Impella percutaneous left ventricular assist device as mechanical circulatory support for cardiogenic shock: A retrospective analysis from a tertiary academic medical center.

OBJECTIVES: To describe hemodynamic efficacy and clinical outcomes of Impella percutaneous left ventricular assist device (pLVAD) in patients with cardiogenic shock (CS). BACKGROUND: Percutaneous LVADs are increasingly used in CS management. However, device-related outcomes and optimal utilization remain active areas of investigation. METHODS: All CS patients receiving pLVAD as mechanical circulatory support (MCS) between 2011 and 2017 were identified. Clinical characteristics and outcomes were analyzed. A multivariable logistic regression model was created to predict MCS escalation despite pLVAD. Outcomes were compared between early and late implantation. RESULTS: A total of 115 CS patients (mean age 63.6 ± 13.8 years; 69.6% male) receiving pLVAD as MCS were identified, the majority with CS secondary to acute myocardial infarction (AMI; 67.0%). Patients experienced significant cardiac output improvement (median 3.39 L/min to 3.90 L/min, p = .002) and pharmacological support reduction (median vasoactive-inotropic score [VIS] 25.4 to 16.4, p = .049). Placement of extracorporeal membrane oxygenation (ECMO) occurred in 48 (41.7%) of patients. Higher pre-pLVAD VIS was associated with subsequent MCS escalation in the entire cohort and AMI subgroup (OR 1.27 [95% CI 1.02-1.58], p = .034 and OR 1.72 [95% CI 1.04-2.86], p = .035, respectively). Complications were predominantly access site related (bleeding [9.6%], vascular injury [5.2%], and limb ischemia [2.6%]). In-hospital mortality was 57.4%, numerically greater survival was noted with earlier device implantation. CONCLUSIONS: Treatment with pLVAD for CS improved hemodynamic status but did not uniformly obviate MCS escalation. Mortality in CS remains high, though earlier device placement for appropriately selected patients may be beneficial.

Improving Fluid Output Monitoring in the Intensive Care Unit.

PURPOSE: To assess the potential clinical impact of an automated urine output (UOP) monitoring system in the intensive care unit. METHODS: Frequency of UOP documentation during a 20-month period was assessed in records of inpatients on the medicine floor, cardiac intensive care (CCU), and cardiothoracic-intensive care units (CTICU). Documentation timeliness (time between expected and observed UOP recording) was assessed over a 3-month period. A novel reusable device that monitors UOP based on continuous analysis of the weight of a urine collection container was tested in the CCU/CTICU. RESULTS: A total of 165,363 UOP measurements were recorded for 2,039 CCU/CTICU admissions. Sixty percent of CCU/CTICU admissions had UOP recorded in the electronic medical record (EMR) less than every 2 hours. One-third of CCU/CTICU measurements were documented more than 2 hours late, and only 10% were recorded less than 20 minutes late. Half of these patients had fewer than 2 measurements recorded per nursing shift and recordings were documented an average of 85 minutes late. There was no significant difference between daytime and nighttime shifts. UOP values obtained by the novel electronic monitoring device were within 27 ml (-224 ml, +228 ml) of nurses documented values, across 74 patients over a 24-hour period. CONCLUSIONS: Automating UOP monitoring using a reusable weight-based device is feasible and can improve timeliness of documentation and reduce nursing workload without compromising accuracy.

COVID-19 and Cardiovascular Disease.

Coronavirus disease 2019 (COVID-19) is a global pandemic affecting 185 countries and >3 000 000 patients worldwide as of April 28, 2020. COVID-19 is caused by severe acute respiratory syndrome coronavirus 2, which invades cells through the angiotensin-converting enzyme 2 receptor. Among patients with COVID-19, there is a high prevalence of cardiovascular disease, and >7% of patients experience myocardial injury from the infection (22% of critically ill patients). Although angiotensin-converting enzyme 2 serves as the portal for infection, the role of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers requires further investigation. COVID-19 poses a challenge for heart transplantation, affecting donor selection, immunosuppression, and posttransplant management. There are a number of promising therapies under active investigation to treat and prevent COVID-19.

Epidemiology, clinical course, and outcomes of critically ill adults with COVID-19 in New York City: a prospective cohort study.

BACKGROUND: Over 40 000 patients with COVID-19 have been hospitalised in New York City (NY, USA) as of April 28, 2020. Data on the epidemiology, clinical course, and outcomes of critically ill patients with COVID-19 in this setting are needed. METHODS: This prospective observational cohort study took place at two NewYork-Presbyterian hospitals affiliated with Columbia University Irving Medical Center in northern Manhattan. We prospectively identified adult patients (aged ≥18 years) admitted to both hospitals from March 2 to April 1, 2020, who were diagnosed with laboratory-confirmed COVID-19 and were critically ill with acute hypoxaemic respiratory failure, and collected clinical, biomarker, and treatment data. The primary outcome was the rate of in-hospital death. Secondary outcomes included frequency and duration of invasive mechanical ventilation, frequency of vasopressor use and renal replacement therapy, and time to in-hospital clinical deterioration following admission. The relation between clinical risk factors, biomarkers, and in-hospital mortality was modelled using Cox proportional hazards regression. Follow-up time was right-censored on April 28, 2020 so that each patient had at least 28 days of observation. FINDINGS: Between March 2 and April 1, 2020, 1150 adults were admitted to both hospitals with laboratory-confirmed COVID-19, of which 257 (22%) were critically ill. The median age of patients was 62 years (IQR 51-72), 171 (67%) were men. 212 (82%) patients had at least one chronic illness, the most common of which were hypertension (162 [63%]) and diabetes (92 [36%]). 119 (46%) patients had obesity. As of April 28, 2020, 101 (39%) patients had died and 94 (37%) remained hospitalised. 203 (79%) patients received invasive mechanical ventilation for a median of 18 days (IQR 9-28), 170 (66%) of 257 patients received vasopressors and 79 (31%) received renal replacement therapy. The median time to in-hospital deterioration was 3 days (IQR 1-6). In the multivariable Cox model, older age (adjusted hazard ratio [aHR] 1·31 [1·09-1·57] per 10-year increase), chronic cardiac disease (aHR 1·76 [1·08-2·86]), chronic pulmonary disease (aHR 2·94 [1·48-5·84]), higher concentrations of interleukin-6 (aHR 1·11 [95%CI 1·02-1·20] per decile increase), and higher concentrations of D-dimer (aHR 1·10 [1·01-1·19] per decile increase) were independently associated with in-hospital mortality. INTERPRETATION: Critical illness among patients hospitalised with COVID-19 in New York City is common and associated with a high frequency of invasive mechanical ventilation, extrapulmonary organ dysfunction, and substantial in-hospital mortality. FUNDING: National Institute of Allergy and Infectious Diseases and the National Center for Advancing Translational Sciences, National Institutes of Health, and the Columbia University Irving Institute for Clinical and Translational Research.

The cardiac intensive care unit and the cardiac intensivist during the COVID-19 surge in New York City.

Critical care cardiology has been impacted by the coronavirus disease-2019 (COVID-19) pandemic. COVID-19 causes severe acute respiratory distress syndrome, acute kidney injury, as well as several cardiovascular complications including myocarditis, venous thromboembolic disease, cardiogenic shock, and cardiac arrest. The cardiac intensive care unit is rapidly evolving as the need for critical care beds increases. Herein, we describe the changes to the cardiac intensive care unit and the evolving role of critical care cardiologists and other clinicians in the care of these complex patients affected by the COVID-19 pandemic. These include practical recommendations regarding structural and organizational changes to facilitate care of patients with COVID-19; staffing and personnel changes; and health and safety of personnel. We draw upon our own experiences at NewYork-Presbyterian Columbia University Irving Medical Center to offer insights into the unique challenges facing critical care clinicians and provide recommendations of how to address these challenges during this unprecedented time.

Pulmonary hyperinflation and left ventricular mass: the Multi-Ethnic Study of Atherosclerosis COPD Study.

BACKGROUND: Left ventricular (LV) mass is an important predictor of heart failure and cardiovascular mortality, yet determinants of LV mass are incompletely understood. Pulmonary hyperinflation in chronic obstructive pulmonary disease (COPD) may contribute to changes in intrathoracic pressure that increase LV wall stress. We therefore hypothesized that residual lung volume in COPD would be associated with greater LV mass. METHODS AND RESULTS: The Multi-Ethnic Study of Atherosclerosis (MESA) COPD Study recruited smokers 50 to 79 years of age who were free of clinical cardiovascular disease. LV mass was measured by cardiac magnetic resonance. Pulmonary function testing was performed according to guidelines. Regression models were used to adjust for age, sex, body size, blood pressure, and other cardiac risk factors. Among 119 MESA COPD Study participants, the mean age was 69±6 years, 55% were male, and 65% had COPD, mostly of mild or moderate severity. Mean LV mass was 128±34 g. Residual lung volume was independently associated with greater LV mass (7.2 g per 1-SD increase in residual volume; 95% confidence interval, 2.2-12; P=0.004) and was similar in magnitude to that of systolic blood pressure (7.6 g per 1-SD increase in systolic blood pressure; 95% confidence interval, 4.3-11; P<0.001). Similar results were observed for the ratio of LV mass to end-diastolic volume (P=0.02) and with hyperinflation measured as residual volume to total lung capacity ratio (P=0.009). CONCLUSIONS: Pulmonary hyperinflation, as measured by residual lung volume or residual lung volume to total lung capacity ratio, is associated with greater LV mass.

Prevalence and anatomical features of acute longitudinal stent deformation: An intravascular ultrasound study.

OBJECTIVES: We report the prevalence and anatomical features of longitudinal stent deformation as detected by intravascular ultrasound (IVUS) BACKGROUND: Angiographic studies have recently reported longitudinal stent deformation as a mechanical complication occurring during percutaneous coronary intervention; however, there are no IVUS studies on this phenomenon METHODS: We retrospectively analyzed 1,489 consecutive stent-treated lesions in 1,057 patients who underwent IVUS post-stent implantation RESULTS: Seventeen longitudinal stent deformations in 17 lesions (1.1% per lesion) in 17 patients (1.6% per patient) were identified by IVUS. Of the 17 IVUS-detected deformations, only three deformations (17.6%) were detectable by angiography. By IVUS, there were three patterns of longitudinal stent deformation: (1) Deformation with intra-stent wrinkling and overlapping of the proximal and distal stent fragments within a single stent (n = 14), (2) deformation with elongation (n = 2), and (3) deformation with shortening (n = 1). Most of the deformations were located near to the proximal stent edge (88%), consistent with the finding that they were observed in 11 ostial (65%) and eight left main lesions (47%), and 8.3% of 96 left main stented lesions had evidence of deformation CONCLUSIONS: By IVUS, longitudinal stent deformation during percutaneous coronary intervention was seen more frequently than in previous studies; however, it is still uncommon (1.1%) except in the left main location. The most frequent pattern was intrastent wrinkling and overlapping of the proximal and distal stent fragments.

Ostial right coronary artery lesion morphology and outcomes after treatment with drug-eluting stents.

BACKGROUND: Outcomes after percutaneous coronary intervention (PCI) for de novo ostial right coronary artery (RCA) lesions are poor. AIMS: We used intravascular ultrasound (IVUS) to clarify the morphological patterns of de novo ostial RCA lesions and their associated clinical outcome. METHODS: Among 5,102 RCA IVUS studies, 170 de novo ostial RCA stenoses (within 3 mm from the aorto-ostium) were identified. These were classified as 1) isolated ostial lesions (no disease extending beyond 10 mm from the ostium and without a calcified nodule [CN]); 2) ostial CN, typically with diffuse disease (disease extending beyond 10 mm); and 3) ostial lesions with diffuse disease but without a CN. The primary outcome was target lesion failure (TLF: cardiac death, target vessel myocardial infarction, definite stent thrombosis, and ischaemia-driven target lesion revascularisation). RESULTS: The prevalence of an isolated ostial lesion was 11.8% (n=20), 47.6% (n=81) were ostial CN, and 40.6% (n=69) were ostial lesions with diffuse disease. Compared to ostial lesions with diffuse disease, isolated lesions were more common in women (75.0% vs 42.0%; p=0.01), and CN were associated with older age (median [first, third quartile] 76 [70, 83] vs 69 [63, 81] years old; p=0.002). The Kaplan-Meier rate of TLF at 2 years was significantly higher in patients with CN (21.6%) compared to diffuse lesions (8.2%) (p=0.04), and patients with isolated lesions had no events. A multivariable Cox proportional hazard model revealed that CN were significantly associated with TLF (hazard ratio 6.63, 95% confidence interval: 1.28-34.3; p=0.02). CONCLUSIONS: Ostial RCA lesions have specific morphologies - detectable by IVUS - that may be associated with long-term clinical outcomes.

Presence and Relevance of Myocardial Bridge in LAD-PCI of CTO and Non-CTO Lesions.

BACKGROUND: Intravascular ultrasound (IVUS) studies show that one-quarter of left anterior descending (LAD) arteries have a myocardial bridge. An MB may be associated with stent failure when the stent extends into the MB. OBJECTIVES: The aim of this study was to investigate: 1) the association between an MB and chronic total occlusion (CTO) in any LAD lesions; and 2) the association between an MB and subsequent clinical outcomes after percutaneous coronary intervention in LAD CTOs. METHODS: A total of 3,342 LAD lesions with IVUS-guided percutaneous coronary intervention (280 CTO and 3,062 non-CTO lesions) were included. The primary outcome was target lesion failure (cardiac death, target vessel myocardial infarction, definite stent thrombosis, and ischemic-driven target lesion revascularization). RESULTS: An MB by IVUS was significantly more prevalent in LAD CTOs than LAD non-CTOs (40.4% [113/280] vs 25.8% [789/3,062]; P < 0.0001). The discrepancy in CTO length between angiography and IVUS was greater in 113 LAD CTOs with an MB than 167 LAD CTOs without an MB (6.0 [Q1, Q3: 0.1, 12.2] mm vs 0.2 [Q1, Q3: -1.4, 8.4] mm; P < 0.0001). Overall, 48.7% (55/113) of LAD CTOs had a stent that extended into an MB after which target lesion failure was significantly higher compared to a stent that did not extend into an MB (26.3% vs 0%; P = 0.0004) or compared to an LAD CTO without an MB (26.3% vs 9.6%; P = 0.02). CONCLUSIONS: An MB was more common in LAD CTO than non-CTO LAD lesions. If present, approximately one-half of LAD CTOs had a stent extending into an MB that, in turn, was associated with worse outcomes.

Interleukin 6 plasma concentration associates with cognitive decline: the northern Manhattan study.

BACKGROUND: Interleukin 6 (IL-6) is an inflammatory cytokine that has been associated with vascular disease and cognitive impairment, but few studies have examined these relationships in population-based studies that include Hispanic and Black people who often have a greater prevalence of vascular risk factors and are at an elevated risk of dementia than Whites. We examined relative elevations of plasma IL-6 concentrations in relation to cognitive decline in a stroke-free racially/ethnically diverse community-based sample from Northern Manhattan. METHODS: We used mixed effects models to measure the effect of IL-6 on change in performance on the modified Telephone Interview for Cognitive Status (TICS-m) measured annually in our cohort, adjusting for sociodemographic and vascular risk factors. RESULTS: There were 1,224 participants with IL-6 levels (median 1.5 pg/ml, interquartile range 0.83-2.57 pg/ml) and TICS-m data available (mean = 31.6 points, SD 6.5). The mean age was 71 (SD 9.3; 64% women, 59% Hispanic, 19% Black, 19% White) with 3,406 person-years and a median 3.0 years of follow-up (interquartile range 1.1-4.0 years). Participants with IL-6 levels above the median showed greater cognitive decline on the TICS-m compared to those with levels below the median, adjusting for sociodemographic and vascular factors (ß = -0.17 points/year, p = 0.02). Decline on the TICS-m among participants with IL-6 above the median differed by age (p for interaction <0.001). There was no interaction by race/ethnicity, vascular risk factors, C-reactive protein, apolipoprotein ε4 allele status, or the metabolic syndrome among nondiabetics. CONCLUSIONS: IL-6 associated with cognitive decline among older participants in this racially/ethnically diverse sample independent of other vascular risk factors and C-reactive protein.

Magnetic positioning system in coronary angiography and percutaneous intervention: a feasibility and safety study.

OBJECTIVES: This study sought to evaluate the safety and feasibility of a magnetic medical positioning system (MPS) to determine the three-dimensional (3D) position and orientation of intracoronary wires and catheters and to guide angiography and percutaneous coronary intervention (PCI). BACKGROUND: Coronary angiography relies on fluoroscopy for catheter navigation and often fails to accurately portray vessel tortuosity, overlap, and length because of complex anatomy and foreshortening of curved coronary segments. METHODS: Forty adult participants underwent coronary angiography and/or PCI with MPS guidance. Two interventional cardiologists independently scored (1-5) the accuracy of MPS catheter tracking projected on live fluoroscopy, recorded cine loops, and 3D vessel reconstructions. Measurements from MPS reconstructions were compared to conventional two-dimensional (2D) quantitative coronary angiography (QCA) measurements. Device procedural success was defined as the ability of the MPS-enabled catheter to reach the target vessel, perform the intended operations, and be retrieved without major adverse cardiac events. RESULTS: Diagnostic coronary angiography was performed in 19 (47.5%) and PCI in 21 patients (52.5%). MPS procedural success was achieved in 36 (90%) of the cases. MPS accuracy was highest with the MPS superimposed on live fluoroscopy (4.9 ± 0.2/5) and the 3D vessel reconstruction (4.7 ± 0.5/5). MPS length measurements were more accurate than conventional QCA. CONCLUSIONS: This study demonstrates the feasibility and safety of magnetic catheter tracking with 3D positional data during diagnostic angiography and PCI. Catheter position was accurately projected on real-time fluoroscopy, recorded cine loops, and 3D reconstructions. An MPS may serve as a platform for device navigation and positioning during PCI.

Volumetric intravascular ultrasound assessment of mechanisms and results of stent expansion in heart transplant patients.

BACKGROUND: Percutaneous coronary intervention with stent placement for the treatment of patients with cardiac allograft vasculopathy is common, but data regarding stent behavior in this setting is lacking. OBJECTIVES: We investigated mechanisms and potential differences in stent expansion among transplant patients vs. patients with native coronary artery atherosclerotic disease ("controls"). METHODS: We compared pre- and poststent intravascular ultrasound in 12 transplant patients (17 lesions) and 33 control patients (34 lesions) matched according to age (60.1 ± 9.2 years), diabetes mellitus, and lesion location. Planar and volumetric analysis was conducted for every 1 mm at the lesion site as well as the first 5 mm proximal and distal to the stent edge. Focal stent expansion was defined as minimum stent area (MSA) divided by mean reference lumen area. Diffuse stent expansion was defined as mean stent area divided by mean reference lumen area. RESULTS: Transplant patients had more plaque than "controls" prestenting, but similar MSA and focal and diffuse stent expansion afterwards. The increase in mean lumen area correlated with the increase in mean vessel area in both groups, transplant (R = 0.64, P = 0.008) and controls (R = 0.70, P < 0.0001), but correlated inversely with changes in mean plaque area only in the transplant group (R = 0.55, P = 0.027). There were no differences in calcification between the two groups and no axial plaque distribution from the lesion into the reference segments in either group. CONCLUSIONS: The mechanism of stent expansion in transplant vasculopathy appears to be similar to de novo atherosclerosis-i.e., mainly vessel expansion to achieve similar acute results.

Twenty Years of an Institutional Chest Pain Pathway: What's Come and What's Yet to Come.

Acute coronary syndromes (ACS) remain one of the leading causes of cardiovascular morbidity and mortality in the United States and around the world. Because of the acute nature of ACS presentations, timely identification, risk stratification, and intervention are of the utmost importance. Twenty years ago, we published the first iteration of our institutional chest pain clinical pathway in this journal, which separated patients presenting with chest pain into one of the 4 levels of decreasing acuity, with associated actions and interventions for providers based on the level. This chest pain clinical pathway has undergone regular review and updates under a collaborative team of cardiologists, emergency department physicians, cardiac nurse practitioners, and other associated stakeholders in the treatment of patients presenting with chest pain. This review will discuss the key changes that our institutional chest pain algorithm has undergone over the last 2 decades and what the future holds for chest pain algorithms.

Flexible-Interval High-Sensitivity Troponin Velocity for the Detection of Acute Coronary Syndromes.

Many algorithms for emergency department (ED) evaluation of acute coronary syndrome (ACS) using high-sensitivity troponin assays rely on the detection of a "delta," the difference in concentration over a predetermined interval, but collecting specimens at specific times can be difficult in the ED. We evaluate the use of troponin "velocity," the rate of change of troponin concentration over a flexible short interval for the prediction of major adverse cardiac events (MACEs) at 30 days. We conducted a prospective, observational study on a convenience sample of 821 patients who underwent ACS evaluation at a high-volume, urban ED. We determined the diagnostic performance of a novel velocity-based algorithm and compared the performance of 1- and 2-hour algorithms adapted from the European Society of Cardiology (ESC) using delta versus velocity. A total of 7 of 332 patients (2.1%) classified as low risk by the velocity-based algorithm experienced a MACE by 30 days compared with 35 of 221 (13.8%) of patients classified as greater than low risk, yielding a sensitivity of 83.3% (95% confidence interval [CI] 68.6% to 93.0%) and negative predictive value (NPV) of 97.9% (95% CI 95.9% to 98.9%). The ESC-derived algorithms using delta or velocity had NPVs ranging from 98.4% (95% CI 96.4% to 99.3%) to 99.6% (95% CI 97.0% to 99.9%) for 30-day MACEs. The NPV of the novel velocity-based algorithm for MACE at 30 days was borderline, but the substitution of troponin velocity for delta in the framework of the ESC algorithms performed well. In conclusion, specimen collection within strict time intervals may not be necessary for rapid evaluation of ACS with high-sensitivity troponin.

Updating a Healthcare System-wide Clinical Pathway for Managing Chest Pain and Acute Coronary Syndromes.

Clinical pathways are useful tools for conveying and reinforcing best practices to standardize care and optimize patient outcomes across myriad conditions. The NewYork-Presbyterian Healthcare System has utilized a clinical chest pain pathway for more than 20 years to facilitate the timely recognition and management of patients presenting with chest pain syndromes and acute coronary syndromes. This chest pain pathway is regularly updated by an expanding group of key stakeholders, which has extended from the Columbia University Irving Medical Center to encompass the entire regional healthcare system, which includes 8 hospitals. In this 2023 update of the NewYork-Presbyterian clinical chest pain pathway, we present the key changes to the healthcare system-wide clinical chest pain pathway.

Mechanisms and treatment outcomes of ostial right coronary artery in-stent restenosis.

BACKGROUND: Despite a high rate of in-stent restenosis (ISR) after stenting the right coronary artery (RCA) ostium, the mechanism of ostial RCA ISR is not well understood. AIMS: We aimed to clarify the cause of ostial RCA ISR using intravascular ultrasound (IVUS). METHODS: Overall, 139 ostial RCA ISR lesions were identified with IVUS, pre-revascularisation. Primary ISR mechanisms were classified as follows: 1) neointimal hyperplasia (NIH); 2) neoatherosclerosis; 3) ostium not covered by the stent; 4) stent fracture or deformation; 5) stent underexpansion (old minimum stent area <4.0 mm2 or stent expansion <50%); or 6) a protruding calcified nodule. RESULTS: The median duration from prior stenting was 1.2 (first quartile 0.6, third quartile 3.1) years. The primary mechanisms of ISR were NIH in 25% (n=35) of lesions, neoatherosclerosis in 22% (n=30), uncovered ostium in 6% (n=9) (biological cause 53%, n=74), stent fracture or deformation in 25% (n=35), underexpansion in 11% (n=15), and protruding calcified nodules in 11% (n=15) (mechanical cause 47%, n=65). Including secondary mechanisms, 51% (n=71) of ostial RCA ISRs had stent fractures that were associated with greater hinge motion of the ostial-aorta angle during the cardiac cycle. The Kaplan-Meier rate of target lesion failure at 1 year was 11.5%. When the mechanically caused ISRs were treated without new stents, they suffered a higher subsequent event rate (41.4%) compared with non-mechanical causes or mechanical causes treated without restenting (7.8%, unadjusted hazard ratio 6.44, 95% confidence interval: 2.33-17.78; p<0.0001). CONCLUSIONS: Half of the ostial RCA ISRs were due to mechanical causes. Subsequent event rates were high, especially in mechanically caused ISRs treated without the implantation of a new stent.

Humanized mouse model of thrombosis is predictive of the clinical efficacy of antiplatelet agents.

BACKGROUND: In vivo testing of novel antiplatelet agents requires informative biomarkers. By genetically modifying mouse von Willebrand factor (VWF(R1326H)), we have developed a small animal model that supports human but not mouse platelet-mediated thrombosis. Here, we evaluate the use of this biological platform as a pharmacodynamic biomarker for antithrombotic therapies. METHODS AND RESULTS: The antithrombotic effects of several αIIbß3 inhibitors were determined in VWF(R1326H) mutant mice infused with human platelets. Administration of abciximab, eptifibatide, or tirofiban at doses recommended for percutaneous coronary intervention (per 1 kg of body weight) significantly reduced human platelet-mediated thrombus formation in laser-injured arterioles by > 75% (P < 0.001). In contrast, clot size in wild-type control animals remained essentially unchanged (P > 0.05), results consistent with observed species differences in IC50 values obtained by aggregometry. To further demonstrate that our biological platform is unique among standard mouse models, we evaluated the thrombogenic potential of platelets from healthy volunteers before and after clopidogrel therapy. Consistent with the antithrombotic effect of this agent, platelets postdrug administration formed smaller thrombi than cells before therapy and were less responsive to ADP-induced aggregation (P < 0.001). CONCLUSIONS: The ability of αIIbß3 and P2Y12 inhibitors to limit human platelet clot formation at doses recommended by the American College of Cardiology/American Heart Association suggests that VWF(R1326H) mutant mice can serve as both a pharmacodynamic and a functional response biomarker, attributes essential for not only expediting drug development but also designing clinical studies.

Impact of leukocyte count on mortality and bleeding in patients with myocardial infarction undergoing primary percutaneous coronary interventions: analysis from the Harmonizing Outcome with Revascularization and Stent in Acute Myocardial Infarction trial.

BACKGROUND: The relationship between white blood cell count (WBCc) and mortality in patients with ST-segment-elevation acute myocardial infarction treated with percutaneous coronary intervention is poorly understood. Furthermore, whether there is a relationship between WBCc and risk of noncardiac mortality and bleeding after percutaneous coronary intervention is unknown. METHODS AND RESULTS: The baseline WBCc was available in 3193 of 3345 patients (95.5%) who underwent percutaneous coronary intervention in the Harmonizing Outcome With Revascularization and Stent in Acute Myocardial Infarction (HORIZONS-AMI) trial. In a propensity-adjusted multivariable analysis, WBCc was an independent predictor of 1-year cardiac mortality (hazard ratio, 1.15; 95% confidence interval, 1.09 to 1.22), noncardiac mortality (hazard ratio, 1.19; 95% confidence interval, 1.10 to 1.29), and major bleeding (hazard ratio, 1.08; 95% confidence interval, 1.04 to 1.12). After adjustment for baseline creatinine phosphokinase levels and left ventricular ejection fraction, WBCc remained an independent predictor of 1-year all-cause mortality and cardiac mortality. In patients matched for baseline creatinine phosphokinase levels at hospital admission, the median peak creatinine phosphokinase level was significantly higher in patients with high WBCc (>11 000 per 1 mm(3)) compared with low WBCc (1851 U/L [range, 880-3307 U/L] versus 1241 U/L [range, 540 to 2,78], respectively; P<0.0001). In this subgroup of patients, WBCc was an independent correlate of peak creatinine phosphokinase level, and remained an independent predictor of 1-year mortality. CONCLUSIONS: In patients with ST-segment-elevation acute myocardial infarction undergoing percutaneous coronary intervention, elevated baseline WBCc is an independent predictor of infarct size, as assessed by peak creatinine phosphokinase level, and of 1-year cardiac mortality, noncardiac mortality, and major bleeding.

Impact of a rapid high-sensitivity troponin pathway on patient flow in an urban emergency department.

Study Objective: To evaluate whether the introduction of a 1-hour high-sensitivity cardiac troponin-T (hs-TnT) pathway for patients who present to the emergency department (ED) with suspected acute coronary syndrome (ACS) improves ED patient flow without changing the rate of "missed" major adverse cardiac events (MACE), compared to use of conventional cardiac troponin with an associated 3-hour pathway. Methods: This was a prospective, uncontrolled observational study conducted before and after implementation of a 1-hour hs-TnT pathway at a high-volume urban ED. Patients undergoing evaluation for ACS in the ED were enrolled during their initial visit and clinical outcomes were assessed at 30 and 90 days. Throughput markers were extracted from the electronic medical record and compared. The primary outcome was provider-to-disposition decision time. Results: A total of 1892 patients were enrolled, 1071 patients while using conventional troponin and 821 after introduction of hs-TnT. With the new assay and pathway, median interval between troponin tests decreased from 4.7 hours (interquartile range [IQR] 3.9-5.7 hours) to 2.3 hours (IQR 1.5-3.4 hours) (P < 0.001). However, there was no difference in median provider-to-disposition decision time, which measured 4.7 hours (IQR 2.9-7.2) and 4.8 hours (IQR 3.1-7.1) (P = 0.428) respectively. Total 30-day MACE rate in discharged patients was low in both groups, occurring in only 4/472 (0.85%) encounters in the first cohort and 4/381 (1.0%) encounters in the second. Conclusion: Introduction of a 1-hour hs-TnT ACS evaluation pathway reduced the troponin collection interval but did not reduce provider to disposition time. There was no difference in rate of 30-day MACE in patients discharged from the ED.