Background:
Patients with a normal stress technetium 99m sestamibi study were shown to have a favorable outcome at intermediate-term follow-up. however, long-term survival has not been studied. the aim of this study was to evaluate the incidence and predictors of mortality and cardiac events at long-term follow-up after a normal exercise stress sestamibi study. methods and results we studied 218 patients (mean age, 53 +/- 10 years, 108 men) who had normal myocardial perfusion assessed by tc-99m sestamibi single photon emission computed tomography at rest and during symptom-limited bicycle exercise stress test. endpoints during a follow-up period of 7.4 +/- 1.8 years were hard cardiac events (cardiac death and nonfatal myocardial infarction) and all-cause mortality. during follow-up, 13 patients died of various causes (cardiac death in 1 patient). ten patients had nonfatal myocardial infarction (a total of 11 hard cardiac events). by multivariate analysis, independent predictors of cardiac events were history of coronary artery disease (chi(2) = 5, p =.03) and lower exercise heart rate (chi(2) = 12, p =.001). independent predictors of all-cause mortality were age (chi(2) = 4, p =.05) and exercise heart rate (chi(2) = 5, p =.03). the annual mortality rate was 0.6% in the first 5 years and 1.8% between the sixth and eighth years. the annual hard cardiac event rate was 0.7% in the first 5 years and 1.5% between the sixth and eighth years. receiver operating characteristic curves identified an exercise heart rate lower than 130 beats/min as the cutoff value that separated patients with regard to their risk for mortality and hard cardiac events.
Conclusions:
It is concluded that the annual mortality and cardiac event rate is less than 1% during 5-year follow-up after a normal exercise sestamibi study. therefore repeated testing would not be required unless there is a change in symptoms. follow-up should be closer in patients with a history of coronary artery disease and in those who fail to achieve an exercise heart rate of 130 beats/min or greater.