tailieunhanh - Cardiovascular Imaging A handbook for clinical practice - Part 5

Điểm số là hữu ích trong việc quyết định những bệnh nhân có nguy cơ thấp sau khi thử nghiệm thông thường máy chạy bộ điện tâm đồ sẽ được hưởng lợi từ sự phân tầng nguy cơ hơn nữa với hình ảnh tưới máu cơ tim căng thẳng. | 110 Chapter 9 Figure Adjusted risk of cardiac death CD per year relative to the percent stress defect on stress 99mTc-sestamibi SPECT myocardial perfusion imaging. Note that for either the 17-segment seg model or the two-segment model the relationship between perfusion defect size and subsequent cardiac death is similar. Reproduced with permission from Berman etal. 2004 .10 score was useful in deciding which patients at low risk after conventional ECG treadmill testing would benefit from further risk stratification with myocardial stress perfusion imaging. Variables incorporated in the clinical score were male gender history of prior myocardial infarction diabetes typical angina and advanced age. Patients with a high clinical score and a low Duke Treadmill Score were further successfully risk stratified by myocardial perfusion imaging variables. Diabetics are a subgroup of patients who may benefit significantly from risk stratification by stress myocardial perfusion In this multicenter study diabetic women with ischemia on stress SPECT imaging in two or more coronary vascular regions had only a 60 event-free survival rate over the subsequent 3 years compared with 79 for diabetic men with multivessel ischemia. The higher cardiac event rate in diabetics with either a low-risk or a high-risk scan is depicted in Fig. Note that in this pooled analysis diabetic women had a greater than 10 hard event rate per year with a high-risk scan. Pharmacologic stress imaging provides comparable prognostic information at exercise stress imaging although the cardiac event rate in patients with normal pharmacologic stress scans is higher than the event rate seen in patients normal exercise perfusion 5 6 This is because the patient population is a clinically higher risk one given that referral for pharmacologic stress implies either inability to exercise adequately . from peripheral vascular disease or concomitant pulmonary disease with bronchospasm .