Pd/Pa and FFR: is there a relationship? - Mamas Mamas

1. Pd/Pa and FFR: is there a relationship?
Mamas Mamas
Professor of Cardiology
Keele Cardiovascular Research Group
Keele University, UK

2. Disclosure
I have no conflict of interest to declare

4. Reclassification of Management strategy
OMT by angiography
PCI by angiography

5. Introduction
• Despite large body of evidence & best practice guidelines
around use of FFR, adoption has not been universal
• Pharmacological infusion with adenosine to minimise distal
bed coronary resistance:
– Time consuming particular MVD
– Associated with significant symptomatology in patients
– Transient AV block in the elderly
– Expense / availability in some countries
• Increasing interest in resting indices

6. J Invasive Cardiol. 2010;22(6):260-5
• Previously believed poor correlation between resting Pd/Pa
and FFR obtained during maximal hyperaemia with
pharmacological stress.
• Aim of this study were to:
• Define relationship between resting Pd/Pa and FFR
• Determine whether resting Pd/Pa values are predictive
of a positive or negative FFR result.

7. Resting Pd/Pa
%Pressurewirecases

8. Graph illustrating relationship between
initial resting Pd/Pa & FFR
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0.7 0.8 0.9 1
FFR
Pd/Pa
Correlation coefficient 0.73 (P<0.0001)

9. ≤ 0.87
PPV=94.6
≥ 0.96
NPV=
93%
60
70
80
90
100
0.73 0.78 0.83 0.88 0.93 0.98
0
20
40
60
80
100
0.73 0.78 0.83 0.88 0.93 0.98
POSITIVE PREDICTIVE VALUE NEGATIVE PREDICTIVE VALUE

10. Hybrid Strategy
0
10
20
30
40
50
60
<0.87 0.88-0.95 >0.96
Pd/Pa
%Pressurewirecases ≤ 0.87
Pd/Pa
0.88-95
FFR
≥ 0.96
Pd/Pa
7% 53% 40%

12. Excellent Reproducibility
Johnson et al. JACC Cardiovasc Interv. 2016 Apr 25;9(8):757-767
763 subjects were enrolled from 12 international centers

13. • ADVISE, VERIFY, Johnson et al and 6 other study sites
• 1593 lesions
• Core laboratory to analyse IFR, Pd/Pa and study their utility
compared to FFR

14. Diagnostic accuracy vs grey zone
IFR or
Pd/Pa
TREAT
IFR or
Pd/Pa
DEFER
GRAYZONE

15. 763 PTS, 12 CENTRES
PROSPECTIVE

16. Using Binary cutoff 0.92 Using hybrid approach <0.87 Pd/Pa >0.94

17. Prospectve Study: 763 patients, 12 institutions
Diagnostic accuracy
LMS / Prox LAD
Other vessel
AUC 0.81
AUC 0.90

18. Summary
Johnson JACC Intv 2016