Denna sida har översatts automatiskt och översättningens korrekthet kan inte garanteras. Vänligen se engelsk version för en källtext.

Prolongation of the Interval Between Prothrombin Time Tests in Stable Patients II (PRINT-II)

18 mars 2014 uppdaterad av: Sam Schulman, McMaster University

Prolongation of the Interval Between Prothrombin Time Tests in Stable Patients II (the PRINT II Study): a Randomized Controlled, Non-inferiority Trial Comparing 4-weekly With 12-weekly Testing and Dose-assessment

More than 2 million patients in North America are treated with warfarin - a "blood thinner" - to prevent blood clots in arteries or veins. The treatment has to be monitored with a blood test and the dose changed accordingly every 1-4 weeks. One third of the patients have very stable results and hardly ever have to change the dose. The investigators wish to show that the level of control of the treatment with warfarin in these very stable patients is not worse with 12-weekly testing. A pilot study the investigators performed indicated that 12-weekly testing would be safe but this has to be confirmed in a large study. One third of patients taking warfarin have not had any changes in the dose for the past 6 months or longer. These patients will be asked about participation in the study. They will be randomized to testing and dosing every 4 or 12 weeks. Each patient is in the study until it ends, which will be minimum 1 year and can be up to about 4 years. The study is designed to show that 12-weekly testing does not significantly increase the risk for major bleeding or blood clots. The results would be important for a large number of patients. An increase of the interval between blood tests from 4 to 12 weeks would reduce the burden for these patients on life-long treatment considerably.

Studieöversikt

Status

Indragen

Betingelser

Intervention / Behandling

Detaljerad beskrivning

The study is a randomized, controlled, open-label, multi-center non-inferiority trial to demonstrate that the interval between internation normalized ration (INR) tests can be extended from the recommended 4 weeks to 12 weeks for patients with stable INRs. PROBE design. Patients receiving warfarin therapy that have exhibited INR stability, defined as no change in maintenance dose for at least 6 months, are potentially eligible for enrolment in the study. The primary outcome is a composite of major bleeding (ISTH criteria) plus objectively verified arterial or venous thromboembolism (excluding superficial thrombophlebitis) plus death related to thromboembolism. Justification: the study is not reflecting a "trade-off" scenario where one regimen is expected to be more effective at the cost of increased harm compared to the other regimen. Conversely, the potential disadvantage of the experimental regimen in this trial is increased variability in INR, which may result in an increased rate of low as well as high INRs and therefore potentially an increase of both types of clinical events.

Studietyp

Interventionell

Fas

  • Fas 3

Kontakter och platser

Det här avsnittet innehåller kontaktuppgifter för dem som genomför studien och information om var denna studie genomförs.

Studieorter

  • Kanada
    • Ontario
      • Hamilton, Ontario, Kanada, L8L 2X2
        • Hamilton Health Sciences - General Hospital

Deltagandekriterier

Forskare letar efter personer som passar en viss beskrivning, så kallade behörighetskriterier. Några exempel på dessa kriterier är en persons allmänna hälsotillstånd eller tidigare behandlingar.

Urvalskriterier

Åldrar som är berättigade till studier

18 år och äldre (Vuxen, Äldre vuxen)

Tar emot friska volontärer

Nej

Kön som är behöriga för studier

Allt

Beskrivning

Inclusion Criteria:

  • long-term warfarin for prophylaxis of arterial embolism due to atrial fibrillation or mechanical heart valve replacement OR secondary prophylaxis after VTE
  • therapeutic INR range of 2.0-3.0 or 2.5-3.5
  • anticoagulation therapy has been managed by the study site for at least 6 months prior to enrollment
  • warfarin maintenance dose has remained unchanged for the previous 6 months or longer

Exclusion Criteria:

  • Age < 18 years
  • Life expectancy of less than 1 year
  • Congestive heart failure or other diagnosis where the condition or its treatment is expected to affect the stability of INR (e.g. cancer requiring chemotherapy)
  • Attending physician believes that patient is not suitable for the study (for instance, psychiatric disorder; history of non-compliance; newly diagnosed disease which by itself, via the treatment required or the effects thereof may cause instability of INRs)
  • Patients who perform self-testing
  • Geographic inaccessibility
  • Failure to obtain written consent

Studieplan

Det här avsnittet ger detaljer om studieplanen, inklusive hur studien är utformad och vad studien mäter.

Hur är studien utformad?

Designdetaljer

  • Primärt syfte: Behandling
  • Tilldelning: Randomiserad
  • Interventionsmodell: Parallellt uppdrag
  • Maskning: Ingen (Open Label)

Vapen och interventioner

Deltagargrupp / Arm
Intervention / Behandling
Inget ingripande: Standard interval between PT testing
Prothrombin time (PT) is tested every 4 weeks, according to American College of Chest Physicians (ACCP) Guidelines up to 2008 for stable patients on warfarin.
Experimentell: Prolonged interval between PT testing
Prothrombin time (PT) is tested every 12 weeks, according to suggestion in American College of Chest Physicians (ACCP) Guidelines of 2012 for stable patients on warfarin.
Övrig: Prolonged interval between PT testing
Patients in the intervention group will be scheduled for prothrombin time testing and dosing of warfarin every 12 weeks instead of every 4 weeks. This has been suggested in the latest edition of the ACCP guidelines as a possibility for very stable patients. In order to change this from a suggestion to a formal recommendation a study powered for clinically important outcomes is needed.
Andra namn:
  • INR (International Normalized Ratio) tests

Vad mäter studien?

Primära resultatmått

Resultatmått
Åtgärdsbeskrivning
Tidsram
Composite of major bleeding and objectively verified arterial or venous thromboembolism
Tidsram: Average 3 years
The justification for a composite outcome including both bleeding and thromboembolism is that the study is not reflecting a "trade-off" scenario where one regimen is expected to be more effective at the cost of increased harm compared to the other regimen. Conversely, the potential disadvantage of the experimental regimen in this trial is increased variability in prothrombin time, which may result in an increased rate of short as well as long prothrombin times and therefore potentially an increase of both types of clinical events.
Average 3 years

Sekundära resultatmått

Resultatmått
Åtgärdsbeskrivning
Tidsram
All-cause mortality
Tidsram: Average 3 years
Average 3 years
Any bleeding
Tidsram: Average 3 years
This is the composite of major and minor bleeding
Average 3 years

Samarbetspartners och utredare

Det är här du hittar personer och organisationer som är involverade i denna studie.

Sponsor

McMaster University

Publikationer och användbara länkar

Den som ansvarar för att lägga in information om studien tillhandahåller frivilligt dessa publikationer. Dessa kan handla om allt som har med studien att göra.

Allmänna publikationer

Studieavstämningsdatum

Dessa datum spårar framstegen för inlämningar av studieposter och sammanfattande resultat till ClinicalTrials.gov. Studieposter och rapporterade resultat granskas av National Library of Medicine (NLM) för att säkerställa att de uppfyller specifika kvalitetskontrollstandarder innan de publiceras på den offentliga webbplatsen.

Studera stora datum

Studiestart

1 april 2014

Primärt slutförande (Förväntat)

1 april 2018

Avslutad studie (Förväntat)

1 oktober 2018

Studieregistreringsdatum

Först inskickad

21 juli 2012

Först inskickad som uppfyllde QC-kriterierna

26 juli 2012

Första postat (Uppskatta)

31 juli 2012

Uppdateringar av studier

Senaste uppdatering publicerad (Uppskatta)

20 mars 2014

Senaste inskickade uppdateringen som uppfyllde QC-kriterierna

18 mars 2014

Senast verifierad

1 mars 2014

Mer information

Termer relaterade till denna studie

Nyckelord

Ytterligare relevanta MeSH-villkor

Andra studie-ID-nummer

  • PRINT-II-2012

Denna information hämtades direkt från webbplatsen clinicaltrials.gov utan några ändringar. Om du har några önskemål om att ändra, ta bort eller uppdatera dina studieuppgifter, vänligen kontakta register@clinicaltrials.gov. Så snart en ändring har implementerats på clinicaltrials.gov, kommer denna att uppdateras automatiskt även på vår webbplats .

Kliniska prövningar på Perifer arteriell sjukdom

Sök liknande försök

Sponsorer och medarbetare

Medicinska tillstånd

Läkemedelsinterventioner

CROs by country

CROs in Hungary

Betingelser

Sällsynta sjukdomar

Läkemedelsinterventioner

Kosttillskott

Sponsor / medarbetare

Platser

3
Prenumerera