Kutyifa V, et al. - In view of the previously reported benefit from cardiac resynchronization therapy with a defibrillator (CRT-D) in mild heart failure (HF) patients with diabetes with HF event reduction, researchers herein investigated if HF remission with CRT-D translates into reduced mortality during long-term follow-up in diabetes patients. Cardiac resynchronization therapy with defibrillator provided a significant long-term survival benefit in mild HF patients with diabetes, similar to those with no diabetes, as observed in MADIT-CRT. Within the diabetes subgroup, the mortality benefit from CRT-D seemed to be confined to diabetes patients treated with insulin.

• In the enrollees of the MADIT-CRT, the impacts of CRT-D vs an ICD-only to reduce long-term risk of death were assessed in left bundle branch block (LBBB) patients with diabetes (DM) (n=386) and without diabetes (n=982).
• Further subdivision of the DM patients by insulin and non-insulin medical therapy was done.
• Researchers utilized Kaplan-Meier survival analyses and multivariate Cox proportional hazards regression models.

• At 7-year follow-up, researchers observed the association of CRT-D with a significantly lower mortality in DM patients compared to ICD alone (21 vs 42%, p=0.02), similar to non-DM patients (16 vs 24%, 0.014).
• They noted that CRT-D was related to a significant 41% reduction in the risk of long-term all-cause mortality in DM patients (HR=0.59, 95% CI: 0.36-0.96, p=0.033), and similar attenuation in non-DM patients (HR=0.69, 95% CI: 0.48-0.99, p=0.045, treatment-diabetes interaction p=0.611).
• In addition, findings demonstrated mortality benefit in insulin treated patients (HR=0.40, p=0.030), but not in those not treated with insulin (HR=0.79, p=0.476), among diabetes patients.
• In all groups, the presence of reductions in HF events was reported.