Denne siden ble automatisk oversatt og nøyaktigheten av oversettelsen er ikke garantert. Vennligst referer til engelsk versjon for en kildetekst.

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

18. mars 2014 oppdatert 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.

Studieoversikt

Status

Tilbaketrukket

Forhold

Intervensjon / Behandling

Detaljert beskrivelse

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.

Studietype

Intervensjonell

Fase

  • Fase 3

Kontakter og plasseringer

Denne delen inneholder kontaktinformasjon for de som utfører studien, og informasjon om hvor denne studien blir utført.

Studiesteder

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

Deltakelseskriterier

Forskere ser etter personer som passer til en bestemt beskrivelse, kalt kvalifikasjonskriterier. Noen eksempler på disse kriteriene er en persons generelle helsetilstand eller tidligere behandlinger.

Kvalifikasjonskriterier

Alder som er kvalifisert for studier

18 år og eldre (Voksen, Eldre voksen)

Tar imot friske frivillige

Nei

Kjønn som er kvalifisert for studier

Alle

Beskrivelse

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

Denne delen gir detaljer om studieplanen, inkludert hvordan studien er utformet og hva studien måler.

Hvordan er studiet utformet?

Designdetaljer

  • Primært formål: Behandling
  • Tildeling: Randomisert
  • Intervensjonsmodell: Parallell tildeling
  • Masking: Ingen (Open Label)

Våpen og intervensjoner

Deltakergruppe / Arm
Intervensjon / Behandling
Ingen inngripen: 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.
Eksperimentell: 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.
Annen: 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.
Andre navn:
  • INR (International Normalized Ratio) tests

Hva måler studien?

Primære resultatmål

Resultatmål
Tiltaksbeskrivelse
Tidsramme
Composite of major bleeding and objectively verified arterial or venous thromboembolism
Tidsramme: 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

Sekundære resultatmål

Resultatmål
Tiltaksbeskrivelse
Tidsramme
All-cause mortality
Tidsramme: Average 3 years
Average 3 years
Any bleeding
Tidsramme: Average 3 years
This is the composite of major and minor bleeding
Average 3 years

Samarbeidspartnere og etterforskere

Det er her du vil finne personer og organisasjoner som er involvert i denne studien.

Sponsor

McMaster University

Publikasjoner og nyttige lenker

Den som er ansvarlig for å legge inn informasjon om studien leverer frivillig disse publikasjonene. Disse kan handle om alt relatert til studiet.

Generelle publikasjoner

Studierekorddatoer

Disse datoene sporer fremdriften for innsending av studieposter og sammendragsresultater til ClinicalTrials.gov. Studieposter og rapporterte resultater gjennomgås av National Library of Medicine (NLM) for å sikre at de oppfyller spesifikke kvalitetskontrollstandarder før de legges ut på det offentlige nettstedet.

Studer hoveddatoer

Studiestart

1. april 2014

Primær fullføring (Forventet)

1. april 2018

Studiet fullført (Forventet)

1. oktober 2018

Datoer for studieregistrering

Først innsendt

21. juli 2012

Først innsendt som oppfylte QC-kriteriene

26. juli 2012

Først lagt ut (Anslag)

31. juli 2012

Oppdateringer av studieposter

Sist oppdatering lagt ut (Anslag)

20. mars 2014

Siste oppdatering sendt inn som oppfylte QC-kriteriene

18. mars 2014

Sist bekreftet

1. mars 2014

Mer informasjon

Begreper knyttet til denne studien

Nøkkelord

Ytterligere relevante MeSH-vilkår

Andre studie-ID-numre

  • PRINT-II-2012

Denne informasjonen ble hentet direkte fra nettstedet clinicaltrials.gov uten noen endringer. Hvis du har noen forespørsler om å endre, fjerne eller oppdatere studiedetaljene dine, vennligst kontakt register@clinicaltrials.gov. Så snart en endring er implementert på clinicaltrials.gov, vil denne også bli oppdatert automatisk på nettstedet vårt. .

Abonnere