Which is better for post-cardiac surgery atrial fibrillation (AF)—rate control or rhythm control? This randomized trial compared rate control to rhythm control for the management of AF after cardiac surgery. A total of 1500 patients who developed new-onset AF following cardiac surgery were randomized to receive either a rate-control strategy (using beta-blockers or calcium channel blockers) or a rhythm-control strategy (using antiarrhythmic drugs or electrical cardioversion). The study found no significant difference in clinical outcomes, including mortality or stroke, between the two strategies. The incidence of adverse events was similar in both groups. These findings suggest that both treatment strategies are equally effective.