- The DARE-AF Trial (Dapagliflozin/SGLT2i):

1. Objective: To test if dapagliflozin could reduce early AF recurrence after catheter ablation in persistent AF patients without standard indications for SGLT2 inhibitors (diabetes, heart failure, CKD).
2. Design: 200 patients were randomized post-ablation to dapagliflozin 10 mg or control for three months.
3. Results: There was no significant difference in AF burden at three months between the groups.
4. Conclusion: The anti-arrhythmic effect of SGLT2 inhibitors likely stems from improving underlying cardiometabolic conditions rather than a direct effect. This reinforces the importance of proven lifestyle and risk factor modification.

- The META-AF Trial (Metformin):

1. Objective: To test if metformin could reduce AF recurrence after catheter ablation in overweight or obese patients without diabetes.
2. Design: Patients were randomized to metformin plus lifestyle counseling or lifestyle counseling alone.
3. Results: The metformin arm had greater freedom from recurrent atrial arrhythmia (78%) compared to the control arm (58%). The effect was not explained by significant changes in weight or A1c.
4. Conclusion: Despite limitations (open-label, single-center, high intolerance rate), the provocative results suggest metformin may have an anti-arrhythmic benefit and warrant further investigation in a larger trial.

- The DECAF Trial (Coffee):

1. Objective: To test the effect of coffee consumption on AF recurrence after elective cardioversion.
2. Design: Patients who regularly drank coffee were randomized to either continue drinking at least one cup per day or abstain from all caffeine for six months.
3. Results: The coffee consumption group had a significantly lower risk of recurrent AF or flutter compared to the abstinence group (a 30% lower hazard).
4. Conclusion: This supports the new guideline recommendation that caffeine cessation is given a Class 3 (no benefit) recommendation for preventing AF. Random allocation to coffee consumption resulted in less arrhythmia.