Five hundred and ten consecutive patients, who had undergone myocardial perfusion SPECT between 2005 and 2006, were prospectively followed-up. Patients鈥?data were collected from recorded files. Follow-ups were performed by scripted telephone interviews by a physician blinded to the patients鈥?MPI results and also from the hospital records. The total completed follow-ups consisted of 482 patients (follow-up rate, 94.5%).
Over the mean follow-up period of 434 卤 62 days, 14 out of 482 patients (2.9%) died from cardiac events. Also in 61 patients (12.7%), the clinical condition led to a cardiac intervention (Percutaneous coronary intervention or coronary artery bypass grafting). Those patients without cardiac events on follow-up (including cardiac death or myocardial infarction) were younger and with less severity of MPI abnormalities. Severe MPI abnormalities (Summed Stress Score > 13) were found in 42.9%of those with cardiac death, while in 17.2%of those with myocardial infarction. The rate of cardiac death had a direct relationship with the severity of scan abnormalities, however, the same association was not found between the severity of MPI abnormality and the rate of myocardial infarction.
MPI is a valuable tool for risk stratification and prediction of future fatal cardiac events in Asian population. The risk of cardiac death as a mid-term outcome of coronary artery disease increases significantly with severity of MPI abnormalities.