Impact of new-onset diabetes mellitus and glycemic control on the prognosis of heart failure patients: a propensity-matched study in the community.

OBJECTIVES: To assess the incidence of type 2 diabetes mellitus (DM) in patients with heart failure (HF), and to evaluate the effect of new-onset DM and glycemic control on the prognosis of HF patients treated with a contemporary medical regimen. METHODS: Prospective study of 5314 HF patients and previously unknown DM during 9 years. Their mean age was 71.8 ± 7.9 years, 53.0% were women, and 50.2% had non-systolic HF. During a median follow-up of 56.9 ± 18.2 months, 68.9% of the patients died, 88.6% were hospitalized for HF, and 1519 (27.3%) developed new-onset DM. We propensity-matched those 1519 HF patients with DM, with 1519 HF patients non-diagnosed with DM. RESULTS: The age- and sex-adjusted incidence (per 100 HF patients/years) of DM in HF patients was 3.20, higher in women and in patients with non-systolic HF (p<0.01). Patients with HF and DM and those with a mean HbA1c>7.0% presented an increased mortality (HR of death [CI 95%]: 2.44 [1.68-3.19] and, HR: 2.56 [1.77-3.35], respectively), mainly due to an increased cardiovascular mortality (HR ≥ 2.40 [1.46-3.34]) (P<0.001). The rate of hospitalization, of 30-day readmissions, and the number of visits were higher among HF patients with DM or with HbA1c>7.0% (p<0.001). These relationships of DM and its poor metabolic control with prognosis were maintained, independently of the gender, the type of HF (systolic or, non-systolic), the comorbidities, and the medication used (P<0.01). CONCLUSION: New-onset diabetes mellitus and its poor metabolic control (HbA1c>7.0%) are associated with a increased mortality and morbidity of patients with heart failure.

Metformin therapy and prognosis of patients with heart failure and new-onset diabetes mellitus. A propensity-matched study in the community.

OBJECTIVE: To assess the effect of the commencement of metformin therapy (CMet) on the prognosis of patients with newly diagnosed heart failure (HF) and new-onset diabetes mellitus (DM) treated with a contemporary medical regimen. METHODS: Prospective study of 1519 HF patients with DM during 9 years. Mean age was 71.7+/-7.8 years, 817 (53.8%) were women, and 780 (51.3%) had preserved systolic function. During a median follow-up of 56.9+/-18.2 months, 1045 patients (68.8%) died, 1344 (88.5%) were hospitalized for worsening HF, 593 (39.0%) did not CMet, and 391 of the patients CMet (42.2%) had a mean HbA1c=<7.0%. No case of lactic acidosis due to metformin was observed. We propensity-score matched 592 patients who CMet with another 592 patients non-CMet. RESULTS: CMet was associated with a decreased mortality (HR [CI 95%]: .85 [.82-.88]), mainly due to a reduced cardiovascular mortality (HR: .78 [.74-.82]), and with a lower hospitalization rate (HR: .81 [.79-.84]). Nevertheless, CMet was not associated with an improved prognosis of HF patients with a mean HbA1c=<7.0%. These relationships of CMet with prognosis were maintained, independently of the gender, the type of HF (systolic or, non-systolic), the comorbidities, and the medication used (P<.01). CONCLUSION: Metformin therapy is associated with a reduced mortality of heart failure patients with new-onset diabetes mellitus, mainly due to a decreased cardiovascular mortality, and with a lower hospitalization rate. Nevertheless, CMet was not associated with an improved prognosis of HF patients with a mean HbA1c=<7.0%.