Risk factors for hospital readmission in adult patients with heart failure with reduced ejection fraction: a systematic review

Objective:The objective of this review was to identify and synthesize evidence on risk factors associated with hospital readmission within the first year after heart failure hospitalization among patients with heart failure with reduced left ventricular ejection fraction.Introduction:Heart failure is associated with a high risk of hospital readmission. Readmissions are associated with higher mortality and health care costs. It is a high health care priority to identify vulnerable patients with heart failure who may potentially benefit from targeted personalized care interventions aiming to reduce readmissions.Inclusion criteria:This review considered studies including adult patients who had heart failure with a reduced left ventricular ejection fraction <= 40% who were discharged after a heart failure hospitalization. The authors included studies with experimental and observational designs evaluating risk factors for i) all-cause hospital readmission, ii) heart failure hospital readmission, and iii) composite outcomes within seven, 15, 30, 60, 90, 180, and 365 days after hospital discharge. Composite outcomes included end points where all-cause readmission and/or heart failure readmission were part of a defined end point (i.e. all-cause readmission or mortality; heart failure readmission or mortality; cardiovascular readmission; cardiovascular readmission or mortality; and readmission, mortality, or cardiac transplant). Studies reporting all-cause readmission and/or heart failure readmission as a primary outcome, secondary outcome, or part of a composite outcome were included.Methods:PubMed, Embase, CINAHL, Cochrane CENTRAL, PsycINFO, OpenGrey, MedNar, DART-Europe, ProQuest Dissertations and Theses, and the Grey Literature Report in Public Health were searched to find both published and unpublished studies in English, Swedish, Norwegian, or Danish from 2000 to June 2018. Study selection, critical appraisal, data extraction, and data synthesis followed the JBI approach for systematic reviews. Statistical pooling was not possible due to clinical and methodological heterogeneity of the studies included and the lack of risk factors reported more than once. A narrative summary of the findings was performed.Results:Fifty-two studies, including one randomized controlled trial and 51 cohort studies with a total of 128,186 participants, were included. Risk factors for readmission were reported for 30-day outcome in 16 studies, 60-day in three studies, 90-day in 15 studies, 180-day in 12 studies, and 365-day outcome in 15 studies. Based on multivariable analyses from 43 cohort studies and results from one randomized controlled trial, the authors identified several factors associated with higher risk of all-cause readmission, heart failure readmission, and composite outcomes (e.g. readmission or death) within 30, 60, 90, 180, and 365 days after discharge for a heart failure hospitalization.Conclusions:This review provides a comprehensive overview of factors associated with a clinical outcome after a heart failure hospitalization in patients with heart failure with left ventricular ejection fraction <= 40%. Owing to the heterogeneity of variables investigated and the lack of comparability of findings, the clinical impact of the identified risk factors remains uncertain. This review highlights research gaps and the need for a standardized way to define and measure all-cause readmission, heart failure readmission, and composite end points in clinical research to improve study quality and enable comparison of findings between studies.