DPP4 and hydrops fetalis: In the Cardiovascular Outcome Trial of Linagliptin versus Glimepiride in Type 2 Diabetes (CAROLINA) RCT, linagliptin use was also not associated with an increased risk of HHF compared with glimepiride (HR: 1.21 (95% CI: 0.92–1.59)) [109], suggesting that the harmful effect of DPP-4 inhibitors on HF are not class effects.