Table 1.

Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) “cut-off” and “hybrid” strategy.

Treatment decision	FFR only	iFR only	iFR hybrid
Revascularize	≤0.8	≤0.89	<0.86
Gray zone	NA	NA	0.86–0.93 (proceed to FFR)
Defer treatment	>0.8	>0.89	>0.93