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coronary microvascular resistance

Sebastian Völz, Sara Svedlund, Bert Andersson, Gan Li-Ming, Bengt Rundqvist
Resistant hypertension is associated with increased risk for cardiovascular events. Coronary flow reserve (CFR) is impaired in patients with hypertension and an independent predictor of cardiac mortality. However, there are no published data on CFR in the subset of treatment-resistant hypertension. The aim of this study was to assess CFR in patients with resistant hypertension. Twenty-five consecutive patients with primary resistant hypertension, scheduled for renal denervation, 25 matched patients with controlled hypertension, and 25 healthy controls underwent transthoracic colour Doppler echocardiography at rest and during adenosine infusion...
October 17, 2016: Clinical Research in Cardiology: Official Journal of the German Cardiac Society
Sang-Don Park, Man-Jong Lee, Yong-Soo Baek, Sung-Woo Kwon, Sung-Hee Shin, Seong-Ill Woo, Dae-Hyeok Kim, Jun Kwan, Keum-Soo Park
AIMS: Ticagrelor has shown greater, more rapid and more consistent platelet inhibition than clopidogrel. However, the superiority of ticagrelor for preventing ischaemic damage in STEMI patients has not been proven. The aim of this trial was to assess whether ticagrelor is superior to clopidogrel in preventing microvascular injury in ST-elevation myocardial infarction (STEMI). METHODS AND RESULTS: Patients with STEMI underwent prospective random assignment to receive a loading dose (LD) of clopidogrel 600 mg or ticagrelor 180 mg (1:1 ratio) before primary percutaneous coronary intervention (PCI)...
October 10, 2016: EuroIntervention
David Carrick, Caroline Haig, Jaclyn Carberry, Vannesa Teng Yue May, Peter McCartney, Paul Welsh, Nadeem Ahmed, Margaret McEntegart, Mark C Petrie, Hany Eteiba, Mitchell Lindsay, Stuart Hood, Stuart Watkins, Ahmed Mahrous, Samuli M O Rauhalammi, Ify Mordi, Ian Ford, Aleksandra Radjenovic, Naveed Sattar, Keith G Oldroyd, Colin Berry
BACKGROUND: Failed myocardial reperfusion is common and prognostically important after acute ST-elevation myocardial infarction (STEMI). The purpose of this study was to investigate coronary flow reserve (CFR), a measure of vasodilator capacity, and the index of microvascular resistance (IMR; mmHg × s) in the culprit artery of STEMI survivors. METHODS: IMR (n = 288) and CFR (n = 283; mean age [SD], 60 [12] years) were measured acutely using guide wire-based thermodilution...
May 5, 2016: JCI Insight
Yuji Odaka, Jun Takahashi, Ryuji Tsuburaya, Kensuke Nishimiya, Kiyotaka Hao, Yasuharu Matsumoto, Kenta Ito, Yasuhiko Sakata, Satoshi Miyata, Daisuke Manita, Yuji Hirowatari, Hiroaki Shimokawa
AIMS: Although the importance of coronary microvascular dysfunction (CMD) has been emerging, reliable biomarkers for CMD remain to be developed. We examined the potential usefulness of plasma concentration of serotonin to diagnose CMD in patients with suspected angina and unobstructive coronary arteries. METHODS AND RESULTS: We enrolled 198 consecutive patients (M/F 116/82, 60.2 ± 13.3 years old) who underwent acetylcholine provocation test and measured plasma serotonin concentration...
October 2, 2016: European Heart Journal
Matthew Lumley, Rupert Williams, Kaleab N Asrress, Satpal Arri, Natalia Briceno, Howard Ellis, Ronak Rajani, Maria Siebes, Jan J Piek, Brian Clapp, Simon R Redwood, Michael S Marber, John B Chambers, Divaka Perera
BACKGROUND: Severe aortic stenosis (AS) can manifest as exertional angina even in the presence of unobstructed coronary arteries. OBJECTIVES: The authors describe coronary physiological changes during exercise and hyperemia in the healthy heart and in patients with severe AS. METHODS: Simultaneous intracoronary pressure and flow velocity recordings were made in unobstructed coronary arteries of 22 patients with severe AS (mean effective orifice area 0...
August 16, 2016: Journal of the American College of Cardiology
Juefei Wu, David Barton, Feng Xie, Edward O'Leary, John Steuter, Gregory Pavlides, Thomas R Porter
BACKGROUND: Real-time myocardial contrast echocardiography (RTMCE) directly measures capillary flow (CBF), which in turn is a major regulator of coronary flow and resistance during demand or hyperemic stress. Although fractional flow reserve (FFR) was developed to assess the physiological relevance of an epicardial stenosis, it assumes maximal microvascular vasodilation and minimal resistance during vasodilator stress. Therefore, we sought to determine the relationship between CBF assessed with RTMCE during stress echocardiography and FFR in intermediate coronary lesions...
August 2016: Circulation. Cardiovascular Imaging
S R Merger, W Kerner, M Stadler, A Zeyfang, P Jehle, M Müller-Korbsch, R W Holl
BACKGROUND: A growing number of people with type 1 diabetes (T1DM) are identified with features of metabolic syndrome (MS) known as "double diabetes", but epidemiologic data on the prevalence of MS in T1DM and its comorbidities are still lacking. Aim of this cross sectional study is to better estimate the prevalence of MS in T1DM, and to assess its association with comorbidities. METHODS: Data of 31,119 persons with autoimmune diabetes mellitus were analysed for signs of MS and presence of late complications...
September 2016: Diabetes Research and Clinical Practice
Tadashi Murai, Tetsumin Lee, Yoshihisa Kanaji, Junji Matsuda, Eisuke Usui, Makoto Araki, Takayuki Niida, Keiichi Hishikari, Sadamitsu Ichijyo, Rikuta Hamaya, Taishi Yonetsu, Mitsuaki Isobe, Tsunekazu Kakuta
This study investigates whether hyperemic microvascular resistance (MR) is influenced by elective percutaneous coronary intervention (PCI) by using the index of microcirculatory resistance (IMR). Seventy-one consecutive patients with stable angina pectoris undergoing elective PCI were prospectively studied. The IMR was measured before and after PCI and at the 10-mo follow-up. The IMR significantly decreased until follow-up; the pre-PCI, post-PCI, and follow-up IMRs had a median of 19.8 (interquartile range, 14...
September 1, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Sonnet S Jonker, Lowell Davis, Divya Soman, J Todd Belcik, Brian P Davidson, Tamara M Atkinson, Adrienne Wilburn, Samantha Louey, George D Giraud, Jonathan R Lindner
Fetal anemia causes cardiac adaptations that have immediate and life-long repercussions on heart function and health. It is known that resting and maximal coronary conductance both increase during chronic fetal anemia, but the coronary microvascular changes responsible for the adaptive response are unknown. Until recently, technical limitations have prevented quantifying functional capillary-level adaptations in the in vivo fetal heart. Our objective was to characterize functional microvascular adaptations in chronically anemic fetal sheep...
June 13, 2016: Journal of Physiology
Mustafa Çetin, Emrullah Kiziltunc, Özgül Uçar Elalmış, Zehra Güven Çetin, Muhammed Bora Demirçelik, Hülya Çiçekçioğlu, Alparslan Kurtul, Selçuk Özkan, Candan Mansuroğlu Avan, Ender Örnek, Feridun Vasfi Ulusoy
BACKGROUND: Increased microvascular resistance due to chronic inflammation is assumed to be one of the mechanisms associated with coronary slow flow (CSF). Previous studies have shown that the platelet-to-lymphocyte ratio (PLR) and the neutrophil-lymphocyte ratio (NLR) are markers of inflammation for various diseases. In this study we aimed to evaluate the relationship between CSF and PLR-NLR. METHODS: Seventy-eight patients with CSF and 50 patients with normal coronary flow were enrolled into this study...
May 2016: Acta Cardiol Sin
Yan-Hua Gao, Ju-Ying Qian, Zhang-Wei Chen, Ming-Qiang Fu, Jian-Feng Xu, Yan Xia, Xue-Feng Ding, Xiang-Dong Yang, Yuan-Yuan Cao, Yun-Zeng Zou, Jun Ren, Ai-Jun Sun, Jun-Bo Ge
Microvascular obstruction (MO), one of unfavorable complications of percutaneous coronary intervention (PCI), is responsible for the lost benefit of reperfusion therapy. Determination of microRNA-19a, a member of the miR-17-92 cluster, using quantitative real-time polymerase chain reaction (PCR) revealed notably down-regulated microRNA-19a, in myocardium with MO. Nonetheless, the role of miR-19a in MO and the underlying mechanism remains to be elucidated. To this end, an in vitro microembolization model in cardiomyocytes was used...
August 22, 2016: Toxicology Letters
Tadashi Murai, Yoshihisa Kanaji, Taishi Yonetsu, Tetsumin Lee, Junji Matsuda, Eisuke Usui, Makoto Araki, Takayuki Niida, Mitsuaki Isobe, Tsunekazu Kakuta
BACKGROUND: Epicardial focal coronary artery stenosis, diffuse coronary disease, and microvascular resistance (MR) may limit coronary flow. The purpose of percutaneous coronary intervention (PCI) is to increase coronary flow by targeting epicardial lesions. After PCI, MR might change and affect coronary flow. We investigated whether PCI influences MR using the index of microcirculatory resistance (IMR) and if pre-PCI fractional flow reserve (FFR) or MR predicts the post-PCI change in hyperaemic coronary flow...
May 24, 2016: Catheterization and Cardiovascular Interventions
Ole Geir Solberg, Knut Stavem, Asgrimur Ragnarsson, Dan Ioanes, Satish Arora, Knut Endresen, Jūratė Šaltytė Benth, Lars Gullestad, Einar Gude, Arne K Andreassen, Lars Aaberge
BACKGROUND: Microvascular function in transplanted hearts can be evaluated by methods used in routine left heart catheterization follow-up after heart transplantation (HTx). This sub-study of a randomized study compared the effects of everolimus (EVR) and calcineurin inhibitor (CNI) treatment on microvascular function as expressed by the index of microvascular resistance (IMR) at 1 year after HTx. A secondary objective was to compare the change in IMR from 7-11 weeks to 1 year after HTx between randomized groups...
August 2016: Journal of Heart and Lung Transplantation
Gladys N Janssens, Maarten A H van Leeuwen, Nina W van der Hoeven, Guus A de Waard, Robin Nijveldt, Roberto Diletti, Felix Zijlstra, Clemens von Birgelen, Javier Escaned, Marco Valgimigli, Niels van Royen
Microvascular injury is present in a large proportion of patients with ST-elevation myocardial infarction (STEMI) despite successful revascularization. Ticagrelor potentially mitigates this process by exerting additional adenosine-mediated effects. This study aims to determine whether ticagrelor is associated with a better microvascular function compared to prasugrel as maintenance therapy after STEMI. A total of 110 patients presenting with STEMI and additional intermediate stenosis in another coronary artery will be studied after successful percutaneous coronary intervention (PCI) of the infarct-related artery...
June 2016: Journal of Cardiovascular Translational Research
Monica B Patel, Linh P Bui, Richard L Kirkeeide, K Lance Gould
Microvascular dysfunction or disease is most commonly associated with diffuse epicardial coronary atherosclerosis and endothelial dysfunction, whereas it is less common as a distinct, separate, isolated pathophysiology. The different manifestations of coronary artery disease in women relate in part to their smaller coronary arteries, higher coronary blood flow, and higher endothelial shear stress, which have profound effects on endothelial function and development or resistance to atherosclerosis, its symptomatic presentation, outcomes, and treatment...
April 2016: JACC. Cardiovascular Imaging
Tuncay Yetgin, Matthijs van Kranenburg, Tim Ten Cate, Dirk J Duncker, Menko-Jan de Boer, Roberto Diletti, Robert-Jan M van Geuns, Felix Zijlstra, Olivier C Manintveld
BACKGROUND: Whether ischemic postconditioning (IPOC) immediately after routine thrombus aspiration (TA) reduces infarct size (IS) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI) has not been established. STUDY DESIGN: The POstconditioning Rotterdam Trial (PORT) is a dual-center, prospective, open-label, randomized trial with blinded endpoint evaluation enrolling 72 subjects with first-time STEMI, and an occluded infarct-related artery (IRA) without collaterals undergoing PPCI...
September 10, 2015: Catheterization and Cardiovascular Interventions
Sung Gyun Ahn, Olivia Y Hung, Jun-Won Lee, Ji Hyun Lee, Young Jin Youn, Min-Soo Ahn, Jang-Young Kim, Byung-Su Yoo, Seung-Hwan Lee, Junghan Yoon, Woocheol Kwon, Habib Samady
OBJECTIVES: The aim of this study was to investigate the predictive accuracy of invasive coronary microvascular indexes for identifying microvascular obstruction (MVO) on cardiac magnetic resonance imaging (CMR) in patients treated with primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). BACKGROUND: We hypothesized that a combination of the index of microcirculatory resistance (IMR) and the thermodilution-derived coronary flow reserve (CFRthermo) will enhance the predictive accuracy of detecting MVO compared with either index alone...
April 25, 2016: JACC. Cardiovascular Interventions
Joo Myung Lee, Ji-Hyun Jung, Doyeon Hwang, Jonghanne Park, Yongzhen Fan, Sang-Hoon Na, Joon-Hyung Doh, Chang-Wook Nam, Eun-Seok Shin, Bon-Kwon Koo
BACKGROUND: The prognostic impact of microvascular status in patients with high fractional flow reserve (FFR) is not clear. OBJECTIVES: The goal of this study was to investigate the implications of coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR) in patients who underwent FFR measurement. METHODS: Patients with high FFR (>0.80) were grouped according to CFR (≤2) and IMR (≥23 U) levels: group A, high CFR with low IMR; group B, high CFR with high IMR; group C, low CFR with low IMR; and group D, low CFR with high IMR...
March 15, 2016: Journal of the American College of Cardiology
M Engholm, M J Mulvany, A Eftekhari, O N Mathiassen, N H Buus, K L Christensen
Increased systemic vascular resistance and coronary microvascular dysfunction are well-documented in essential hypertension (EH). We investigated the effect of additional vasodilating treatment on coronary and peripheral resistance circulation in EH patients with high systemic vascular resistance index (SVRI) despite well-treated blood pressure (BP). We enroled patients on stable antihypertensive treatment that were given intensified vasodilating therapy (ACE inhibitor, angiotensin II receptor blocker or calcium channel blocker)...
March 10, 2016: Journal of Human Hypertension
Christopher J Arthurs, Kevin D Lau, Kaleab N Asrress, Simon R Redwood, C Alberto Figueroa
This work presents a mathematical model of the metabolic feedback and adrenergic feedforward control of coronary blood flow that occur during variations in the cardiac workload. It is based on the physiological observations that coronary blood flow closely follows myocardial oxygen demand, that myocardial oxygen debts are repaid, and that control oscillations occur when the system is perturbed and so are phenomenological in nature. Using clinical data, we demonstrate that the model can provide patient-specific estimates of coronary blood flow changes between rest and exercise, requiring only the patient's heart rate and peak aortic pressure as input...
May 1, 2016: American Journal of Physiology. Heart and Circulatory Physiology
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