1. Age 18-80 years 
2. Patients with at least 1 ≥50% stenosis in a coronary vessel, subjected to FFR assessment, who exhibit variation in Pd / Pa ratio ≥ 0.05 (e.g. difference of max Pd/Pa minus min Pd/Pa) during steady state hyperaemia (determined by visual assessment). 
3. Written informed consent 

NCT02350439_inc_T4
Person
Age
NCT02350439_inc_T5
Value
18-80 years
NCT02350439_inc_T6
Multiplier
at least 1
NCT02350439_inc_T7
Value
≥50%
NCT02350439_inc_T8
Measurement
stenosis in a coronary vessel
NCT02350439_inc_T9
Procedure
FFR assessment
NCT02350439_inc_T10
Measurement
Pd / Pa ratio
NCT02350439_inc_T11
Value
≥ 0.05
NCT02350439_inc_T12
Measurement
max Pd/Pa
NCT02350439_inc_T13
Measurement
min Pd/Pa
NCT02350439_inc_T14
Condition
hyperaemia
NCT02350439_inc_T15
Qualifier
steady state
NCT02350439_inc_T16
Procedure
visual assessment
NCT02350439_inc_T17
Scope
(e.g. difference of max Pd/Pa minus min Pd/Pa)
NCT02350439_inc_T18
Condition
variation in Pd / Pa ratio