Atrial fibrillation (AF) has the luxury (and curse) of being one of those conditions for which large scale randomized clinical trials (such as RELY, ROCKET-AF, ARISTOTLE, ENGAGE-TIMI48) have paved the way for understanding risk and guiding disease management. However, the downside of these well-controlled clinical trials is that they don’t produce the “real world” data that more appropriately reflects the types of patients that we take care of in clinic.
That situation changed in late August at the European Society of Cardiology Scientific Sessions 2015 when results of GARFIELD-AF were presented. The Global Anticoagulant Registry in the Field – Atrial Fibrillation was an international, observational, multicenter two-year registry of 57,000 patients with nonvalvular AF from 35 countries. The patients were recruited sequentially in 5 different cohorts and included all patients with newly-diagnosed nonvalvular AF. The AF had to be diagnosed within the previous 6 weeks and there had to be at least one additional risk factor for stroke, making each patient a potential candidate for anticoagulation therapy. There was a minimum follow-up of 2 years up to a maximum follow-up of 8 years. Natural disease progression and the impact of treatment decisions were among the many trends closely followed.
The two-year data produced many interesting observations:
- All-cause death (3.83%) was more frequent than stroke (1.25%) or major bleeding (0.70%) in about ~17,000 newly diagnosed AF patients (cohorts 1 and 2).
- Those with more co-morbidities fared significantly worse than the general population with respect to death if they had AF:
o Moderate to severe chronic kidney disease: 9.4% vs. 4.0% (2-fold higher rate of death and major bleeding and 1.4-fold higher rate of stroke)
o Prior MI: 6.9 % vs. 4.0%
- There was more use of anticoagulants (from 57.1% to 71.1%) with fewer patients being treated with vitamin K antagonists or antiplatelet agents (N~40,000); the rate of newer oral anticoagulant use was widely variable geographically, ranging from 2.6% to 58.0%.
Being the largest ongoing registry of newly diagnosed AF in patients who have at least one risk factor for thromboembolism, GARFIELD-AF offers new insights into the natural history of AF and its complications. Furthermore, it allows us to better understand how aggressively to target and treat certain high-risk patient subtypes, such as those with CKD who are at higher risk for thromboembolism and bleeding.