Temporal trends (2003-2018) of in-hospital and 30-day mortality in patients hospitalized with acute heart failure

Background: Limited temporal data on in-hospital mortality trends of patients hospitalized with acute heart failure (AHF) have been reported. We evaluated whether, in AHF hospitalized patients, the rate of in-hospital and 30-day mortality, and 30-day re-hospitalization for AHF have changed in the past 15 years. Methods and results: We examined administrative data from the Lombardy region, Italy and analysed data of all adults hospitalized for AHF from 2003 to 2018. Patients were stratified according to the hospitalization period: 2003-2006; 2007-2010; 2011-2014; 2015-2018. Primary endpoint was the comparison of in-hospital mortality rates among periods. Secondary endpoints were 30-day mortality rates and temporal trends of re-hospitalization for AHF. During this period, 414,164 hospitalizations with a primary diagnosis of AHF were identified, involving 286,028 patients aged 18 and older. In-hospital and 30-day mortality in the entire cohort showed a progressive increase over time (from 6.7 % to 8.5 % and from 12.4 % to 14.5 %, respectively). Thirty-day re-hospitalization for AHF was 2 %, showing a progressive decrease over the years. However, patient' age and complexity increased in the most recently hospitalized patients. After adjusting for major confounders, in-hospital and 30-day mortality risks were similar moving from one study period to the next (relative risk for trend 1.00 [95 % CI 0.99-1.01] and 1.00 [95 % CI 0.98-1.01], respectively), while that of 30-day AHF re-hospitalization decreased progressively (hazard ratio for trend 0.86 [95 % CI 0.84-0.88]). Conclusions: In our study, the increasing age and complexity of patients largely accounted for the continued rise in early mortality observed in patients hospitalized with AHF.