Importance of pseudoaneurysms after TAVI - a retrospective analysis of 2063 patients.

Background: Bifemoral arterial access is common in patients undergoing transcatheter aortic valve implantation (TAVI), with a primary treatment access (TAVI access) and a secondary non-TAVI access. Pseudoaneurysm (PSA) is an important complication of femoral arterial puncture. Major vascular complications after TAVI are well described, but little is known about PSA. Patients and methods: A total of 2063 patients underwent transfemoral TAVI between January 2014 and January 2020. Vascular ultrasound of the common femoral artery was assessed before and after TAVI. We compared patient characteristics, periprocedural risk scores, procedural characteristics, and access site bleeding events according to Valve Academic Research Consortium 3 (VARC-3) criteria, length of stay (LOS), and all-cause mortality at one year between patients with (46) and without (2017) PSA. Results: The incidence of PSA after TAVI was 2.2% (46/2063). All PSA were successfully treated with ultrasound-guided manual compression (UGMC) or thrombin injection (UGTI) without complications. Patients with PSA had lower platelet counts (210×1000/µl vs. 234×1000/µl; p<0.05), more heart failure symptoms on admission (91% vs. 25%; p<0.05), were more often treated with (N)OACs for atrial fibrillation (AF; 54% vs. 38%; p <0.05), and were less often treated with aspirin (35% vs. 51%; p<0.03). Multivariate analysis identified secondary access site (odds ratio [OR] 8.11; p<0.001) and (N)OAC therapy (OR 1.31; p = 0.037) as risk factors for PSA development. PSA is associated with VARC-3 type 1-3 access site bleeding and longer LOS (15.2 ± 11.3 d vs. 11.6 ± 8.9 d; p<0.01), but this did not affect one year mortality (17% vs. 14%; p = 0.53). Conclusions: Pseudoaneurysms are an important complication after TAVI and are associated with access site bleeding and prolonged hospital stay. (N)OAC therapy and secondary access are important risk factors. Pseudoaneurysms can be safely and effectively treated with thrombin injection and do not affect one-year mortality.

Quantitative assessment of angioplasty-induced vascular inflammation with 19F cardiovascular magnetic resonance imaging.

BACKGROUND: Macrophages play a pivotal role in vascular inflammation and predict cardiovascular complications. Fluorine-19 magnetic resonance imaging (19F MRI) with intravenously applied perfluorocarbon allows a background-free direct quantification of macrophage abundance in experimental vascular disease models in mice. Recently, perfluorooctyl bromide-nanoemulsion (PFOB-NE) was applied to effectively image macrophage infiltration in a pig model of myocardial infarction using clinical MRI scanners. In the present proof-of-concept approach, we aimed to non-invasively image monocyte/macrophage infiltration in response to carotid artery angioplasty in pigs using 19F MRI to assess early inflammatory response to mechanical injury. METHODS: In eight minipigs, two different types of vascular injury were conducted: a mild injury employing balloon oversize angioplasty only (BA, n = 4) and a severe injury provoked by BA in combination with endothelial denudation (BA + ECDN, n = 4). PFOB-NE was administered intravenously three days after injury followed by 1H and 19F MRI to assess vascular inflammatory burden at day six. Vascular response to mechanical injury was validated using X-ray angiography, intravascular ultrasound and immunohistology in at least 10 segments per carotid artery. RESULTS: Angioplasty was successfully induced in all eight pigs. Response to injury was characterized by positive remodeling with predominantly adventitial wall thickening and concomitant infiltration of monocytes/macrophages. No severe adverse reactions were observed following PFOB-NE administration. In vivo 19F signals were only detected in the four pigs following BA + ECDN with a robust signal-to-noise ratio (SNR) of 14.7 ± 4.8. Ex vivo analysis revealed a linear correlation of 19F SNR to local monocyte/macrophage cell density. Minimum detection limit of infiltrated monocytes/macrophages was estimated at approximately 410 cells/mm2. CONCLUSIONS: In this proof-of-concept study, 19F MRI enabled quantification of monocyte/macrophage infiltration after vascular injury with sufficient sensitivity. This may provide the opportunity to non-invasively monitor vascular inflammation with MRI in patients after angioplasty or even in atherosclerotic plaques.

Impact of high on-treatment platelet reactivity after angioplasty in patients with peripheral arterial disease.

Objective: High on-treatment platelet reactivity (HTPR) to dual antiplatelet therapy (DAPT) predicts adverse events in coronary artery disease patients. In peripheral artery disease (PAD) patients, data concerning the clinical impact of HTPR are limited. Therefore, we evaluated the incidence of (i) HTPR to DAPT and (ii) its impact on 6 months outcome after angioplasty.Methods and results: In this prospective single center analysis, we investigated 102 consecutive patients with PAD from 2016 to 2017. All patients underwent peripheral endovascular treatment due to intermittent claudication (Fontaine IIb). Clopidogrel effects were measured using vasodilator-stimulated protein phosphorylation (VASP) assay, aspirin effects by light-transmission aggregometry (LTA). Major adverse limb events (MALE), major adverse cardiac and cerebrovascular events (MACCE) and BARC bleeding (bleeding academic research consortium classification) within 6 months were assessed. HTPR to clopidogrel (n = 37, 36%), to aspirin (n = 11, 11%) and to both (n = 11, 11%) were frequent. Compared to sufficient platelet inhibition by aspirin and clopidogrel (n = 43, 42%), patients with dual HTPR showed a higher risk of MALE at 6 months (27% vs. 7%; hazard ratio [HR]: 4.45; 95% confidence interval [CI]: 1.1 to 67.8; p = .03). This was independent of diabetes, creatinine, body mass index, and age as well as of procedural details in a multivariate logistic regression analysis. MACCE (n = 2) and BARC bleeding rates (n = 2) were low.Conclusion: In this small exploratory study, HTPR was frequent in PAD patients. Furthermore, the results are suggestive that MALE might be associated with dual HTPR. This leads to the hypothesis that optimized antithrombotic regimens post percutaneous transluminal angioplasty should be tested in clinical trials.

Depletion of circulating blood NOS3 increases severity of myocardial infarction and left ventricular dysfunction.

Nitric oxide (NO) derived from endothelial NO synthase (NOS3) plays a central role in myocardial ischemia/reperfusion (I/R)-injury. Subsets of circulating blood cells, including red blood cells (RBCs), carry a NOS3 and contribute to blood pressure regulation and RBC nitrite/nitrate formation. We hypothesized that the circulating blood born NOS3 also modulates the severity of myocardial infarction in disease models. We cross-transplanted bone marrow in wild-type and NOS3(-/-) mice with wild-type mice, producing chimeras expressing NOS3 only in vascular endothelium (BC-/EC+) or in both blood cells and vascular endothelium (BC+/EC+). After 60-min closed-chest coronary occlusion followed by 24 h reperfusion, cardiac function, infarct size (IS), NOx levels, RBCs NO formation, RBC deformability, and vascular reactivity were assessed. At baseline, BC-/EC+ chimera had lower nitrite levels in blood plasma (BC-/EC+: 2.13 ± 0.27 µM vs. BC+/EC+ 3.17 ± 0.29 µM; *p < 0.05), reduced DAF FM associated fluorescence within RBCs (BC-/EC+: 538.4 ± 12.8 mean fluorescence intensity (MFI) vs. BC+/EC+: 619.6 ± 6.9 MFI; ***p < 0.001) and impaired erythrocyte deformability (BC-/EC+: 0.33 ± 0.01 elongation index (EI) vs. BC+/EC+: 0.36 ± 0.06 EI; *p < 0.05), while vascular reactivity remained unaffected. Area at risk did not differ, but infarct size was higher in BC-/EC+ (BC-/EC+: 26 ± 3 %; BC+/EC+: 14 ± 2 %; **p < 0.01), resulting in decreased ejection fraction (BC-/EC+ 46 ± 2 % vs. BC+/EC+: 52 ± 2 %; *p < 0.05) and increased end-systolic volume. Application of the NOS inhibitor S-ethylisothiourea hydrobromide was associated with larger infarct size in BC+/EC+, whereas infarct size in BC-/EC+ mice remained unaffected. Reduced infarct size, preserved cardiac function, NO levels in RBC and RBC deformability suggest a modulating role of circulating NOS3 in an acute model of myocardial I/R in chimeric mice.

Temporary decrease in microvascular tissue saturation after transcatheter aortic valve implantation.

BACKGROUND: Data on the effect of transcatheter aortic valve implantation (TAVI) on peripheral microcirculation are limited. OBJECTIVE: The aim of this study is to evaluate peripheral microvascular tissue saturation (StO2) before and after TAVI in relation to central and peripheral hemodynamics, cardiac and renal function. METHODS: In this single-center prospective study, patients with severe aortic stenosis (sAS) scheduled for TAVI or cardiac catheterization (control) were assessed before and up to five days after the procedure. Cardiac function including cardiac output (CO) was assessed by echocardiography. Brachial (bBP) and central blood pressure (cBP), ankle brachial index (ABI), and parameters of arterial stiffness, including augmentation pressure (AP) and augmentation index adjusted for heart rate (AIx@HR75) were measured to assess hemodynamic changes. StO2 was measured in all extremities using a near-infrared spectroscopy (NIRS) camera. Renal function was measured by creatinine levels. RESULTS: 26 patients underwent TAVI and 11 patients served as control. Cardiac output was significantly increased, whereas hemodynamic parameters and peripheral StO2 were significantly decreased after TAVI. At follow-up, StO2 returned to baseline values. Changes in StO2 were negatively related to creatinine levels. CONCLUSION: Transcatheter aortic valve implantation causes a temporary decrease in microvascular tissue saturation that is associated with renal function.

Impact of Peripheral Angioplasty on Wound Oxygenation and Healing in Patients with Chronic Limb-Threatening Ischemia Measured by Near-Infrared Spectroscopy.

Managing chronic limb-threatening ischemia (CLTI) is challenging due to difficulties in assessing tissue oxygen saturation in ulcers. Near-infrared spectroscopy (NIRS) is a non-invasive method for measuring tissue oxygen saturation (StO2). This study evaluated the effects of endovascular treatment (EVT) on StO2 and wound healing in CLTI patients, comparing NIRS to standard ankle-brachial index (ABI) measurements. Using the Duesseldorf PTA Registry, 43 CLTI patients were analyzed: 27 underwent EVT, and 16 received conservative treatment. ABI assessed macrocirculation, while NIRS measured wound, wound area, and mean foot StO2 at baseline, post-EVT, and four-month follow-up. Wound severity was classified by wound area and wound, ischemia, and foot infection (WIfI) score. Wound StO2 increased significantly (median (interquartile range (IQR)), 38 (49.3) to 60 (34.5)%, p = 0.004), as did wound area StO2 (median (IQR), 70.9 (21.6) to 72.8 (18.3)%, p < 0.001), with no significant changes in the control group by four-month follow-up. Wound area decreased significantly after EVT (mean ± SD, 343.1 ± 267.8 to 178.1 ± 268.5 mm2, p = 0.01) but not in the control group. Changes in wound StO2, wound area StO2, and WIfI score correlated with wound area reduction, unlike ABI. This small exploratory study shows that NIRS-measured StO2 improvements after EVT correlate with reduced wound area and WIfI scores, highlighting NIRS as a potential enhancement for CLTI wound management in addition to ABI.

Endovascular Treatment of Flow-Limiting Iliofemoral Stenosis Improves Left Ventricular Diastolic Function in Patients With HFpEF by Reducing Aortic Pulsatile Load.

BACKGROUND: Recent research indicates that there is a high prevalence of heart failure with preserved ejection fraction in patients with peripheral artery disease. We hypothesized that endovascular treatment (EVT) of flow-limiting peripheral stenosis improves left ventricular (LV) diastolic function. METHODS: Thirty patients with symptomatic peripheral artery disease and heart failure with preserved ejection fraction according to Heart Failure Association-preserved ejection fraction score who were scheduled for EVT or angiography were investigated at baseline, the day after EVT (n=25) or angiography (control, n=5), and at 4 months follow-up. Peripheral hemodynamics were determined by the total peripheral resistance, common femoral artery flow, and ankle brachial index. Aortic function was measured by arterial compliance, augmentation index, and pulse wave velocity. Aortic pulsatile load was estimated as the characteristic impedance of the proximal aorta and the magnitude of wave reflection (reflection coefficient). LV mass index, LV mean wall thickness, and systolic and diastolic function were assessed using echocardiography. Patient-centered outcomes were treadmill walking distance and New York Heart Association class. RESULTS: After EVT, peripheral hemodynamics changed significantly with a decrease in total peripheral resistance and an increase in common femoral artery flow and ankle brachial index. Aortic function improved after EVT, with significantly reduced augmentation index and pulse wave velocity and increased compliance immediately and at follow-up, resulting in a reduction in aortic pulsatile load (characteristic impedance of the proximal aorta and reflection coefficient). Concurrently, LV diastolic function improved after EVT compared with control, acutely and at follow-up, with increased septal and lateral e´ velocities and decreased E/e´ and left atrial volume index. The LV mass index and LV mean wall thickness decreased at follow-up. The New York Heart Association class and treadmill walking distance improved post-EVT at follow-up. Augmentation index, pulse wave velocity, and arterial compliance were identified as independent contributors to E/e´. CONCLUSIONS: Endovascular treatment of flow-limiting iliofemoral stenosis reduces aortic pulsatile load and concurrently lowers total peripheral resistance. This beneficial effect is associated with an acute and sustained improvement of left ventricular diastolic function. REGISTRATION: URL: http://www.clinicaltrials.gov; Unique identifier: NCT02728479.

A patient with chest pain and a high-risk ECG pattern: The Wellens' syndrome.

This case highlights the ECG interpretation in acute coronary syndrome absence from ST - elevation myocardial infarction. A patient with acute chest pain and biphasic T - waves or deep inverted T- waves in V2-V3 is at risk for myocardial infarction. Timely cardiological assessment and coronary angiography is required.

Endovascular snare retrieval of an Angio-Seal causing acute limb ischemia.

Vascular complications (VCs) remain an important source of morbidity and mortality following percutaneous arterial catheterization. Vascular closure devices are popular and frequently used, but sometimes cause vessel occlusions that may require vascular surgery or complex endovascular procedures. In this case report, we describe the endovascular retrieval of an embolized Angio-Seal device causing acute limb ischemia in a severely diseased 75-year-old female patient. This case highlights the endovascular technique using a snare catheter and adds another example to the growing evidence of an endovascular approach to manage vascular access site complications in comorbid patients at risk.

Angioplasty of Flow-Limiting Stenosis Reduces Aortic and Brachial Blood Pressure in Patients With Peripheral Artery Disease.

Background Arterial hypertension affects cardiovascular outcome in patients with peripheral artery disease (PAD). We hypothesized that angioplasty of peripheral arterial stenoses decreases aortic (aBP) and brachial blood pressure (bBP). Methods and Results In an index cohort (n=30), we simultaneously measured aBP, bBP, augmentation index (AIx), and aortic pulse wave velocity (PWV) before and after angioplasty of the iliac and femoropopliteal arteries; diagnostic angiography served as a control. In an all-comer registry cohort (n=381), we prospectively measured bBP in patients scheduled for angioplasty of the iliac, femoral, and crural arteries or diagnostic angiography. Systolic aBP decreased after iliac (Δ-25 mmHg; 95% CI, -30 to -20; P<0.0001) and femoropopliteal angioplasty (Δ-12 mmHg; 95% CI, -17 to -5; P<0.0001) as compared with diagnostic angiography. Diastolic aBP decreased after iliac (Δ-9 mmHg; 95% CI, -13 to -1; P=0.01) but not femoropopliteal angioplasty. In parallel, AIx significantly dropped, whereas PWV remained stable. In the registry cohort, systolic bBP decreased after angioplasty of the iliac (Δ-17 mmHg; 95% CI, -31 to -8; P=0.0005) and femoropopliteal arteries (Δ-10 mmHg; 95% CI, -23 to -1; P=0.04) but not the crural arteries, as compared with diagnostic angiography. Diastolic bBP decreased after iliac (Δ-10 mmHg; 95% CI, -17 to -2; P=0.01) and femoropopliteal angioplasty (Δ-9 mmHg; 95% CI, -15 to -1; P=0.04). Multivariate analysis identified baseline systolic bBP and site of lesion as determinants of systolic bBP drop after endovascular treatment. Conclusions Angioplasty of flow-limiting stenoses in patients with peripheral artery disease lowers aortic and brachial blood pressure with more pronounced effects at more proximal lesion sites and elevated baseline systolic blood pressure. These data indicate a role of endovascular treatment to acutely optimize blood pressure in patients with peripheral artery disease. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02728479.

Impact of high on-treatment platelet reactivity after angioplasty in patients with critical limb ischemia.

OBJECTIVES: Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel is standard of care in patients with peripheral artery disease (PAD) after percutaneous transluminal angioplasty (PTA). However, high on treatment platelet reactivity (HTPR) to DAPT is frequent and associated with major adverse limb events (MALE) in PAD patients. Nevertheless, association of MALE and HTPR in patients with critical limb ischemia (CLI) is not known. Moreover, comorbidities might confound response to antiplatelet medication further. Hence, in this trial we analyzed pharmacodynamic responses to DAPT and clinical events in CLI patients post PTA. METHODS: In this prospective single center pilot analysis, we included 71 CLI patients. Patients received DAPT after PTA. Antiplatelet effect were measured by light transmission aggregometry (LTA) and vasodilator-stimulated protein phosphorylation assay (VASP). MALE, major adverse cardiac and cerebrovascular events (MACCE) and BARC bleeding within 12 months follow-up were assessed. RESULTS: Mean age of patients was 73.37 ± 7.36 years and 47 (66.2%) were male. Overall HTPR appeared in 46 patients (64.8%). MALE and MACCE showed no differences between patients with and patients without HTPR. However, bleeding was higher in patients with sufficient pharmacodynamic response to DAPT (Bleeding - HTPR: 13.4% vs. no HTPR: 36.0%; log-rank HR: 0.32; 95% CI 0.1079 to 0.9396 p = 0.0217). This finding remained robust in multivariate analysis. CONCLUSION: HTPR to DAPT is frequent in CLI patients. However, bleeding was higher in patients with sufficient response to DAPT. Ischemic events did not differ. Hence, CLI patients might benefit from an alternative antithrombotic approach.

Clinical significance of precedent asymptomatic non-sustained ventricular tachycardias on subsequent ICD interventions and heart failure hospitalization in primary prevention ICD patients.

BACKGROUND: The prognostic implications of non-sustained ventricular tachycardia (NSVT) and their significance as therapeutic targets in patients without prior sustained ventricular arrhythmias remain undetermined. The aim of this study was to investigate the prognostic significance of asymptomatic NSVT in patients who had primary prevention implantable cardioverter-defibrillator (ICD) implantation due to ischemic or non-ischemic cardiomyopathy (ICM, NICM). METHODS: We enrolled 157 consecutive primary prevention ICD patients without previous appropriate ICD therapy (AIT). Patients were allocated to two groups depending on the presence or absence of NSVT in a 6-month period prior to enrollment. The incidence of AIT and unplanned hospitalization due to decompensated heart failure (HF) were assessed during follow-up. RESULTS: In 51 patients (32%), precedent NSVT was documented. During a median follow-up of 1011 days, AIT occurred in 36 patients (23%) and unplanned HF hospitalization was observed in 32 patients (20%). In precedent NSVT patients, the incidence of AIT and unplanned HF hospitalization was significantly higher as compared to patients without precedent NSVT (AIT: 29/51 [57%] vs. 7/106 [7%], P < 0.001, log-rank; HF hospitalization: 16/51 [31%] vs. 16/106 [15%], P = 0.043, log-rank). Cox-regression demonstrated that precedent NSVT independently predicted AIT (P < 0.0001). In subgroup analyses, precedent NSVT predicted AIT in both ICM and NICM (P < 0.0001, P = 0.020), but predicted HF hospitalization only in patients with ICM (P = 0.0030). CONCLUSIONS: Precedent non-sustained VT in patients with primary prevention ICDs is associated with subsequent appropriate ICD therapies, and is an independent predictor of unplanned heart failure hospitalizations in patients with ischemic cardiomyopathy.

Blue light (λ=453 nm) nitric oxide dependently induces ß-endorphin production of human skin keratinocytes in-vitro and increases systemic ß-endorphin levels in humans in-vivo.

ß-Endorphin exerts a broad spectrum of physiological activity on mood, immune functions, pain management, reward effects, and behavioral stability. ß-Endorphin is produced in certain neurons within the central and peripheral nervous system but also in the skin, especially in response to ultraviolet radiation. In the present study we have investigated the impact of visible blue light at λ = 453 nm (BL) on ß-endorphin production of primary human skin keratinocytes (hKC) in-vitro as well as on systemic ß-endorphin formation of whole-body exposed subjects in-vivo. We found that BL irradiation significantly enhanced both keratinocytic ß-endorphin production of hKC cultures as well as systemic ß-endorphin concentrations in light exposed healthy subjects. Interestingly, in hKC cultures elevated ß-endorphin formation was paralleled by significantly increased levels of non-enzymatically generated nitric oxide (NO), whereas elevated systemic ß-endorphin values of BL-exposed subjects were accompanied by enhanced systemic concentration of bioactive NO-derivates. These findings point to a pivotal role of NO in the molecular mechanism of the observed BL-induced effects, and indeed, exogenously applied NO was able to significantly enhance ß-endorphin production in hKC cultures. Thus, our finding of BL-induced increases in systemic ß-endorphin concentration in-vivo can be plausibly explained by an event sequence comprising 1.) BL-driven non-enzymatic formation of NO in the exposed skin tissue, 2.) systemic distribution of cutaneously produced NO in the form of bioactive nitroso compounds, 3.) a subsequent NO-dependent induction of ß-endorphin synthesis in epidermal keratinocytes, and 4.) probably also a NO-dependent modulation of ß-endorphin synthesis in specialized neurons within the central and peripheral nervous system.

Blue light exposure decreases systolic blood pressure, arterial stiffness, and improves endothelial function in humans.

AIMS: Previous studies have shown that ultraviolet light can lead to the release of nitric oxide from the skin and decrease blood pressure. In contrast to visible light the local application of ultraviolet light bears a cancerogenic risk. Here, we investigated whether whole body exposure to visible blue light can also decrease blood pressure and increase endothelial function in healthy subjects. METHODS: In a randomised crossover study, 14 healthy male subjects were exposed on 2 days to monochromatic blue light or blue light with a filter foil (control light) over 30 minutes. We measured blood pressure (primary endpoint), heart rate, forearm vascular resistance, forearm blood flow, endothelial function (flow-mediated dilation), pulse wave velocity and plasma nitric oxide species, nitrite and nitroso compounds (secondary endpoints) during and up to 2 hours after exposure. RESULTS: Blue light exposure significantly decreased systolic blood pressure and increased heart rate as compared to control. In parallel, blue light significantly increased forearm blood flow, flow-mediated dilation, circulating nitric oxide species and nitroso compounds while it decreased forearm vascular resistance and pulse wave velocity. CONCLUSION: Whole body irradiation with visible blue light at real world doses improves blood pressure, endothelial function and arterial stiffness by nitric oxide released from photolabile intracutanous nitric oxide metabolites into circulating blood.

Circulating NOS3 modulates left ventricular remodeling following reperfused myocardial infarction.

PURPOSE: Nitric oxide (NO) is constitutively produced and released from the endothelium and several blood cell types by the isoform 3 of the NO synthase (NOS3). We have shown that NO protects against myocardial ischemia/reperfusion (I/R) injury and that depletion of circulating NOS3 increases within 24 h of ischemia/reperfusion the size of myocardial infarction (MI) in chimeric mice devoid of circulating NOS3. In the current study we hypothesized that circulating NOS3 also affects remodeling of the left ventricle following reperfused MI. METHODS: To analyze the role of circulating NOS3 we transplanted bone marrow of NOS3-/- and wild type (WT) mice into WT mice, producing chimerae expressing NOS3 only in vascular endothelium (BC-/EC+) or in both, blood cells and vascular endothelium (BC+/EC+). Both groups underwent 60 min of coronary occlusion in a closed-chest model of reperfused MI. During the 3 weeks post MI, structural and functional LV remodeling was serially assessed (24 h, 4 d, 1 w, 2 w and 3 w) by echocardiography. At 72 hours post MI, gene expression of several extracellular matrix (ECM) modifying molecules was determined by quantitative RT-PCR analysis. At 3 weeks post MI, hemodynamics were obtained by pressure catheter, scar size and collagen content were quantified post mortem by Gomori's One-step trichrome staining. RESULTS: Three weeks post MI, LV end-systolic (53.2±5.9 µl; ***p≤0.001; n = 5) and end-diastolic volumes (82.7±5.6 µl; *p<0.05; n = 5) were significantly increased in BC-/EC+, along with decreased LV developed pressure (67.5±1.8 mm Hg; n = 18; ***p≤0.001) and increased scar size/left ventricle (19.5±1.5%; n = 13; **p≤0.01) compared to BC+/EC+ (ESV: 35.6±2.2 µl; EDV: 69.1±2.6 µl n = 8; LVDP: 83.2±3.2 mm Hg; n = 24; scar size/LV13.8±0.7%; n = 16). Myocardial scar of BC-/EC+ was characterized by increased total collagen content (20.2±0.8%; n = 13; ***p≤0.001) compared to BC+/EC+ (15.9±0.5; n = 16), and increased collagen type I and III subtypes. CONCLUSION: Circulating NOS3 ameliorates maladaptive left ventricular remodeling following reperfused myocardial infarction.