<International Circulation>: You have just given a presentation on CAD and the elderly. Could you briefly outline what differentiates elderly patients with CAD from middle-aged patients for instance?

　　《国际循环》：您刚在大会上做了关于CAD和老年人的演讲。您能简短地谈谈老年CAD患者和中年CAD患者之间的区别吗？
　　Dr Wenger: I discussed predominantly the acute coronary syndromes rather than the totality of coronary artery disease. We were exploring why it is that the elderly patients with acute coronary syndromes don’t do as well. One of the major reasons is that they have their disease superimposed on the cardiovascular changes of ageing. The ageing heart has a number of limitations that do not do well when exposed to unusual stress as in an acute coronary syndrome. There is an increased afterload on the ventricles so that often the ventricles have hypertrophy. There is impaired endothelial function so there is less capacity to vasodilate. There is less maximal oxygen uptake aerobic capacity with ageing. The sinus node has a loss of cells so there may be an arrhythmia called sick sinus syndrome. The ventricle， because it is stiff， is very dependent on the atrial contribution for ventricular filling so if atrial rhythms are lost， the heart does not compensate as well. We see a decrease in beta-adrenergic responsiveness so that so many of the features that we count on to compensate when an acute stress occurs are very limited in the elderly patients. Then we have the problem that there is not just the cardiac illness. There is often renal disease and pulmonary disease and diabetes and so forth so that these limit the compensatory ability as well. Very often what we see at a very elderly age is that a patient who is hospitalized for pneumonia or another acute illness has an acute coronary syndrome secondary to the acute illness. It unmasks the coronary syndrome. We have to be suspicious of it and now we are treating a combined illness. But so many of the elderly patients do not have the typical severe chest pain presentation. They will present with weakness， fatigue， diaphoresis， they may have gastrointestinal symptoms or they may have changes in behavior or changes in mental state or even have episodes of syncope. So a high index of suspicion is very important; just to think that of any acute event as possibly being an acute coronary syndrome. In addition， there may be baseline electrocardiographic abnormalities that make it harder to detect the signals of the disease compared to the background noise. There is a whole variety of these features. Obviously because there is difficulty in diagnosis， diagnosis may be delayed， the initiation of therapy may be delayed and elderly patients don’t have the same response to therapies. Often they are on multiple drugs; there may be drug-drug interactions. The physician must be very aware that many drugs are excreted by the kidney so they have to be dosed appropriately. Elderly patients are more prone to bleeding complications and even with simple doses of aspirin either alone or as a component of dual antiplatelet therapy， any aspirin dose more than 100mg increases the risk of bleeding without benefit. So we need to be very careful with aspirin dosing in elderly patients.

　　Wenger博士: 我主要谈论的是急性冠状动脉（冠脉）综合征而不是全部的冠心病患者。我们正在研究为什么老年急性冠脉综合征患者预后不好。其中一个很重要的原因是他们所患的疾病与心血管系统的老化改变相互叠加。老化的心脏有很多弱点，因此当它们暴露于压力应激比如急性冠脉综合征的情况下就会出现不良后果。老年患者心室后负荷增加导致心室肥厚。内皮功能也出现障碍致使血管舒张功能更差。随着年龄的增加最大摄氧量减少，有氧代谢能力降低。窦房结内的细胞减少，可能发生病态窦房结综合征等心律失常。由于心室僵硬顺应性差，主要依靠心房收缩来充盈心室，因此如果心房节律紊乱，心脏就不能很好的代偿。我们还发现老年患者对β肾上腺受体的反应性降低，当发生急性应激时通常出现的许多代偿功能在老年患者体内非常有限。这时我们面临的问题不仅仅是心脏病。老年患者常常还合并肾脏疾病、肺部疾病、糖尿病以及其他疾病，这些疾病也降低了代偿功能。很多时候我们会发现因为肺炎或其他急性疾病住院的高龄患者会在急性疾病之后继发急性冠脉综合征。这些急性疾病还会掩盖急性冠脉综合征。我们需要警惕这种情况的发生而且目前我们治疗的是复合型疾病。但是很多老年患者并不表现为典型的严重胸痛。他们的症状常常是疲乏、无力、多汗，还可能有胃肠道症状或行为学的改变或精神状态的变化或甚至发生晕厥。所以对于老年患者保持高度的警惕性是非常必要的，尽可能把任何急性事件都考虑到是否为急性冠脉综合征。除此之外，老年患者还存在基础的心电图异常从而使疾病检测变得更加困难。这些都是老年患者的特点。很明显因为诊断很困难，所以诊断可能被延误，对患者的治疗也可能会被推迟，并且老年患者对治疗的反应常常不好。通常他们需要服用很多药物，还可能存在药物之间的相互作用。医生必须非常谨慎，很多药物都是通过肾脏排泄因此必须使用合适剂量的药物。老年患者还容易发生出血并发症，甚至是在单独使用常规剂量阿司匹林或双联抗血小板治疗时，阿司匹林的剂量超过100 mg会增加出血的风险而无获益。因此我们在给老年患者使用阿司匹林时需要非常小心。