Efficacy and Safety of Non-Vitamin-K Antagonist Oral Anticoagulants Versus Warfarin Across the Spectrum of Body Mass Index and Body Weight: An Individual Patient Data Meta-Analysis of 4 Randomized Clinical Trials of Patients With Atrial Fibrillation.

BACKGROUND: The efficacy and safety of non-vitamin-K antagonist oral anticoagulants (NOACs) across the spectrum of body mass index (BMI) and body weight (BW) remain uncertain. METHODS: We analyzed data from COMBINE AF (A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in Atrial Fibrillation), which pooled patient-level data from the 4 pivotal randomized trials of NOAC versus warfarin in patients with atrial fibrillation. The primary efficacy and safety outcomes were stroke or systemic embolic events (stroke/SEE) and major bleeding, respectively; secondary outcomes were ischemic stroke/SEE, intracranial hemorrhage, death, and the net clinical outcome (stroke/SEE, major bleeding, or death). Each outcome was examined across BMI and BW. Because few patients had a BMI <18.5 kg/m2 (n=598), the primary analyses were restricted to those with a BMI ≥18.5 kg/m2. RESULTS: Among 58 464 patients, the median BMI was 28.3 (interquartile range, 25.2-32.2) kg/m2, and the median BW was 81.0 (interquartile range, 70.0-94.3) kg. The event probability of stroke/SEE was lower at a higher BMI irrespective of treatment, whereas the probability of major bleeding was lower at a higher BMI with warfarin but relatively unchanged across BMI with NOACs. NOACs reduced stroke/SEE overall (adjusted hazard ratio [HRadj], 0.80 [95% CI, 0.73-0.88]; P<0.001), with a generally consistent effect across BMI (Ptrend across HRs, 0.48). NOACs also reduced major bleeding overall (HRadj, 0.88 [95% CI, 0.82-0.94]; P<0.001), but with attenuation of the benefit at a higher BMI (trend test across BMI [Ptrend], 0.003). The overall treatment effects of NOACs versus warfarin for secondary outcomes were consistent across BMI, with the exception of the net clinical outcome and death. While these outcomes were overall reduced with NOACs (net clinical outcome, HRadj, 0.91 [95% CI, 0.87-0.95]; P<0.001; death, HRadj, 0.91 [95% CI, 0.86-0.97]; P=0.003), these benefits were attenuated at higher BMI (Ptrend, 0.001 and 0.08, respectively). All findings were qualitatively similar when analyzed across BW. CONCLUSIONS: The treatment effect of NOACs versus warfarin in atrial fibrillation is generally consistent for stroke/SEE across the spectrum of BMI and BW, whereas the reduction in major bleeding is attenuated in those with higher BMI or BW. Death and the net clinical outcome are overall reduced with NOACs over warfarin, although there remain uncertainties for these outcomes at a very high BMI and BW.

Direct Oral Anticoagulants Versus Warfarin Across the Spectrum of Kidney Function: Patient-Level Network Meta-Analyses From COMBINE AF.

BACKGROUND: There is uncertainty surrounding the use of direct oral anticoagulants (DOACs) in patients with kidney dysfunction. METHODS: Using the COMBINE AF (A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in Atrial Fibrillation) database (data from RE-LY [Randomized Evaluation of Long-term Anticoagulation Therapy], ROCKET AF [Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation], ARISTOTLE [Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation], and ENGAGE AF-TIMI 48 [Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48]), we performed an individual patient-level network meta-analysis to evaluate the safety and efficacy of DOACs versus warfarin across continuous creatinine clearance (CrCl). A multivariable Cox model including treatment-by-CrCl interaction with random effects was fitted to estimate hazard ratios for paired treatment strategies (standard-dose DOAC, lower-dose DOAC, and warfarin). Outcomes included stroke and systemic embolism (S/SE), major bleeding, intracranial hemorrhage (ICH), and death. RESULTS: Among 71 683 patients (mean age, 70.6±9.4 years; 37.3% female; median follow-up, 23.1 months), the mean CrCl was 75.5±30.5 mL/min. The incidence of S/SE, major bleeding, ICH, and death increased significantly with worsening kidney function. Across continuous CrCl values down to 25 mL/min, the hazard of major bleeding did not change for patients randomized to standard-dose DOACs compared with those randomized to warfarin (Pinteraction=0.61). Compared with warfarin, standard-dose DOAC use resulted in a significantly lower hazard of ICH at CrCl values <122 mL/min, with a trend for increased safety with DOAC as CrCl decreased (6.2% decrease in hazard ratio per 10-mL/min decrease in CrCl; Pinteraction=0.08). Compared with warfarin, standard-dose DOAC use resulted in a significantly lower hazard of S/SE with CrCl <87 mL/min, with a significant treatment-by-CrCl effect (4.8% decrease in hazard ratio per 10-mL/min decrease in CrCl; Pinteraction=0.01). The hazard of death was significantly lower with standard-dose DOACs for patients with CrCl <77 mL/min, with a trend toward increasing benefit with lower CrCl (2.1% decrease in hazard ratio per 10-mL/min decrease in CrCl; Pinteraction=0.08). Use of lower-dose rather than standard-dose DOACs was not associated with a significant difference in incident bleeding or ICH in patients with reduced kidney function but was associated with a higher incidence4 of death and S/SE. CONCLUSIONS: Standard-dose DOACs are safer and more effective than warfarin down to a CrCl of at least 25 mL/min. Lower-dose DOACs do not significantly lower the incidence of bleeding or ICH compared with standard-dose DOACs but are associated with a higher incidence of S/SE and death. These findings support the use of standard-dose DOACs over warfarin in patients with kidney dysfunction.

Donor utilization in heart transplant with donation after circulatory death in the United States.

Heart transplantation using donation after circulatory death (DCD) was recently adopted in the United States. This study aimed to characterize organ yield from adult (≥18 years) DCD heart donors in the United States using the United Network for Organ Sharing registry. The registry does not identify potential donors who do not progress to circulatory death, and only those who progressed to death were included for analysis. Outcomes included organ recovery from the donor operating room and organ utilization for transplant. Multiple logistic regression was used to identify predictors of heart recovery and utilization. Among 558 DCD procurements, recovery occurred in 89.6%, and 92.5% of recovered hearts were utilized for transplant. Of 506 DCD procurements with available data, 65.0% were classified as direct procurement and perfusion and 35.0% were classified as normothermic regional perfusion (NRP). Logistic regression identified that NRP, shorter agonal time, younger donor age, and highest volume of organ procurement organizations were independently associated with increased odds for heart recovery. NRP independently predicted heart utilization after recovery. DCD heart utilization in the United States is satisfactory and consistent with international experience. NRP procurements have a higher yield for DCD heart transplantation compared with direct procurement and perfusion, which may reflect differences in donor assessment and acceptance criteria.

The management of heart failure cardiogenic shock: an international RAND appropriateness panel.

BACKGROUND: Observational data suggest that the subset of patients with heart failure related CS (HF-CS) now predominate critical care admissions for CS. There are no dedicated HF-CS randomised control trials completed to date which reliably inform clinical practice or clinical guidelines. We sought to identify aspects of HF-CS care where both consensus and uncertainty may exist to guide clinical practice and future clinical trial design, with a specific focus on HF-CS due to acute decompensated chronic HF. METHODS: A 16-person multi-disciplinary panel comprising of international experts was assembled. A modified RAND/University of California, Los Angeles, appropriateness methodology was used. A survey comprising of 34 statements was completed. Participants anonymously rated the appropriateness of each statement on a scale of 1 to 9 (1-3 as inappropriate, 4-6 as uncertain and as 7-9 appropriate). RESULTS: Of the 34 statements, 20 were rated as appropriate and 14 were rated as inappropriate. Uncertainty existed across all three domains: the initial assessment and management of HF-CS; escalation to temporary Mechanical Circulatory Support (tMCS); and weaning from tMCS in HF-CS. Significant disagreement between experts (deemed present when the disagreement index exceeded 1) was only identified when deliberating the utility of thoracic ultrasound in the immediate management of HF-CS. CONCLUSION: This study has highlighted several areas of practice where large-scale prospective registries and clinical trials in the HF-CS population are urgently needed to reliably inform clinical practice and the synthesis of future societal HF-CS guidelines.

Outcomes of patients with atrial fibrillation and ischemic stroke while on oral anticoagulation.

AIMS: The prognosis of patients with atrial fibrillation (AF) and ischemic stroke while taking oral anticoagulation is poorly understood. This study aimed to characterize the outcomes of patients following a stroke event while on oral anticoagulation. METHODS AND RESULTS: Individual participant data from five pivotal randomized trials of antithrombotic therapy in AF were used to assess the outcomes of patients with a post-randomization ischemic stroke while on study medication (warfarin, standard-, or lower-dose direct oral anticoagulant regimen) during trial follow-up. The primary outcome was recurrent ischemic stroke after the first post-randomization ischemic stroke. The primary analysis included 1163 patients with a first post-randomization ischemic stroke while on study medication (median age 73 years, 39.3% female, 35.4% history of stroke before trial enrollment). During a median continued follow-up of 337 days, 74 patients had a recurrent ischemic stroke [cumulative incidence at 1 year: 7.0%, 95% confidence interval (CI) 5.2%-8.7%]. The cumulative incidence of mortality at 3 months after stroke was 12.4% (95% CI 10.5%-14.4%). Consistent results for the incidence of recurrent ischemic stroke at 1 year were obtained in an analysis accounting for the competing risk of death (6.2%, 95% CI 4.8%-7.9%) and in a landmark analysis excluding the first 2 weeks after the index stroke and only including patients without permanent study drug discontinuation since then (6.8%, 95% CI 4.6%-8.9%). CONCLUSION: Patients with AF and ischemic stroke while on oral anticoagulation are at increased risk of recurrent ischemic stroke and death. These patients currently have an unmet medical need.

Direct Oral Anticoagulants Versus Warfarin in Patients With Atrial Fibrillation: Patient-Level Network Meta-Analyses of Randomized Clinical Trials With Interaction Testing by Age and Sex.

BACKGROUND: Direct oral anticoagulants (DOACs) are preferred over warfarin for stroke prevention in atrial fibrillation. Meta-analyses using individual patient data offer substantial advantages over study-level data. METHODS: We used individual patient data from the COMBINE AF (A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in Atrial Fibrillation) database, which includes all patients randomized in the 4 pivotal trials of DOACs versus warfarin in atrial fibrillation (RE-LY [Randomized Evaluation of Long-Term Anticoagulation Therapy], ROCKET AF [Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation], ARISTOTLE [Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation], and ENGAGE AF-TIMI 48 [Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48]), to perform network meta-analyses using a stratified Cox model with random effects comparing standard-dose DOAC, lower-dose DOAC, and warfarin. Hazard ratios (HRs [95% CIs]) were calculated for efficacy and safety outcomes. Covariate-by-treatment interaction was estimated for categorical covariates and for age as a continuous covariate, stratified by sex. RESULTS: A total of 71 683 patients were included (29 362 on standard-dose DOAC, 13 049 on lower-dose DOAC, and 29 272 on warfarin). Compared with warfarin, standard-dose DOACs were associated with a significantly lower hazard of stroke or systemic embolism (883/29 312 [3.01%] versus 1080/29 229 [3.69%]; HR, 0.81 [95% CI, 0.74-0.89]), death (2276/29 312 [7.76%] versus 2460/29 229 [8.42%]; HR, 0.92 [95% CI, 0.87-0.97]), and intracranial bleeding (184/29 270 [0.63%] versus 409/29 187 [1.40%]; HR, 0.45 [95% CI, 0.37-0.56]), but no statistically different hazard of major bleeding (1479/29 270 [5.05%] versus 1733/29 187 [5.94%]; HR, 0.86 [95% CI, 0.74-1.01]), whereas lower-dose DOACs were associated with no statistically different hazard of stroke or systemic embolism (531/13 049 [3.96%] versus 1080/29 229 [3.69%]; HR, 1.06 [95% CI, 0.95-1.19]) but a lower hazard of intracranial bleeding (55/12 985 [0.42%] versus 409/29 187 [1.40%]; HR, 0.28 [95% CI, 0.21-0.37]), death (1082/13 049 [8.29%] versus 2460/29 229 [8.42%]; HR, 0.90 [95% CI, 0.83-0.97]), and major bleeding (564/12 985 [4.34%] versus 1733/29 187 [5.94%]; HR, 0.63 [95% CI, 0.45-0.88]). Treatment effects for standard- and lower-dose DOACs versus warfarin were consistent across age and sex for stroke or systemic embolism and death, whereas standard-dose DOACs were favored in patients with no history of vitamin K antagonist use (P=0.01) and lower creatinine clearance (P=0.09). For major bleeding, standard-dose DOACs were favored in patients with lower body weight (P=0.02). In the continuous covariate analysis, younger patients derived greater benefits from standard-dose (interaction P=0.02) and lower-dose DOACs (interaction P=0.01) versus warfarin. CONCLUSIONS: Compared with warfarin, DOACs have more favorable efficacy and safety profiles among patients with atrial fibrillation.

Clinical trajectory of patients with a worsening heart failure event and reduced ventricular ejection fraction.

BACKGROUND: Recent data suggest that patients with heart failure with reduced ejection fraction (HFrEF) and worsening heart failure (WHF) have potential for greater benefit from newer HF therapies. We investigated characteristics and outcomes of patients with HFrEF and WHF by severity of left ventricular dysfunction. METHODS: We identified patients with chronic symptomatic HFrEF (left ventricular ejection fraction [LVEF] ≤35%) and evidence of WHF (emergency department visit or hospitalization for acute HF within 12 months of index echocardiogram) treated at Duke University between 1/2009 and 12/2018. Patients were stratified by LVEF≤25% or 26% to35%. Cox models were used to estimate cause-specific hazard ratios and 5-year event incidence of death and hospitalization across the range of LVEF. RESULTS: Of 2823 patients with HFrEF and WHF, 1620 (57.4%) had an LVEF≤25% and 1203 (42.6%) had an LVEF 26% to35%. Compared to patients with LVEF 26% to35%, those with LVEF≤25% were younger and more commonly men with a lower cardiovascular comorbidity burden. Patients with LVEF≤25% were less commonly on beta blockers (85.9% vs 90.5%) but more commonly treated with mineralocorticoid receptor antagonists (49.3% vs 41.1%) and implantable defibrillators (41.3% vs 28.2%). Patients with LVEF≤25% had significantly higher hazards for death (HR 1.24 [95% CI 1.11 - 1.38]), all-cause hospitalization (HR 1.21 [95% CI 1.10 - 1.33]), and HF hospitalization (HR 1.25 [95% CI 1.1 - 1.38]) through 5-years. CONCLUSIONS: More than half of patients with chronic HFrEF and WHF have severe LV dysfunction. Important differences in comorbidities, HF therapies, and outcomes exist between those with LVEF≤25% and those with LVEF 26% to35%.

The Road Not Yet Traveled: Distinction in Critical Care Cardiology through the Advanced Heart Failure and Transplant Cardiology Training Pathway.

As the acuity, complexity, and illness severity of patients admitted to cardiac intensive care units have increased, the need to recognize critical care cardiology (CCC) as a dedicated subspecialty in cardiovascular disease has received increasing support. Differing viewpoints exist regarding the optimal pathway for CCC training. Currently, all proposed CCC training pathways involve permutations of individual training years culminating in subspecialty certification across multiple disciplines; however, there are significant disadvantages to these training paradigms. We propose an innovative, pragmatic approach to CCC training through tailored subspecialty training in advanced heart failure and transplant cardiology (AHFTC), using elective time to enrich AHFTC training with skills and experiences necessary to become a highly skilled critical care cardiologist. The completion of this pathway would lead to completion of AHFTC training with a novel designation: distinction in critical care cardiology.

Individual Patient Data from the Pivotal Randomized Controlled Trials of Non-Vitamin K Antagonist Oral Anticoagulants in Patients with Atrial Fibrillation (COMBINE AF): Design and Rationale: From the COMBINE AF (A Collaboration between Multiple institutions to Better Investigate Non-vitamin K antagonist oral anticoagulant use in Atrial Fibrillation) Investigators.

BACKGROUND: Non-vitamin K antagonist oral anticoagulants (NOACs) are the preferred class of medications for prevention of stroke and systemic embolism in patients with atrial fibrillation unless contraindications exist. Five large, international, randomized, controlled trials of NOACs versus either warfarin or aspirin have been completed to date. DESIGN: COMBINE AF incorporates de-identified individual patient data from 77,282 patients with atrial fibrillation at risk for stroke randomized to NOAC, warfarin, or aspirin from 5 pivotal randomized controlled trials. All patients randomized in the constituent trials are included. Variables common to ≥3 of the constituent trials are included in the master database. Individual trial data sets from the 4 coordinating centers were combined at the Duke Clinical Research Institute. The final database will be securely shared with the 4 academic coordinating centers. The combined master database will be used to perform statistical analyses aimed at better understanding underlying risk factors and outcomes in patients with atrial fibrillation treated with oral anticoagulants, with a special focus on patient subgroups and uncommon outcomes. The initial analysis from COMBINE AF will be a network meta-analysis investigating the relative efficacy and safety of pooled higher-dose NOACs versus pooled lower-dose NOACs versus warfarin with respect to multiple time-to-event efficacy and safety outcomes. COMBINE AF is registered with PROSPERO (CRD42020178771). CONCLUSION: In conclusion, COMBINE AF provides a rich and robust database consisting of individual patient data and will offer opportunities to investigate oral anticoagulants across many patient subgroups. Data sharing and collaboration across academic institutions and investigators will serve as overarching themes.

The Range of Cardiogenic Shock Survival by Clinical Stage: Data From the Critical Care Cardiology Trials Network Registry.

OBJECTIVES: Cardiogenic shock presents with variable severity. Categorizing cardiogenic shock into clinical stages may improve risk stratification and patient selection for therapies. We sought to determine whether a structured implementation of the 2019 Society for Cardiovascular Angiography and Interventions clinical cardiogenic shock staging criteria that is ascertainable in clinical registries discriminates mortality in a contemporary population with or at-risk for cardiogenic shock. DESIGN: We developed a pragmatic application of the Society for Cardiovascular Angiography and Interventions cardiogenic shock staging criteria-A (at-risk), B (beginning), C (classic cardiogenic shock), D (deteriorating), or E (extremis)-and examined outcomes by stage. SETTING: The Critical Care Cardiology Trials Network is an investigator-initiated multicenter research collaboration coordinated by the TIMI Study Group (Boston, MA). Consecutive admissions with or at-risk for cardiogenic shock during two annual 2-month collection periods (2017-2019) were analyzed. PATIENTS: Patients with or at-risk for cardiogenic shock. MEASUREMENTS AND MAIN RESULTS: Of 8,240 CICU admissions reviewed, 1,991 (24%) had or were at-risk for cardiogenic shock. Distributions across the five stages were as follows: A: 33%; B: 7%; C: 16%; D: 23%; and E: 21%. Overall in-hospital mortality among patients with established cardiogenic shock was 39%; however, mortality varied from only 15.8% to 32.1% to 62.5% across stages C, D, and E (Cochran-Armitage ptrend < 0.0001). The Society for Cardiovascular Angiography and Interventions stages improved mortality prediction beyond the Sequential Organ Failure Assessment and Intra-Aortic Balloon Pumpin Cardiogenic Shock II scores. CONCLUSIONS: Although overall mortality in cardiogenic shock remains high, it varies considerably based on clinical stage, identifying stage C as relatively lower risk. We demonstrate a pragmatic adaptation of the Society for Cardiovascular Angiography and Interventions cardiogenic shock stages that effectively stratifies mortality risk and could be leveraged for future clinical research.

Sacubitril/Valsartan Initiation and Postdischarge Adherence Among Patients Hospitalized for Heart Failure.

BACKGROUND: We investigated associations between timing of sacubitril/valsartan initiation and postdischarge adherence among patients hospitalized for heart failure with reduced ejection fraction (HFrEF). Clinical trials support initiation of sacubitril/valsartan among patients hospitalized with HFrEF. The association between timing of initiation and postdischarge adherence is unknown. METHODS AND RESULTS: We analyzed patients hospitalized for HFrEF (EF of ≤40%) within the Get With The Guidelines Heart Failure registry linked with Medicare claims between October 2015 and September 2017 who were eligible for sacubitril/valsartan. Follow-up was through December 2018. Patients were grouped by timing of sacubitril/valsartan initiation. Sacubitril/valsartan adherence at 90 and 365 days after discharge was assessed by calculating proportion of days covered (PDC) using medication fills. Among 4666 patients, 108 (2.3%) were continued on sacubitril/valsartan (on sacubitril/valsartan at admission and discharge), 191 (4.1%) were initiated as inpatients, 130 (2.8%) were initiated at discharge, and 4237 (90.1%) were discharged without sacubitril/valsartan. Median (25th, 75th) proportion of days covered through 90 days among those continued, initiated as inpatients, and initiated at discharge was 0.9 (0.6-0.1), 0.3 (0.0-0.7), and 0.0 (0.0-0.7), respectively (P < .001). Patients discharged without sacubitril/valsartan had very low rates of any sacubitril/valsartan fills within 90 and 365 days of discharge (2.1% and 7.7% of surviving patients, respectively). CONCLUSIONS: In 2015-2017 US clinical practice, more than 90% of eligible patients hospitalized for HFrEF were discharged without sacubitril/valsartan. Patients initiated as inpatients had a higher postdischarge proportion of days covered than patients initiated at discharge. Patients discharged without sacubitril/valsartan were unlikely to receive it during follow-up. These findings highlight the importance of initiating sacubitril/valsartan during hospitalization to improve the quality of care.

De Novo vs Acute-on-Chronic Presentations of Heart Failure-Related Cardiogenic Shock: Insights from the Critical Care Cardiology Trials Network Registry.

BACKGROUND: Heart failure-related cardiogenic shock (HF-CS) accounts for an increasing proportion of cases of CS in contemporary cardiac intensive care units. Whether the chronicity of HF identifies distinct clinical profiles of HF-CS is unknown. METHODS AND RESULTS: We evaluated admissions to cardiac intensive care units for HF-CS in 28 centers using data from the Critical Care Cardiology Trials Network registry (2017-2020). HF-CS was defined as CS due to ventricular failure in the absence of acute myocardial infarction and was classified as de novo vs acute-on-chronic based on the absence or presence of a prior diagnosis of HF, respectively. Clinical features, resource use, and outcomes were compared among groups. Of 1405 admissions with HF-CS, 370 had de novo HF-CS (26.3%), and 1035 had acute-on-chronic HF-CS (73.7%). Patients with de novo HF-CS had a lower prevalence of hypertension, diabetes, coronary artery disease, atrial fibrillation, and chronic kidney disease (all P < 0.01). Median Sequential Organ Failure Assessment (SOFA) scores were higher in those with de novo HF-CS (8; 25th-75th: 5-11) vs acute-on-chronic HF-CS (6; 25th-75th: 4-9, P < 0.01), as was the proportion of Society of Cardiovascular Angiography and Intervention (SCAI) shock stage E (46.1% vs 26.1%, P < 0.01). After adjustment for clinical covariates and preceding cardiac arrest, the risk of in-hospital mortality was higher in patients with de novo HF-CS than in those with acute-on-chronic HF-CS (adjusted hazard ratio 1.36, 95% confidence interval 1.05-1.75, P = 0.02). CONCLUSIONS: Despite having fewer comorbidities, patients with de novo HF-CS had more severe shock presentations and worse in-hospital outcomes. Whether HF disease chronicity is associated with time-dependent compensatory adaptations, unique pathobiological features and responses to treatment in patients presenting with HF-CS warrants further investigation.

Resource utilization and hospital readmission associated with gastrointestinal bleeding in patients with continuous-flow left ventricular assist devices.

Gastrointestinal bleeding (GIB) occurs in up to 40% of patients with continuous-flow (CF) left ventricular assist devices (LVADs). We sought to identify targets to improve hospital resource utilization and decrease readmissions after GIB. We performed a single-center, retrospective analysis of LVAD-associated GIB resulting in hospital admission between July 2011 and April 2014. Follow-up data were collected through March 2015. We analyzed 57 admissions for GIB in 23 patients. One or more diagnostic imaging study was performed in 47% of admissions, with a definite or probable source of GIB identified in 23%. A total of 76 endoscopies were performed (≥ 1 endoscopy in 79% of admissions, ≥ 2 in 42%). Definite or probable bleeding sources were identified in 25% and 12% of endoscopies, respectively. Patients who underwent multiple endoscopies were no more likely to have a bleeding source identified (OR 1.48; 95% CI 0.50-4.32; p = 0.59) and had longer hospital stays (11.1 vs. 7.8 days, p < 0.02). Readmission rates for GIB at 30 and 90 days were 33% and 53%, respectively. A decrease in antiplatelet regimen at discharge was associated with lower rate of readmission for GIB (OR 0.16; 95% CI 0.03-0.82; p = 0.03) or any cause (OR 0.21; 95% CI 0.05-0.85; p = 0.04) at 30 and 90 days. GIB in patients with CF-LVADs is associated with significant in-hospital resource utilization and high rates of readmission. Imaging and endoscopy are common, but have low diagnostic yield and infrequently result in successful intervention. Strategies to reduce resource utilization and prevent readmission are warranted.

Predictive multivariate regression to increase the specificity of carotid duplex ultrasound for high-grade stenosis in asymptomatic patients.

BACKGROUND: Carotid duplex ultrasound (CDUS) is commonly used to screen for carotid artery stenosis. Specificities of CDUS criteria however are lower than sensitivities, potentially resulting in false-positive examinations with subsequent unnecessary imaging or surgery. Our objective was to establish a multivariate logistic regression to increase the specificity of CDUS for high-grade (≥70%) stenosis. METHODS: A retrospective review collected CDUS velocities and radiographic measurements from patients who underwent both CDUS and computed tomography angiography (CTA). After stratification with standard CDUS criteria, a logistic regression was created using peak systolic velocity (PSV), end diastolic velocity (EDV), and PSV ratio (PSV of internal carotid artery [ICA]/PSV of common carotid artery [CCA]) as predictor variables. A receiver operating characteristic curve was generated to test the model's predictive ability. A cutoff probability for unequivocal high-grade stenosis was chosen based on optimal specificity. The regression model was applied to patients with equivocal high-grade stenosis. Probabilities for detection of high-grade stenosis were calculated. Descriptive statistics were generated to quantify the accuracy of the model. RESULTS: A total of 244 vessels were included. Standardized velocity criteria for ≥70% stenosis yielded a sensitivity of 90.6% (95% confidence interval [CI], 82.3-95.6%), specificity of 63.5% (95% CI, 55.4-70.5%), positive predictive value (PPV) of 57.0% (95% CI, 48.8-65.5%), and negative predictive value (NPV) of 92.7% (95% CI, 85.8-96.5%). Regression analysis produced a model for predicting the probability of high-grade stenosis defined as probability = logit(-1) (-4.97 + [0.00938 × PSV] + [0.0135 × EDV] + [0.103 × PSV ICA/CCA ratio]). A cutoff probability of 0.65 for high-grade stenosis yielded a sensitivity of 54.7% (95% CI, 43.9-65.0%), specificity of 94.3% (95% CI, 89.3-97.2%), PPV of 83.9% (95% CI, 71.6-91.9%), and NPV of 79.3% (95% CI, 72.8-84.5%). A cutoff PSV of 400 cm/sec was chosen for unequivocal stenosis of ≥70%. A total of 94 patients were found to meet criteria for high-grade stenosis (PSV ≥ 230 cm/sec) but fall short of criteria for unequivocal high-grade stenosis (PSV < 400 cm/sec). Application of the regression model resulted in identification of 15 patients with probability ≥0.65 for high-grade stenosis and 79 patients with probability <0.65. This resulted in a 16% potential reduction in CTA scans. CONCLUSIONS: Our regression model provides increased specificity of CDUS for high-grade stenosis in patients who have met initial highly sensitive screening criteria. Application of this model may limit the need for additional imaging and increase the threshold for operative intervention in asymptomatic patients with equivocal high-grade carotid stenosis.

CT angiography-derived duplex ultrasound velocity criteria in patients with carotid artery stenosis.

BACKGROUND: Validation of carotid duplex ultrasound velocity criteria (CDUS VC) to grade the severity of extracranial carotid artery stenosis has traditionally been based on conventional angiography measurements. In the last decade, computed tomographic angiography (CTA) has largely replaced conventional arch and carotid arteriography (CA) for diagnostic purposes. Given the low number of CA being performed, it is impractical to expect noninvasive vascular laboratories to be validated using this modality. CDUS VC have not been developed with the use of CTA-derived measurements. The objective was to determine optimal CDUS VC from CTA-derived measurements with the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method for 50% and 80% stenosis. METHODS: A retrospective review of all patients who underwent CDUS and CTA from 2000 to 2009 was performed. Vessel diameters were measured on CTA, and corresponding CDUS velocities were recorded. Percent stenosis was calculated using the NASCET method. Receiver operating characteristic (ROC) curves were generated for internal carotid artery (ICA) peak systolic velocity (PSV), ICA end diastolic velocity (EDV), and ICA PSV to common carotid artery PSV ratio (PSVR) for 50% and 80% stenosis. Velocity cut points were determined with equal weighting of sensitivity and specificity. RESULTS: A total of 575 vessels were analyzed to create the ROC curves. A 50% stenosis analysis yielded ideal cut points for PSV, EDV, and PSVR of 130 cm/sec, 42 cm/sec, and 1.75. An 80% stenosis analysis yielded ideal cut points for PSV, EDV, and PSVR of 297 cm/sec, 84 cm/sec, and 3.06. CONCLUSIONS: CTA-derived CDUS VC appeared to be reliable in defining 50% and 80% stenosis in patients with carotid artery stenosis. Although CDUS VC defined in this study were different from many of the previously published VC for the same percent stenosis, there were many similarities to those reported by the Society of Radiologists in Ultrasound consensus conference. We feel that CTA should be the gold standard imaging technique for validating CDUS VC.