Records of patients in the Truven Health MarketScan Commercial and Medicare Supplemental Databases who underwent a major abdominal surgery from 2005 to 2017 were included. These databases contain de-identified records of health services for more than 250 million patients with primary or Medicare supplemental health insurance coverage through employer-based fee-for-service, point-of-service, or capitated plans. Patients were classified based on the presence of an outpatient claim for resting transthoracic echocardiography within 60 days of surgery. Appropriateness was determined via International Classification of Diseases, Ninth Revision-Clinical Modification, and International Classification of Diseases, Tenth Revision-Clinical Modification principal and secondary diagnosis codes associated with the claims, and classified as "appropriate," "rarely appropriate," or "unclassifiable" using the Appropriate Use Criteria for Echocardiography. RESULTS: Among 230,535 patients in the authors' cohort, preoperative resting transthoracic echocardiography was performed in 6.0% (13,936) of patients. There were 12,638 (91%) studies classifiable by the Appropriate Use Criteria for Echocardiography, and 1,298 (9%) were unable to be classified. Among the classifiable studies, 8,959 (71%) were deemed "appropriate," while 3,679 (29%) were deemed "rarely appropriate." Surveillance of chronic ischemic heart disease and uncomplicated hypertension accounted for 43% (1,588 of 3,679) of "rarely appropriate" echocardiograms. CONCLUSIONS: More than one in four preoperative resting echocardiograms were considered "rarely appropriate" according to the Appropriate Use Criteria for Echocardiography. A narrow set of patient characteristics accounts for a large proportion of "rarely appropriate" preoperative resting echocardiograms.

Morbidity and Mortality After Acute Myocardial Infarction After Elective Major Noncardiac Surgery.

OBJECTIVES: To develop parsimonious models of in-hospital mortality and morbidity risk after perioperative acute myocardial infarction (AMI). DESIGN: Retrospective data analysis. SETTING: National Inpatient Sample (2008-2013), a 20% sample of all non-federal in-patient hospitalizations in the United States. PARTICIPANTS: Patients 45 years or older who experienced perioperative AMI during elective admission for noncardiac surgery. INTERVENTIONS: The study used a mixed principal components analysis and multivariate logistic regression to identify risk factors for in-hospital mortality after perioperative AMI. A model incorporating only preoperative risk factors, defined by the Revised Cardiac Risk Index (RCRI), was compared with a "full risk factor" model, incorporating a large set of preoperative AMI risk factors. The risk of post-AMI disposition to an intermediate care or skilled nursing facility, a marker of functional impairment, then was evaluated. MEASUREMENTS AND MAIN RESULTS: In the present study, 15,574 cases of AMI after elective noncardiac surgery were identified (0.42%, corresponding with 78,122 cases nationally), with a 12.4% in-hospital mortality rate. The "RCRI-only" model was the best-fit model of post-AMI in-hospital mortality risk, without loss of predictive accuracy compared with the "full risk factor" model (area under the receiver operator characteristic curve 0.80, 95% confidence interval [CI] [0.77-0.82] v area under the receiver operator characteristic curve 0.81, 95% CI [0.77-0.83], respectively). Post-AMI mortality risk was the highest for perioperative complications, including sepsis (odds ratio 4.95, 95% CI [4.32-5.67]). Conversely, functional impairment was best predicted by the "full-risk factor" model and depended strongly on chronic preoperative comorbidities. CONCLUSIONS: The RCRI provides a simple but adequate model of preoperative risk factors for in-hospital mortality after perioperative AMI.

Trends in Central Venous Catheter Insertions by Anesthesia Providers: An Analysis of the Medicare Physician Supplier Procedure Summary From 2007 to 2016.

BACKGROUND: Central line insertion is a core skill for anesthesiologists. Although recent technical advances have increased the safety of central line insertion and reduced the risk of central line-associated infection, noninvasive hemodynamic monitoring and improved intravenous access techniques have also reduced the need for perioperative central venous access. We hypothesized that the number of central lines inserted by anesthesiologists has decreased over the past decade. To test our hypothesis, we reviewed the Medicare Physician Supplier Procedure Summary (PSPS) database from 2007 to 2016. METHODS: Claims for central venous catheter placement were identified in the Medicare PSPS database for nontunneled and tunneled central lines. Pulmonary artery catheter insertion was included as a nontunneled line claim. We stratified line insertion claims by specialty for Anesthesiology (including Certified Registered Nurse Anesthetists and Anesthesiology Assistants), Surgery, Radiology, Pulmonary/Critical Care, Emergency Physicians, Internal Medicine, and practitioners who were not anesthesia providers such as Advanced Practice Nurses (APNs) and Physician Assistants (PAs). Utilization rates per 10,000 Medicare beneficiaries were then calculated by specialty and year. Time-based trends were analyzed using Joinpoint linear regression, and the Average Annual Percent Change (AAPC) was calculated. RESULTS: Between 2007 and 2016, total claims for central venous catheter insertions of all types decreased from 440.9 to 325.3 claims/10,000 beneficiaries (AAPC = -3.4, 95% confidence interval [CI], -3.6 to -3.2: P < .001). When analyzed by provider specialty and year, the number of nontunneled line insertion claims fell from 43.1 to 15.9 claims/10,000 (AAPC = -7.1; -7.3 to -7.0: P < .001) for surgeons, from 21.3 to 18.5 claims/10,000 (AAPC = -2.5; -2.8 to -2.1: P < .001) for radiologists, and from 117.4 to 72.7 claims/10,000 (AAPC = -5.2; 95% CI, -6.3 to -4.0: P < .001) for anesthesia providers. In contrast, line insertions increased from 18.2 to 26.0 claims/10,000 (AAPC = 3.2; 2.3-4.2: P < .001) for Emergency Physicians and from 3.2 to 9.3 claims/10,000 (AAPC = 6.0; 5.1-6.9: P < .001) for PAs and APNs who were not anesthesia providers. Among anesthesia providers, the share of line claims made by nurse anesthetists increased by 14.5% over the time period. CONCLUSIONS: We observed a 38.3% decrease in claims for nontunneled central lines placed by anesthesiologists from 2007 to 2016. These findings have implications for anesthesiology resident training and maintenance of competence among practicing clinicians. Further research is needed to clarify the effect of decreasing line insertion numbers on line insertion competence among anesthesiologists.

Development and Pilot Study of an iOS Smartphone Application for Perioperative Functional Capacity Assessment.

BACKGROUND: Functional capacity assessment plays a core role in the preoperative evaluation. The Duke Activity Status Index (DASI) and the 6-minute walk test (6MWT) are 2 methods that have demonstrated the ability to evaluate functional capacity and predict perioperative outcomes. Smartphones offer a novel method to facilitate functional capacity assessment as they can easily administer a survey and accelerometers can track patient activity during a 6MWT. We developed a smartphone application to administer a 6MWT and DASI survey and performed a pilot study to evaluate the accuracy of a smartphone-based functional capacity tool in our Anesthesia and Perioperative Medicine Clinic. METHODS: Using the Apple ResearchKit software platform, we developed an application that administers a DASI survey and 6MWT on an iOS smartphone. The DASI was presented to the patient 1 question on the screen at a time and the application calculated the DASI score and estimated peak oxygen uptake (VO2). The 6MWT used the CMPedometer class from Apple's core motion facility to retrieve accelerometer data collected from the device's motion coprocessor to estimate steps walked. Smartphone estimated steps were compared to a research-grade pedometer using the intraclass correlation coefficient (ICC). Distance walked was directly measured during the 6MWT and we performed a multivariable linear regression with biometric variables to create a distance estimation algorithm to estimate distance walked from the number of steps recorded by the application. RESULTS: Seventy-eight patients were enrolled in the study and completed the protocol. Steps measured by the smartphone application as compared to the pedometer demonstrated moderate agreement with an ICC (95% CI) of 0.87 (0.79-0.92; P = .0001). The variables in the distance estimation algorithm included (ß coefficient [slope], 95% CI) steps walked (0.43, 0.29-0.57; P < .001), stride length (0.38, 0.22-0.53; P < .001), age in years (-1.90, -3.06 to -0.75; P = .002), and body mass index (-2.59, -5.13 to -0.06; P = .045). The overall model fit was R = 0.72, which indicates a moderate level of goodness of fit and explains 72% of the variation of distance walked during a 6MWT. CONCLUSIONS: Our pilot study demonstrated that a smartphone-based functional capacity assessment is feasible using the DASI and 6MWT. The DASI was easily completed by patients and the application clearly presented the results of the DASI to providers. Our application measured steps walked during a 6MWT moderately well in a preoperative patient population; however, future studies are needed to improve the smartphone application's step-counting accuracy and distance estimation algorithm.

Predicting Risk of Perioperative Ischemic Optic Neuropathy in Spine Fusion Surgery: A Cohort Study Using the National Inpatient Sample.

BACKGROUND: Ischemic optic neuropathy (ION) is a rare complication of anesthesia and surgery that causes vision loss in spine fusion. We sought to develop a predictive model based on known preoperative risk factors for perioperative ION to guide patient and physician preoperative decision-making. METHODS: In the National Inpatient Sample (NIS) for 1998-2012, discharges for posterior thoracic, lumbar, and sacral spine fusion were identified and classified by ION status. Variables were selected without weighting via variable clustering using Principal Component Analysis of Mixed Data (PCA-MIX). Hierarchical clustering with 4 clusters was performed, and the variable with largest squared loading in each cluster was chosen. By splitting our sample into a training and testing data set, we developed and internally validated a predictive model. The final model using variables known preoperatively was constructed to allow determination of relative and absolute risk of developing perioperative ION and was tested for calibration and discrimination. RESULTS: The final predictive model based on hierarchical clustering contained 3 preoperative factors, age, male or female sex, and the presence of obstructive sleep apnea (OSA). The predictive model based on these factors had an area under the receiver operating characteristic curve (AUC) of 0.65 and good calibration. A score cutoff of >1 had 100% sensitivity, while score of 3 had 96.5% specificity. The highest estimated absolute risk (844.5/million) and relative risk of ION (46.40) was for a man, age 40-64 years, with OSA. CONCLUSIONS: The predictive model could enable screening for patients at higher risk of ION to provide more accurate risk assessment and surgical and anesthetic planning for perioperative ION in spine fusion.

Accuracy of Physical Function Questions to Predict Moderate-Vigorous Physical Activity as Measured by Hip Accelerometry.

BACKGROUND: Functional capacity assessment is a core component of current perioperative cardiovascular evaluation and management guidelines for noncardiac surgery. The authors investigated the ability of standardized physical function questions to predict whether participants engaged in moderate physical activity as measured by hip accelerometers. METHODS: Participant responses to physical functioning questions and whether they engaged in moderate physical activity were extracted from the National Health and Nutrition Examination Survey (2003 to 2004 and 2005 to 2006). Physical activity intensity was measured using hip accelerometers. Adult participants with at least one Revised Cardiac Risk Index condition were included in the analysis. Standardized physical function questions were evaluated using a classification and regression tree analysis. Training and test datasets were randomly generated to create and test the analysis. RESULTS: Five hundred and twenty-two participants were asked the physical functioning questions and 378 of 522 (72.4%) had a bout of moderate-vigorous activity. Classification and regression tree analysis identified a "no difficulty" response to walking up 10 stairs and the ability to walk two to three blocks as the most sensitive questions to predict the presence of a 2-min bout of moderate activity. Participants with positive responses to both questions had a positive likelihood ratio of 3.7 and a posttest probability greater than 90% of a 2-min bout of moderate-vigorous activity. The sensitivity and specificity of positive responses to physical functioning questions in the pruned tree were 0.97 (95% CI, 0.94 to 0.98) and 0.16 (95% CI, 0.10 to 0.23) for training data, and 0.88 (95% CI, 0.75 to 0.96) and 0.10 (95% CI, 0.00 to 0.45) for the test data. Participants with at least one 2-min bout of moderate activity had a greater percentage of overall daily active time (35.4 ± 0.5 vs. 26.7 ± 1.2; P = 0.001) than those without. CONCLUSIONS: Standardized physical function questions are highly sensitive but poorly specific to identify patients who achieve moderate physical activity. Additional strategies to evaluate functional capacity should be considered.

Big Data Research in Neuro-Ophthalmology: Promises and Pitfalls.

BACKGROUND: Big data clinical research involves application of large data sets to the study of disease. It is of interest to neuro-ophthalmologists but also may be a challenge because of the relative rarity of many of the diseases treated. EVIDENCE ACQUISITION: Evidence for this review was gathered from the authors' experiences performing analysis of large data sets and review of the literature. RESULTS: Big data sets are heterogeneous, and include prospective surveys, medical administrative and claims data and registries compiled from medical records. High-quality studies must pay careful attention to aspects of data set selection, including potential bias, and data management issues, such as missing data, variable definition, and statistical modeling to generate appropriate conclusions. There are many studies of neuro-ophthalmic diseases that use big data approaches. CONCLUSIONS: Big data clinical research studies complement other research methodologies to advance our understanding of human disease. A rigorous and careful approach to data set selection, data management, data analysis, and data interpretation characterizes high-quality studies.

Perioperative Retinal Artery Occlusion: Incidence and Risk Factors in Spinal Fusion Surgery From the US National Inpatient Sample 1998-2013.

BACKGROUND: Retinal artery occlusion (RAO) is a rare but devastating complication of spinal fusion surgery. We aimed to determine its incidence and associated risk factors. METHODS: Hospitalizations involving spinal fusion surgery were identified by searching the National Inpatient Sample, a database of hospital discharges, from 1998 to 2013. RAO cases were identified using ICD-9-CM codes. Using the STROBE guidelines, postulated risk factors were chosen based on literature review and identified using ICD-9-CM codes. Multivariate logistic models with RAO as outcome, and risk factors, race, age, admission, and surgery type evaluated associations. RESULTS: Of an estimated 4,784,275 spine fusions in the United States from 1998 to 2013, there were 363 (CI: 291-460) instances of RAO (0.76/10,000 spine fusions, CI: 0.61-0.96). Incidence ranged from 0.35/10,000 (CI: 0.11-1.73) in 2001-2002 to 1.29 (CI: 0.85-2.08) in 2012-2013, with no significant trend over time (P = 0.39). Most strongly associated with RAO were stroke, unidentified type (odds ratio, OR: 14.33, CI: 4.54-45.28, P < 0.001), diabetic retinopathy (DR) (OR: 7.00, CI: 1.18-41.66, P = 0.032), carotid stenosis (OR: 4.94, CI: 1.22-19.94, P = 0.025), aging (OR for age 71-80 years vs 41-50 years referent: 4.07, CI: 1.69-10.84, P = 0.002), and hyperlipidemia (OR: 2.96, CI: 1.85-4.73, P < 0.001). There was an association between RAO and transforaminal lumbar interbody fusion (OR: 2.95, CI: 1.29-6.75, P = 0.010). RAO was more likely to occur with spinal surgery performed urgently or emergently compared with being done electively (OR: 0.40, CI: 0.23-0.68, P < 0.001). CONCLUSIONS: Patient-specific associations with RAO in spinal fusion include aging, carotid stenosis, DR, hyperlipidemia, stroke, and specific types of surgery. DR may serve as an observable biomarker of heightened risk of RAO in patients undergoing spine fusion.

Perioperative Retinal Artery Occlusion: Risk Factors in Cardiac Surgery from the United States National Inpatient Sample 1998-2013.

PURPOSE: To study the incidence and risk factors for retinal artery occlusion (RAO) in cardiac surgery. DESIGN: Retrospective study using the National Inpatient Sample (NIS). METHODS: The NIS was searched for cardiac surgery. Retinal artery occlusion was identified by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Postulated risk factors based on literature review were included in multivariate logistic models. MAIN OUTCOME MEASURES: Diagnosis of RAO. RESULTS: A total of 5 872 833 cardiac operative procedures were estimated in the United States from 1998 to 2013, with 4564 RAO cases (95% confidence interval [95% CI], 4282-4869). Nationally estimated RAO incidence was 7.77/10 000 cardiac operative procedures from 1998 to 2013 (95% CI, 7.29-8.29). Associated with increased RAO were giant cell arteritis (odds ratio [OR], 7.73; CI, 2.78-21.52; P < 0.001), transient cerebral ischemia (OR, 7.67; CI, 5.31-11.07; P < 0.001), carotid artery stenosis (OR, 7.52; CI, 6.22-9.09; P < 0.001), embolic stroke (OR, 4.43; CI, 3.05-6.42; P < 0.001), hypercoagulability (OR, 2.90; CI, 1.56-5.39; P < 0.001), myxoma (OR, 2.43; CI, 1.39-4.26; P = 0.002), diabetes mellitus (DM) with ophthalmic complications (OR, 1.89; CI, 1.10-3.24; P = 0.02), and aortic insufficiency (OR, 1.85; CI, 1.26-2.71; P = 0.002). Perioperative bleeding, aortic and mitral valve surgery, and septal surgery increased the odds of RAO. Negatively associated with RAO were female gender (OR, 0.77; CI, 0.66-0.89; P < 0.001), thrombocytopenia (OR, 0.79; CI, 0.62-1.00; P = 0.049), acute coronary syndrome (OR, 0.72; CI, 0.58-0.89; P = 0.003), atrial fibrillation (OR, 0.82; CI, 0.70-0.95; P = 0.01), congestive heart failure (OR, 0.73; CI, 0.60-0.88; P < 0.001), DM 2 (OR, 0.74; CI, 0.61-0.89; P = 0.001), and smoking (OR, 0.82; CI, 0.70-0.97; P = 0.02). CONCLUSIONS: Risk factors for RAO in cardiac surgery include giant cell arteritis, carotid stenosis, stroke, hypercoagulable state, and DM with ophthalmic complications; associated with lower risk were female gender, thrombocytopenia, acute coronary syndrome, atrial fibrillation, congestive heart failure, DM 2, and smoking. Surgery in which the heart was opened (e.g., septal repair) versus surgery in which it was not (e.g., CABG) and perioperative bleeding increased the risk of RAO.

Ischemic Optic Neuropathy in Cardiac Surgery: Incidence and Risk Factors in the United States from the National Inpatient Sample 1998 to 2013.

BACKGROUND: Ischemic optic neuropathy is the most common form of perioperative visual loss, with highest incidence in cardiac and spinal fusion surgery. To date, potential risk factors have been identified in cardiac surgery by only small, single-institution studies. To determine the preoperative risk factors for ischemic optic neuropathy, the authors used the National Inpatient Sample, a database of inpatient discharges for nonfederal hospitals in the United States. METHODS: Adults aged 18 yr or older admitted for coronary artery bypass grafting, heart valve repair or replacement surgery, or left ventricular assist device insertion in National Inpatient Sample from 1998 to 2013 were included. Risk of ischemic optic neuropathy was evaluated by multivariable logistic regression. RESULTS: A total of 5,559,395 discharges met inclusion criteria with 794 (0.014%) cases of ischemic optic neuropathy. The average yearly incidence was 1.43 of 10,000 cardiac procedures, with no change during the study period (P = 0.57). Conditions increasing risk were carotid artery stenosis (odds ratio, 2.70), stroke (odds ratio, 3.43), diabetic retinopathy (odds ratio, 3.83), hypertensive retinopathy (odds ratio, 30.09), macular degeneration (odds ratio, 4.50), glaucoma (odds ratio, 2.68), and cataract (odds ratio, 5.62). Female sex (odds ratio, 0.59) and uncomplicated diabetes mellitus type 2 (odds ratio, 0.51) decreased risk. CONCLUSIONS: The incidence of ischemic optic neuropathy in cardiac surgery did not change during the study period. Development of ischemic optic neuropathy after cardiac surgery is associated with carotid artery stenosis, stroke, and degenerative eye conditions.

Perioperative Visual Loss in Spine Fusion Surgery: Ischemic Optic Neuropathy in the United States from 1998 to 2012 in the Nationwide Inpatient Sample.

BACKGROUND: Perioperative ischemic optic neuropathy (ION) causes visual loss in spinal fusion. Previous case-control studies are limited by study size and lack of a random sample. The purpose of this study was to study trends in ION incidence in spinal fusion and risk factors in a large nationwide administrative hospital database. METHODS: In the Nationwide Inpatient Sample for 1998 to 2012, procedure codes for posterior thoracic, lumbar, or sacral spine fusion and diagnostic codes for ION were identified. ION was studied over five 3-yr periods (1998 to 2000, 2001 to 2003, 2004 to 2006, 2007 to 2009, and 2010 to 2012). National estimates were obtained using trend weights in a statistical survey procedure. Univariate and Poisson logistic regression assessed trends and risk factors. RESULTS: The nationally estimated volume of thoracic, lumbar, and sacral spinal fusion from 1998 to 2012 was 2,511,073. ION was estimated to develop in 257 patients (1.02/10,000). The incidence rate ratio (IRR) for ION significantly decreased between 1998 and 2012 (IRR, 0.72 per 3 yr; 95% CI, 0.58 to 0.88; P = 0.002). There was no significant change in the incidence of retinal artery occlusion. Factors significantly associated with ION were age (IRR, 1.24 per 10 yr of age; 95% CI, 1.05 to 1.45; P = 0.009), transfusion (IRR, 2.72; 95% CI, 1.38 to 5.37; P = 0.004), and obesity (IRR, 2.49; 95% CI, 1.09 to 5.66; P = 0.030). Female sex was protective (IRR, 0.30; 95% CI, 0.16 to 0.56; P = 0.0002). CONCLUSIONS: Perioperative ION in spinal fusion significantly decreased from 1998 to 2012 by about 2.7-fold. Aging, male sex, transfusion, and obesity significantly increased the risk.

Factors Predicting 90-Day Readmissions for US Older Adult Burn Patients From the 2016-2018 Nationwide Readmissions Database.

Older adults with burn injuries have a high risk of readmission after the initial burn admission. Frailty is associated with poor outcomes from the initial burn injury, however, it remains unknown if frailty impacts readmission in older adults after the initial index burn admission. Our study aims to examine patient, frailty, burn, surgical, and hospital factors that contribute to 90-day readmissions in older adults with an acute burn. Patients ≥ 50 years of age with an acute burn diagnosis in the Nationwide Readmissions Database (2016-2018) were included. Patients who died during index admissions were excluded from the readmission analysis. Patient, burn, hospital stay, and hospital characteristics were analyzed. Using variables significant from univariate logistic regression analysis, we performed a multivariable logistic regression analysis to identify factors associated with 90-day readmissions. A total of 41,500 weighted index burn admissions were included. The 90-day readmission rate was 25.6% (10,641/41,500). Almost all the readmissions were unplanned (96.5%). The most common primary readmission diagnoses based on Clinical Classifications Software Refined were burn injury and septicemia. Multivariable logistic regression analysis demonstrated an increased hospital frailty risk and lower-body-only burns were associated with an increased risk of readmission. Notably, surgical treatment of the burn injury during the index admission was associated with a decreased risk of readmission. This highlights the importance and challenges of surgical decision-making for older adults with high comorbidity burden. Future studies are needed to develop decision guides to help clinicians identify patients who would benefit from surgical treatment versus more conservative strategies in older adult patients with burns.

Prognostic Factors for In-Hospital Mortality of Geriatric Burns From the US National Inpatient Sample 2016 to 2018.

Older adults with an acute burn experience a high frequency of in-hospital mortality. However, traditional burn mortality prediction models are less accurate for older adults likely because they do not account for geriatric specific factors, such as frailty. This study aims to investigate the impact of frailty on in-hospital mortality in older adult burn patients. Patients ≥50 years of age with an acute burn diagnosis in the National Inpatient Sample (2016-2018) were included in the cohort. Three multivariable logistic regression models to predict in-hospital mortality were generated and compared. The models were 1) age and percent total body surface area, 2) age, percent total body surface area and the Elixhauser Comorbidity Index, and 3) age, percent total body surface area, and Hospital Frailty Risk Score. A total of 60,515 weighted discharges were included in the cohort. In-hospital mortality increased with age, as 3.3% of 50- to 64-year-olds, 5.3% of 65- to 74-year-olds, 6.6% of 75- to 84-year-olds, and 9.9% of ≥85-year-olds died during the acute burn admission (P < .001). The multivariable model that included Hospital Frailty Risk Score had a higher area under the receiver operating characteristics curve than the model with age and percent total body surface area (0.84 vs 0.79; P < .001) and the model with Elixhauser Comorbidity Index (0.84 vs 0.83; P = .013). Frailty improved prediction of in-hospital mortality for older adult acute burn patients and burn specialists should consider implementing a frailty instrument to evaluate older adults with an acute burn injury.

Cardiac Comorbidity Risk Score: Zero-Burden Machine Learning to Improve Prediction of Postoperative Major Adverse Cardiac Events in Hip and Knee Arthroplasty.

Background In this retrospective, observational study we introduce the Cardiac Comorbidity Risk Score, predicting perioperative major adverse cardiac events (MACE) after elective hip and knee arthroplasty. MACE is a rare but important driver of mortality, and existing tools, eg, the Revised Cardiac Risk Index demonstrate only modest accuracy. We demonstrate an artificial intelligence-based approach to identify patients at high risk of MACE within 4 weeks (primary outcome) of arthroplasty, that imposes zero additional burden of cost/resources. Methods and Results Cardiac Comorbidity Risk Score calculation uses novel machine learning to estimate MACE risk from patient electronic health records, without requiring blood work or access to any demographic data beyond that of sex and age, and accounts for variable/missing/incomplete information across patient records. Validated on a deidentified cohort (age >45 years, n=445 391), performance was evaluated using the area under the receiver operator characteristics curve (AUROC), sensitivity/specificity, positive predictive value, and positive/negative likelihood ratios. In our cohort (age 63.5±10.5 years, 58.2% women, 34.2%/65.8% hip/knee procedures), 0.19% (882) experienced the primary outcome. Cardiac Comorbidity Risk Score achieved area under the receiver operator characteristics curve=80.0±0.4% (95% CI) for women and 80.1±0.5% (95% CI) for males, with 36.4% and 35.1% sensitivities, respectively, at 95% specificity, significantly outperforming Revised Cardiac Risk Index across all studied age-, sex-, risk-, and comorbidity-based subgroups. Conclusions Cardiac Comorbidity Risk Score, a novel artificial intelligence-based screening tool using known and unknown comorbidity patterns, outperforms state-of-the-art in predicting MACE within 4 weeks postarthroplasty, and can identify patients at high risk that do not demonstrate traditional risk factors.