Table 1.

General interpretation and classification of risk in relation to global MBFR

MBFR	Interpretation	Relative risk
>2	Normal	Low
1.7-2	Mildly abnormal	Intermediate
1.2—< 1.7	Abnormal	High
<1.2 with a perfusion defect	Highly abnormal	Very high
<1.2 without a perfusion defect	Consider non-diagnostic study	Indeterminate

Cutoffs are generally arbitrary and may vary slightly between labs, software used, stressors used, and published studies. The principle is that the lower the flow reserve the greater the relative risk