Absence of interaction of diabetes mellitus with chronic kidney disease on mortality in acute heart failure

Objectives: To evaluate how chronic kidney disease (CKD) and diabetes mellitus (DM) influence in-hospital mortality in patients urgently admitted for acute heart failure (HF).

Methods: We used data from the Spanish "Minimum Basic Data Set" for 2006-2007 to evaluate clinical differences and crude mortality rates for patients having versus non-having CKD or DM. We tested pre-specified predictive factors of in-hospital mortality in a multivariate logistic regression model, which included age, sex, CKD, DM, acute respiratory failure, a modified Charlson Comorbidity Index-excluding CKD/DM- and a CKD × DM-interaction variable. p Values < 0.05 were considered significant.

Main findings: A total of 275,176 episodes of acute HF were analyzed (47.9% male, mean age 76.2 ± 12.8 years). CKD patients (N = 25,174, 9.1%) were older (78.4 ± 10.1 vs. 76.0 ± 13.1 years; p < 0.001) and more frequently had coexisting medical conditions. DM patients (N = 88,994, 32.3%) more often had vascular risk factors and CKD (11.4% vs. 8.1%; p < 0.001). Overall in-hospital mortality rate for admitted HF patients was 10.4%. Mortality was lower for DM versus non-DM patients (9.2% vs. 11.0%; p < 0.001), but higher for CKD versus non-CKD patients (14.1% vs. 10.0%; p < 0.001). No interaction effect was found between CKD and DM on survival for a HF episode (odds ratio; OR = 1.01, 95% CI: 0.91-1.10; p for interaction = 0.73). DM remained protective (OR = 0.85, 95% CI: 0.82-0.87; p < 0.001), while CKD was associated with increased mortality (OR = 1.46, 95% CI: 1.39-1.53; p < 0.001).

Conclusions: In patients urgently admitted for HF, the association of CKD with higher in-hospital mortality was homogeneous irrespectively of the absence or presence of DM.