Background: Heart rate trajectory with multiple heart rate measurements is considered to be a more sensitive predictor of outcomes than single heart rate measurements. The association of heart rate trajectory patterns with acute heart failure outcomes has not been well studied. We examined the association of heart rate trajectory patterns with post-discharge outcomes. Methods: This prospective cohort study was based on an acute heart failure registry in Taiwan. A total of 1509 patients were enrolled in the Taiwan Society of Cardiology – Heart Failure with Reduced Ejection Fraction Registry from May 2013 to October 2015. The outcomes were post-discharge all-cause mortality and heart failure readmission. Results: Two heart trajectory patterns were identified in group-based trajectory analysis. One started with a higher heart rate and had an increasing trend over 6 months then a subsequent decline (high-increasing-decreasing group; n = 352; 23.9%). The other started with a lower heart rate and had a relatively s