The Effect on Blood Cells, Known as Platelets, Using Prasugrel vs Clopidogrel in Patients With the Heart Problem Acute Coronary Syndrome (ACS)

A Randomized Double-Blind Cross-Over Study Comparing the Pharmacodynamic (PD)Response in Subjects With ACS Receiving 14 Days 10-mg Maintenance Dose (MD) Prasugrel vs 14 Days 150-mg MD Clopidogrel After Using a 900-mg Loading Dose (LD) of Clopidogrel to Reduce Ongoing Platelet Activation

Status

Completed

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00385944

Enrollment

Registered

2006-10-11

Start date

2007-03-31

Completion date

2007-10-31

Last updated

2010-09-16

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Acute Coronary Syndrome

Brief summary

This is a multicenter, randomized, double-blind, cross-over study to compare the pharmacodynamic response in subjects with Acute Coronary Syndrome receiving a 10-mg maintenance dose (MD) of prasugrel compared with a 150-mg maintenance dose of clopidogrel, following a 900-mg loading dose (LD) of clopidogrel.

Interventions

DRUGPrasugrel

Prasugrel 10-mg tablet taken orally as a daily maintenance dose for a 14-day treatment period.

DRUGClopidogrel

Clopidogrel two 75-mg tablets taken orally as a daily maintenance dose for a 14-day treatment period.

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

TREATMENT

Masking

QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

18 Years to 85 Years

Healthy volunteers

Inclusion criteria

* Present with acute coronary syndrome (ACS) and have planned treatment with a one-time 900-mg loading dose of commercially available clopidogrel (administered as a single or cumulative dose). * Are between the ages of 18 and 85 years. * Willing and able to sign informed consent.

Exclusion criteria

* Have overt ST-segment elevation myocardial infarction (STEMI). * Have cardiogenic shock. * Have refractory ventricular arrhythmias. * Have New York Heart Association (NYHA) Class IV congestive heart failure. * Have severe and uncontrolled hypertension. * Have active internal bleeding or history of bleeding diathesis. * Have an increased risk of bleeding. * Have history of cerebrovascular accidents. * Have certain abnormal blood level values. * Are currently receiving chemotherapy or radiation therapy.

Design outcomes

Primary

Measure	Time frame	Description
Maximum Platelet Aggregation (MPA) to 20 Micromolar (μM) Adenosine Diphosphate (ADP)	14 days after maintenance dose (MD)	Maximum platelet aggregation (MPA) to 20 μM adenosine diphosphate (ADP) was assessed by light transmission aggregometry (LTA).

Secondary

Measure	Time frame	Description
Mean Residual Platelet Aggregation (RPA) to 20 µM ADP	14 days after maintenance dose (MD)	Residual platelet aggregation is the percentage (%) aggregation value as measured by LTA at 6 minutes after the addition of ADP.
Mean Residual Platelet Aggregation (RPA) to 5 µM ADP	14 days after maintenance dose (MD)	Residual platelet aggregation is the percentage (%) aggregation value as measured by LTA at 6 minutes after the addition of ADP.
Inhibition Platelet Aggregation (IPA) to 20 μM ADP	14 days after maintenance dose (MD)	IPA is calculated as a percent decrease of MPA from baseline using the following formula: (\[MPA at baseline - MPA at time of postbaseline\] / MPA at baseline) x 100%
Inhibition Platelet Aggregation (IPA) to 5 μM ADP	14 days after maintenance dose (MD)	IPA is calculated as a percent decrease of MPA from baseline using the following formula: (\[MPA at baseline - MPA at time of postbaseline\] / MPA at baseline) x 100%
Inhibition of Residual Platelet Aggregation (IRPA) to 20 μM ADP	14 days after maintenance dose (MD)	IRPA is calculated as a percent decrease of RPA from baseline using the following formula: (\[RPA at baseline - RPA at time of postbaseline\] / RPA at baseline) x 100%
Inhibition of Residual Platelet Aggregation (IRPA) to 5 μM ADP	14 days after maintenance dose (MD)	IRPA is calculated as a percent decrease of RPA from baseline using the following formula: (\[RPA at baseline - RPA at time of postbaseline\] / RPA at baseline) x 100%
Platelet Reactivity Index (PRI)	14 days after maintenance dose (MD)	Platelet Reactivity Index percentage was assessed by Vasodilator-stimulated phosphoprotein (VASP). PRI percent (%) was calculated using the median fluorescence intensity (MFI) of samples included with prostaglandin E1 (PGE1) and ADP, according to the following formula: PRI%=\[(MFI(PGE1)-MFI(PGE1 + ADP)/MFI(PGE1)\]x100 Lower PRI% values indicate greater P2Y12 receptor blockade.
P2Y12 Reaction Units (PRU)	14 days after maintenance dose (MD)	P2Y12 Reaction Units (PRU) assessed by Accumetrics Verify NowTM P2Y12. PRU represents the rate and extent of adenosine (ADP)-stimulated platelet aggregation. Lower values indicate greater P2Y12 platelet inhibition.
MPA to 5 μM ADP	14 days after maintenance dose (MD)	Maximum platelet aggregation to 5 μM ADP was assessed by LTA.
Change in MPA to 20 μM ADP From Baseline to 6-18 Hrs Post Loading Dose (LD)	Baseline to 6-18 hrs post loading dose (LD)	Maximum platelet aggregation to 20 μM ADP was assessed by LTA.
Change in MPA to 20 μM ADP From 6-18 Hrs Post Loading Dose (LD) to 14 Days After the First Maintenance Dose (MD)	6-18 hrs post loading dose (LD) to 14 days after the first maintenance dose (MD)	Maximum platelet aggregation to 20 μM ADP was assessed by LTA.
MPA to 20 μM ADP at 14 Days After the First Maintenance Dose (MD)	14 days after the first maintenance dose (MD)	Maximum platelet aggregation to 20 μM ADP was assessed by LTA.
MPA to 20 μM ADP at 14 Days After the Second Maintenance Dose (MD)	14 days after the second maintenance dose (MD)	Maximum platelet aggregation to 20 μM ADP was assessed by LTA.
Number of Participants With Bleeding Events According to Thrombolysis in Myocardial Infarction Study Group (TIMI) Criteria	14 days after maintenance dose (MD)	Bleeding events will be classified as Major Bleeding, Minor Bleeding, or Insignificant Bleeding according to the TIMI criteria. Major bleeding: any intracranial hemorrhage (ICH) OR any clinically overt bleeding (including bleeding evident on imaging studies) associated with a fall in hemoglobin (Hgb) of ≥5 gm/dL from baseline. Minor Bleeding: any clinically overt bleeding associated with a fall in Hgb of ≥3 grams/deciliter (gm/dL) but \<5 gm/dL from baseline. Insignificant bleeding: any bleeding event that does not meet criteria for a Major or Minor bleed.
Number of Participants With Bleeding Events According to Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO)	14 days after maintenance dose (MD)	Bleeding events will be classified according to the GUSTO definitions as follows: Severe or Life-Threatening Bleeding: any ICH OR any bleeding event resulting in substantial hemodynamic compromise requiring treatment. Moderate Bleeding: any bleeding event resulting in the need for transfusion. Minor bleeding: any other bleeding event that does not require transfusion or cause hemodynamic compromise.
Correlation of MPA to 20 μM ADP and PRU	Baseline through 29 days of treatment	Pearson-correlation estimated between MPA to 20 μM ADP and Accumetrics VerifyNowTM P2Y12 PRU
Poor Responder of MPA to 20 μM ADP Following Maintenance Dose (MD)	14 days after maintenance dose (MD)	Poor responder is defined as MPA to 20 μM ADP \>75th percentile of the value at 6-18 hours post-clopidogrel LD.

Countries

France

Participant flow

Pre-assignment details

A total of 56 patients received a clopidogrel loading dose (LD) of 900 mg and were then randomized to receive a maintenance dose (MD) of either 10-mg prasugrel or 150-mg clopidogrel. Two patients withdrew from the study after randomization but prior to receiving a MD, one due to subject decision and one due to physician decision.

Participants by arm

Arm	Count
Prasugrel/Clopidogrel One time oral loading dose (LD) of 900-mg clopidogrel (a single or cumulative dose) followed by a once daily MD of prasugrel 10 mg and 100 mg aspirin, for 14 days. Patients cross-over to a daily MD of clopidogrel 150 mg and 100 mg aspirin for an additional 14 days.	29
Clopidogrel/Prasugrel One time oral loading dose (LD) of 900-mg clopidogrel (a single or cumulative dose) followed by a once daily MD of clopidogrel 150 mg and 100 mg aspirin, for 14 days. Patients cross-over to a daily MD of prasugrel 10 mg and 100 mg aspirin for an additional 14 days.	27
Total	56

Withdrawals & dropouts

Period	Reason	FG000	FG001
1st Maintenance Dose Period	Entry Criteria Exclusion	0	1
1st Maintenance Dose Period	Invalid Pharmacodynamic Data	3	0
1st Maintenance Dose Period	Physician Decision	1	0
2nd Maintenance Dose Period	Invalid PD Data	2	3

Baseline characteristics

Characteristic	Prasugrel/Clopidogrel	Clopidogrel/Prasugrel	Total
Age Continuous	63 years STANDARD_DEVIATION 13.7	58 years STANDARD_DEVIATION 10.7	61 years STANDARD_DEVIATION 12.4
Race/Ethnicity, Customized African	1 Participants	2 Participants	3 Participants
Race/Ethnicity, Customized Caucasian	28 Participants	25 Participants	53 Participants
Region of Enrollment France	29 participants	27 participants	56 participants
Sex: Female, Male Female	3 Participants	6 Participants	9 Participants
Sex: Female, Male Male	26 Participants	21 Participants	47 Participants

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk	EG002 affected / at risk	EG003 affected / at risk	EG004 affected / at risk
deaths Total, all-cause mortality	— / —	— / —	— / —	— / —	— / —
other Total, other adverse events	20 / 56	7 / 29	7 / 25	3 / 24	2 / 22
serious Total, serious adverse events	1 / 56	3 / 29	0 / 25	1 / 24	1 / 22

Outcome results

Primary

Maximum Platelet Aggregation (MPA) to 20 Micromolar (μM) Adenosine Diphosphate (ADP)

Maximum platelet aggregation (MPA) to 20 μM adenosine diphosphate (ADP) was assessed by light transmission aggregometry (LTA).

Time frame: 14 days after maintenance dose (MD)

Population: The primary analysis was performed on the intent-to-treat (ITT) population, that is, all randomized subjects with a maintenance dose MPA measured for at least one of the treatments.

Arm	Measure	Value (MEAN)	Dispersion
Prasugrel	Maximum Platelet Aggregation (MPA) to 20 Micromolar (μM) Adenosine Diphosphate (ADP)	27.1 Percentage aggregation	Standard Deviation 10.55
Clopidogrel	Maximum Platelet Aggregation (MPA) to 20 Micromolar (μM) Adenosine Diphosphate (ADP)	40.3 Percentage aggregation	Standard Deviation 14.96

p-value: <0.00195% CI: [-17.02, -8.81]Mixed Models Analysis

Secondary

Change in MPA to 20 μM ADP From 6-18 Hrs Post Loading Dose (LD) to 14 Days After the First Maintenance Dose (MD)

Maximum platelet aggregation to 20 μM ADP was assessed by LTA.

Time frame: 6-18 hrs post loading dose (LD) to 14 days after the first maintenance dose (MD)

Arm	Measure	Value (MEAN)	Dispersion
Prasugrel	Change in MPA to 20 μM ADP From 6-18 Hrs Post Loading Dose (LD) to 14 Days After the First Maintenance Dose (MD)	-9 Percentage aggregation	Standard Deviation 15.71
Clopidogrel	Change in MPA to 20 μM ADP From 6-18 Hrs Post Loading Dose (LD) to 14 Days After the First Maintenance Dose (MD)	-0.6 Percentage aggregation	Standard Deviation 12.56

Comparison: Paired t-test for each arm separatelyp-value: 0.011two-sided paired t-test

Comparison: Paired t-test for each arm separatelyp-value: 0.847two-sided paired t-test

Secondary

Change in MPA to 20 μM ADP From Baseline to 6-18 Hrs Post Loading Dose (LD)

Maximum platelet aggregation to 20 μM ADP was assessed by LTA.

Time frame: Baseline to 6-18 hrs post loading dose (LD)

Population: Note: This was calculated only for subjects with a true clopidogrel-free measure at baseline (Visit 1)

Arm	Measure	Value (MEAN)	Dispersion
Prasugrel	Change in MPA to 20 μM ADP From Baseline to 6-18 Hrs Post Loading Dose (LD)	-35.5 Percentage aggregation	Standard Deviation 17.5

p-value: <0.001two-sided paired t-test

Secondary

Correlation of MPA to 20 μM ADP and PRU

Pearson-correlation estimated between MPA to 20 μM ADP and Accumetrics VerifyNowTM P2Y12 PRU

Time frame: Baseline through 29 days of treatment

Arm	Measure	Value (NUMBER)
Prasugrel	Correlation of MPA to 20 μM ADP and PRU	0.8 Correlation coefficient

Secondary

Inhibition of Residual Platelet Aggregation (IRPA) to 20 μM ADP

IRPA is calculated as a percent decrease of RPA from baseline using the following formula: (\[RPA at baseline - RPA at time of postbaseline\] / RPA at baseline) x 100%

Time frame: 14 days after maintenance dose (MD)

Population: Note: This was calculated only for subjects with a true clopidogrel-free measure at baseline (Visit 1)

Arm	Measure	Value (MEAN)	Dispersion
Prasugrel	Inhibition of Residual Platelet Aggregation (IRPA) to 20 μM ADP	87.1 Percentage inhibition	Standard Deviation 15.26
Clopidogrel	Inhibition of Residual Platelet Aggregation (IRPA) to 20 μM ADP	75.9 Percentage inhibition	Standard Deviation 25.99

p-value: 0.01595% CI: [2.17, 18.34]Mixed Models Analysis

Secondary

Inhibition of Residual Platelet Aggregation (IRPA) to 5 μM ADP

IRPA is calculated as a percent decrease of RPA from baseline using the following formula: (\[RPA at baseline - RPA at time of postbaseline\] / RPA at baseline) x 100%

Time frame: 14 days after maintenance dose (MD)

Population: Note: This was calculated only for subjects with a true clopidogrel-free measure at baseline (Visit 1)

Arm	Measure	Value (MEAN)	Dispersion
Prasugrel	Inhibition of Residual Platelet Aggregation (IRPA) to 5 μM ADP	95.6 Percentage inhibition	Standard Deviation 6.5
Clopidogrel	Inhibition of Residual Platelet Aggregation (IRPA) to 5 μM ADP	91.4 Percentage inhibition	Standard Deviation 15.18

p-value: 0.12395% CI: [-1.13, 8.84]Mixed Models Analysis

Secondary

Inhibition Platelet Aggregation (IPA) to 20 μM ADP

IPA is calculated as a percent decrease of MPA from baseline using the following formula: (\[MPA at baseline - MPA at time of postbaseline\] / MPA at baseline) x 100%

Time frame: 14 days after maintenance dose (MD)

Population: Note: This was calculated only for subjects with a true clopidogrel-free measure at baseline (Visit 1)

Arm	Measure	Value (MEAN)	Dispersion
Prasugrel	Inhibition Platelet Aggregation (IPA) to 20 μM ADP	64.2 Percentage inhibition	Standard Deviation 14.39
Clopidogrel	Inhibition Platelet Aggregation (IPA) to 20 μM ADP	48.5 Percentage inhibition	Standard Deviation 18.58

p-value: <0.00195% CI: [7.05, 23.26]Mixed Models Analysis

Secondary

Inhibition Platelet Aggregation (IPA) to 5 μM ADP

IPA is calculated as a percent decrease of MPA from baseline using the following formula: (\[MPA at baseline - MPA at time of postbaseline\] / MPA at baseline) x 100%

Time frame: 14 days after maintenance dose (MD)

Population: Note: This was calculated only for subjects with a true clopidogrel-free measure at baseline (Visit 1)

Arm	Measure	Value (MEAN)	Dispersion
Prasugrel	Inhibition Platelet Aggregation (IPA) to 5 μM ADP	72.4 Percentage inhibition	Standard Deviation 12.76
Clopidogrel	Inhibition Platelet Aggregation (IPA) to 5 μM ADP	58.8 Percentage inhibition	Standard Deviation 17.33

p-value: 0.00195% CI: [5.56, 19.81]Mixed Models Analysis

Secondary

Mean Residual Platelet Aggregation (RPA) to 20 µM ADP

Residual platelet aggregation is the percentage (%) aggregation value as measured by LTA at 6 minutes after the addition of ADP.

Time frame: 14 days after maintenance dose (MD)

Arm	Measure	Value (MEAN)	Dispersion
Prasugrel	Mean Residual Platelet Aggregation (RPA) to 20 µM ADP	9.4 Percentage aggregation	Standard Deviation 11.43
Clopidogrel	Mean Residual Platelet Aggregation (RPA) to 20 µM ADP	21.6 Percentage aggregation	Standard Deviation 21.54

p-value: <0.00195% CI: [-17.06, -6.9]Mixed Models Analysis

Secondary

Mean Residual Platelet Aggregation (RPA) to 5 µM ADP

Residual platelet aggregation is the percentage (%) aggregation value as measured by LTA at 6 minutes after the addition of ADP.

Time frame: 14 days after maintenance dose (MD)

Arm	Measure	Value (MEAN)	Dispersion
Prasugrel	Mean Residual Platelet Aggregation (RPA) to 5 µM ADP	2.7 Percentage aggregation	Standard Deviation 5.26
Clopidogrel	Mean Residual Platelet Aggregation (RPA) to 5 µM ADP	7.1 Percentage aggregation	Standard Deviation 10.64

p-value: 0.00195% CI: [-6.84, -1.76]Mixed Models Analysis

Secondary

MPA to 20 μM ADP at 14 Days After the First Maintenance Dose (MD)

Maximum platelet aggregation to 20 μM ADP was assessed by LTA.

Time frame: 14 days after the first maintenance dose (MD)

Population: Subjects providing evaluable MPA to 20 μM ADP at 14 days after the first maintenance dose (MD)

Arm	Measure	Value (MEAN)	Dispersion
Prasugrel	MPA to 20 μM ADP at 14 Days After the First Maintenance Dose (MD)	28.9 Percentage aggregation	Standard Deviation 11.14
Clopidogrel	MPA to 20 μM ADP at 14 Days After the First Maintenance Dose (MD)	38.2 Percentage aggregation	Standard Deviation 12.86

p-value: 0.00895% CI: [-15.99, -2.49]t-test, 2 sided

Secondary

MPA to 20 μM ADP at 14 Days After the Second Maintenance Dose (MD)

Maximum platelet aggregation to 20 μM ADP was assessed by LTA.

Time frame: 14 days after the second maintenance dose (MD)

Population: Subjects providing evaluable MPA to 20 μM ADP at Day 29.

Arm	Measure	Value (MEAN)	Dispersion
Prasugrel	MPA to 20 μM ADP at 14 Days After the Second Maintenance Dose (MD)	42.5 Percentage aggregation	Standard Deviation 16.89
Clopidogrel	MPA to 20 μM ADP at 14 Days After the Second Maintenance Dose (MD)	25 Percentage aggregation	Standard Deviation 9.58

p-value: <0.00195% CI: [9.22, 25.83]t-test, 2 sided

Secondary

MPA to 5 μM ADP

Maximum platelet aggregation to 5 μM ADP was assessed by LTA.

Time frame: 14 days after maintenance dose (MD)

Arm	Measure	Value (MEAN)	Dispersion
Prasugrel	MPA to 5 μM ADP	16.9 Percentage aggregation	Standard Deviation 8.3
Clopidogrel	MPA to 5 μM ADP	25.0 Percentage aggregation	Standard Deviation 11.09

p-value: <0.00195% CI: [-10.96, -4.65]Mixed Models Analysis

Secondary

Number of Participants With Bleeding Events According to Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO)

Bleeding events will be classified according to the GUSTO definitions as follows: Severe or Life-Threatening Bleeding: any ICH OR any bleeding event resulting in substantial hemodynamic compromise requiring treatment. Moderate Bleeding: any bleeding event resulting in the need for transfusion. Minor bleeding: any other bleeding event that does not require transfusion or cause hemodynamic compromise.

Time frame: 14 days after maintenance dose (MD)

Arm	Measure	Group	Value (NUMBER)
Prasugrel	Number of Participants With Bleeding Events According to Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO)	Severe or life-threatening	0 Participants
Prasugrel	Number of Participants With Bleeding Events According to Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO)	Moderate	0 Participants
Prasugrel	Number of Participants With Bleeding Events According to Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO)	Minor	3 Participants
Clopidogrel	Number of Participants With Bleeding Events According to Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO)	Severe or life-threatening	0 Participants
Clopidogrel	Number of Participants With Bleeding Events According to Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO)	Moderate	0 Participants
Clopidogrel	Number of Participants With Bleeding Events According to Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO)	Minor	2 Participants

Secondary

Number of Participants With Bleeding Events According to Thrombolysis in Myocardial Infarction Study Group (TIMI) Criteria

Bleeding events will be classified as Major Bleeding, Minor Bleeding, or Insignificant Bleeding according to the TIMI criteria. Major bleeding: any intracranial hemorrhage (ICH) OR any clinically overt bleeding (including bleeding evident on imaging studies) associated with a fall in hemoglobin (Hgb) of ≥5 gm/dL from baseline. Minor Bleeding: any clinically overt bleeding associated with a fall in Hgb of ≥3 grams/deciliter (gm/dL) but \<5 gm/dL from baseline. Insignificant bleeding: any bleeding event that does not meet criteria for a Major or Minor bleed.

Time frame: 14 days after maintenance dose (MD)

Arm	Measure	Group	Value (NUMBER)
Prasugrel	Number of Participants With Bleeding Events According to Thrombolysis in Myocardial Infarction Study Group (TIMI) Criteria	Major	0 Participants
Prasugrel	Number of Participants With Bleeding Events According to Thrombolysis in Myocardial Infarction Study Group (TIMI) Criteria	Minor	0 Participants
Prasugrel	Number of Participants With Bleeding Events According to Thrombolysis in Myocardial Infarction Study Group (TIMI) Criteria	Insignificant	3 Participants
Clopidogrel	Number of Participants With Bleeding Events According to Thrombolysis in Myocardial Infarction Study Group (TIMI) Criteria	Major	0 Participants
Clopidogrel	Number of Participants With Bleeding Events According to Thrombolysis in Myocardial Infarction Study Group (TIMI) Criteria	Minor	1 Participants
Clopidogrel	Number of Participants With Bleeding Events According to Thrombolysis in Myocardial Infarction Study Group (TIMI) Criteria	Insignificant	1 Participants

Secondary

P2Y12 Reaction Units (PRU)

P2Y12 Reaction Units (PRU) assessed by Accumetrics Verify NowTM P2Y12. PRU represents the rate and extent of adenosine (ADP)-stimulated platelet aggregation. Lower values indicate greater P2Y12 platelet inhibition.

Time frame: 14 days after maintenance dose (MD)

Arm	Measure	Value (MEAN)	Dispersion
Prasugrel	P2Y12 Reaction Units (PRU)	44 PRU	Standard Deviation 38.59
Clopidogrel	P2Y12 Reaction Units (PRU)	98.7 PRU	Standard Deviation 63.69

p-value: <0.00195% CI: [-70.87, -38.01]Mixed Models Analysis

Secondary

Platelet Reactivity Index (PRI)

Platelet Reactivity Index percentage was assessed by Vasodilator-stimulated phosphoprotein (VASP). PRI percent (%) was calculated using the median fluorescence intensity (MFI) of samples included with prostaglandin E1 (PGE1) and ADP, according to the following formula: PRI%=\[(MFI(PGE1)-MFI(PGE1 + ADP)/MFI(PGE1)\]x100 Lower PRI% values indicate greater P2Y12 receptor blockade.

Time frame: 14 days after maintenance dose (MD)

Arm	Measure	Value (MEAN)	Dispersion
Prasugrel	Platelet Reactivity Index (PRI)	22.1 Percentage PRI	Standard Deviation 14.33
Clopidogrel	Platelet Reactivity Index (PRI)	39.4 Percentage PRI	Standard Deviation 21.05

p-value: <0.00195% CI: [-23.05, -10.62]Mixed Models Analysis

Secondary

Poor Responder of MPA to 20 μM ADP Following Maintenance Dose (MD)

Poor responder is defined as MPA to 20 μM ADP \>75th percentile of the value at 6-18 hours post-clopidogrel LD.

Time frame: 14 days after maintenance dose (MD)

Arm	Measure	Group	Value (NUMBER)
Prasugrel	Poor Responder of MPA to 20 μM ADP Following Maintenance Dose (MD)	Responder	48 Participants
Prasugrel	Poor Responder of MPA to 20 μM ADP Following Maintenance Dose (MD)	Poor Responder	1 Participants
Clopidogrel	Poor Responder of MPA to 20 μM ADP Following Maintenance Dose (MD)	Responder	35 Participants
Clopidogrel	Poor Responder of MPA to 20 μM ADP Following Maintenance Dose (MD)	Poor Responder	12 Participants

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026

The Effect on Blood Cells, Known as Platelets, Using Prasugrel vs Clopidogrel in Patients With the Heart Problem Acute Coronary Syndrome (ACS)

Conditions

Brief summary

Related papers

Interventions

Sponsors

Study design

Eligibility

Inclusion criteria

Exclusion criteria

Design outcomes

Primary

Secondary

Countries

Participant flow

Pre-assignment details

Participants by arm

Withdrawals & dropouts

Baseline characteristics

Adverse events

Outcome results

Maximum Platelet Aggregation (MPA) to 20 Micromolar (μM) Adenosine Diphosphate (ADP)

Change in MPA to 20 μM ADP From 6-18 Hrs Post Loading Dose (LD) to 14 Days After the First Maintenance Dose (MD)

Change in MPA to 20 μM ADP From Baseline to 6-18 Hrs Post Loading Dose (LD)

Correlation of MPA to 20 μM ADP and PRU

Inhibition of Residual Platelet Aggregation (IRPA) to 20 μM ADP

Inhibition of Residual Platelet Aggregation (IRPA) to 5 μM ADP

Inhibition Platelet Aggregation (IPA) to 20 μM ADP

Inhibition Platelet Aggregation (IPA) to 5 μM ADP

Mean Residual Platelet Aggregation (RPA) to 20 µM ADP

Mean Residual Platelet Aggregation (RPA) to 5 µM ADP

MPA to 20 μM ADP at 14 Days After the First Maintenance Dose (MD)

MPA to 20 μM ADP at 14 Days After the Second Maintenance Dose (MD)

MPA to 5 μM ADP

Number of Participants With Bleeding Events According to Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO)

Number of Participants With Bleeding Events According to Thrombolysis in Myocardial Infarction Study Group (TIMI) Criteria

P2Y12 Reaction Units (PRU)

Platelet Reactivity Index (PRI)

Poor Responder of MPA to 20 μM ADP Following Maintenance Dose (MD)