DPP4 and heart failure: Heart failure events were not increased in EXAMINE [alogliptin, HR = 1.07 (124)], TECOS [sitagliptin; HR = 1.00 (126)], or CARMELINA [linagliptin; HR = 0.90 (125)], even in those patients with previous heart failure (132–134), suggesting that the increased risk with saxagliptin is not mechanistically related to the inhibition of DPP-4 per se, but the cause is still unexplained.