Reyes Eliana, Pennell Dudley J
National Heart and Lung Institute, Imperial College, London SW7 2AZ, UK.
Expert Opin Med Diagn. 2010 Sep;4(5):447-54. doi: 10.1517/17530059.2010.506909. Epub 2010 Aug 5.
Stress myocardial perfusion scintigraphy (MPS) plays a major role in the detection of obstructive coronary artery disease and provides valuable diagnostic and prognostic information to guide clinical decision-making with regard to medical therapy and coronary revascularisation. Current stress techniques for MPS are effective but their use may be limited by reduced tolerability, contraindications and untoward side effects. The recently developed selective adenosine A2A receptor agonists have the potential for improving stress tolerability, hence expanding the indications for functional imaging in the assessment of coronary artery disease.
This article reviews the basic principles underlying activation of coronary arteriolar adenosine A2A receptors. It describes the benefits and limitations of current vasodilator stress agents and highlights the effectiveness, side effect profile and tolerability of regadenoson, the only selective adenosine A2A receptor agonist available at present for clinical use.
The reader will gain an understanding of the pharmacokinetics and mechanism of action of regadenoson for the assessment of coronary artery disease when combined with myocardial perfusion imaging. The reader will also become aware of the available evidence on the clinical usefulness of regadenoson MPS and its future applications.
Selective activation of coronary arteriolar adenosine A2A receptors by regadenoson provides an effective modality of stress for the detection of inducible perfusion abnormality in patients with known or suspected coronary disease. The effectiveness of regadenoson is similar to that of adenosine, but test tolerability is improved with regadenoson. The use of this agent simplifies stress testing and has the potential for expanding the applications of functional imaging to patient populations unsuitable for conventional vasodilator stress with adenosine or dipyridamole.
负荷心肌灌注显像（MPS）在阻塞性冠状动脉疾病的检测中发挥着重要作用，并为指导药物治疗和冠状动脉血运重建的临床决策提供有价值的诊断和预后信息。目前用于MPS的负荷技术是有效的，但它们的使用可能会受到耐受性降低、禁忌症和不良副作用的限制。最近开发的选择性腺苷A2A受体激动剂有可能提高负荷耐受性，从而扩大功能成像在冠状动脉疾病评估中的应用指征。
本文回顾了冠状动脉小动脉腺苷A2A受体激活的基本原理。它描述了当前血管扩张剂负荷剂的益处和局限性，并强调了瑞加腺苷的有效性、副作用特征和耐受性，瑞加腺苷是目前唯一可用于临床的选择性腺苷A2A受体激动剂。
读者将了解瑞加腺苷与心肌灌注成像联合用于评估冠状动脉疾病时的药代动力学和作用机制。读者还将了解有关瑞加腺苷MPS临床实用性的现有证据及其未来应用。
瑞加腺苷对冠状动脉小动脉腺苷A2A受体的选择性激活为检测已知或疑似冠心病患者的诱发性灌注异常提供了一种有效的负荷方式。瑞加腺苷的有效性与腺苷相似，但瑞加腺苷的试验耐受性更好。使用这种药物简化了负荷试验，并有可能将功能成像的应用扩展到不适合使用腺苷或双嘧达莫进行传统血管扩张剂负荷试验的患者群体。
