Prevalence and Correlates of Elevated NT-proBNP in Pregnant Women in the General U.S. Population.

BACKGROUND: Physiologic changes in N-terminal pro-B-type natriuretic peptide (NT-proBNP) across trimesters of pregnancy have not been well studied. OBJECTIVES: The authors aimed to measure NT-proBNP in adult women, by pregnancy status and trimester, in a nationally representative sample from the National Health and Nutrition Examination Survey 1999 to 2004. METHODS: We conducted a cross-sectional analysis of 2,134 women (546 pregnant) aged 20 to 40 years without a history of cardiovascular disease. RESULTS: Among pregnant women in the first trimester, the prevalence of elevated NT-proBNP (>125 pg/mL) was 20.0% (SE, 6.6%) compared to 2.4% (SE, 0.8%) among women in the third trimester and 8.0% among nonpregnant women. After adjustment for demographics and cardiovascular risk factors, NT-proBNP was 44% higher (absolute difference 26.4 [95% CI: 11.2-41.6] pg/mL) in the first trimester of pregnancy compared to nonpregnant women. Among pregnant women only, adjusted NT-proBNP was 46% lower (absolute difference -22.2 [95% CI: -36.9 to -7.5] pg/mL) in women in the third trimester compared to women in the first trimester. NT-proBNP was inversely associated with body mass index and with systolic blood pressure. CONCLUSIONS: Women in the first trimester of pregnancy had significantly higher NT-proBNP than those in the third trimester and compared to similarly aged nonpregnant women. The dynamic nature of NT-proBNP should be taken into consideration when ordering NT-proBNP lab tests in pregnant women.

Instituting a Curriculum for Cardio-Obstetrics Subspecialty Fellowship Training.

Maternal mortality is rising in the United States, and cardiovascular disease is the leading cause. Adverse pregnancy outcomes such as preeclampsia and gestational diabetes heighten the risk of cardiovascular complications during pregnancy and the peripartum period and are associated with long-term cardiovascular risks. The field of cardio-obstetrics is a subspecialty within adult cardiology that focuses on the management of women with or at high risk for heart disease who are considering pregnancy or have become pregnant. There is growing recognition of the need for more specialists with dedicated expertise in cardio-obstetrics to improve the cardiovascular care of this high-risk patient population. Current recommendations for cardiovascular fellowship training programs accredited by the Accreditation Council for Graduate Medical Education involve establishing core competency in the knowledge of managing heart disease in pregnancy. However, little granular detail is available of what such training should entail, which can lead to knowledge gaps. Additionally, dedicated advanced subspecialty training in this area is not commonly offered. Multidisciplinary collaborative teams have been shown to improve outcomes in cardiac patients during pregnancy, and cardiovascular fellows-in-training interested in cardio-obstetrics should have the opportunity to participate in and contribute to a pregnancy heart team. In this document, we describe a proposed specialized cardio-obstetrics training pathway that could serve to adequately prepare trainees to competently and comprehensively care for women with cardiovascular disease before, during, and after pregnancy.

Plasma Proprotein Convertase Subtilisin/kexin Type 9 (PCSK9) in the Acute Respiratory Distress Syndrome.

Background: Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a serine protease that is a mediator of the immune response to sepsis. PCSK9 is also highly expressed in pneumocytes and pulmonary endothelial cells. We hypothesized that serum PCSK9 levels would be associated with death and ICU outcomes in patients with ARDS. Methods: Using data and plasma samples from the NIH BioLINCC data repository, we assembled a cohort of 1,577 patients with the acute respiratory distress syndrome (ARDS) enrolled in two previously completed clinical trials, EDEN and SAILS. We measured PCSK9 levels in plasma within 24 h of intubation using commercially available ELISA kits (R&D Systems). We assessed the association of PCSK9 with mortality using Cox proportional hazard models. We also assessed clinical factors associated with PCSK9 level and the association of PCSK9 with the number of days free of mechanical ventilation and days free of ICU care. Results: In 1,577 ARDS patients, median age was 53 years (IQR 42-65 years) and median APACHE III score 91 (72-111) connoting moderate critical illness. PCSK9 levels were 339.3 ng/mL (IQR 248.0-481.0). In multivariable models, race, cause of ARDS, body mass index, pre-existing liver disease, body temperature, sodium, white blood cell count and platelet count were associated with PCSK9 level. Presence of sepsis, use of vasopressors and ventilator parameters were not associated with PCSK9 level. PCSK9 levels were not associated with in-hospital mortality (HR per IQR 0.96, 95% CI 0.84-1.08, P = 0.47). Higher PCSK9 levels were associated with fewer ICU and ventilator free days. Conclusions: Plasma PCSK9 is not associated with mortality in ARDS, however higher PCSK9 levels are associated with secondary outcomes of fewer ICU free and ventilator free days. Clinical factors associated with PCSK9 in ARDS are largely unmodifiable. Further research to define the mechanism of this association is warranted.

The Trajectory of Lipoprotein(a) During the Peri- and Early Postinfarction Period and the Impact of Proprotein Convertase Subtilisin/Kexin Type 9 Inhibition.

Lipoprotein(a), or Lp(a), levels and the effect of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition on Lp(a) during the peri-infarction and early postinfarction period are not well characterized. This study aimed to describe the trajectory of Lp(a), as well as the effect of PCSK9 inhibition on that trajectory during the peri-infarction and early postinfarction period. Lp(a) levels were obtained within 24 hours of hospital admission as well as within 24 hours of hospital discharge and at 30 days from 74 participants who presented with a NSTEMI (troponin I >5 ng/ml) or with a STEMI and were enrolled in 2 randomized, double-blind trials of evolocumab and placebo (Evolocumab in Acute Coronary Syndrome [EVACS I]; ClinicalTrials.gov, NCT03515304 and Evolocumab in Patients With STEMI [EVACS II]; ClinicalTrials.gov Identifier: NCT04082442). There was a significant increase from the pretreatment level in the placebo-treated patients, from 64 (41,187) nmol/L to 80 (47, 172) nmol/L at hospital discharge and to 82 (37, 265) at 30 days. This was primarily driven by the results from participants with high Lp(a) at hospital admission (>75 nmol/L) in whom the median increase was 28% as compared with a 10% increase in those with pretreatment Lp(a) of <75 nmol/L. In contrast, there was no significant change from the pretreatment level in the evolocumab-treated patients regardless of pretreatment Lp(a) levels. In conclusion, Lp(a) rises during the peri-infarction and early postinfarction period in patients with acute myocardial infarction. The increase was prevented by a single dose of subcutaneous evolocumab given within 24 hours of hospital admission.

Advanced Respiratory Support in the Contemporary Cardiac ICU.

The medical complexity and critical care needs of patients admitted to cardiac ICUs are increasing, and prospective studies examining the underlying cardiac and noncardiac diagnoses, the management strategies, and the prognosis of cardiac ICU patients with respiratory failure are needed. DESIGN: Prospective cohort study. SETTING: The Critical Care Cardiology Trials Network is a research collaborative of cardiac ICUs across the United States and Canada. PATIENTS: We included all medical cardiac ICU admissions at 25 cardiac ICUs during two consecutive months annually at each center from 2017 to 2019. MEASUREMENTS: We evaluated the use of advanced respiratory therapies including invasive mechanical ventilation, noninvasive ventilation, and high-flow nasal cannula versus no advanced respiratory support across admission diagnoses and the association with in-hospital mortality. MAIN RESULTS: Of 8,240 cardiac ICU admissions, 1,935 (23.5%) were treated with invasive mechanical ventilation, 573 (7.0%) with noninvasive ventilation, and 281 (3.4%) with high-flow nasal cannula. Admitting diagnoses among those with advanced respiratory support were diverse including general medical problems in patients with heart disease as well as primary cardiac problems. In-hospital mortality was higher in patients who received invasive mechanical ventilation (38.1%; adjusted odds ratio, 2.53; 2.02-3.16) and noninvasive ventilation or high-flow nasal cannula (8.8%; adjusted odds ratio, 2.25; 1.73-2.93) compared with patients without advanced respiratory support (4.6%). Reintubation rate was 7.6%. The most common variables associated with respiratory insufficiency included heart failure, infection, chronic obstructive pulmonary disease, and pulmonary vascular disease. CONCLUSIONS: One-third of cardiac ICU admissions receive respiratory support with associated increased mortality. These data provide benchmarks for quality improvement ventures in the cardiac ICU, inform cardiac critical care training and staffing patterns, and serve as foundation for future studies aimed at improving outcomes.

Highest Obesity Category Associated With Largest Decrease in N-Terminal Pro-B-Type Natriuretic Peptide in Patients Hospitalized With Heart Failure With Preserved Ejection Fraction.

Background Heart failure with preserved ejection fraction (HFpEF) constitutes half of hospitalized heart failure cases and is commonly associated with obesity. The role of natriuretic peptide levels in hospitalized obese patients with HFpEF, however, is not well defined. We sought to evaluate change in NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels by obesity category and related clinical outcomes in patients with HFpEF hospitalized for acute heart failure. Methods and Results A total of 89 patients with HFpEF hospitalized with acute decompensated heart failure were stratified into 3 obesity categories: nonobese (body mass index [BMI] <30.0 kg/m2, 19%), obese (BMI 30.0-39.9 kg/m2, 29%), and severely obese (BMI ≥40.0 kg/m2, 52%), and compared for percent change in NT-proBNP during hospitalization and clinical outcomes. Clinical characteristics were compared between patients with normal NT-proBNP (≤125 pg/mL) and elevated NT-proBNP. Admission NT-proBNP was inversely related to BMI category (nonobese, 2607 pg/mL [interquartile range, IQR: 2112-5703]; obese, 1725 pg/mL [IQR: 889-3900]; and severely obese, 770.5 pg/mL [IQR: 128-1268]; P<0.01). Severely obese patients had the largest percent change in NT-proBNP with diuresis (-64.8% [95% CI, -85.4 to -38.9] versus obese -40.4% [95% CI, -74.3 to -12.0] versus nonobese -46.9% [95% CI, -57.8 to -37.4]; P=0.03). Nonobese and obese patients had significantly worse 1-year survival compared with severely obese patients (63% versus 76% versus 95%, respectively; P<0.01). Patients with normal NT-proBNP (13%) were younger, with higher BMI, less atrial fibrillation, and less structural heart disease than those with elevated NT-proBNP. Conclusions In hospitalized patients with HFpEF, NT-proBNP was inversely related to BMI with the largest decrease in NT-proBNP seen in the highest obesity category. These findings have implications for the role of NT-proBNP in the diagnosis and assessment of treatment response in obese patients with HFpEF.

Incidence, Predictors, and Outcomes of Failure of Noninvasive Ventilation in Acute Heart Failure Hospitalization.

BACKGROUND: Some patients with acute heart failure (AHF) who are treated initially with noninvasive ventilation (NIV) will require endotracheal intubation, which indicates NIV failure. The incidence and prognosis of NIV failure in patients with AHF are not well characterized. METHODS: Using the National In-Patient Sample (NIS), we conducted a retrospective cohort study of subjects hospitalized with AHF between 2008 and 2014 who were treated with NIV within 24 h of hospital admission. We determined predictors of NIV failure and determined the association between NIV failure and in-hospital mortality using Cox proportional hazard models. RESULTS: Of 279,534 subjects hospitalized with AHF and treated with NIV, 4,257 (1.52%) failed NIV and required intubation. Cardiogenic shock (odds ratio 8.79, 95% CI 6.89-11.2) and in-hospital arrest (odds ratio 24.9, 95% CI 18.71-33.14) were associated with NIV failure. In-hospital mortality was 26.5% for NIV failure compared to 5.6% for those without NIV (P < .001). After adjustment for demographics, comorbidities, cardiogenic shock, and in-hospital arrest, NIV failure was associated with nearly a 2-fold risk of in-hospital mortality (odds ratio 1.95, 95% CI 1.59-2.40). CONCLUSIONS: Intubation after initial NIV treatment was required in 1.5% of subjects hospitalized with AHF and treated with NIV, and was associated with high in-hospital mortality. These findings can guide future prospective interventional trials and quality improvement ventures.

Usefulness of Noninvasively Measured Pulse Amplitude Changes During the Valsalva Maneuver to Identify Hospitalized Heart Failure Patients at Risk of 30-Day Heart Failure Events (from the PRESSURE-HF Study).

The pulse amplitude ratio (PAR), the ratio of pulse pressure at the end of the Valsalva maneuver to before the onset, correlates with cardiac filling pressure. We have developed a handheld device that uses finger photoplethysmography to measure PAR and estimate left ventricular end diastolic pressure (LVEDP). Patients hospitalized with heart failure (HF) performed three 10-second trials of a standardized Valsalva maneuver (at 20 mm Hg measured via pressure transducer), while photoplethysmography waveforms were recorded, at admission and discharge. Combined primary outcome was 30-day HF hospitalization, intravenous diuresis, or death. Fifty-two subjects had discharge PAR testing; 12 met the primary outcome. Median PAR on admission was 0.55 (interquartile range: 0.40 to 0.70, n = 48) and on discharge was 0.50 (interquartile range: 0.36 to 0.69). Mean PAR-estimated LVEDP was significantly higher in subjects that had an event (20.2 vs 16.9 mm Hg, p = 0.043). Subjects with PAR-estimated LVEDP >19.5 mm Hg had an event rate hazard ratio of 4.57 (95% confidence interval 1.37, 15.19, p = 0.013) compared with patients with LVEDP 19.5 mm Hg or below, with significantly lower 30-day event-free survival (log-rank p = 0.006). In conclusion, noninvasively estimated LVEDP using the pulse amplitude response to a Valsalva maneuver in patients hospitalized for HF changes with diuresis and identifies patients at high risk for 30-day HF events. Detection of elevated filling pressures before hospital discharge may be useful in guiding HF management to reduce HF events.

In-Hospital Management and Outcomes of Patients With Acute Myocardial Infarction and Influenza.

Patients with influenza infection are at increased risk of acute myocardial infarction (AMI). There are limited data on the short-term prognosis and management of patients with AMI and concomitant influenza. We examined the National Inpatient Sample from 2010 to 2014 for adult patients with a diagnosis of AMI. Patients were stratified into those with or without concomitant influenza. In-hospital therapies and outcomes were compared between groups in unadjusted and adjusted analyses. Standardized differences of >10% and p values <0.05 were considered significant. Propensity matching was performed using a caliper radius of 0.01*sigma. Of 4,285,641 patients with a discharge diagnosis of AMI, 12,830 had concomitant influenza. Patients with influenza were older, had a higher burden of co-morbidities, and more often presented with non-ST elevation AMI (90% vs 74%) as compared with those without influenza. Coronary angiography (23% vs 54%) and revascularization (11% vs 41%) were less often pursued in AMI patients with influenza. Patients with AMI and influenza had elevated in-hospital mortality (14%) and multiorgan failure (33%). In a propensity-matched analysis of 23,415 patients, in-hospital mortality (odds ratio [OR] 1.26; p = 0.01), acute kidney injury (OR 1.36; p <0.01), multiorgan failure (OR 1.81; p <0.01), length-of-stay, and hospital costs were significantly higher in those with influenza. In conclusion, patients with AMI and concomitant influenza have an adverse in-hospital prognosis as compared with those without influenza.

Crossing the Bridge to Heart Transplantation: Biventricular Impella to Support an Unstable LVAD Patient.

We report the first case of a patient with a durable left ventricular assist device admitted with cardiogenic shock and managed with biventricular Impella support as a successful bridge to heart transplantation. (Level of Difficulty: Advanced.).

Healthy diet reduces markers of cardiac injury and inflammation regardless of macronutrients: Results from the OmniHeart trial.

BACKGROUND: Despite diet being a first-line strategy for preventing cardiovascular disease, the optimal macronutrient profile remains unclear. We studied the effects of macronutrient profile on subclinical cardiovascular injury and inflammation. METHODS: OmniHeart was a randomized 3-period, crossover feeding study in 164 adults with high blood pressure or hypertension (SBP 120-159 or DBP 80-99 mm Hg). Participants were fed each of 3 diets (emphasizing carbohydrate (CARB), protein (PROT), or unsaturated fat (UNSAT)) for 6-weeks, with feeding periods separated by a washout period. Weight was held constant. Fasting serum was collected at baseline while participants ate their own diets and after each feeding period. High-sensitivity cardiac troponin I (hs-cTnI) and high-sensitivity C-reactive protein (hs-CRP) were measured in stored specimens. RESULTS: The average age was 53.6 years, 55% were African American, and 45% were women. At baseline, the median (25th-percentile, 75th-percentile) hs-cTnI was 3.3 ng/L (1.9, 5.6) and hs-CRP was 2.2 mg/L (1.1, 5.2). Compared to baseline, all 3 diets reduced hs-cTnI: CARB -8.6% (95%CI: -16.1, -0.4), PROT -10.8% (-18.4, -2.5), and UNSAT -9.4% (-17.4, -0.5). Hs-CRP was similarly changed by -13.9 to -17.0%. Hs-cTnI and hs-CRP reductions were of similar magnitudes as SBP and low-density lipoprotein cholesterol (LDLc) but were not associated with these risk-factor reductions (P-values = 0.09). There were no between-diet differences in hs-cTnI and hs-CRP reductions. CONCLUSIONS: Healthy diet, regardless of macronutrient emphasis, directly mitigated subclinical cardiac injury and inflammation in a population at risk for cardiovascular disease. These findings support dietary recommendations emphasizing healthy foods rather than any one macronutrient. TRIAL REGISTRATION: This trial is registered at clinicaltrials.gov, number: NCT00051350; URL: https://clinicaltrials.gov/ct2/show/NCT00051350.

Clinical Practice Patterns in Temporary Mechanical Circulatory Support for Shock in the Critical Care Cardiology Trials Network (CCCTN) Registry.

BACKGROUND: Temporary mechanical circulatory support (MCS) devices provide hemodynamic assistance for shock refractory to pharmacological treatment. Most registries have focused on single devices or specific etiologies of shock, limiting data regarding overall practice patterns with temporary MCS in cardiac intensive care units. METHODS: The CCCTN (Critical Care Cardiology Trials Network) is a multicenter network of tertiary CICUs in North America. Between September 2017 and September 2018, each center (n=16) contributed a 2-month snapshot of consecutive medical CICU admissions. RESULTS: Of the 270 admissions using temporary MCS, 33% had acute myocardial infarction-related cardiogenic shock (CS), 31% had CS not related to acute myocardial infarction, 11% had mixed shock, and 22% had an indication other than shock. Among all 585 admissions with CS or mixed shock, 34% used temporary MCS during the CICU stay with substantial variation between centers (range: 17%-50%). The most common temporary MCS devices were intraaortic balloon pumps (72%), Impella (17%), and veno-arterial extracorporeal membrane oxygenation (11%), although intraaortic balloon pump use also varied between centers (range: 40%-100%). Patients managed with intraaortic balloon pump versus other forms of MCS (advanced MCS) had lower Sequential Organ Failure Assessment scores and less severe metabolic derangements. Illness severity was similar at high- versus low-MCS utilizing centers and at centers with more advanced MCS use. CONCLUSIONS: There is wide variation in the use of temporary MCS among patients with shock in tertiary CICUs. While hospital-level variation in temporary MCS device selection is not explained by differences in illness severity, patient-level variation appears to be related, at least in part, to illness severity.

The Dose and Timing of Fentanyl Impacts on Ticagrelor Absorption and Platelet Inhibition During Percutaneous Coronary Intervention: The PACIFY Randomized Clinical Trial.

OBJECTIVE: In this secondary analysis of the PACIFY randomized trial, we assessed whether dose and timing of fentanyl have implications for the pharmacokinetics and pharmacodynamics of ticagrelor loading during percutaneous coronary intervention (PCI). METHODS: Among 212 patients undergoing clinically indicated coronary angiography, a total of 70 required PCI and received 180 mg oral ticagrelor. Of these, thirty-two patients received no fentanyl and 38 received fentanyl (with variability in the timing of administration and cumulative dose among those randomized to fentanyl, given that both were provided at the interventional cardiologist's discretion). A time-weighted cumulative fentanyl exposure variable was calculated based on total dose of fentanyl and proximity in time of fentanyl administrations to the ticagrelor load. Patients were stratified based on receiving above or below the median time-weighted cumulative dose. Outcomes included ticagrelor concentrations by mass spectrometry (24-hour area under the curve) and platelet function measured using both VerifyNow platelet reactivity units (PRU) and light-transmission aggregometry (LTA). RESULTS: Unadjusted ticagrelor 24-hour area under the curve was significantly lower across the categories of increasing fentanyl exposure (P=.02). In adjusted regression models, this difference only remained when comparing the no-fentanyl group with the time-weighted cumulative dose above the median group (P=.04). Similarly, with the no-fentanyl group as the reference, adjusted models testing 2-hour PRU and LTA values demonstrated significant differences (with less platelet inhibition for both tests) only among those with time-weighted cumulative fentanyl exposures above the median value (5.1 µg/min). CONCLUSIONS: We have previously shown that fentanyl slows absorption of oral ticagrelor, attenuating its effect on platelet inhibition. We now demonstrate this mechanism appears to be dose- and time-dependent.

Demographics, Care Patterns, and Outcomes of Patients Admitted to Cardiac Intensive Care Units: The Critical Care Cardiology Trials Network Prospective North American Multicenter Registry of Cardiac Critical Illness.

Importance: Single-center and claims-based studies have described substantial changes in the landscape of care in the cardiac intensive care unit (CICU). Professional societies have recommended research to guide evidence-based CICU redesigns. Objective: To characterize patients admitted to contemporary, advanced CICUs. Design, Setting, and Participants: This study established the Critical Care Cardiology Trials Network (CCCTN), an investigator-initiated multicenter network of 16 advanced, tertiary CICUs in the United States and Canada. For 2 months in each CICU, data for consecutive admissions were submitted to the central data coordinating center (TIMI Study Group). The data were collected and analyzed between September 2017 and 2018. Main Outcomes and Measures: Demographics, diagnoses, management, and outcomes. Results: Of 3049 participants, 1132 (37.1%) were women, 797 (31.4%) were individuals of color, and the median age was 65 years (25th and 75th percentiles, 55-75 years). Between September 2017 and September 2018, 3310 admissions were included, among which 2557 (77.3%) were for primary cardiac problems, 337 (10.2%) for postprocedural care, 253 (7.7%) for mixed general and cardiac problems, and 163 (4.9%) for overflow from general medical ICUs. When restricted to the initial 2 months of medical CICU admissions for each site, the primary analysis population included 3049 admissions with a high burden of noncardiovascular comorbidities. The top 2 CICU admission diagnoses were acute coronary syndrome (969 [31.8%]) and heart failure (567 [18.6%]); however, the proportion of acute coronary syndrome was highly variable across centers (15%-57%). The primary indications for CICU care included respiratory insufficiency (814 [26.7%]), shock (643 [21.1%]), unstable arrhythmia (521 [17.1%]), and cardiac arrest (265 [8.7%]). Advanced CICU therapies or monitoring were required for 1776 patients (58.2%), including intravenous vasoactive medications (1105 [36.2%]), invasive hemodynamic monitoring (938 [30.8%]), and mechanical ventilation (652 [21.4%]). The overall CICU mortality rate was 8.3% (95% CI, 7.3%-9.3%). The CICU indications that were associated with the highest mortality rates were cardiac arrest (101 [38.1%]), cardiogenic shock (140 [30.6%]), and the need for renal replacement therapy (51 [34.5%]). Notably, patients admitted solely for postprocedural observation or frequent monitoring had a mortality rate of 0.2% to 0.4%. Conclusions and Relevance: In a contemporary network of tertiary care CICUs, respiratory failure and shock predominated indications for admission and carried a poor prognosis. While patterns of practice varied considerably between centers, a substantial, low-risk population was identified. Multicenter collaborative networks, such as the CCCTN, could be used to help redesign cardiac critical care and to test new therapeutic strategies.

Intravascular Stem Cell Bioreactor for Prevention of Adverse Remodeling After Myocardial Infarction.

Background Prevention of adverse remodeling after myocardial infarction (MI) is an important goal of stem cell therapy. Clinical trial results vary, however, and poor cell retention and survival after delivery likely limit the opportunity to exert beneficial effects. To overcome these limitations, we built an implantable intravascular bioreactor (IBR) designed to protect contained cells from washout, dilution, and immune attack while allowing sustained release of beneficial paracrine factors. Methods and Results IBRs were constructed using semipermeable membrane adhered to a clinical-grade catheter shaft. Mesenchymal stem cell (MSC) viability in and paracrine factor release from IBRs were assessed in vitro and IBR biocompatibility and immune protection confirmed in vivo. In a porcine anterior MI model, IBRs containing 25 million allogeneic MSCs (IBR-MSCs) were compared with IBRs containing media alone (IBR-Placebo; n=8 per group) with adverse remodeling assessed by magnetic resonance imaging. Four weeks after MI, IBR-MSCs had no significant change in end-diastolic volume (+0.33±4.32 mL; P=0.89), end-systolic volume (+2.14±4.13 mL; P=0.21), and left ventricular ejection fraction (-2.27±2.94; P=0.33) while IBR-Placebo had significant increases in end-diastolic volume (+10.37±3.84 mL; P=0.01) and ESV (+11.35±2.88 mL; P=0.01), and a significant decrease in left ventricular ejection fraction (-5.78±1.70; P=0.025). Eight weeks after MI, adherent pericarditis was present in 0 of 8 IBR-MSCs versus 4 of 8 IBR-Placebo (P=0.02), suggesting an anti-inflammatory effect. In a separate study, 25 million allogeneic pig MSCs directly injected in the peri-infarct zone 3 days after MI (n=6) showed no significant benefit in adverse remodeling at 4 weeks compared with IBR-MSCs. Conclusions MSCs deployed inside an implantable, removable, and potentially rechargeable bioreactor in a large animal model remain viable, are immunoprotected, and attenuate adverse remodeling 4 weeks after MI.