The timing and impact of follow-up studies after normal stress single-photon emission computed tomography sestamibi studies

Background-The purpose of this study was to determine the prevalence and timing of routine follow-up single-photon emission computed tomography (SPECT) studies after a normal stress SPECT scan compared with the patient's warranty period (ie, time to 1% risk of death or myocardial infarction). Methods and Results-We identified patients at Mayo Clinic Rochester who had normal stress SPECT scans in 2002. Of 2354 patients without prior coronary artery disease, 309 (13%) had routine follow-up scans. The time to routine follow-up was a median of 2.1 years (25th percentile, 1.2 years; 75th percentile, 3.6 years). This interval was a median of 45% of the warranty period. Of the 309 patients, only 9 (3%) underwent subsequent coronary angiography, without revascularization. Of 656 patients with prior coronary artery disease, 171 (26%) had routine follow-up scans. The time to routine follow-up was a median of 1.6 years (25th percentile, 1.0 years; 75th percentile, 2.7 years). This interval was a median of 164% of the warranty period. Of the 171 patients, only 7 (4%) underwent coronary angiography, without revascularization. Conclusions-In patients without prior coronary artery disease, routine follow-up SPECT scans are performed infrequently but well before the end of the patient's warranty period. Routine follow-up scans are performed more commonly in patients with prior coronary artery disease but generally after the end of the warranty period. Routine follow-up SPECT scans have minimal impact on referral to catheterization or revascularization.