Roland Matsouaka

Urinary Biomarkers for Sensitive and Specific Detection of Acute Kidney Injury in Humans

Acute kidney injury (AKI) is associated with high morbidity and mortality. The lack of sensitive and specific injury biomarkers has greatly impeded the development of therapeutic strategies to improve outcomes of AKI.

INHIBITION OF THE NFAT PATHWAY ALLEVIATES AMYLOID BETA NEUROTOXICITY IN A MOUSE MODEL OF ALZHEIMER’S DISEASE

Amyloid β (Aβ) peptides, the main pathological species associated with Alzheimers disease (AD), disturb intracellular calcium homeostasis, which in turn activates the calcium-dependent phosphatase calcineurin (CaN). CaN activation induced by Aβ leads to pathological morphological changes in neurons, and overexpression of constitutively active calcineurin is sufficient to generate a similar phenotype, even without Aβ. Here, we tested the hypothesis that calcineurin mediates neurodegenerative effects via activation of the nuclear transcription factor of activated T-cells (NFAT). We found that both spine loss and dendritic branching simplification induced by Aβ exposure were mimicked by constitutively active NFAT, and abolished when NFAT activation was blocked using the genetically encoded inhibitor VIVIT. When VIVIT was specifically addressed to the nucleus, identical beneficial effects were observed, thus enforcing the role of NFAT transcriptional activity in Aβ-related neurotoxicity. In vivo, when VIVIT or its nuclear counterpart were overexpressed in a transgenic model of Alzheimers disease via a gene therapy approach, the spine loss and neuritic abnormalities observed in the vicinity of amyloid plaques were blocked. Overall, these results suggest that NFAT/calcineurin transcriptional cascades contribute to Aβ synaptotoxicity, and may provide a new specific set of pathways for neuroprotective strategies.

Gait Speed Predicts 30-Day Mortality After Transcatheter Aortic Valve Replacement Results From the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry

Background— Surgical risk scores do not include frailty assessments (eg, gait speed), which are of particular importance for patients with severe aortic stenosis considering transcatheter aortic valve replacement. Methods and Results— We assessed the association of 5-m gait speed with outcomes in a cohort of 8039 patients who underwent transcatheter aortic valve replacement (November 2011–June 2014) and were included in the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry. We evaluated the association between continuous and categorical gait speed and 30-day all-cause mortality before and after adjustment for Society of Thoracic Surgeons–predicted risk of mortality score and key variables. Secondary outcomes included in-hospital mortality, bleeding, acute kidney injury, and stroke. The overall median gait speed was 0.63 m/s (25th–75th percentile, 0.47–0.79 m/s), with the slowest walkers (<0.5 m/s) constituting 28%, slow walkers (0.5–0.83 m/s) making up 48%, and normal walkers (>0.83 m/s) constituting 24% of the population. Thirty-day all-cause mortality rates were 8.4%, 6.6%, and 5.4% for the slowest, slow, and normal walkers, respectively (P<0.001). Each 0.2-m/s decrease in gait speed corresponded to an 11% increase in 30-day mortality (adjusted odds ratio, 1.11; 95% confidence interval, 1.01–1.22). The slowest walkers had 35% higher 30-day mortality than normal walkers (adjusted odds ratio, 1.35; 95% confidence interval, 1.01–1.80), significantly longer hospital stays, and a lower probability of being discharged to home. Conclusions— Gait speed is independently associated with 30-day mortality after transcatheter aortic valve replacement. Identification of frail patients with the slowest gait speeds facilitates preprocedural evaluation and anticipation of a higher level of postprocedural care. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01737528.

Association of the Hospital Readmissions Reduction Program Implementation With Readmission and Mortality Outcomes in Heart Failure

Importance Public reporting of hospitals’ 30-day risk-standardized readmission rates following heart failure hospitalization and the financial penalization of hospitals with higher rates have been associated with a reduction in 30-day readmissions but have raised concerns regarding the potential for unintended consequences. Objective To examine the association of the Hospital Readmissions Reduction Program (HRRP) with readmission and mortality outcomes among patients hospitalized with heart failure within a prospective clinical registry that allows for detailed risk adjustment. Design, Setting, and Participants Interrupted time-series and survival analyses of index heart failure hospitalizations were conducted from January 1, 2006, to December 31, 2014. This study included 115 245 fee-for-service Medicare beneficiaries across 416 US hospital sites participating in the American Heart Association Get With The Guidelines-Heart Failure registry. Data analysis took place from January 1, 2017, to June 8, 2017. Exposures Time intervals related to the HRRP were before the HRRP implementation (January 1, 2006, to March 31, 2010), during the HRRP implementation (April 1, 2010, to September 30, 2012), and after the HRRP penalties went into effect (October 1, 2012, to December 31, 2014). Main Outcomes and Measures Risk-adjusted 30-day and 1-year all-cause readmission and mortality rates. Results The mean (SD) age of the study population (n = 115 245) was 80.5 (8.4) years, 62 927 (54.6%) were women, and 91 996 (81.3%) were white and 11 037 (9.7%) were black. The 30-day risk-adjusted readmission rate declined from 20.0% before the HRRP implementation to 18.4% in the HRRP penalties phase (hazard ratio (HR) after vs before the HRRP implementation, 0.91; 95% CI, 0.87-0.95; P < .001). In contrast, the 30-day risk-adjusted mortality rate increased from 7.2% before the HRRP implementation to 8.6% in the HRRP penalties phase (HR after vs before the HRRP implementation, 1.18; 95% CI, 1.10-1.27; P < .001). The 1-year risk-adjusted readmission and mortality rates followed a similar pattern as the 30-day outcomes. The 1-year risk-adjusted readmission rate declined from 57.2% to 56.3% (HR, 0.92; 95% CI, 0.89-0.96; P < .001), and the 1-year risk-adjusted mortality rate increased from 31.3% to 36.3% (HR, 1.10; 95% CI, 1.06-1.14; P < .001) after vs before the HRRP implementation. Conclusions and Relevance Among fee-for-service Medicare beneficiaries discharged after heart failure hospitalizations, implementation of the HRRP was temporally associated with a reduction in 30-day and 1-year readmissions but an increase in 30-day and 1-year mortality. If confirmed, this finding may require reconsideration of the HRRP in heart failure.

Conscious Sedation Versus General Anesthesia for Transcatheter Aortic Valve Replacement: Insights from the National Cardiovascular Data Registry Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry

Background: Conscious sedation is used during transcatheter aortic valve replacement (TAVR) with limited evidence as to the safety and efficacy of this practice. Methods: The National Cardiovascular Data Registry Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry was used to characterize the anesthesia choice and clinical outcomes of all US patients undergoing elective percutaneous transfemoral TAVR between April 1, 2014, and June 30, 2015. Raw and inverse probability of treatment-weighted analyses were performed to compare patients undergoing TAVR with general anesthesia with patients undergoing TAVR with conscious sedation on an intention-to-treat basis for the primary outcome of in-hospital mortality, and secondary outcomes including 30-day mortality, in-hospital and 30-day death/stroke, procedural success, intensive care unit and hospital length-of-stay, and rates of discharge to home. Post hoc falsification end point analyses were performed to evaluate for residual confounding. Results: Conscious sedation was used in 1737/10 997 (15.8%) cases with a significant trend of increasing usage over the time period studied (P for trend<0.001). In raw analyses, intraprocedural success with conscious sedation and general anesthesia was similar (98.2% versus 98.5%, P=0.31). The conscious sedation group was less likely to experience in-hospital (1.6% versus 2.5%, P=0.03) and 30-day death (2.9% versus 4.1%, P=0.03). Conversion from conscious sedation to general anesthesia was noted in 102 of 1737 (5.9%) of conscious sedation cases. After inverse probability of treatment-weighted adjustment for 51 covariates, conscious sedation was associated with lower procedural success (97.9% versus 98.6%, P<0.001) and a reduced rate of mortality at the in-hospital (1.5% versus 2.4%, P<0.001) and 30-day (2.3% versus 4.0%, P<0.001) time points. Conscious sedation was associated with reductions in procedural inotrope requirement, intensive care unit and hospital length of stay (6.0 versus 6.5 days, P<0.001), and combined 30-day death/stroke rates (4.8% versus 6.4%, P<0.001). Falsification end point analyses of vascular complications, bleeding, and new pacemaker/defibrillator implantation demonstrated no significant differences between groups after adjustment. Conclusions: In US practice, conscious sedation is associated with briefer length of stay and lower in-hospital and 30-day mortality in comparison with TAVR with general anesthesia in both unadjusted and adjusted analyses. These results suggest the safety of conscious sedation in this population, although comparative effectiveness analyses using observational data cannot definitively establish the superiority of one technique over another.Background —Conscious sedation is used during transcatheter aortic valve replacement (TAVR) with limited evidence as to the safety and efficacy of this practice. Methods —The NCDR STS/ACC TVT Registry was used to characterize the anesthesia choice and clinical outcomes of all U.S. patients undergoing elective percutaneous transfemoral TAVR between April 1, 2014 and June 30, 2015. Raw and inverse probability of treatment weighted (IPTW) analyses were performed to compare general anesthesia patients with conscious sedation patients on an intention-to-treat basis for the primary outcome of in-hospital mortality, and secondary outcomes including 30-day mortality, in-hospital and 30-day death/stroke, procedural success, ICU and hospital length-of-stay, and rates of discharge to home. Post-hoc falsification endpoint analyses were performed to evaluate for residual confounding. Results —Conscious sedation was used in 1,737/10,997 (15.8%) cases with a significant trend of increasing usage over the time period studied (p for trend Conclusions —In U.S. practice, conscious sedation is associated with briefer length of stay and lower in-hospital and 30-day mortality compared to TAVR with general anesthesia in both unadjusted and adjusted analyses. These results suggest the safety of conscious sedation in this population, though comparative effectiveness analyses using observational data cannot definitively establish the superiority of one technique over another.

Association of Intracerebral Hemorrhage Among Patients Taking Non–Vitamin K Antagonist vs Vitamin K Antagonist Oral Anticoagulants With In-Hospital Mortality

Importance Although non–vitamin K antagonist oral anticoagulants (NOACs) are increasingly used to prevent thromboembolic disease, there are limited data on NOAC-related intracerebral hemorrhage (ICH). Objective To assess the association between preceding oral anticoagulant use (warfarin, NOACs, and no oral anticoagulants [OACs]) and in-hospital mortality among patients with ICH. Design, Setting, and Participants Retrospective cohort study of 141 311 patients with ICH admitted from October 2013 to December 2016 to 1662 Get With The Guidelines–Stroke hospitals. Exposures Anticoagulation therapy before ICH, defined as any use of OACs within 7 days prior to hospital arrival. Main Outcomes and Measures In-hospital mortality. Results Among 141 311 patients with ICH (mean [SD] age, 68.3 [15.3] years; 48.1% women), 15 036 (10.6%) were taking warfarin and 4918 (3.5%) were taking NOACs preceding ICH, and 39 585 (28.0%) and 5783 (4.1%) were taking concomitant single and dual antiplatelet agents, respectively. Patients with prior use of warfarin or NOACs were older and had higher prevalence of atrial fibrillation and prior stroke. Acute ICH stroke severity (measured by the National Institutes of Health Stroke Scale) was not significantly different across the 3 groups (median, 9 [interquartile range, 2-21] for warfarin, 8 [2-20] for NOACs, and 8 [2-19] for no OACs). The unadjusted in-hospital mortality rates were 32.6% for warfarin, 26.5% for NOACs, and 22.5% for no OACs. Compared with patients without prior use of OACs, the risk of in-hospital mortality was higher among patients with prior use of warfarin (adjusted risk difference [ARD], 9.0% [97.5% CI, 7.9% to 10.1%]; adjusted odds ratio [AOR], 1.62 [97.5% CI, 1.53 to 1.71]) and higher among patients with prior use of NOACs (ARD, 3.3% [97.5% CI, 1.7% to 4.8%]; AOR, 1.21 [97.5% CI, 1.11-1.32]). Compared with patients with prior use of warfarin, patients with prior use of NOACs had a lower risk of in-hospital mortality (ARD, −5.7% [97.5% CI, −7.3% to −4.2%]; AOR, 0.75 [97.5% CI, 0.69 to 0.81]). The difference in mortality between NOAC-treated patients and warfarin-treated patients was numerically greater among patients with prior use of dual antiplatelet agents (32.7% vs 47.1%; ARD, −15.0% [95.5% CI, −26.3% to −3.8%]; AOR, 0.50 [97.5% CI, 0.29 to 0.86]) than among those taking these agents without prior antiplatelet therapy (26.4% vs 31.7%; ARD, −5.0% [97.5% CI, −6.8% to −3.2%]; AOR, 0.77 [97.5% CI, 0.70 to 0.85]), although the interaction P value (.07) was not statistically significant. Conclusions and Relevance Among patients with ICH, prior use of NOACs or warfarin was associated with higher in-hospital mortality compared with no OACs. Prior use of NOACs, compared with prior use of warfarin, was associated with lower risk of in-hospital mortality.

Evaluating marker‐guided treatment selection strategies

A potential venue to improve healthcare efficiency is to effectively tailor individualized treatment strategies by incorporating patient level predictor information such as environmental exposure, biological, and genetic marker measurements. Many useful statistical methods for deriving individualized treatment rules (ITR) have become available in recent years. Prior to adopting any ITR in clinical practice, it is crucial to evaluate its value in improving patient outcomes. Existing methods for quantifying such values mainly consider either a single marker or semi-parametric methods that are subject to bias under model misspecification. In this article, we consider a general setting with multiple markers and propose a two-step robust method to derive ITRs and evaluate their values. We also propose procedures for comparing different ITRs, which can be used to quantify the incremental value of new markers in improving treatment selection. While working models are used in step I to approximate optimal ITRs, we add a layer of calibration to guard against model misspecification and further assess the value of the ITR non-parametrically, which ensures the validity of the inference. To account for the sampling variability of the estimated rules and their corresponding values, we propose a resampling procedure to provide valid confidence intervals for the value functions as well as for the incremental value of new markers for treatment selection. Our proposals are examined through extensive simulation studies and illustrated with the data from a clinical trial that studies the effects of two drug combinations on HIV-1 infected patients.

Quality-of-Life Outcomes After Transcatheter Aortic Valve Replacement in an Unselected Population: A Report From the STS/ACC Transcatheter Valve Therapy Registry

Importance In clinical trials, transcatheter aortic valve replacement (TAVR) has been shown to improve symptoms and quality of life. As this technology moves into general clinical practice, evaluation of the health status outcomes among unselected patients treated with TAVR is of critical importance. Objective To examine the short- and long-term health status outcomes of surviving patients after TAVR in the context of an unselected population. Design, Setting, and Participants This observational cohort study included patients with severe aortic stenosis who underwent TAVR in the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy (TVT) Registry from November 1, 2011, to March 31, 2016, at more than 450 clinical sites. Main Outcomes and Measures Disease-specific health status was assessed at baseline and at 30 days and 1 year after TAVR using the Kansas City Cardiomyopathy Questionnaire overall summary (KCCQ-OS) score (range, 0-100 points; higher scores indicate less symptom burden and better quality of life). Factors associated with health status at 1 year after TAVR were examined using multivariable linear regression, with adjustment for baseline health status and accounting for clustering of patients within sites. Results The 30-day analytic sample included 31 636 patients, and the 1-year cohort included 7014 surviving patients (3454 women [49.2%] and 3560 men [50.8%]; median [interquartile range] age, 84 [78-88] years). The mean (SD) baseline KCCQ-OS score was 42.3 (23.7), indicating substantial health status impairment. Surviving patients had, on average, large improvements in health status at 30 days that persisted to 1 year, with a mean improvement in the KCCQ-OS score of 27.6 (95% CI, 27.3-27.9) points at 30 days and 31.9 (95% CI, 31.3-32.6) points at 1 year. Worse baseline health status, older age, higher ejection fraction, lung disease, home oxygen use, lower mean aortic valve gradients, prior stroke, diabetes, pacemaker use, atrial fibrillation, slow gait speed, and nonfemoral access were significantly associated with worse health status at 1 year. Overall, 62.3% of patients had a favorable outcome at 1 year (alive with reasonable quality of life [KCCQ-OS score, ≥60] and no significant decline [≥10 points] from baseline), with the lowest rates seen among patients with severe lung disease (51.4%), those undergoing dialysis (47.7%), or those with very poor baseline health status (49.2%). Conclusions and Relevance In a national, contemporary clinical practice cohort of unselected patients, improvement in health status after TAVR was similar to that seen in the pivotal clinical trials. Although the health status results were favorable for most patients, approximately 1 in 3 still had a poor outcome 1 year after TAVR. Continued efforts are needed to improve patient selection and procedural/postprocedural care to maximize health status outcomes of this evolving therapy.

Increase in Endovascular Therapy in Get With The Guidelines-Stroke After the Publication of Pivotal Trials

Background: Beginning in December 2014, a series of pivotal trials showed that endovascular thrombectomy (EVT) was highly effective, prompting calls to reorganize stroke systems of care. However, there are few data on how these trials influenced the frequency of EVT in clinical practice. We used data from the Get With The Guidelines-Stroke program to determine how the frequency of EVT changed in US practice. Methods: We analyzed prospectively collected data from a cohort of 2 437 975 patients with ischemic stroke admitted to 2222 participating hospitals between April 2003 and the third quarter of 2016. Weighted linear regression with 2 linear splines and a knot at January 2015 was used to compare the slope of the change in EVT use before and after the pivotal trials were published. Potentially eligible patients were defined as last known well to arrival time ⩽4.5 hours and National Institutes of Health Stroke Scale score ≥6. Results: The frequency of EVT use was slowly increasing before January 2015 but then sharply accelerated thereafter. In the third quarter 2016, EVT was provided to 3.3% of all patients with ischemic stroke at all hospitals, representing 15.1% of all patients who were potentially eligible for EVT based on stroke duration and severity. At EVT-capable hospitals, 7.5% of all patients with ischemic stroke were treated in the third quarter of 2016, including 27.3% of the potentially eligible patients. From 2013 to 2016, case volumes nearly doubled at EVT-capable hospitals. Mean case volume per EVT-capable hospital was 37.6 per year in the last 4 quarters. EVT case volumes increased in nearly all US states from 2014 to the last 4 quarters, but with persistent geographic variation unexplained by differences in potential patient eligibility. Conclusions: EVT use is increasing rapidly; however, there are still opportunities to treat more patients. Reorganizing stroke systems to route patients to adequately resourced EVT-capable hospitals might increase treatment of eligible patients, improve outcomes, and reduce disparities.

Delays in Door-to-Needle Times and Their Impact on Treatment Time and Outcomes in Get With The Guidelines-Stroke

Background and Purpose— Despite quality improvement programs such as the American Heart Association/American Stroke Association Target Stroke initiative, a substantial portion of acute ischemic stroke patients are still treated with tissue-type plasminogen activator (alteplase) later than 60 minutes from arrival. This study aims to describe the documented reasons for delays and the associations between reasons for delays and patient outcomes. Methods— We analyzed the characteristics of 55 296 patients who received intravenous alteplase in 1422 hospitals participating in Get With The Guidelines-Stroke from October 2012 to April 2015, excluding transferred patients and inpatient strokes. We assessed eligibility, medical, and hospital reasons for delays in door-to-needle time. Results— There were 27 778 patients (50.2%) treated within 60 minutes, 10 086 patients (18.2%) treated >60 minutes without documented delays, and 17 432 patients (31.5%) treated >60 minutes with one or more documented reasons for delay. Delayed door-to-needle times were associated with delayed diagnosis (36 minutes longer than those without delay in diagnosis) and hypoglycemia or seizure (34 minutes longer than without those conditions). The presence of documented delays was associated with higher odds of in-hospital mortality (odds ratio, 1.2; 95% confidence interval, 1.1–1.3) and symptomatic intracranial hemorrhage (odds ratio, 1.2; 95% confidence interval, 1.1–1.3) and lower odds of independent ambulation at discharge (odds ratio, 0.92; 95% confidence interval, 0.9–1.0) after adjusting for patient and hospital characteristics. Conclusions— Hospital and eligibility delays such as delay diagnosis and inability to determine eligibility were associated with longer door-to-needle times. Improved stroke recognition and management of acute comorbidities may help to reduce door-to-needle times.