Deanfield J E
St. Bartholomew's Hospital, West Smithfield, London, UK.
Cardiovasc Drugs Ther. 1990 Aug;4 Suppl 4:833-9. doi: 10.1007/BF00051289.
In patients with coronary artery disease, angina pectoris provides an unreliable underestimation of disease activity and risk. Unheralded myocardial infarction and sudden death are common clinical presentations. Furthermore, objective testing, in hospital and more recently during the patient's normal daily activities, has demonstrated frequent and asymptomatic episodes of ischemia, as indicated by transient ST-segment depression. Since the underlying pathophysiologic disturbances of myocardial perfusion appear to be similar in painful and painless episodes, it seems appropriate to consider them together as the "total ischemic burden" on the myocardium. Research into this functional expression of coronary disease has indicated that active ischemia is associated with an increased risk of morbid events in all clinical subgroups of patients, including those with stable angina, unstable angina, peripheral vascular disease and following myocardial infarction. If this is confirmed in prospective trials, the assessment of total ischemic burden is likely to become part of the clinical investigation of patients with coronary disease. Clinical trials testing the efficacy of interventions will need to examine the effect on ischemic activity during normal daily life, in addition to symptoms and exercise tolerance. Evidence is still required to demonstrate whether therapy aimed at reducing the total ischemic burden will prolong life. The total ischemic burden provides a marker to follow the dynamic changes of the atherosclerotic lesion. Future research may have to concentrate on treatment aimed at altering the natural history of obstructive coronary atherosclerosis in order to affect the long-term outlook for patients with coronary artery disease.
在冠心病患者中，心绞痛对疾病活动和风险的评估并不可靠，常出现低估情况。无预兆的心肌梗死和猝死是常见的临床表现。此外，在医院以及最近在患者日常正常活动期间进行的客观检查表明，短暂性ST段压低提示存在频繁的无症状性缺血发作。由于心肌灌注的潜在病理生理紊乱在疼痛和无痛发作中似乎相似，因此将它们一并视为心肌的“总缺血负荷”似乎是合适的。对冠心病这种功能表现的研究表明，在所有临床亚组患者中，包括稳定型心绞痛、不稳定型心绞痛、外周血管疾病患者以及心肌梗死后患者，活动性缺血都与不良事件风险增加相关。如果在前瞻性试验中得到证实，总缺血负荷的评估很可能会成为冠心病患者临床研究的一部分。测试干预措施疗效的临床试验除了要检查对症状和运动耐量的影响外，还需要研究对日常生活中缺血活动的影响。仍需证据来证明旨在降低总缺血负荷的治疗是否会延长寿命。总缺血负荷为追踪动脉粥样硬化病变的动态变化提供了一个指标。未来的研究可能需要集中于旨在改变阻塞性冠状动脉粥样硬化自然病程的治疗方法，以影响冠心病患者的长期预后。
