November 15th, 2010
ROCKET AF Hits Chicago
Larry Husten, PHD
ROCKET AF hit the AHA on Monday morning. Results of ROCKET AF (Stroke Prevention Using the Oral Direct Factor Xa Inhibitor Rivaroxaban Compared With Warfarin in Patients with Nonvalvular Atrial Fibrillation) had been the topic of intense speculation and interest.
The trial showed that the experimental factor Xa inhibitor rivaroxaban was as effective as warfarin in preventing stroke in 14,264 AF patients and did not increase their risk of bleeding. In the per-protocol analysis, the rate of stroke and embolism was lower in the rivaroxaban group than in the warfarin group (P<0.001 for noninferiority, P=0.018 for superiority). Major bleeding complications occurred at a similar rate in the two groups (P=0.576).
Rate of stroke and embolism:
- Rivaroxaban: 1.71 events per 100 patient-years
- Warfarin: 2.16 events per 100 patient-years
Major bleeding complications:
- Rivaroxaban: 3.60 events per 100 patient-years
- Warfarin: 3.45 events per 100 patient-years
However, in the full intention-to-treat analysis, the superiority of rivaroxaban over warfarin did not achieve statistical significance (P=0.177). Intracerebral hemorrhage occurred in 55 patients on rivaroxaban and 84 on warfarin (P=0.019).
“The main implication is that we have an alternative to warfarin,” said Robert Califf, M.D., co-principal investigator of the study, in an AHA press release. “Equally important, there was no increase in bleeding, so we have a drug you can take once a day, without monitoring, that is at least as good as warfarin and carries no additional risk.”
Note: The AHA 2010 presentation slides for ROCKET-AF can be found on the Duke Clinical Research Institute website.
In this sunset-time for warfarin, the problem remains the same as with dabigratan: the global cost of the new therapy and to be sure that the patient is taking the drug. Patients on warfarin at steady-stae make an INR control once a month or also every 45 days and the dose is almost fixed and, finally, the cost very low.I think we have to consider all these factors before to do a such important choice, as to shift a patient to a new antithrombotic strategy. This consideration is quite different in patients at the beginning of therapy or, probably more important, in patients that are not compliant or live in remote areas where the INR control could be very difficult.
Competing interests pertaining specifically to this post, comment, or both:
No conflicts of interest.
There was no difference in benefit in RE-LY between warfarin- naive and experiencedpatients. The reduction in ICBs with dabigatran was independent of time in therapeutic range with warfarin. A cost analysis in Annals of Int Med was favorable to the thrombin inhibitor. Hence there is a good argument try dabig on all qualifying pts.
Competing interests pertaining specifically to this post, comment, or both:
Anticipate speaker for zBI
There are several advantages to dabigatran over coumadin, as Dr. Powell mentions. I wonder if the twice a day dosing of dabigatran and lack of regular INR monitoring will result in lower patient compliance than would occur with coumadin.