Aortic Stiffness Index and Aortic Distensibility Measured by Echocardiography May Help to Improve the Equivocal Results of Myocardial Perfusion Scintigraphy

Özet

Objectives: Myocardial perfusion scintigraphy (MPS) is a well-established method for diagnosing coronary artery disease and risk stratification of individuals with chest pain. However, while MPS has high sensitivity and specificity for the detection of significant coronary artery disease, it has some drawbacks due to several technical difficulties. We suggest that aortic stiffness indexes measured by echocardiography, which is a well-known marker of atherosclerotic burden, may improve the equivocal test results obtained in MPS. Materials and Methods: We prospectively enrolled 149 consecutive patients between the ages of 18 and 65 years without any previous cardiovascular disease with suspected coronary artery disease, who had undergone both SPECT MPS using Technetium-99m-sestamibi (99mTc MIBI) and transthoracic echocardiography between November 2013 and June 2014. Subjects were divided into three categories according to MPS results as normal, equivocal and ischemic groups. Results: Aortic stiffness index (ASI) and aortic distensibility (AD) of the normal and equivocal groups were similar, and the ischemic group had higher ASI values compared to the normal and equivocal groups. The equivocal group had statistically lower ASI and higher AD values compared to the ischemia group (p 3.05 was accepted as abnormal, the frequency of abnormal ASI in the normal, equivocal, and ischemia groups were 11%, 19%, and 98%, respectively. The equivocal group had similar number of patients with abnormal ASI compared to the normal group (p=0.262) while it had statistically a lower number of patients with abnormal ASI than the ischemia group (p<0.001) Conclusion: However, aortic stiffness and aortic AD indexes alone cannot diagnose coronary artery disease (CAD), but may help to discriminate patients with CAD from those without CAD whose MPS results are equivocal.