The Value Of The Adenosine Stress Gated Myocardial Perfusion Imaging In The Diagnosis Of Coronary Artery Disease Of The Elderly

Objective To explore the value of the adenosine stress gated myocardial perfusion imaging in the diagnosis of coronary artery disease of the elderly, and to find the best clinical manner for the diagnosis of coronary heart disease in older people. Providing the basis for the clinic treatment and prognosis of the elderly.Methods Seventy-three patients of suspected coronary heart disease in the elderly, from September2011to June2013, aged60～79years were enrolled.Of which thirty-nine cases suffered type2diabetes mellitus. All patients were excluded who had undergone coronary artery bypass grafting surgery or percutaneous coronary intervention percutaneous coronary intervention, and those who had old myocardial infarction, rheumatic heart disease, elderly valvular heart disease, severe aortic stenosis, obstructive hypertrophic cardiomyopathy, pulmonary embolism or pulmonary infarction, decompensated heart failure, etc. And all patients had completed inspection of the adenosine stress gated myocardial perfusion imaging and coronary angiography within two months. The results of the adenosine stress gated myocardial perfusion imaging were analyzed by qualitative and semi-quantitative methods: Some myocardial segment with decrease or defect of radioactivity at stress test in two or more than two myocardial tomography is diagnosed as MPI positive. Semi-quantitative analysis of the left ventricle using paragraph17scoring models, all myocardial segments are used for all4points scoring system:0, normal distribution of radioactivity;1, distribution of radioactivity slightly reduced;2, distribution of radioactivity moderate reduce;3, distribution of radioactivity serious reduce;4, no radioactivity distribution. The results of the coronary angiography were judged positive if the stenosis of coronary arteries equal or larger than50%in one of three main coronary arteries at least, when the narrow ranges from50%to75%it was defined clear stenosis, and defined severe stenosis was>75%.When the lesions involved equal or more than2branches were regarded as multivessel disease.Resu I ts There were fifty patients had imaging agent sparse or missing in the adenosine stress gated myocardial perfusion imaging. The sensitivity, specificity, the rate of missed diagnosis, misdiagnosis rate, positive predictive value, negative predictive value and the accuracy of adenosine stress myocardial perfusion imaging for the elderly in detecting coronary artery were86.3%(44/51),72.7%%(16/22), 13.7%(7/51),27.3%(6/22),88.0%(44/50),69.6%(16/23),82.2%(60/73) respectively, and there were no significant difference between the value of MPI and CAG in the diagnosis of CAD (P>0.05). With the increasing degree of coronary artery stenosis the sensitivity of MPI also increases. The sensitivity of MPI detecting stenosis<50%was37.5%, and68.7%for a narrow50%to75%,94.2%for the stenosis≥75%.There was significant difference of MPI for coronary artery stenosis between50%and75%(P<0.05), the difference of the sensitivity was statistically significant for the stenosis>75%and the stenosis<75%(P<0.05). The sensitivity and the specificity of MPI in the diagnosis of CAD with diabetes mellitus are85.2%,83.3%respectively have no obvious difference compared with the result of patients without diabetes mellitus (P>0.05). In evaluating diabetes affected blood vessels, the positive rate of MPI was obviously higher than that of non diabetic group (P<0.05). Conclusionl、The stress myocardial perfusion imaging has a higher sensitivity and specificity in the diagnosis of coronary artery disease in the elderly, there has a higher coincidence rate between the MPI and CAG. The stress myocardial perfusion provides a new means of checking for the elderly who is not willing or suitable for the coronary angiography as a noninvasive clinic inspection methods.2、The elderly is easily combined with other diseases attributing to the body dysfunction, especially with type2diabetes. Compared with patients with type2diabetes the range of coronary artery lesions were more wide than those without type2diabetes, double and three vessels involvement more common, and mainly involving the left anterior descending artery. The sensitivity and specificity of stress myocardial perfusion imaging in the diagnosis of this population is relatively high.3、The stress myocardial perfusion imaging has a higher sensitivity in the elderly with coronary stenosis of50%to75%, which was called critical lesions, and provides an objective basis for the clinical follow-up treatment and prognosis.