The value of myocardial MIBI washout rate in risk stratification of coronary artery disease

Abstract

Abstract Background Although it is well established that MIBI does not redistribute as thallium within the myocardium, it showed a reverse redistribution phenomenon that can be expressed by the rate of myocardial MIBI washout. The aim in this study was calculating the global myocardial washout of the MIBI (GWR) in patients diagnosed with coronary artery disease (CAD) of different risk stratifications. Results This prospective study included 100 patients. All patients were stratified into low-, intermediate-, and high-risk groups according to clinical evaluation using Framingham score, stress ECG results using Duke’s score and finally myocardial perfusion imaging prognostic findings. GWR was estimated in each of these groups. GWR mean was 9.5%, 13%, and 18% within clinically stratified patients into low-, intermediate-, and high-risk patients respectively with correlation coefficient 0.4. In addition, GWR mean was 9.7%, 15.4%, and 18.7% within patients stratified according to exercise ECG findings into low-, intermediate-, and high-risk patients respectively with correlation coefficient 0.6. Combining all myocardial perfusion findings, GWR mean was 7.9%, 15.1%, and 19.3% in patient with low-, intermediate-, and high-risk imaging findings respectively with correlation coefficient 0.71. Conclusion GWR is positively correlated with the risk stratifications of the CAD patients. GWR can be used as an additional parameter to assess the risk of CAD patients.

Keywords

• Risk stratification
• GWR
• Framingham
• Duke’s score