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Presents abstracts of studies the on regulation of skeletal muscle and coronary circulation, presented at the Experimental Biology/International Union of Physiological Sciences 2005 congress held in San Diego, California. "ATP Control of Coronary Blood Flow," by Martin Farias III, Mark W. Gorman et al. "Red Blood Cell Velocity and Capillary Luminal Diameter in Atrophied Rat Soleus and Gastrocnomius Muscles," by Hisaharu Kohzuki, Hidemi Fujino et al.; "Evidence for Nitric Oxide-Independent Vasorelaxation in Coronary Arteries From Insulin Receptor Null Mice," by J. David Symons, J. Johnson et al.; "Effective Local NO Inhibition Blunts Exercise Hyperemia Without Altering Oxygen Uptake in the Human Thigh," by Mikael Sander, Thore Hilig et al.

Presents abstracts of studies on coronary circulation presented at the Experimental Biology/International Union of Physiological Sciences 2005 congress in San Diego, California. "Expression of Smoothelin in Cultured Coronary Smooth Muscle Cells From Wild Type and A1 Adenosine Receptor-Deficient Mice (A1AR-/-)," by Bunyen Teng, Habib R. Ansari, et al; "Role of Endothelin in α-Adrenoreceptor Coronary Vasoconstriction During Exercise," by Mark W. Gorman, Martin Farias III, et al; "Dysregulation of Coronary Arteriolar Response to the Metabolic Vasodilator Adenosine in Hypertrophic Cardiomyopathy: Role of NO and O2-," by Robert Shipley, Travis Hein, et al.

An abstract of the article "Multicenter evaluation of dynamic three dimensional whole-heart myocardial perfusion imaging for the detection of coronary artery disease defined by fractional flow reserve," by Robert Manka and colleagues is presented.

An abstract of the article "Impaired coronary flow reserve determined by MR measurement of coronary sinus flow predicts adverse outcome in patients with known or suspected coronary artery disease," by Masaki Ishida and colleagues is presented.

An abstract of the article "T2-prepared steady-state free-precession for detection of hemodynamic significance of coronary artery stenosis - a comparison to fractional flow reserve," by Thomas Walcher and colleagues is presented.

Presents abstracts of studies on coronary vascular pharmacology, presented at the Experimental Biology/International Union of Physiological Sciences 2005 congress held in San Diego, California. "Inhibition of Rhi-Kinase by Hydroxyfasudil Prevents Vasopressin-Induced Myocardial Ischemia in Donryu Rats by Inhibiting Coronary Vasoconstriction," by Jon Vincelette, Rene Pagila et al.; "Cloning and Identification of the Porcine A1 Adenosine Receptor Mediating a Novel Mitogenic Action of Adenosine in Coronary Artery Smooth Muscle Cells," by Jianzhong Shen, Michael Sturek et al.; "Effect of Selective COX-2 Inhibition on Coronary Artery Reactivity," by Jimbo Huang, Ting-Ting Hong et al.

An abstract of the article "3 Tesla is the preferred field strength for perfusion imaging in coronary artery disease: a comparison to 1.5 Tesla and fractional flow reserve," by P. Bernhardt and colleagues is presented.

An abstract on the comparison of 1.5 and 3 Tesla quantification of myocardial perfusion reserve with fractional flow reserve is presented.

Background: Stent thrombosis (ST) is associated with a significant burden of coronary thrombus and potential microvascular obstruction. Aspiration thrombectomy may decrease the extent of microvascular obstruction in patients with acute myocardial infarction but its role in the treatment of ST is uncertain. The present study sought to evaluate the association between aspiration thrombectomy, procedural success and long-term outcomes among patients presenting with ST., Methods: In a multicenter cohort of patients with definite ST, procedural success, long-term mortality, and major adverse cardiovascular events (death, stroke, re-infarction, revascularization) were ascertained. Propensity weighting was used to determine the association between aspiration thrombectomy and long-term outcomes., Results: A total of 205 patients with ST were identified. Among these, 115 (56%) patients underwent adjunctive aspiration thrombectomy during percutaneous coronary intervention. Patients undergoing aspiration thrombectomy were more likely to present with ST-elevation myocardial infarction (75% vs. 52%, P < 0.003) and require hemodynamic support (19% vs. 10%, P = 0.07). Aspiration thrombectomy was associated with improved procedural outcomes including postprocedural TIMI 3 flow, resulting in higher angiographic and procedural success (each 96% vs. 83%, P < 0.001). Despite improved angiographic outcomes, the use of aspiration thrombectomy was not associated with a difference in long-term mortality (adjusted HR 0.99, 95% CI 0.44-2.24) or major adverse cardiovascular events (adjusted HR 1.06, 95% CI 0.45-2.48)., Conclusions: Aspiration thrombectomy is associated with improved coronary flow and procedural success but is not associated with improved long-term outcomes among patients undergoing percutaneous intervention for definite ST., Clinical Trial Registration: NCT00931502 (http://www.clinicaltrials.gov/ct2/show/NCT00931502), (Copyright © 2013 Wiley Periodicals, Inc.)

Rationale: CD34+ transplantation in dilated cardiomyopathy was associated with short-term improvement in left ventricular ejection fraction and exercise tolerance., Objective: We investigated long-term effects of intracoronary CD34+ cell transplantation in dilated cardiomyopathy and the relationship between intramyocardial cell homing and clinical response., Methods and Results: Of 110 dilated cardiomyopathy patients, 55 were randomized to receive CD34+ stem cell transplantation (SC group) and 55 received no cell therapy (controls). In the SC group, CD34+ cells were mobilized by granulocyte colony-stimulating factor and collected via apheresis. Patients underwent myocardial scintigraphy and cells were injected in the artery supplying segments with the greatest perfusion defect. At baseline, 2 groups did not differ in age, sex, left ventricular ejection fraction, or N-terminal B-type natriuretic peptide levels. At 5 years, stem cell therapy was associated with increased left ventricular ejection fraction (from 24.3 ± 6.5% to 30.0 ± 5.1%; P=0.02), increased 6-minute walk distance (from 344 ± 90 m to 477 ± 130 m; P<0.001), and decreased N-terminal B-type natriuretic peptide (from 2322 ± 1234 pg/mL to 1011 ± 893 pg/mL; P<0.01). Left ventricular ejection fraction improvement was more significant in patients with higher myocardial homing of injected cells. During follow-up, 27 (25%) patients died and 9 (8%) underwent heart transplantation. Of the 27 deaths, 13 were attributed to pump failure and 14 were attributed to sudden cardiac death. Total mortality was lower in the SC group (14%) than in controls (35%; P=0.01). The same was true of pump failure (5% vs. 18%; P=0.03), but not of sudden cardiac death (9% vs. 16%; P=0.39)., Conclusions: Intracoronary stem cell transplantation may be associated with improved ventricular function, exercise tolerance, and long-term survival in patients with dilated cardiomyopathy. Higher intramyocardial homing is associated with better stem cell therapy response.

Objectives: This study sought to investigate a novel method to calculate the index of microcirculatory resistance (IMR) in the presence of significant epicardial stenosis without the need for balloon dilation to measure the coronary wedge pressure (P(w))., Background: The IMR provides a quantitative measure of coronary microvasculature status. However, in the presence of significant epicardial stenosis, IMR calculation requires incorporation of the coronary fractional flow reserve (FFR(cor)), which requires balloon dilation within the coronary artery for P(w) measurement., Methods: A method to calculate IMR by estimating FFR(cor) from myocardial FFR (FFR(myo)), which does not require P(w) measurement, was developed from a derivation cohort of 50 patients from a single institution. This method to calculate IMR was then validated in a cohort of 72 patients from 2 other different institutions. Physiology measurements were obtained with a pressure-temperature sensor wire before coronary intervention in both cohorts., Results: From the derivation cohort, a strong linear relationship was found between FFR(cor) and FFR(myo) (FFR(cor) = 1.34 × FFR(myo) - 0.32, r(2) = 0.87, p < 0.001) by regression analysis. With this equation to estimate FFR(cor) in the validation cohort, there was no significant difference between IMR calculated from estimated FFR(cor) and measured FFR(cor) (21.2 ± 12.9 U vs. 20.4 ± 13.6 U, p = 0.161). There was good correlation (r = 0.93, p < 0.001) and agreement by Bland-Altman analysis between calculated and measured IMR., Conclusions: The FFR(cor), and, by extension, microcirculatory resistance can be derived without the need for P(w). This method enables assessment of coronary microcirculatory status before or without balloon inflation, in the presence of epicardial stenosis., (Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: This study sought to determine whether arterial spin labeled (ASL) cardiac magnetic resonance (CMR) is capable of detecting clinically relevant increases in regional myocardial blood flow (MBF) with vasodilator stress testing in human myocardium., Background: Measurements of regional myocardial perfusion at rest and during vasodilatation are used to determine perfusion reserve, which indicates the presence and distribution of myocardial ischemia. ASL CMR is a perfusion imaging technique that does not require any contrast agents, and is therefore safe for use in patients with end-stage renal disease, and capable of repeated or continuous measurement., Methods: Myocardial ASL scans at rest and during adenosine infusion were incorporated into a routine CMR adenosine induced vasodilator stress protocol and was performed in 29 patients. Patients who were suspected of having ischemic heart disease based on first-pass imaging also underwent x-ray angiography. Myocardial ASL was performed using double-gated flow-sensitive alternating inversion recovery tagging and balanced steady-state free precession imaging at 3-T., Results: Sixteen patients were found to be normal and 13 patients were found to have visible perfusion defect based on first-pass CMR using intravenous gadolinium chelate. In the normal subjects, there was a statistically significant difference between MBF measured by ASL during adenosine infusion (3.67 ± 1.36 ml/g/min), compared to at rest (0.97 ± 0.64 ml/g/min), with p < 0.0001. There was also a statistically significant difference in perfusion reserve (MBF(stress)/MBF(rest)) between normal myocardial segments (3.18 ± 1.54) and the most ischemic segments in the patients with coronary artery disease identified by x-ray angiography (1.44 ± 0.97), with p = 0.0011., Conclusions: This study indicates that myocardial ASL is capable of detecting clinically relevant increases in MBF with vasodilatation and has the potential to identify myocardial ischemia., (Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)