The concept of warranty period, the duration of time during which the patient's risk remains low, is appealing. However, some points remain to be resolved before its translation in the clinical arena. Methodological issues should be standardized in order to compare the results of studies in different patient populations. Also, the definition of a "normal" study should always take into consideration the history of prior revascularization, the achieved level of exercise, and the stressor used. The promise of warranty can be questioned by the patient's baseline demographic and clinical characteristics and may also be influenced by life-style modification in the course of the follow-up. The "warranty period" concept should shift from data reflecting the time to a cardiac event to the development of ischemia, given an opportunity for intervention before a cardiac event occurs. In this context, clarify the role of serial imaging can be extremely useful, in particular to evaluate if and when retesting a patient after a normal scan.
Keywords: Myocardial perfusion imaging; SPECT; gated SPECT; ischemia; myocardial; outcomes research.