1. Individualizing Treatment Duration of Dual Antiplatelet Therapy after Percutaneous Coronary Intervention: An Analysis from the DAPT Study
Robert W. Yeh, Eric A. Secemsky, Dean J. Kereiakes, Sharon-Lise T. Normand, Anthony H. Gershlick, David J. Cohen, John A. Spertus, P. Gabriel Steg, Donald E. Cutlip, Michael J. Rinaldi, Edoardo Camenzind, William Wijns, Patricia K. Apruzzese, Yang Song, Joseph M. Massaro, and Laura Mauri, for the Dual Antiplatelet Therapy (DAPT) Study Investigators

2. Disclosures
Funding The DAPT Study was sponsored by Harvard Clinical Research Institute, and funded by Abbott, Boston Scientific Corporation, Cordis Corporation, Medtronic, Inc., Bristol-Myers Squibb Company/Sanofi Pharmaceuticals Partnership, Eli Lilly and Company, and Daiichi Sankyo Company Limited and the US Department of Health and Human Services (1RO1FD ). This analysis was supported by the National Heart, Lung and Blood Institute (K23HL118138) and Harvard Clinical Research Institute. Disclosures Personal fees from Abbott Vascular, Boston Scientific, and Merck.

3. Risk Difference (Continued Thienopyridine – Placebo), 12-30M
Background
In the DAPT Study, continuation of dual antiplatelet therapy beyond 12 months reduced ischemic complications after coronary stenting compared with aspirin alone, yet increased moderate or severe bleeding.
Risk Difference (Continued Thienopyridine – Placebo), 12-30M
Stent
Thrombosis
Death, MI,
Or Stroke
(MACCE)
Myocardial
Infarction
GUSTO
Mod/Severe
Bleed
Death
HR 0.47 (0.37–0.61)
P<0.001
HR 0.71 (0.59–0.85)
P<0.001
Mauri, Kereiakes, Yeh et al. NEJM Dec 4:371:

4. Objective
To develop a decision tool to identify whether an individual patient is more likely to derive benefit or harm from continuation of dual antiplatelet therapy beyond 1 year.
Simultaneously accounting for risks of ischemia AND bleeding with continued therapy.

5. Design
Inclusion: FDA-approved DES or BMS, candidates for thienopyridine
Excluded: Oral anticoagulant therapy; life expectancy < 3y
Randomized: Free from MI, stroke, repeat revascularization, moderate/severe bleeding, and adherent with therapy at 12 months
Mauri, Kereiakes et al. AHJ. 2010;160(6): ClinicalTrials.gov number NCT 5 5 5

6. Methods – Models to Predict Ischemic and Bleeding Events
Development of 2 Prediction Models within the randomized DAPT Study population (N=11648).
Ischemic Model: Myocardial infarction or stent thrombosis between months after index PCI. Includes fatal events.
Bleeding Model: GUSTO moderate or severe bleeding between months after index PCI. Includes fatal events.
Cox regression, stepwise selection among 37 candidate variables, including randomized treatment arm. In addition, several interaction terms with treatment arm evaluated. P value of 0.05 for retention.
Validated externally within the PROTECT trial population*
*Camenzind, Wijns, Mauri et al. Lancet. 380;9851:

7. Methods – Predicting Net Treatment Effect
Predicted Ischemic Event Rate with Placebo
Predicted Ischemic Event Rate with Rx
Predicted Bleeding Event Rate with Rx
Predicted Bleeding Event Rate with Placebo
Predicted Risk Reduction in Ischemic Events
(Beneficial Effect)
Predicted Risk Increase in Bleeding Events
(Harmful Effect)
Predicted Net Treatment Effect
(Range from Negative to Positive)
Predictors of net treatment effect with continued thienopyridine determined from linear regression and simplified to an integer point score (DAPT Score)
Actual outcomes presented by randomized treatment arm stratified by DAPT Score. Sensitivity analysis without paclitaxel-eluting stent-treated subjects.

8. Baseline Characteristics; All Randomized Patients With vs
Baseline Characteristics; All Randomized Patients With vs. Without Ischemic or Bleeding Events
Myocardial Infarction or Stent Thrombosis Events
GUSTO Severe/Moderate Events
Measure*
MI or Stent Thrombosis
N=348
No MI or Stent Thrombosis
N=11300 P
Bleeding
N=215
No Bleeding N=11433
Age (years)
61.7
61.3
0.47
66.4
61.2
<.001
Female
26.4%
25.1%
0.57
29.3%
25.0%
0.15
BMI (Kg/m2)
30.1
30.4
0.28
29.5
0.01
Diabetes mellitus
39.9%
28.9%
31.3%
29.2%
0.50
Hypertension
81.0%
73.1%
84.2%
73.2%
Cigarette smoker
33.0%
27.2%
0.02
18.2%
27.6%
0.002
Congestive heart failure
10.4%
4.3%
8.0%
4.5%
LVEF < 30%
4.6%
1.9%
3.1%
Prior PCI
42.4%
28.6%
37.7%
Prior CABG
17.5%
10.5%
14.4%
10.7%
0.09
Prior myocardial infarction
32.7%
21.1%
22.2%
21.4%
0.80
Indication for index procedure
STEMI
1.00
10.2%
14.5%
0.08
NSTEMI
22.1%
16.1%
0.004
12.1%
16.4%
0.11
Renal insufficiency/failure
7.9%
3.9%
0.001
9.4%
Peripheral arterial disease
10.9%
5.5%
14.3%
Continued thienopyridine
35.3%
50.8%
 < 0.001
62.8%
50.1%
< 0.001 

9. Multivariable Prediction Models
Predictors of Myocardial Infarction or Stent Thrombosis
Predictors of Moderate/Severe Bleeding
Predictors of Events
HR (95% CI) P
Continued Thienopyridine vs. Placebo
0.52 (0.42 – 0.65)
<0.001
1.66 ( )
MI at Presentation
1.65 (1.31 – 2.07) -
Prior PCI or Prior MI
1.79 (1.43 – 2.23)
CHF or LVEF < 30%
1.88 (1.35 – 2.62)
Vein Graft PCI
1.75 (1.13 – 2.73)
0.01
Stent Diameter < 3 mm
1.61 (1.30 – 1.99)
Paclitaxel-Eluting Stent
1.57 (1.26 – 1.97)
Cigarette Smoker
1.40 (1.11 – 1.76)
Diabetes
1.38 (1.10 – 1.72)
Peripheral Arterial Disease
1.49 (1.05 – 2.13)
0.03
2.16 (1.46, 3.20)
Hypertension
1.37 (1.03 – 1.82)
1.45 (1.00, 2.11)
0.05
Renal Insufficiency
1.55 (1.03 – 2.32)
0.04
1.66 (1.04, 2.66)
Age (per 10 years)
1.54 (1.34, 1.78)
*The ischemia model C-statistic: 0.70 in DAPT Study; 0.64 in PROTECT
**The bleeding model C-statistic: 0.68 in DAPT Study; 0.64 in PROTECT

10. Predictors of Net Treatment Effect
Characteristics
Impact on Net Treatment Effect
% of Variation Explained
Age ≥ 75
Age 65 - < 75
Age < (reference)
-1.2%
-0.5% -
6.0%
2.1%
Prior PCI or MI
1.1%
14.6%
Stent Diameter < 3 mm
0.9%
10.1%
CHF or LVEF < 30%
1.9%
9.9%
MI at Presentation
1.0%
9.6%
Paclitaxel-Eluting Stent
8.8%
Cigarette Smoker
0.7%
4.3%
Diabetes
0.6%
Vein Graft PCI
1.6%
3.7%
Hypertension
0.2%
0.4%
Renal Insufficiency
0.3%
PAD
-0.1%
0.04%
Bleeding
Predictors
Ischemia
Predictors
Bleeding
and
Ischemia
Predictors

11. The DAPT Score Variable Points Patient Characteristic Age ≥ 75 -2
65 - <75 -1
< 65
Diabetes Mellitus 1
Current Cigarette Smoker
Prior PCI or Prior MI
CHF or LVEF < 30% 2
Index Procedure Characteristic
MI at Presentation
Vein Graft PCI
Stent Diameter < 3mm
Distribution of DAPT Scores among all
randomized subjects in the DAPT Study

12. Risk Difference (Continued Thienopyridine – Placebo), 12-30M
Continued Thienopyridine vs. Placebo Treatment Effect by DAPT Score Quartile (N = 11,648)
Q1 = DAPT Score -2 to 0
Q3 = DAPT Score 2
Q2 = DAPT Score 1
Q4 = DAPT Score > 2
Risk Difference (Continued Thienopyridine – Placebo), 12-30M
Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4

13. Risk Difference (Continued Thienopyridine – Placebo), 12-30M
Continued Thienopyridine vs. Placebo Treatment Effect by DAPT Score Quartile (N = 11,648)
Risk Difference (Continued Thienopyridine – Placebo), 12-30M
Mortality
Net Adverse
Events
Q Q Q Q4
Q Q Q Q4
DAPT Score
< 2
DAPT Score
≥ 2
DAPT Score
< 2
DAPT Score
≥ 2 13 13

14. Continued Thienopyridine vs. Placebo DAPT Score <2 (Low); N=5731
Myocardial Infarction or Stent Thrombosis
Death, MI, or Stroke (MACCE)
10%
Continued Thienopyridine Placebo
10%
Continued Thienopyridine Placebo 8% 8% 6% 6%
Cumulative Incidence of ST/MI
Cumulative Incidence of MACCE 4%
1.7% vs. 2.3%
P=0.07 4%
3.7% vs. 3.8%
P=0.73 2% 2% 0% 0% 12 15 18 21 24 27 30 12 15 18 21 24 27 30
Months After Enrollment
Months After Enrollment
10%
Continued Thienopyridine Placebo 8%
GUSTO
Moderate/
Severe
Bleeding 6%
Cumulative Incidence of GUSTO Moderate/
Severe Bleed 4%
3.0% vs. 1.4%
P<0.001 2% 0% 12 15 18 21 24 27 30
Months After Enrollment

15. Continued Thienopyridine vs. Placebo DAPT Score ≥ 2 (High); N=5917
Myocardial Infarction or Stent Thrombosis
Death, MI or Stroke (MACCE)
10%
Continued Thienopyridine Placebo
10%
Continued Thienopyridine Placebo 8% 8% 6% 6%
4.9% vs. 7.6%
P<0.001
Cumulative Incidence of ST/MI
2.7% vs. 5.7%
P<0.001
Cumulative Incidence of MACCE 4% 4% 2% 2% 0% 0% 12 15 18 21 24 27 30 12 15 18 21 24 27 30
Months After Enrollment
Months After Enrollment
10%
Continued Thienopyridine Placebo 8%
GUSTO
Moderate/
Severe
Bleeding 6%
Cumulative Incidence of GUSTO Moderate/
Severe Bleed
1.8% vs. 1.4%
P=0.26 4% 2% 0% 12 15 18 21 24 27 30
Months After Enrollment

16. Continued Thienopyridine vs. Placebo High vs. Low DAPT Score
Myocardial Infarction
or Stent Thrombosis
GUSTO Moderate
or Severe Bleed
Net Adverse
Events
Mortality
(Continued Thienopyridine – Placebo), 12-30M
Risk Difference
P<0.001
P=0.02
P<0.001
P=0.14
P values are for comparison of risk differences across DAPT Score category (interaction).

17. Continued Thienopyridine vs. Placebo, by DAPT Score, Excluding PES
Myocardial Infarction
or Stent Thrombosis
GUSTO Moderate
or Severe Bleed
Net Adverse
Events
Mortality
(Continued Thienopyridine – Placebo), 12-30M
Risk Difference
P=0.06
P=0.07
P=0.003
P=0.17
P values are for comparison of risk differences across DAPT Score category (interaction).

18. Limitations Modest discrimination of ischemic and bleeding models
Greater than values observed in many validation cohorts for the CH2AD2-VASC or HAS-BLED Scores*
In PROTECT, high DAPT score patients had higher ischemic risk (HR 2.01, p = 0.002) AND trend toward lower bleeding risk (HR , p = 0.31), compared with low DAPT score patients
Post hoc analysis, not powered to examine differences in individual outcomes between subgroups
Limited ability to identify rare or unmeasured predictors of events
Models not evaluated in patients receiving ticagrelor or other antiplatelet combinations
*Lip et al. Chest. 2010;137(2):
Lip et al. JACC 2011:57(2):

19. Conclusions DAPT Score may help clinicians decide who should,
Among patients who have not had a major ischemic or bleeding event within the first year after PCI:
The DAPT Score identified patients for whom ischemic benefits outweighed bleeding risks, and patients for whom bleeding risks outweighed ischemic benefits.
Low DAPT Score (< 2)
NNT to prevent ischemia = 153
NNH to cause bleeding = 64
High DAPT Score ≥ 2
NNT to prevent ischemia = 34
NNH to cause bleeding = 272 -2 10
DAPT Score may help clinicians decide who should,
and who should not be treated with extended DAPT

20. DAPT Score Calculator
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