Todd A. MacKenzie

Preoperative serum ST2 level predicts acute kidney injury after adult cardiac surgery

Objective The purpose of this study was to evaluate the relationship between preoperative levels of serum soluble ST2 (ST2) and acute kidney injury (AKI) after cardiac surgery. Previous research has shown that biomarkers facilitate the prediction of AKI and other complications after cardiac surgery. Methods Preoperative ST2 proteins were measured in 1498 patients undergoing isolated coronary artery bypass graft surgery at 8 hospitals participating in the Northern New England Biomarker Study from 2004 to 2007. AKI severity was defined using the Acute Kidney Injury Network (AKIN) definition. Preoperative ST2 levels were measured using multiplex assays. Ordered logistic regression was used to examine the relationship between ST2 levels and levels of AKI severity. Results Participants in this study showed a significant association between elevated preoperative ST2 levels and acute kidney risk. Before adjustment, the odds of patients developing AKIN stage 2 or 3, compared with AKIN stage 1, are 2.43 times higher (95% confidence interval, 1.86‐3.16; P < .001) for patients in the highest tercile of preoperative ST2. After adjustment, patients in the highest tercile of preoperative ST2 had significantly greater odds of developing AKIN stage 2 or 3 AKI (odds ratio, 1.99; 95% confidence interval, 1.50‐2.65; P < .001) compared with patients with AKIN stage 1. Conclusions Preoperative ST2 levels are associated with postoperative AKI risk and can be used to identify patients at higher risk of developing AKI after cardiac surgery.

Mortality Risk Along the Frailty Spectrum: Data from the National Health and Nutrition Examination Survey 1999 to 2004

To determine the relationship between frailty and overall and cardiovascular mortality.

The Association Between Novel Biomarkers and 1-Year Readmission or Mortality After Cardiac Surgery

BACKGROUNDnNovel cardiac biomarkers including soluble suppression of tumorigenicity 2, galectin-3, and the N-terminal prohormone of brain natriuretic peptide may be associated with long-term adverse outcomes after cardiac surgery. We sought to measure the association between cardiac biomarker levels and 1-year hospital readmission or mortality.nnnMETHODSnPlasma biomarkers from 1,047 patients discharged alive after isolated coronary artery bypass graft surgery from 8 medical centers were measured in a cohort from the Northern New England Cardiovascular Disease Study Group between 2004 and 2007. We evaluated the association between preoperative and postoperative biomarkers and 1-year readmission or mortality using Kaplan-Meier estimates and Cox proportional hazards modeling, adjusting for covariates used in The Society of Thoracic Surgeons 30-day readmission model.nnnRESULTSnThe median follow-up time was 365 days. After adjustment for established risk factors, above-median levels of postoperative galectin-3 (median 10.35 ng/mL; hazard ratio, 1.40; 95% confidence interval, 1.08 to 1.80; pxa0= 0.010) and N-terminal prohormone of brain natriuretic peptide (medianxa0= 15.21 ng/mL, hazard ratio, 1.42; 95% confidence interval, 1.07 to 1.87; pxa0= 0.014) were each significantly associated with 1-year readmission or mortality.nnnCONCLUSIONSnIn patients undergoing cardiac surgery, novel cardiac biomarkers were associated with readmission or mortality independent of established risk factors. Measurement of these biomarkers may improve our ability to identify patients at highest risk for readmission or mortality before discharge. This will also allow resource allocation accordingly, while implementing strategies for personalized medicine based on the biomarker profile of the patient.

Utility of Biomarkers to Improve Prediction of Readmission or Mortality After Cardiac Surgery

BACKGROUNDnHospital readmission within 30 days is associated with higher risks of complications, death, and increased costs. Accurate statistical models to stratify the risk of 30-day readmission or death after cardiac surgery could help clinical teams focus care on those patients at highest risk. We hypothesized biomarkers could improve prediction for readmission or mortality.nnnMETHODSnLevels of ST2, galectin-3, N-terminal pro-brain natriuretic peptide, cystatin C, interleukin-6, and interleukin-10 were measured in samples from 1,046 patients discharged after isolated coronary artery bypass graft surgery from eight medical centers, with external validation in 1,194 patients from five medical centers. Thirty-day readmission or mortality were ascertained using Medicare, state all-payer claims, and the National Death Index. We tested and externally validated the clinical models and the biomarker panels using area under the receiver-operating characteristics (AUROC) statistics.nnnRESULTSnThere were 112 patients (10.7%) who were readmitted or died within 30 days after coronary artery bypass graft surgery. The Society of Thoracic Surgeons augmented clinical model resulted in an AUROC of 0.66 (95% confidence interval: 0.61 to 0.71). The biomarker panel with The Society of Thoracic Surgeons augmented clinical model resulted in an AUROC of 0.74 (bootstrapped 95% confidence interval: 0.69 to 0.79, p < 0.0001). External validation of the model showed limited improvement with the addition of a biomarker panel, with an AUROC of 0.51 (95% confidence interval: 0.45 to 0.56).nnnCONCLUSIONSnAlthough biomarkers significantly improved prediction of 30-day readmission or mortality in our derivation cohort, the external validation of the biomarker panel was poor. Biomarkers perform poorly, much like other efforts to improve prediction of readmission, suggesting there are many other factors yet to be explored to improve prediction of readmission.

A comparative analysis of long-term mortality after carotid endarterectomy and carotid stenting

Background: The value of carotid intervention is predicated on long‐term survival for patients to derive a stroke prevention benefit. Randomized trials report no significant difference in survival after carotid endarterectomy (CEA) vs carotid artery stenting (CAS), whereas observational studies of “real‐world” outcomes note that CEA is associated with a survival advantage. Our objective was to examine long‐term mortality after CEA vs CAS using a propensity‐matched cohort. Methods: We studied all patients who underwent CEA or CAS within the Vascular Quality Initiative from 2003 to 2013 (CEA, n = 29,235; CAS, n = 4415). Long‐term mortality information was obtained by linking patients in the registry to their respective Medicare claims file. We assessed the long‐term rate of mortality for CEA and CAS using Kaplan‐Meier estimation. We assessed the crude, adjusted, and propensity‐matched (total matched pairs, n = 4261) hazard ratio (HR) of mortality for CEA vs CAS using Cox regression. Results: The unadjusted Kaplan‐Meier estimated 5‐year mortality was 14.0% for CEA and 18.3% for CAS. The crude HR of all‐cause mortality for CEA vs CAS was 0.75 (95% confidence interval [CI], 0.70‐0.81), indicating that patients who underwent CEA were 25% less likely to die before those who underwent CAS. This survival advantage persisted after adjustment for age, sex, and comorbidities (adjusted HR, 0.75; 95% CI, 0.69‐0.82). This effect was confirmed on a propensity‐matched analysis, with an HR of 0.76 (95% CI, 0.69‐0.85). Finally, these findings were robust to subanalyses that stratified patients by presenting symptoms and were more pronounced in symptomatic patients (adjusted HR, 0.69; 95% CI, 0.61‐0.79) than in asymptomatic patients (adjusted HR, 0.80; 95% CI, 0.71‐0.90). Conclusions: During the last 15 years, patients who underwent CEA in the Vascular Quality Initiative have a long‐term survival advantage over those who underwent CAS in real‐world practice. Despite no difference in long‐term survival in randomized trials, our observational study demonstrated a survival benefit for CEA that did not diminish with risk adjustment. Graphical Abstract Figure. No caption available.

Depression and Handgrip Strength Among U.S. Adults Aged 60 Years and Older from Nhanes 2011-2014

ObjectivesSarcopenia is a gradual loss of muscle mass and strength that occurs with aging. This muscle deterioration is linked to increased morbidity, disability, and other adverse outcomes. Although reduced handgrip strength can be considered a marker of sarcopenia and other aging-related decline in the elderly, there is limited research on this physical health problem in at-risk groups with common biopsychosocial conditions such as depression. Our primary objective was to ascertain level of combined handgrip strength and its relationship with depression among adults aged 60 years and older.DesignUnadjusted and adjusted linear regression models were conducted with a cross-sectional survey dataset.SettingSecondary dataset from the 2011–2014 National Health and Nutrition Examination Survey (NHANES).ParticipantsCommunity-dwelling, noninstitutionalized adults ≥60 years old (n=3,421).MeasurementsThe predictor variables included a positive screen for clinically relevant depression (referent=PHQ-9 score <10). The criterion variable of combined handgrip strength (kg) was determined using a dynamometer.ResultsMean age and BMI were 69.9 years (51.5% female) and 28.8 kg/m2, respectively. Mean combined handgrip strength in the overall cohort was 73.5 and 46.6 kg in males and females, respectively. Three hundred thirty-six (9.8%) reported symptoms of depression. In unadjusted and fully adjusted models, depression was significantly associated with reduced handgrip strength (B =–0.26±0.79 and B =–0.19±0.08, respectively; p<0.001).ConclusionOur findings demonstrate handgrip strength has a significant inverse association with depression. Future longitudinal studies should investigate the causal processes and potential moderators and mediators of the relationships between depression and reduced handgrip strength. This information may further encourage the use of depression and handgrip strength assessments and aid in the monitoring and implementation of health care services that address both physical and mental health limitations among older adult populations.

Surgical outcomes for patients diagnosed with dementia: A coarsened exact matching study

BACKGROUNDnAn increasing number of elderly patients with dementia are undergoing surgical operations. Little is known about the differential impact of dementia on surgical outcomes. We investigated whether demented patients undergoing surgical operations have worse outcomes than their non-demented counterparts.nnnMETHODSnWe performed a cohort study of all patients undergoing a series of surgical operations who were registered in the New York Statewide Planning and Research Cooperative System (SPARCS) database from 2009 to 2013. We examined the association of dementia with inpatient case-fatality, discharge to a facility, and length of stay (LOS). Coarsened exact matching was used to balance comorbidities among the comparison groups, and mixed effect methods were used to control for clustering at the hospital level.nnnRESULTSnDuring the study period, 342,075 patients underwent surgical operations that met the inclusion criteria. Multivariable logistic regression models, after coarsened exact matching, demonstrated that demented patients were not associated with higher case-fatality (OR, 0.43; 95% CI, 0.13-1.36), but were associated with higher rates of discharge to a facility (OR, 1.71; 95% CI, 1.26-2.31) and longer LOS (Adjusted difference, 31%; 95% CI, 26%-36%). These persisted in pre-specified subgroups stratified on particular operations.nnnCONCLUSIONSnUsing a comprehensive all-payer cohort of surgical patients in New York State we identified an association of dementia with increased rate of discharge to rehabilitation and longer LOS. No difference was identified in the case fatality of the two groups. Policy makers, payers, and physicians should take these findings into account when designing new policies, and when counseling patients.

Prevalence rates of arthritis among US older adults with varying degrees of depression: Findings from the 2011 to 2014 National Health and Nutrition Examination Survey

Arthritis and depressive symptoms often interact and negatively influence one another to worsen mental and physical health outcomes. Better characterization of arthritis rates among older adults with different levels of depressive symptoms is an important step toward informing mental health professionals of the need to detect and respond to arthritis and related mental health complications. The primary objective is to determine arthritis rates among US older adults with varying degrees of depression.

Correlation of hospital magnet status with the quality of physicians performing neurosurgical procedures in New York State

Abstract Purpose: The quality of physicians practicing in hospitals recognized for nursing excellence by the American Nurses Credentialing Center has not been studied before. We investigated whether Magnet hospital recognition is associated with higher quality of physicians performing neurosurgical procedures. Materials and methods: We performed a cohort study of patients undergoing neurosurgical procedures from 2009–2013, who were registered in the New York Statewide Planning and Research Cooperative System (SPARCS) database. Propensity score adjusted multivariable regression models were used to adjust for known confounders, with mixed effects methods to control for clustering at the facility level. An instrumental variable analysis was used to control for unmeasured confounding and simulate the effect of a randomized trial. Results: During the study period, 185,277 patients underwent neurosurgical procedures, and met the inclusion criteria. Of these, 66,607 (35.6%) were hospitalized in Magnet hospitals, and 118,670 (64.4%) in non-Magnet institutions. Instrumental variable analysis demonstrated that undergoing neurosurgical operations in Magnet hospitals was associated with a 13.6% higher chance of being treated by a physician with superior performance in terms of mortality (95% CI, 13.2% to 14.1%), and a 4.3% higher chance of being treated by a physician with superior performance in terms of length-of-stay (LOS) (95% CI, 3.8% to 4.7%) in comparison to non-Magnet institutions. The same associations were present in propensity score adjusted mixed effects models. Conclusions: Using a comprehensive all-payer cohort of neurosurgical patients in New York State we identified an association of Magnet hospital recognition with superior physician performance.