Acetaminophen for Prevention and Treatment of Organ Dysfunction in Critically Ill Patients With Sepsis: The ASTER Randomized Clinical Trial.

Importance: Acetaminophen (paracetamol) has many pharmacological effects that might be beneficial in sepsis, including inhibition of cell-free hemoglobin-induced oxidation of lipids and other substrates. Objective: To determine whether acetaminophen increases days alive and free of organ dysfunction in sepsis compared with placebo. Design, Setting, and Participants: Phase 2b randomized, double-blind, clinical trial conducted from October 2021 to April 2023 with 90-day follow-up. Adults with sepsis and respiratory or circulatory organ dysfunction were enrolled in the emergency department or intensive care unit of 40 US academic hospitals within 36 hours of presentation. Intervention: Patients were randomized to 1 g of acetaminophen intravenously every 6 hours or placebo for 5 days. Main Outcome and Measures: The primary end point was days alive and free of organ support (mechanical ventilation, vasopressors, and kidney replacement therapy) to day 28. Treatment effect modification was evaluated for acetaminophen by prerandomization plasma cell-free hemoglobin level higher than 10 mg/dL. Results: Of 447 patients enrolled (mean age, 64 [SD, 15] years, 51% female, mean Sequential Organ Failure Assessment [SOFA] score, 5.4 [SD, 2.5]), 227 were randomized to acetaminophen and 220 to placebo. Acetaminophen was safe with no difference in liver enzymes, hypotension, or fluid balance between treatment arms. Days alive and free of organ support to day 28 were not meaningfully different for acetaminophen (20.2 days; 95% CI, 18.8 to 21.6) vs placebo (19.6 days; 95% CI, 18.2 to 21.0; P = .56; difference, 0.6; 95% CI, -1.4 to 2.6). Among 15 secondary outcomes, total, respiratory, and coagulation SOFA scores were significantly lower on days 2 through 4 in the acetaminophen arm as was the rate of development of acute respiratory distress syndrome within 7 days (2.2% vs 8.5% acetaminophen vs placebo; P = .01; difference, -6.3; 95% CI, -10.8 to -1.8). There was no significant interaction between cell-free hemoglobin levels and acetaminophen. Conclusions and Relevance: Intravenous acetaminophen was safe but did not significantly improve days alive and free of organ support in critically ill sepsis patients. Trial Registration: ClinicalTrials.gov Identifier: NCT04291508.

Thromboembolic Events and Role of Point of Care Ultrasound in Hospitalized Covid-19 Patients Needing Intensive Care Unit Admission.

BACKGROUND: Covid-19 associated coagulopathy (CAC) is associated with prothrombotic state and thromboembolism. However, true incidence of thromboembolic events is difficult to determine in the ICU setting. The aim of our study was to investigate the cumulative incidence of thromboembolic events in Covid-19 patients needing intensive care unit (ICU) admission and assessing the utility of point of care ultrasound (POCUS) to screen for and diagnose lower extremity deep venous thrombosis (DVT). METHODS: We conducted a prospective observational study between April 22nd and May 26th, 2020 where all adult patients with the diagnosis of Covid-19 pneumonia admitted to 8 ICUs of Montefiore Medical Center were included. POCUS exam was performed on all patients at day 1 of ICU admission and at day 7 and 14 after the first exam. RESULTS: The primary outcome was to study the cumulative incidence of thromboembolic events in Covid-19 patients needing ICU admission. A total of 107 patients were included. All patients got POCUS exam on day 1 in the ICU, 62% got day 7 and 41% got day 14 exam. POCUS diagnosed 17 lower extremity DVTs on day 1, 3 new on day 7 and 1 new on day 14. Forty patients developed 52 thromboembolic events, with the rate of 37.3%. We found a high 45-day cumulative incidence of thromboembolic events of 37% and a high 45-day cumulative incidence of lower and upper extremity DVT of 21% and 10% respectively. Twelve (30%) patients had failure of therapeutic anticoagulation. Occurrence of a thromboembolic event was not associated with a higher risk of mortality (HR 1.08, p value = .81). CONCLUSIONS: Covid-19 patients in ICU have a high cumulative incidence of thromboembolic events, but not associated with higher mortality. POCUS is an excellent tool to help screen and diagnose DVT during a pandemic.

Characteristics of Adult Outpatients and Inpatients with COVID-19 - 11 Academic Medical Centers, United States, March-May 2020.

Descriptions of coronavirus disease 2019 (COVID-19) in the United States have focused primarily on hospitalized patients. Reports documenting exposures to SARS-CoV-2, the virus that causes COVID-19, have generally been described within congregate settings, such as meat and poultry processing plants (1) and long-term care facilities (2). Understanding individual behaviors and demographic characteristics of patients with COVID-19 and risks for severe illness requiring hospitalization can inform efforts to reduce transmission. During April 15-May 24, 2020, telephone interviews were conducted with a random sample of adults aged ≥18 years who had positive reverse transcription-polymerase chain reaction (RT-PCR) test results for SARS-CoV-2 in outpatient and inpatient settings at 11 U.S. academic medical centers in nine states. Respondents were contacted 14-21 days after SARS-CoV-2 testing and asked about their demographic characteristics, underlying chronic conditions, symptoms experienced on the date of testing, and potential exposures to SARS-CoV-2 during the 2 weeks before illness onset (or the date of testing among those who did not report symptoms at the time of testing). Among 350 interviewed patients (271 [77%] outpatients and 79 [23%] inpatients), inpatients were older, more likely to be Hispanic and to report dyspnea than outpatients. Fewer inpatients (39%, 20 of 51) reported a return to baseline level of health at 14-21 days than did outpatients (64%, 150 of 233) (p = 0.001). Overall, approximately one half (46%) of patients reported known close contact with someone with COVID-19 during the preceding 2 weeks. This was most commonly a family member (45%) or a work colleague (34%). Approximately two thirds (64%, 212 of 333) of participants were employed; only 35 of 209 (17%) were able to telework. These findings highlight the need for screening, case investigation, contact tracing, and isolation of infected persons to control transmission of SARS-CoV-2 infection during periods of community transmission. The need for enhanced measures to ensure workplace safety, including ensuring social distancing and more widespread use of cloth face coverings, are warranted (3).

Symptom Duration and Risk Factors for Delayed Return to Usual Health Among Outpatients with COVID-19 in a Multistate Health Care Systems Network - United States, March-June 2020.

Prolonged symptom duration and disability are common in adults hospitalized with severe coronavirus disease 2019 (COVID-19). Characterizing return to baseline health among outpatients with milder COVID-19 illness is important for understanding the full spectrum of COVID-19-associated illness and tailoring public health messaging, interventions, and policy. During April 15-June 25, 2020, telephone interviews were conducted with a random sample of adults aged ≥18 years who had a first positive reverse transcription-polymerase chain reaction (RT-PCR) test for SARS-CoV-2, the virus that causes COVID-19, at an outpatient visit at one of 14 U.S. academic health care systems in 13 states. Interviews were conducted 14-21 days after the test date. Respondents were asked about demographic characteristics, baseline chronic medical conditions, symptoms present at the time of testing, whether those symptoms had resolved by the interview date, and whether they had returned to their usual state of health at the time of interview. Among 292 respondents, 94% (274) reported experiencing one or more symptoms at the time of testing; 35% of these symptomatic respondents reported not having returned to their usual state of health by the date of the interview (median = 16 days from testing date), including 26% among those aged 18-34 years, 32% among those aged 35-49 years, and 47% among those aged ≥50 years. Among respondents reporting cough, fatigue, or shortness of breath at the time of testing, 43%, 35%, and 29%, respectively, continued to experience these symptoms at the time of the interview. These findings indicate that COVID-19 can result in prolonged illness even among persons with milder outpatient illness, including young adults. Effective public health messaging targeting these groups is warranted. Preventative measures, including social distancing, frequent handwashing, and the consistent and correct use of face coverings in public, should be strongly encouraged to slow the spread of SARS-CoV-2.

Seroprevalence of SARS-CoV-2 Among Frontline Health Care Personnel in a Multistate Hospital Network - 13 Academic Medical Centers, April-June 2020.

Health care personnel (HCP) caring for patients with coronavirus disease 2019 (COVID-19) might be at high risk for contracting SARS-CoV-2, the virus that causes COVID-19. Understanding the prevalence of and factors associated with SARS-CoV-2 infection among frontline HCP who care for COVID-19 patients are important for protecting both HCP and their patients. During April 3-June 19, 2020, serum specimens were collected from a convenience sample of frontline HCP who worked with COVID-19 patients at 13 geographically diverse academic medical centers in the United States, and specimens were tested for antibodies to SARS-CoV-2. Participants were asked about potential symptoms of COVID-19 experienced since February 1, 2020, previous testing for acute SARS-CoV-2 infection, and their use of personal protective equipment (PPE) in the past week. Among 3,248 participants, 194 (6.0%) had positive test results for SARS-CoV-2 antibodies. Seroprevalence by hospital ranged from 0.8% to 31.2% (median = 3.6%). Among the 194 seropositive participants, 56 (29%) reported no symptoms since February 1, 2020, 86 (44%) did not believe that they previously had COVID-19, and 133 (69%) did not report a previous COVID-19 diagnosis. Seroprevalence was lower among personnel who reported always wearing a face covering (defined in this study as a surgical mask, N95 respirator, or powered air purifying respirator [PAPR]) while caring for patients (5.6%), compared with that among those who did not (9.0%) (p = 0.012). Consistent with persons in the general population with SARS-CoV-2 infection, many frontline HCP with SARS-CoV-2 infection might be asymptomatic or minimally symptomatic during infection, and infection might be unrecognized. Enhanced screening, including frequent testing of frontline HCP, and universal use of face coverings in hospitals are two strategies that could reduce SARS-CoV-2 transmission.

Decline in SARS-CoV-2 Antibodies After Mild Infection Among Frontline Health Care Personnel in a Multistate Hospital Network - 12 States, April-August 2020.

Most persons infected with SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), develop virus-specific antibodies within several weeks, but antibody titers might decline over time. Understanding the timeline of antibody decline is important for interpreting SARS-CoV-2 serology results. Serum specimens were collected from a convenience sample of frontline health care personnel at 13 hospitals and tested for antibodies to SARS-CoV-2 during April 3-June 19, 2020, and again approximately 60 days later to assess this timeline. The percentage of participants who experienced seroreversion, defined as an antibody signal-to-threshold ratio >1.0 at baseline and <1.0 at the follow-up visit, was assessed. Overall, 194 (6.0%) of 3,248 participants had detectable antibodies to SARS-CoV-2 at baseline (1). Upon repeat testing approximately 60 days later (range = 50-91 days), 146 (93.6%) of 156 participants experienced a decline in antibody response indicated by a lower signal-to-threshold ratio at the follow-up visit, compared with the baseline visit, and 44 (28.2%) experienced seroreversion. Participants with higher initial antibody responses were more likely to have antibodies detected at the follow-up test than were those who had a lower initial antibody response. Whether decay in these antibodies increases risk for reinfection and disease remains unanswered. However, these results suggest that serology testing at a single time point is likely to underestimate the number of persons with previous SARS-CoV-2 infection, and a negative serologic test result might not reliably exclude prior infection.

Long term impact of balloon post-dilatation on neointimal formation: an experimental comparative study between second-generation self-expanding versus balloon-expandable stent technologies.

Background: Self-expanding stents (SES) are reemerging as therapeutic alternatives to treat coronary artery disease. It has been proposed that SES can improve clinical outcomes by inducing less injury at implantation and achieving better vessel wall apposition.To date, little data exists comparing the vascular response to both methods of deployment in a controlled experimental setting. Objective: To quantify differences in vascular injury and healing between second-generation SES and balloon-expandable stents (BES) and the effects of balloon post-dilatation in a porcine coronary model. Methods: Seventy-five bare SES (AXXESS or vProtect) and 42 BES (Vision) were implanted in porcine coronaries. A subset of these received balloon post-dilatation(SES 1 D 5 22, BES 1 D 5 20). Follow-up was scheduled at 30 (BES 5 10, BES 1 D 56, SES 5 19, SES 1 D 5 8), 90 (BES 5 6, BES 1 D 5 8, SES 5 19, SES 1 D 5 8), and 180 days (BES 5 6, BES 1 D 5 6, SES 5 15, SES 1 D 5 6). Results: In vivo imaging and histological analysis showed that neointimal formation peaks early (30 days) in BES. Conversely, for SES, the peak occurred later (90 days). However, the neointimal formation achieved in either group equalized at 180 days. For SES, post-dilatation shortened the peak of neointimal formation to 30 days. Conversely, for BES, post-dilatation delayed the peak of neointimal formation to 90 days. At 30 days, histology showed that SES had significantly less injury. However, at 90 days, injury scores tended to be higher for SES. By 180 days, injury scores were comparable between both groups. Conclusions: The mechanism of stent expansion influences the degree of vascular injury and healing. The synergistic use of balloon post dilatation changes the dynamics of healing and may impact the potential beneficial effects inherent to SES technologies.

Long-term effects on vascular healing of bare metal stents delivered via paclitaxel-coated balloons in the porcine model of restenosis.

BACKGROUND: Clinical trials have consistently demonstrated benefits of paclitaxel-coated balloons (PCB) in particular clinical situations such as in-stent restenosis and peripheral vascular interventions. However, the long-term vascular effects of bare metal stents (BMS) delivered via PCB (PCB+BMS) are still unknown. The aim of this study was to assess the long-term effects of PCB+BMS on vascular healing and neointimal formation (NF). METHODS: A total of 208 stents: 56 BMS crimped on PCB, 50 BMS crimped on uncoated balloons (UCB+BMS), 52 Taxus and 50 Cypher stents were implanted in normal coronary arteries of 104 pigs using 1.2:1.0 stent-to-artery ratio. Follow-up occurred at 3, 7, 28, 90, and 180 days. Vascular effects were assessed based on angiographic and histological analysis. Endothelialization was evaluated using an anti von-Willebrand Factor stain. RESULTS: At 28 days, delivery of a BMS using a PCB led to a significant reduction in NF compared to the UCB+BMS and the Taxus stent (P < 0.01). Between 28 and 180 days, the progression of NF tended to be lower in the PCB+BMS compared to all DES groups. At 90 days, the PCB+BMS (2.56 ± 0.43) and the Taxus stents (2.60 ± 0.59) had a trend toward higher inflammatory scores compared to the UCB+BMS group (1.85 ± 1.13, P = 0.09). By 180 days, inflammation and NF had completely normalized between the groups. Expression of peristrut vWF was comparable among all tested groups at 28 days. CONCLUSION: The long-term pattern of vascular healing occurring following PCB+BMS deployment appears to be comparable to what has been reported with DES technologies.

The structure of the ankyrin-binding site of beta-spectrin reveals how tandem spectrin-repeats generate unique ligand-binding properties.

Spectrin and ankyrin participate in membrane organization, stability, signal transduction, and protein targeting; their interaction is critical for erythrocyte stability. Repeats 14 and 15 of betaI-spectrin are crucial for ankyrin recognition, yet the way spectrin binds ankyrin while preserving its repeat structure is unknown. We have solved the crystal structure of the betaI-spectrin 14,15 di-repeat unit to 2.1 A resolution and found 14 residues critical for ankyrin binding that map to the end of the helix C of repeat 14, the linker region, and the B-C loop of repeat 15. The tilt (64 degrees) across the 14,15 linker is greater than in any published di-repeat structure, suggesting that the relative positioning of the two repeats is important for ankyrin binding. We propose that a lack of structural constraints on linker and inter-helix loops allows proteins containing spectrin-like di-repeats to evolve diverse but specific ligand-recognition sites without compromising the structure of the repeat unit. The linker regions between repeats are thus critical determinants of both spectrin's flexibility and polyfunctionality. The putative coupling of flexibility and ligand binding suggests a mechanism by which spectrin might participate in mechanosensory regulation.

Relationship between extreme obesity and mortality in patients with reduced ejection fraction.

AIMS: Although obesity is associated with increased mortality, epidemiologic studies in heart failure have reported lower mortality in obese patients compared with matched nonobese patients (the 'obesity paradox'). However, the relationship between survival and extreme (morbid) obesity (BMI ≥ 40) is poorly understood. We evaluate survival in low ejection fraction patients across a range of BMI categories, including extreme obesity. METHODS: In a retrospective review, 12 181 consecutive patients receiving nuclear stress testing at a tertiary care center were stratified based on BMI and ejection fraction. Eight-year mortality data were collected using the social security death index. RESULTS: Normal ejection fraction patients (internal control, ejection fraction ≥50%) exhibited the J-shaped association between mortality and BMI that is observed in the general population. Among patients with reduced ejection fraction (<50%), survival improved as obesity increased (P < 0.0001). Those with extreme obesity had the lowest mortality (n = 1134, P < 0.05). CONCLUSION: In this cohort of reduced Ejection fraction patients, the obesity paradox was observed in all weight categories, with the highest survival of all observed in the extremely obese BMI category. This further supports hypotheses that an obesity-related physiologic phenomenon affects mortality in reduced ejection fraction patients.

ICU Bed Utilization During the Coronavirus Disease 2019 Pandemic in a Multistate Analysis-March to June 2020.

OBJECTIVES: Given finite ICU bed capacity, knowledge of ICU bed utilization during the coronavirus disease 2019 pandemic is critical to ensure future strategies for resource allocation and utilization. We sought to examine ICU census trends in relation to ICU bed capacity during the rapid increase in severe coronavirus disease 2019 cases early during the pandemic. DESIGN: Observational cohort study. SETTING: Thirteen geographically dispersed academic medical centers in the United States. PATIENTS/SUBJECTS: We obtained daily ICU censuses from March 26 to June 30, 2020, as well as prepandemic ICU bed capacities. The primary outcome was daily census of ICU patients stratified by coronavirus disease 2019 and mechanical ventilation status in relation to ICU capacity. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Prepandemic overall ICU capacity ranged from 62 to 225 beds (median 109). During the study period, the median daily coronavirus disease 2019 ICU census per hospital ranged from 1 to 84 patients, and the daily ICU census exceeded overall ICU capacity for at least 1 day at five institutions. The number of critically ill patients exceeded ICU capacity for a median (interquartile range) of 17 (12-50) of 97 days at these five sites. All 13 institutions experienced decreases in their noncoronavirus disease ICU population, whereas local coronavirus disease 2019 cases increased. Coronavirus disease 2019 patients reached their greatest proportion of ICU capacity on April 12, 2020, when they accounted for 44% of ICU patients across all participating hospitals. Maximum ICU census ranged from 52% to 289% of overall ICU capacity, with three sites less than 80%, four sites 80-100%, five sites 100-128%, and one site 289%. CONCLUSIONS: From March to June 2020, the coronavirus disease 2019 pandemic led to ICU censuses greater than ICU bed capacity at fives of 13 institutions evaluated. These findings demonstrate the short-term adaptability of U.S. healthcare institutions in redirecting limited resources to accommodate a public health emergency.

Characteristics, Outcomes and 60-Day Hospital Mortality of ICU Patients with COVID-19 and Acute Kidney Injury.

Background: AKI has been reported in patients with COVID-19 pneumonia and it is associated with higher mortality. The aim of our study is to describe characteristics, outcomes, and 60-day hospital mortality of patients with COVID-19 pneumonia and AKI in the intensive care unit (ICU). Methods: We conducted a retrospective study in which all adult patients with confirmed COVID-19 who were admitted to ICUs of Montefiore Medical Center and developing AKI were included. The study period ranged from March 10 to April 11, 2020. The 60-day follow-up data through June 11, 2020 were obtained. Results: Of 300 adults admitted to the ICUs with COVID-19 pneumonia, 224 patients (75%) presented with AKI or developed AKI subsequent to admission. A total of 218 (97%) patients required invasive mechanical ventilation for moderate to severe acute respiratory distress syndrome (ARDS). A total of 113 (50%) patients had AKI on day 1 of ICU admission. The peak AKI stages observed were stage 1 in 49 (22%), stage 2 in 35 (16%), and stage 3 in 140 (63%) patients, respectively. Among patients with AKI, 114 patients (51%) required RRT. The mortality rate of patients requiring RRT was 70%. Of the 34 patients who were survivors, 25 (74%) were able to be weaned off RRT completely before hospital discharge. Nonsurvivors were older and had significantly higher admission and peak creatinine levels, admission hemoglobin, and peak phosphate levels compared with survivors. The 60-day hospital mortality was 67%. Conclusions: COVID-19 requiring ICU admission is associated with high incidence of severe AKI, necessitating RRT in approximately half of such patients. The majority of patients with COVID-19 and AKI in ICU developed moderate to severe ARDS, requiring invasive mechanical ventilation. Timing or severity of AKI did not affect outcomes. The 60-day hospital mortality is high (67%). Patients with AKI requiring RRT have high mortality, but survivors have good rates of RRT recovery. Podcast: This article contains a podcast at https://www.asn-online.org/media/podcast/K360/2020_12_31_KID0004282020.mp3.

Low molecular weight heparin in surgical valve procedures: When and how much for an optimal prophylaxis?

BACKGROUND: Periprocedural antithrombotic prophylaxis in patients undergoing surgical valve procedures (SVP) is insufficiently investigated. Low molecular weight heparin (LMWH) has been considered as an alternative to unfractionated heparin (UFH). However, safety and efficacy of this prophylaxis strategy is unknown. This study aimed to investigate safety and efficacy of periprocedural LMWH prophylaxis and determine optimal dosage and timing for periprocedural cessation and initiation. METHODS: The present study is a retrospective, single-center observational analysis of 388 patients who underwent SVP (valve replacement or valvuloplasty) between 2015 and 2016. In-hospital endpoints were bleeding, transfusions, reoperation due to bleeding, and thromboembolic events. RESULTS: Giving the first dose of LMWH on the day of SVP was a risk factor for bleeding (OR 1.07; 95% CI 1.04-1.10; p < 0.001), transfusions (OR 1.04; 95% CI 1.01-1.07; p = 0.008) and reoperation due to bleeding (OR 1.20; 95% CI 1.12-1.28; p < 0.001), with > 40 mg/day as a predictor. A higher dosage of LMWH premedication was an independent risk factor for bleeding (OR 1.02; 95% CI 1.00-1.04; p = 0.03) and transfusion (OR 1.03; 95% CI 1.01-1.05; p = 0.01), with > 60 mg/day as a predictor for these events. LMWH dosed within 24 h prior to SVP increased the risk of transfusion (AUC 0.636; 95% CI 0.496-0.762; p = 0.04). CONCLUSIONS: Bleeding is an important early concern after surgical valve procedures. Safety and efficacy of periprocedural prophylaxis with LMWH depends on dosage and the timing of its administration. The most optimal periprocedural prophylaxis in the SVP population appears to be LMWH in dosage of 40-60 mg/day, which is recommended for deep vein thrombosis prophylaxis, ceased at least one day before SVP.

Influence of heart rate on FFR measurements: An experimental and clinical validation study.

BACKGROUND: Functional lesion assessment in stable coronary disease is considered the gold standard. The result of fractional flow reserve (FFR) in stable coronary disease is often a decision-maker for patient qualification. Taking into account the paramount position of FFR, it is crucial to acknowledge and reduce all potential bias. AIMS: In the present study, we quantified the influence of elevated HR on FFR results using a preclinical model and then validated the results in a clinical setting. METHODS AND RESULTS: The relationship between FFR and HR was first explored experimentally in a porcine model. A clinical validation study was conducted in patients with isolated moderate lesions in the left anterior descending artery (LAD) or right coronary artery (RCA). In both the experimental and clinical arms, FFR was measured at resting HR and with pacing at 100, 130, 160, and 180 (for pigs) beats per minute. In the porcine model and in the clinical settings, a significant correlation between FFR and HR was confirmed in the LAD (r = 0.89, p < .0001; r = 0.53, p = .00002), but not in the RCA (r = -0.19, p = .5; r = 0.14, p = .3). Post hoc analyses revealed that the FFR values in the LAD at 130/min and above tended to be significantly different from the baseline HR. CONCLUSIONS: The results of this study indicate that in an experimental setting, tachycardia might be responsible for an overestimation of FFR results in LAD lesions.

Off-pump epicardial ventricular reconstruction restores left ventricular twist and reverses remodeling in an ovine anteroapical aneurysm model.

OBJECTIVE: The loss of normal apical rotation is associated with left ventricular (LV) remodeling and systolic dysfunction in patients with congestive heart failure after myocardial infarction. The objective of the present study was to evaluate the effect of epicardial ventricular reconstruction, an off-pump, less-invasive surgical reshaping technique, on myocardial strain, LV twist, and the potential alteration of myocardial fiber orientation in an ovine model of LV anteroapical aneurysm. METHODS: LV anteroapical myocardial infarction was induced by coil embolization of the left anterior descending artery. Eight weeks after occlusion, epicardial ventricular reconstruction was performed using left thoracotomy under fluoroscopic guidance in 8 sheep to completely exclude the scar. The peak systolic longitudinal/circumferential strains and LV twist were evaluated using speckle tracking echocardiography before (baseline), after device implantation, and at 6 weeks of follow-up. RESULTS: Epicardial ventricular reconstruction was completed in all sheep without any complications. Immediately after device implantation, LV twist significantly increased (4.18 ± 1.40 vs baseline 1.97 ± 1.92; P = .02). The ejection fraction had increased 17% and LV end-systolic volume had decreased 40%. The global longitudinal strain increased from -5.3% to -9.1% (P < .05). Circumferential strain increased in both middle and apical LV segments, with the greatest improvement in the inferior lateral wall (from -11.4% to -20.6%, P < .001). These effects were maintained ≥6 weeks after device implantation without redilation. CONCLUSIONS: Less invasive than alternative therapies, epicardial ventricular reconstruction on the off-pump beating heart can restore LV twist and systolic strain and reverse LV remodeling in an ovine anteroapical aneurysm model.

Safety and feasibility of percutaneous delivery of a novel circulatory assist device (CircuLite® SYNERGY®) in the swine model.

AIMS: To demonstrate the feasibility and safety of percutaneous delivery of the novel inflow cannula of the CircuLite® SYNERGY® pocket Micro-pump via transseptal access in the swine model. METHODS AND RESULTS: After transseptal puncture, the inflow cannula system was advanced into the left atrium (LA) via the right external jugular vein and anchored onto the atrial septum under fluoroscopic and intracardiac echo guidance in 14 acute animals. Subsequently, chronic studies were performed to examine the long-term healing response to the cannula implantation with an artery-LA shunt (n=10) and overall safety of the Micro-pump components (n=6). Acute studies proved the concept of transcatheter delivery of the inflow cannula via superior venous access. The cannula tips were securely anchored in all chronic animals and appropriately endothelialised as early as two weeks. No thrombi or septal damage was observed. For the chronic pump group, device speed of 22,000 rpm (~2.0 L/min) was maintained without any adverse cardiac events. Plasma free haemoglobin assays confirmed the absence of clinically significant haemolysis. CONCLUSIONS: The transcatheter delivery of the inflow cannula via superior venous access to the LA is feasible and safe. This percutaneous delivery presents a significantly less invasive alternative to deliver partial circulatory support devices.

Epicardial catheter-based ventricular reconstruction: a novel therapy for ischaemic heart failure with anteroapical aneurysm.

OBJECTIVES: Surgical ventricular reconstruction has been used to treat ischaemic cardiomyopathy with large akinetic or dyskinetic areas. However, application of this approach requires a sternotomy, cardiopulmonary bypass and a left ventriculotomy. This study assessed the feasibility and efficacy of minimally invasive, off-pump, epicardial catheter-based ventricular reconstruction (ECVR) in an anteroapical aneurysm ovine model. METHODS: Left ventricular (LV) anteroapical myocardial infarction was induced percutaneously by coil embolization of the left anterior descending coronary artery. Eight weeks after infarction, via mini left thoracotomy and without cardiopulmonary bypass, ECVR was performed in six sheep. The scar was excluded by placing anchor pairs on the LV epicardial anterior wall and the right ventricular side of the interventricular septum under fluoroscopic guidance. LV performance was evaluated before, immediately after device implantation and after 6 weeks by echocardiography. Terminal histopathology was performed. RESULTS: ECVR was completed expeditiously in all animals without complications. Parameters obtained 6 weeks after device implantation were compared with baseline (pre-device). End-systolic volume was decreased by 38% (25.6 ± 6.1 ml vs baseline 41.2 ± 7.2 ml, P = 0.02) with preservation of stroke volume. Ejection fraction was significantly increased by 13% (48.5 ± 7% vs baseline 35.8 ± 7%, P = 0.02). The circumferential strain in the anterior septum (-7.67 ± 5.12% vs baseline -0.96 ± 2.22%, P = 0.03) and anterior wall (-9.01 ± 3.51% vs baseline -4.15 ± 1.36%, P = 0.01) were significantly improved. The longitudinal strain in apex was reversed (-3.08 ± 1.53% vs baseline 3.09 ± 3.39%, P = 0.01). Histopathology showed full endocardial healing over the anchors with appreciable reduction of the chronic infarct in the LV. CONCLUSIONS: ECVR without cardiopulmonary bypass is a less invasive alternative to current standard therapies, reverses LV remodelling and improves cardiac performance in an ovine model of anteroapical aneurysm.

Catheter-based endomyocardial delivery of mesenchymal precursor cells using 3D echo guidance improves cardiac function in a chronic myocardial injury ovine model.

The administration of bone marrow-derived stem cells may provide a new treatment option for patients with heart failure. Transcatheter cell injection may require multi-imaging modalities to optimize delivery. This study sought to evaluate whether endomyocardial injection of mesenchymal precursor cells (MPCs) could be guided by real-time 3D echocardiography (RT3DE) in treating chronic, postinfarction (MI) left ventricular (LV) dysfunction in sheep. Four weeks after induction of an anterior wall myocardial infarction in 39 sheep, allogeneic MPCs in doses of either 25 × 10(6) (n = 10), 75 × 10(6) (n = 9), or 225 × 10(6) (n = 10) cells or nonconditioned control media (n = 10) were administered intramyocardially into infarct and border zone areas using a catheter designed for combined fluoroscopic and RT3DE-guided injections. LV function was assessed before and after injection. Infarct dimension and vascular density were evaluated histologically. RT3DE-guided injection procedures were safe. Compared to controls, the highest dose MPC treatment led to increments in ejection fraction (3 ventricula 3% in 225M MPCs vs. -5 ± 4% in the control group, p < 0.01) and wall thickening in both infarct (4 ± 4% in 225M MPCs vs. -3 ± 6% in the control group, p = 0.02) and border zones (4 ± 6% in 225M MPCs vs. -8 ± 9% in the control group, p = 0.01). Histology analysis demonstrated significantly higher arteriole density in the infarct and border zones in the highest dose MPC-treated animals compared to the lower dose or control groups. Endomyocardial implantation of MPCs under RT3DE guidance was safe and without observed logistical obstacles. Significant increases in LV performance (ejection fraction and wall thickening) and neovascularization resulted from this technique, and so this technique has important implications for treating patients with postischemic LV dysfunction.

Controlled reperfusion with intravenous bivalirudin and intracoronary abciximab combination therapy in the porcine myocardial infarction model.

INTRODUCTION: The reperfusion injury (RI) remains a significant limitation of primary PCI, therefore we evaluated the role of intracoronary abciximab and bivalirudin for anticoagulation on myocardial salvage and RI in the porcine model of ischemia/reperfusion. MATERIALS AND METHODS: Myocardial infarction was induced in 23 pigs by 60-minute over-the-wire (OTW) balloon occlusion of the LAD. Animals received intravenous bivalirudin and then five minutes prior to reperfusion, either a coronary downstream infusion of abciximab (n=11) or saline (n=12) through the central lumen of an OTW catheter. All animals were followed for 48 hours. RESULTS: Histological analysis showed that infarct area (IA) and area at risk (AAR) were comparable between groups (IA/AAR%: 57.6 ± 8% vs. 57.1 ± 7%, p=0.8). Confirming this trend, biochemical markers (troponin I, TNF-alpha, IL-6, hsCRP, adiponectin, and VCAM) and left ventricular ejection fraction were also similar at 48 hours. Adhesion markers like ICAM and P-selectin were significantly decreased in the study group, nevertheless histological evidence of leukocyte extravasation was similar. The enhancement of apoptosis by TUNEL was comparable in both groups. The number of hemorrhagic infarctions confirmed by micro and macroscopic evaluation tended to be higher in the study group (70% vs. 20%, p=0.07). CONCLUSIONS: Despite lowered concentrations of adhesion molecules, intracoronary abciximab with peripheral bivalirudin is not superior to bivalirudin unaided in terms of myocardial salvage caused by RI in the porcine ischemia/reperfusion model. This might be due to local hemorrhage caused by abciximab.

Evaluation of efficacy and dose response of different paclitaxel-coated balloon formulations in a novel swine model of iliofemoral in-stent restenosis.

OBJECTIVES: The authors aimed to validate a novel iliofemoral in-stent restenosis (ISR) model for the efficacy evaluation of paclitaxel-coated balloons (PCB) using the familial hypercholesterolemic swine (FHS). BACKGROUND: Most of the validation work regarding PCB technologies has been performed in the coronary territory of juvenile domestic swine. Although invaluable for safety evaluation, this model is not suited for the evaluation of the efficacy of peripheral PCB technologies. METHODS: Twenty-four iliofemoral segments in 12 FHS underwent balloon injury and self-expanding stent placement. After 21 days, the resulting ISR lesions were treated with either 1 µg/mm(2) dose (n = 8), or 3 µg/mm(2) dose (n = 8) PCB (Cotavance, Bayer Pharma AG/MEDRAD, Indianola, Pennsylvania), or with an identical uncoated control balloon (n = 8). RESULTS: At termination (28 days after treatment), the percent diameter stenosis by quantitative vascular analysis in the control group was higher (31.2 ± 13.7%) compared with the 1 µg/mm(2) (19.3 ± 14.0%, 38% reduction) and 3 µg/mm(2) (8.6 ± 10.7%, 72% reduction) PCB groups. Intravascular ultrasound analysis showed 36% (1 µg/mm(2) dose, p = 0.04) and 55% (3 µg/mm(2) dose, p < 0.01) reductions in neointimal volume stenosis. In the histological analysis, the control group showed the highest degree of percent area stenosis (65 ± 14.3%). The reductions in percent area stenosis was 13.2% (p = 0.5) and 26% (p = 0.04) in the 1 µg/mm(2) and 3 µg/mm(2) dose groups, respectively. CONCLUSIONS: The FHS model of iliofemoral ISR demonstrated a dose-dependent effect on the inhibition of neointimal proliferation of a clinically validated PCB technology. This model represents a positive step toward the efficacy evaluation of PCB in the peripheral vascular territory.