Luo H, et al. - Researchers assessed the heterogeneities of outcomes among control groups of heart failure with preserved ejection fraction (HFpEF) trials. Utilizing randomized controlled trials recruiting HFpEF patients with ejection fraction ≥ 40% and reporting Kaplan-Meier curves for at least 36 months, they extracted and calculated the Kaplan-Meier curves of control groups for hazard ratios and 95% confidence intervals. They intended to validate the reliability and accuracy of their method in two virtually developed trials. They included six trials containing 7,682 HFpEF patients in control groups. They found heterogeneous outcomes in the control groups of HFpEF trials. The highest all-cause mortality, cardiovascular mortality, heart failure mortality, and composite endpoints of cardiovascular mortality and heart failure hospitalization were reported in the DIG trial, while the lowest all-cause mortality, cardiovascular mortality, heart failure hospitalization, and composite of cardiovascular mortality and heart failure hospitalization were seen in the TOPCAT trial.