Dipeptidyl-peptidase-4 Inhibitors and Heart Failure: Class Effect, Substance-Specific Effect, or Chance Effect?

The increased risk of heart failure hospitalizations related to treatment with the DPP-4 inhibitor saxagliptin observed in the SAVOR TIMI 53 trial, is likely not to be a chance effect, but rather a previously unrecognized side effect of this drug, as this risk was very consistently apparent across all subgroups of this large multicenter, prospective, randomized trial. Whether this side effect might represent a class effect of all DPP-4 inhibitors remains to be seen. Results of randomized prospective multicenter trials with the DPP-4 inhibitors alogliptin and vildagliptin have in fact generated new uncertainties and clearly not totally excluded the possibility of a class side effect. A meta-analysis of 59 randomized controlled trials with various DPP-4 inhibitors evaluating data from 36,620 patients with diabetes and a minimal observation period of 24 weeks, confirmed a 21 % increase of heart failure events compared to placebo treatment, however, not in comparison to treatment with other blood glucose lowering drugs. German registry data also did not show an increased risk for heart failure for the latter comparison. Potential interactions of DPP-4 inhibitors with other drugs, e.g. ACE inhibitors, have been discussed in relation to the increased heart failure risk, as well as interactions with peptides regulating cardiovascular functions that are also split by DPP-4 enzymes such as BNP, substance P, and NPY. Results from ongoing large multicenter trials with the DPP-4 inhibitors sitagliptin and linagliptin are expected to clarify the potential heart failure issue related to treatment with DPP-4 inhibitors.