REAP : Red Española de Atención Primaria

1.06.2012

Relation Between Hemoglobin A_1c and Outcomes in Heart Failure Patients With and Without Diabetes Mellitus

Received 24 January 2012; received in revised form 1 February 2012; accepted 1 February 2012. published online 29 March 2012. 

Estudio publicado en el American Journal of Cardiology, que analiza la relación entre la hemoglobina A_1c (HbA_1c) y el pronóstico en pacientes con insuficiencia cardiaca (IC), diabéticos o no.

In patients with diabetes mellitus (DM) in the general population, elevated glycosylated hemoglobin (HbA_1c) increases the risk for developing heart failure (HF). However, in patients with established HF, the association of HbA_1c level with outcomes is not well established. The aim of this study was to investigate the relation between HbA_1c and outcomes in patients with HF with and without DM. 

A total of 845 patients with advanced HF followed at the Ahmanson-UCLA Cardiomyopathy Center were studied, stratified by the presence (n = 358) or absence (n = 487) of DM and by DM-specific HbA_1c quartiles (patients with DM: Q1 ≤6.4%, Q2 6.5% to 7.2%, Q3 7.3% to 8.5%, and Q4 ≥8.6%; patients without DM: Q1 ≤5.6%, Q2 5.7% to 6.0%, Q3 6.1% to 6.5%, and Q4 ≥6.6%). The primary outcomes analyzed were death and death or urgent heart transplantation. In the cohort with DM, 2-year event-free survival was 61% and 65% in Q3 and Q4 compared to 48% and 42% in Q1 and Q2 (p = 0.005). In the cohort without DM, there was no difference in outcomes by HbA_1c quartile. Risk-adjusted analysis in the diabetic cohort showed significantly increased hazard ratios for death or urgent heart transplantation in Q1 and Q2 compared to Q4. For every unit HbA_1c increase, there was a 15% decreased hazard ratio of death or urgent heart transplantation and all-cause mortality (p = 0.006 and p = 0.036, respectively). In the cohort without DM, multivariate models revealed similar hazard ratios among HbA_1c quartiles.

 In conclusion, in this cohort of patients with advanced HF, higher HbA_1c levels were associated with improved outcomes in patients with DM. This relation was not observed in patients without DM. Further investigations into mechanisms underlying the relation between HbA_1c, DM, and survival in advanced HF are warranted.