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.

Prognostic Value of Combined CT Angiography and Myocardial Perfusion Imaging versus Invasive Coronary Angiography and Nuclear Stress Perfusion Imaging in the Prediction of Major Adverse Cardiovascular Events: The CORE320 Multicenter Study.

Purpose To compare the prognostic importance (time to major adverse cardiovascular event [MACE]) of combined computed tomography (CT) angiography and CT myocardial stress perfusion imaging with that of combined invasive coronary angiography (ICA) and stress single photon emission CT myocardial perfusion imaging. Materials and Methods This study was approved by all institutional review boards, and written informed consent was obtained. Between November 2009 and July 2011, 381 participants clinically referred for ICA and aged 45-85 years were enrolled in the Combined Noninvasive Coronary Angiography and Myocardial Perfusion Imaging Using 320-Detector Row Computed Tomography (CORE320) prospective multicenter diagnostic study. All images were analyzed in blinded independent core laboratories, and a panel of physicians adjudicated all adverse events. MACE was defined as revascularization (>30 days after index ICA), myocardial infarction, or cardiac death; hospitalization for chest pain or congestive heart failure; or arrhythmia. Late MACE was defined similarly, except for patients who underwent revascularization within the first 182 days after ICA, who were excluded. Comparisons of 2-year survival (time to MACE) used standard Kaplan-Meier curves and restricted mean survival times bootstrapped with 2000 replicates. Results An MACE (49 revascularizations, five myocardial infarctions, one cardiac death, nine hospitalizations for chest pain or congestive heart failure, and one arrhythmia) occurred in 51 of 379 patients (13.5%). The 2-year MACE-free rates for combined CT angiography and CT perfusion findings were 94% negative for coronary artery disease (CAD) versus 82% positive for CAD and were similar to combined ICA and single photon emission CT findings (93% negative for CAD vs 77% positive for CAD, P < .001 for both). Event-free rates for CT angiography and CT perfusion versus ICA and single photon emission CT for either positive or negative results were not significantly different for MACE or late MACE (P > .05 for all). The area under the receiver operating characteristic curve (AUC) for combined CT angiography and CT perfusion (AUC = 68; 95% confidence interval [CI]: 62, 75) was similar (P = .36) to that for combined ICA and single photon emission CT (AUC = 71; 95% CI: 65, 79) in the identification of MACE at 2-year follow-up. Conclusion Combined CT angiography and CT perfusion enables similar prediction of 2-year MACE, late MACE, and event-free survival similar to that enabled by ICA and single photon emission CT. © RSNA, 2017 Online supplemental material is available for this article.

Coronary Plaque Progression and Regression in Asymptomatic African American Chronic Cocaine Users With Obstructive Coronary Stenoses: A Preliminary Study.

OBJECTIVE: Although rapid progression of coronary atherosclerosis was observed in chronic cocaine users, it is unknown whether reduced cocaine use retards the progression of atherosclerosis. We investigated whether reduced cocaine use over a 12-month period was associated with coronary plaque regression in cocaine users. METHODS: Fifteen African American chronic cocaine users with previously coronary computed tomography angiography (CCTA)-confirmed >50% coronary stenosis in Baltimore, Maryland, were enrolled in a study to investigate whether reduced cocaine use is associated with changes in coronary plaque burden over a 12-month period of cash-based incentive intervention, which was implemented to systematically reinforce cocaine abstinence. In addition to previous CCTA (preintervention), CCTA was performed at the intervention baseline and at postintervention. Plaque analyses were performed to determine the trajectory of plaque changes in the absence of intervention by comparing the preintervention with the intervention baseline studies; the trajectory of plaque changes associated with the intervention by comparing the intervention baseline with the postintervention studies; and (3) whether reduced cocaine use was independently associated with changes in coronary plaque burden. RESULTS: During the 12-month cash-based incentive intervention period, cocaine use in participants was lower. The medians of noncalcified plaque indices were 37.8 (interquartile range [IQR] 29.3-44.0), 43.1 (IQR 38.3-49.0), and 38.7 (IQR 31.2-46.8) mm at preintervention, intervention baseline, and postintervention, respectively. Multivariable generalized estimating equation analysis showed that both total plaque and noncalcified plaque indices at preintervention were significantly lowered as compared with intervention baseline levels; both total plaque and noncalcified plaque indices after intervention were significantly lowered as compared with intervention baseline levels; and reduced cocaine use was independently associated with lower total plaque volume index (P < 0.0001) and noncalcified plaque volume index (P = 0.010). CONCLUSIONS: Our findings suggest that continued cocaine use may be associated with noncalcified plaque progression, whereas reduced cocaine use may be associated with noncalcified plaque regression. Larger studies are needed to confirm these findings.

Utilization of AngioVac and snare for eradication of a mobile right atrial thrombus.

Although there are multiple etiologies of a right atrial thrombus, the presence of a central venous catheter increases the risk for its development. Once diagnosed, an assessment of patient-specific factors will aid in dictating the appropriate management strategy. In cases of chronic disease or adherent thrombotic masses, thrombolytic therapy might not result in complete resolution of the clot burden and could lead to a devastating embolic event. Accordingly, we present a case of a right atrial thrombus not amenable to medical therapy that was removed only after concomitant utilization of an AngioVac Aspiration System (Vortex Medical, Norwell, MA) and percutaneous snare catheterization.

Relationship of left ventricular mass to coronary atherosclerosis and myocardial ischaemia: the CORE320 multicenter study.

AIMS: The aim of this study was to investigate the association of left ventricular mass (LVM) with coronary atherosclerosis and myocardial infarction (MI). METHODS AND RESULTS: Patients (n = 338) underwent 320 × 0.5 mm detector row coronary computed tomography (CT) angiography, invasive coronary angiography (ICA), and single-photon emission CT (SPECT) myocardial perfusion imaging. Quantitative coronary atheroma volume was obtained from the CT images for the entire coronary tree (19-segment model) with an arterial contour detection algorithm. Normalized total atheroma volume (NormTAV) was analysed to reflect quantitative total atheroma volume. LVM was measured on myocardial CT images and indexed to height to the power of 2.7 (LVMi). Patients with obstructive coronary artery disease (CAD) were defined as those with ≥50% diameter stenosis by quantitative ICA. Abnormal perfusion defect was defined as ≥1 abnormal myocardial segment by SPECT. The association of LVMi with coronary atherosclerosis and myocardial perfusion defect on SPECT at the patient level was determined with uni- and multivariable linear and logistic regression analyses. Obstructive CAD was present in 60.0% of enrolled patients. LVMi was independently associated with abnormal summed rest score [SRS; odds ratio (OR), 1.07; 95% confidence interval (CI), 1.03-1.09] and summed stress score (OR, 1.04; 95% CI, 1.01-1.07). An increase in LVMi was also independently associated with that in NormTAV (coefficient, 10.44; 95% CI, 1.50-19.39) and SRS ≥1 (OR, 1.05; 95% CI, 1.01-1.10), even after adjusting for cardiovascular risk factors in patients without previous MI. CONCLUSIONS: LVM was independently associated with the presence of coronary artery atherosclerosis and MI.

Atrial septal angulation varies widely in patients undergoing pulmonary vein isolation.

PURPOSE: Transseptal puncture (TSP) allows left atrial access for curative procedures. Intracardiac echocardiography (ICE) provides direct visualization of the interatrial septum (IAS), but adds time and expense. We reviewed 100 cardiac multidetector computed tomography (MDCT) scans of patients undergoing AF ablation to determine if the angulation and orientation of the IAS are conserved or variable. Significant variability may suggest a potential role for direct visualization of the IAS during TSP. METHODS: We reviewed 100 MDCT scans obtained prior to AF ablation. The IAS plane at the fossa ovalis was identified in axial and coronal images. We measured the angle of the septum relative to an orthogonal plane. Optimal needle orientation was defined as perpendicular to the fossa ovalis. RESULTS: The mean axial plane angle was -60.6 ± 10.6°; range, -29.5° to -88.7°). The mean coronal plane angle was 142.6 ± 9.1°; range, 115° to 162°). The axial angle corresponded to variation in the "clock-face" orientation of the needle during puncture, and was calculated between 4 and 6 o'clock. Coronal plane angulation corresponds to the curvature of the needle tip, which varied by 47°. We found no association between patient characteristics and IAS angle. CONCLUSION: The septal orientation in the axial plane varied widely and was not predicted by clinical variables such as atrial size or prior valve surgery. The high degree of interpatient variability observed suggests that direct visualization of the septum may be helpful in the performance of TSP.

Facilitation of transvenous lead extraction using site-specific delivery of electrosurgical energy.

INTRODUCTION: Excimer laser energy is often required to extract chronically indwelling pacemaker and defibrillator leads from the vasculature and myocardium. This technique can be associated with vascular and right ventricular (RV) injuries. We sought to develop a safer, more effective method by applying site-specific delivery of electrosurgical energy (EE). METHODS: Utilizing a polyacrylamide gel model to simulate soft tissue density, active and passive fixation defibrillator and pacemaker leads were implanted and manually extracted with and without EE delivered to the cathode. The amount of force required for complete removal was measured using a force transducer. The procedure was then repeated in an acute pig model to demonstrate proof of safety. Post mortem gross and histologic specimens were collected from the implantation site. RESULTS: In the gel model, the force required for extraction, using manual traction in the active (83.7 g) and passive (74.6 g) fixation ICD leads, was reduced by 37.8% and 33.5%, respectively with EE (both p < 0.01). The force required for extraction, using manual traction in the active (85.2 g) and passive (71.9 g) fixation pacemaker leads, was reduced by 64.4% and 42.6%, respectively with EE (both p < 0.01). In an acute implantation pig model using an active fixation lead, delivery of EE to the cathode (n = 6) reduced the force required to manually extract the lead (140 g +/- 32.5 versus 82 g +/- 14.7, p = 0.03). Post mortem analysis of the RV displayed formation of an epicardial hemorrhagic lesion that was also present after manual traction and EE. There was absence of pericardial effusion, perforation, and ventricular arrhythmia. CONCLUSIONS: Site-specific delivery of EE to areas of exposed metal along the lead decreased the force necessary for lead extraction in an in vitro and in vivo model. Further studies are needed to evaluate its application in clinical care.

Vitamin D deficiency is associated with development of subclinical coronary artery disease in HIV-infected African American cocaine users with low Framingham-defined cardiovascular risk.

UNLABELLED: Chronic cocaine use may lead to premature atherosclerosis, but the prevalence of and risk factors for coronary artery disease (CAD) in asymptomatic cocaine users have not been reported. The objective of this study was to examine whether vitamin D deficiency is associated with the development of CAD in human immunodeficiency virus (HIV)-infected African American cocaine users with low CAD risk. METHODS: In this prospective follow-up study, we investigated 169 HIV-infected African American cocaine users with low Framingham risk at baseline. The main outcome measures were incidence of subclinical CAD and development of subclinical CAD. RESULTS: Fifty of the 169 African Americans had evidence of subclinical disease on the initial cardiac computed tomography. A second cardiac computed tomography was performed on the 119 African Americans without disease on the first scan. The total sum of person-years of follow-up was 289.6. Subclinical CAD was detected in 11 of these, yielding an overall incidence of 3.80/100 person-years (95% confidence interval 1.90-6.80). Among the factors investigated, only vitamin D deficiency was independently associated with development of subclinical CAD. The study did not find significant associations between CD4 count, HIV viral load, or antiretroviral treatment use and the incidence of subclinical CAD. This study appears to suggest that there is a threshold level of vitamin D (10 ng/mL) above which the effect of vitamin D on subclinical CAD is diminished. CONCLUSION: The incidence of subclinical CAD in HIV-infected African American cocaine users with low CAD risk is high, especially in those with vitamin D deficiency. Well designed randomized clinical trials are warranted to confirm the role of vitamin D deficiency in the development of CAD in HIV-infected African American cocaine users with low CAD risk.

Significance of leukocytosis after cardiac device implantation.

Infection remains a feared complication after cardiac device implantation. Whether early postprocedural leukocytosis, a recognized marker of infection, is an indicator of impending infection is unclear and was the focus of this study. A retrospective chart review of consecutive patients who underwent implantable cardioverter defibrillator or pacemaker implantation was performed. The association between change in white blood cell (WBC) count and development of infection after device implantation was assessed. Infection was defined as pocket or lead infection or as bacteremia or sepsis <60 days after implantation. Pre- and postprocedural WBC counts were obtained within 48 hours of the procedure. Significant leukocytosis was defined as a ≥50% increase in WBC count; 1,245 device implantations met inclusion criteria. Device-related infections occurred in 8 cases (0.6%). A modest 17.6 ± 30.2% increase in WBC count was observed for the entire cohort. Cases resulting in infection demonstrated minimal change in WBC count (mean +5.5 ± 26.5%). No infections occurred in patients with ≥50% increases in WBC count or postprocedural WBC counts >15,000/µl. Subjects with significant leukocytosis were younger (mean age 61.9 ± 16.5 vs 65.6 ± 15.1 years, p <0.01), had longer procedure times (mean 198 ± 97 vs 170 ± 77 minutes, p <0.001), and received biventricular implantable cardioverter-defibrillators (25% vs 13.9%, p <0.001). In conclusion, after device implantation, a ≥50% increase in WBC count occurred in about 10% to 15% of patients. Age, race, type of device, and procedure time influenced the development of significant leukocytosis. Elevation in WBC count after cardiac device implantation was not associated with an increased risk for early infection.

Comparison of allogeneic vs autologous bone marrow­derived mesenchymal stem cells delivered by transendocardial injection in patients with ischemic cardiomyopathy: the POSEIDON randomized trial.

CONTEXT: Mesenchymal stem cells (MSCs) are under evaluation as a therapy for ischemic cardiomyopathy (ICM). Both autologous and allogeneic MSC therapies are possible; however, their safety and efficacy have not been compared. OBJECTIVE: To test whether allogeneic MSCs are as safe and effective as autologous MSCs in patients with left ventricular (LV) dysfunction due to ICM. DESIGN, SETTING, AND PATIENTS: A phase 1/2 randomized comparison (POSEIDON study) in a US tertiary-care referral hospital of allogeneic and autologous MSCs in 30 patients with LV dysfunction due to ICM between April 2, 2010, and September 14, 2011, with 13-month follow-up. INTERVENTION: Twenty million, 100 million, or 200 million cells (5 patients in each cell type per dose level) were delivered by transendocardial stem cell injection into 10 LV sites. MAIN OUTCOME MEASURES: Thirty-day postcatheterization incidence of predefined treatment-emergent serious adverse events (SAEs). Efficacy assessments included 6-minute walk test, exercise peak VO2, Minnesota Living with Heart Failure Questionnaire (MLHFQ), New York Heart Association class, LV volumes, ejection fraction (EF), early enhancement defect (EED; infarct size), and sphericity index. RESULTS: Within 30 days, 1 patient in each group (treatment-emergent SAE rate, 6.7%) was hospitalized for heart failure, less than the prespecified stopping event rate of 25%. The 1-year incidence of SAEs was 33.3% (n = 5) in the allogeneic group and 53.3% (n = 8) in the autologous group (P = .46). At 1 year, there were no ventricular arrhythmia SAEs observed among allogeneic recipients compared with 4 patients (26.7%) in the autologous group (P = .10). Relative to baseline, autologous but not allogeneic MSC therapy was associated with an improvement in the 6-minute walk test and the MLHFQ score, but neither improved exercise VO2 max. Allogeneic and autologous MSCs reduced mean EED by −33.21% (95% CI, −43.61% to −22.81%; P < .001) and sphericity index but did not increase EF. Allogeneic MSCs reduced LV end-diastolic volumes. Low-dose concentration MSCs (20 million cells) produced greatest reductions in LV volumes and increased EF. Allogeneic MSCs did not stimulate significant donor-specific alloimmune reactions. CONCLUSIONS: In this early-stage study of patients with ICM, transendocardial injection of allogeneic and autologous MSCs without a placebo control were both associated with low rates of treatment-emergent SAEs, including immunologic reactions. In aggregate, MSC injection favorably affected patient functional capacity, quality of life, and ventricular remodeling. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01087996.

Vitamin D deficiency is associated with the development of subclinical coronary artery disease in African Americans with HIV infection: a preliminary study.

BACKGROUND: Premature coronary artery disease (CAD) is a major concern in human immunodeficiency virus (HIV)-infected African Americans. The objectives of the study were to estimate the incidence of subclinical CAD, defined by the presence of coronary plaque and/or calcification on cardiac computed tomography (CT), and to identify the associated risk factors in this vulnerable population. SUBJECTS AND METHODS: Between August 2003 and September 2010, 188 HIV-infected African Americans without known, or symptoms of, CAD underwent cardiac CT. The subset without demonstrable disease underwent a second cardiac CT approximately 2 years later. The incidence of disease over that period and the effects of antiretroviral treatment and other known and hypothesized risk factors were investigated. RESULTS: Sixty-nine of these 188 African Americans had evidence of subclinical disease on the initial cardiac CT, confirming prior high prevalence reports. A second cardiac CT was performed on 119 African Americans without disease approximately 2 years later. The total person-years of follow-up was 284.4. Subclinical CAD was detected in 14 of these, yielding an overall incidence of 4.92/100 person-years (95% confidence interval, 2.69-8.26). Among the factors investigated, only male sex and vitamin D deficiency were independently associated with the development of subclinical CAD. The study did not find significant associations between CD4 count, HIV viral load, antiretroviral treatment use, or cocaine use and the incidence of subclinical CAD. CONCLUSIONS: The incidence of subclinical CAD in African Americans with HIV infection is provocatively high. Larger studies are warranted to confirm the role of vitamin D deficiency in the development of CAD in HIV-infected African Americans.

Vitamin D deficiency is associated with significant coronary stenoses in asymptomatic African American chronic cocaine users.

BACKGROUND: Chronic cocaine use may lead to premature atherosclerosis, however, the prevalence of and risk factors for coronary artery disease in asymptomatic cocaine users have not been reported. METHODS: Between August 2007 and June 2010, 385 African American chronic cocaine users aged 25 to 54 years were consecutively enrolled in a study to investigate the prevalence of CT angiographically-defined significant (≥ 50%) coronary stenosis and related risk factors. Sociodemographic, drug-use behavior, medical history and medication data were obtained by interview and confirmed by medical chart review. Clinical examinations were performed as well as extensive laboratory tests including those for fasting lipid profiles, HIV, high sensitivity C-reactive protein, and vitamin D. Contrast-enhanced coronary CT angiography was performed. RESULTS: Significant coronary stenosis was detected in 52 of 385 participants (13.5%). The prevalences were 12% and 30% in those with low risk and with middle-high risk Framingham score, respectively. In those with low risk scores, the prevalences of significant stenosis were 10% and 18% in those without and with vitamin D deficiency, defined as serum 25-(OH) vitamin D< 10 ng/mL (p=0.08). Multiple logistic regression analysis revealed that vitamin D deficiency (adjusted OR=2.18, 95% CI: 1.07-4.43) is independently associated with the presence of significant coronary stenosis after controlling for traditional risk factors. CONCLUSIONS: The study indicates that the prevalence of significant coronary stenoses is high in asymptomatic young and middle-aged African American chronic cocaine users. These findings emphasize the importance of aggressive reduction of risk factors, including vitamin D deficiency in this population.

Extraction of Sterile Leads: Is it Beneficial?

Extraction of sterile leads remains a controversial area. The risks and benefits of abandoning a lead are largely unknown, whereas the risks of lead extraction are better studied. Lead management decisions need to be made on a patient-by-patient basis, with important input from the patient and family. This article presents several representative cases and reviews the major considerations in making the decision of whether or not to extract a sterile lead that has become either no longer needed or no longer functional.

End-stage renal disease predicts complications in pacemaker and ICD implants.

INTRODUCTION: Patients with chronic kidney disease (CKD) have increased morbidity following invasive procedures. We hypothesized that patients with CKD have higher complication rates following device implantation than patients with normal renal function. METHODS: We reviewed the medical records of patients undergoing ICD or pacemaker implantation from August 2004 to August 2007. The estimated glomerular filtration rate (GFR) was calculated using the Cockroft-Gault equation. Those with GFR ≥ 90 cc/min served as controls. The remainder was grouped according to American Kidney Foundation stages of CKD. Bleeding complications were defined as need for pocket exploration or blood transfusion; cardiac tamponade; or hematoma requiring pressure dressing, change in medications or prolonged hospitalization. Infection was defined as infection of the pocket or lead system, or development of bacteremia/sepsis within 60 days. RESULTS: There were 82 bleeding complications (5.7%) and 7 infections (0.5%) temporally related to device implantation in 1,440 patients. End-stage renal disease (ESRD), defined as GFR < 15 mL/min or need for dialysis, was identified in 32 patients. Infection rates were significantly higher in patients with ESRD versus controls (12.5% vs 0.2%; P < 0.0001). A significant increase in bleeding complications was observed in ESRD versus controls (21.9% vs 3.2%, respectively; P<0.0001). Bleeding complications were considerably greater than controls in moderate (GFR 30-59 mL/min) and severe (GFR 15-29 mL/min) CKD (7.4% and 9.8% vs 3.2%, respectively; P < 0.005). CONCLUSION: ESRD markedly increases bleeding and device-related infections. The risk of both complications parallels the severity of CKD. Further research is needed to reduce adverse outcomes in this high-risk population.

Computed Tomography Imaging in Atrial Fibrillation Ablation.

Atrial fibrillation (AF) is the most common supraventricular arrhythmia in adults and catheter ablation has increasingly become the therapy of choice for symptomatic, recurrent, drug refractory AF. The purpose of this review is to evaluate the utility of computed tomography (CT) imaging in guiding radiofrequency catheter ablation (RFCA), as well as highlight the additional radiographic and functional anatomic data provided by CT in comparison to alternative radiographic modalities.