We are experiencing 4 week turn-around time in review of submissions and resubmissions. We recommend commencing this process concurrently with your ethics submission and allowing at least 8 weeks for registration to be completed from date of first submission. We currently do not have the capacity to expedite reviews.

Note also there are delays to review of updates. We appreciate your patience.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Plavix response in coronary intervention (PRINC)
Scientific title
A randomised controlled trial to assess the antiplatelet effect of a 600mg (single-dose) and 1,200mg (split-dose) loading dose of clopidogrel and the impact of verapamil, a potent CYP3A4 inhibitor, on the incidence of clopidogrel resistance defined by the VerifyNow? (Accumetrics Ltd) P2Y12 platelet function analyzer in patients with coronary disease.
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Coronary artery disease 1096 0
Condition category
Condition code
Cardiovascular 1176 1176 0 0
Other cardiovascular diseases

Study type
Description of intervention(s) / exposure
Patients will be randomised to receive intravenously verapamil 5mg, orally 600mg clopidogrel or 1,200mg clopidogrel (split dose 600mg followed by 600mg 2 hours later, whilst in hospital). The drug effects will be monitored by platelet function analysis. Patients at discharge will be randomised to 75mg daily or 150mg daily of clopidogrel and platelet function measured at one week. Patients will receive standard dose clopidogrel 75mg once daily for either 3 weeks or 6 months depending on whether they receive bare metal coronary stents or drug eluting stents respectively.
Intervention code [1] 970 0
Treatment: Drugs
Comparator / control treatment
Control group

Primary outcome [1] 1586 0
Platelet function measured by VerifyNow? (Accumetrics Ltd) P2Y12 platelet function analyzer
Timepoint [1] 1586 0
At 2, 4, 7 hours and 7 days from Percutaneous Coronary Intervention (PCI)
Primary outcome [2] 1587 0
Peak troponin, Creatinine Kinase (CK)
Timepoint [2] 1587 0
At 4 and 7 hours from PCI.
Secondary outcome [1] 2877 0
Complications associated with PCI i.e. Vascular complications;
1. Haematoma
a. Assessed by clinical examination immediately prior to discharge.
2. Pseudoaneurysm
a. Diagnosed by vascular ultrasound. Ultrasound will be performed in any patient with a haematoma greater than 10cm in its largest dimension or any tender swellings in which the attending clinician has a high suspicion on pseudoaneurysm.
3. Retroperitoneal haemorrhage
a. Diagnosed by CT scan of the pelvis. CT will be perfomed it the haemoglobin drops unexpectedly or if the patient becomes shocked without cardiac cause.
Timepoint [1] 2877 0
Secondary outcome [2] 2878 0
Adverse drug reactions;
1. nausea, vomiting, rash, haematological dyscrasia.
P2Y12 receptor genetic haplotypes
Timepoint [2] 2878 0

Key inclusion criteria
1. Signed informed consent2. All-comers (male and female of any age) with coronary disease on aspirin scheduled for elective PCI
Minimum age
No limit
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
1. A bleeding or platelet disorder2. Previous gastrointestinal bleeding or gastric ulcer/duodenal ulcer/gastritis3. Sensitivity/allergy to aspirin or clopidogrel or verapamil4. Renal failure Cr >0.12mmol/L 5. Anaemia Hb <115mg/dL6. Medication inhibiting CYP3A4.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Numerically Coded medication with matching placebo
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Computerised random allocation
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
2 x 2 factorial, two stage RCT
Phase 4
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 298 0
New Zealand
State/province [1] 298 0

Funding & Sponsors
Funding source category [1] 1285 0
Name [1] 1285 0
National Heart Foundation (NZ)
Address [1] 1285 0
Country [1] 1285 0
New Zealand
Funding source category [2] 1286 0
Government body
Name [2] 1286 0
Greenlane Research and Education Fund
Address [2] 1286 0
Country [2] 1286 0
New Zealand
Primary sponsor type
Auckland City Hospital.
New Zealand
Secondary sponsor category [1] 1137 0
Commercial sector/Industry
Name [1] 1137 0
Environmental Science and Research Unit, NZ
Address [1] 1137 0
Country [1] 1137 0
New Zealand

Ethics approval
Ethics application status
Ethics committee name [1] 2619 0
Auckland City Hospital-Northern X Regional Ethics Committee
Ethics committee address [1] 2619 0
Ethics committee country [1] 2619 0
New Zealand
Date submitted for ethics approval [1] 2619 0
Approval date [1] 2619 0
Ethics approval number [1] 2619 0

Brief summary
This research project is designed to assess the response to a drug known as Plavix®. This drug reduces blood clotting by acting on small blood cells called platelets. A platelet rich blood clot is the cause of the blockage of the arteries of the heart that causes a heart attack. This study will hopefully determine the ideal dose that will give the maximum effect on clotting and help reduce the heart attacks related to the stenting opening of the heart arteries. We will also learn whether a drug called verapamil, given at the time of stenting has any effect on the clotting properties of Plavix®. Research assessing this drug interaction and higher doses of Plavix® has not been undertaken before. Both patients and investigators will be blinded to treatment allocation. One randomisation occurs at the outset, to one of four arms. Each study drug administered is coded to blind subjects and investigators.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 35767 0
Address 35767 0
Country 35767 0
Phone 35767 0
Fax 35767 0
Email 35767 0
Contact person for public queries
Name 10159 0
Dr. Patrick Gladding
Address 10159 0
17 Hoheria Rd
Onehunga Auckland
Country 10159 0
New Zealand
Phone 10159 0
+64 9 6369740
Fax 10159 0
Email 10159 0
Contact person for scientific queries
Name 1087 0
Dr. Patrick Gladding
Address 1087 0
17 Hoheria Rd
Onehunga Auckland
Country 1087 0
New Zealand
Phone 1087 0
+64 9 6369740
Fax 1087 0
Email 1087 0

No information has been provided regarding IPD availability
Summary results
No Results