The largest randomised open label non inferiority trial comparing rivaroxaban with a vitamin K antagonist in more than 4500 patients with rheumatic heart disease associated atrial fibrillation has reported that the composite of clinical events were greater with rivaroxaban than a vitamin K antagonist. This is the INVICTUS trial presented last month in Barcelona (ESC Congress) There was no difference in major bleeding. More than 70% of the patients were women, average age was 50 years, and follow up was for 3.1 years. Mitral stenosis was the valvular lesion in 85% of patients.
There are , however , some gaps still that will need, if possible, another trial.
1) Drop out rate at the end of the trial with rivaroxaban was 22% while it was only 6.5% with a VKA.
2) One cannot extrapolate data to other NOACs such as apixaban or edoxaban.
3) It is probable that the vitamin K antagonist cohort was provided better health care as INR had to be checked once a month. The risk factors may have been managed better.
4) Crucially there is complete silence on the impact of the Covid Pandemic.
5) It would be interesting to learn rate of Covid deaths or vaccine effect on rheumatic heart disease heart, despite lower vaccine uptake in low and middle income group countries.
6) Composite end points were changed at 2 years to include death and myocardial infarction because there was little difference in rate of stroke.