Precipitating Factors in Heart Failure Hospitalization and Morality by Ejection Fraction

Patients hospitalized with heart failure (HF) of different ejection fraction (EF) categories—reduced, borderline, and preserved—have multiple precipitating factors and are independently associated with clinical outcomes, according to a study published in JACC: Heart Failure.

Researchers selected nearly 100 000 HF hospital admissions from the Get With The Guidelines-HF (GWTG-HF) database between 2005 and 2013. The mean patient age was 72.6 ± 14.2 years and about half were female (49%) with a mean EF of 39.3% ± 17.2%. The goal of their study was to assess characterizations and precipitating factors that contributed to hospitalizations, and if whether these factors affect clinical outcomes, including in-hospital mortality and length of stay.

Patients were divided into groups based on EF function: reduced EF (<40% or if EF was missing, qualitative assessment of moderate to severe dysfunction), borderline systolic function (40% ≤ EF <50%) and preserved EF (≥50% or if EF was missing, qualitative assessment of normal or mild dysfunction). Of the total cohort (n=99 825), 48 950 (49.0%) had reduced EF, 12 819 (12.8%) had borderline EF, and 38 056 (38.1%) had preserved EF.

The most common precipitating factors of HF hospitalization were pneumonia/respiratory process (28.2%), arrhythmia (21.7%), medication noncompliance (15.8%), worsening renal failure (14.7%), and uncontrolled hypertension (14.5%). Dietary and medication nonadherence were found more often in patients with reduced EF (16.8% and 19.7%, respectively).  In addition, uncontrolled hypertension was more likely found in patients with borderline EF (16.4%) and pneumonia/respiratory process was more likely in patients with preserved EF (32.7%).

Overall, patients most often presented with dyspnea (71.2%) and volume overload/weight gain (11.3%). Dizziness, implantable cardioverter device shock/sustained ventricular arrhythmia, volume overload/weight gain, and worsening fatigue occurred more frequently in patients with reduced EF vs other groups. However, dyspnea was present in patients with borderline EF more frequently than other groups.

The median hospital length of stay was 4 days among all of the patients and in each EF subgroup (interquartile range: 25th to 75th; 3 to 7 days, respectively). Patients with reduced EF and pneumonia experienced longer hospital stays (determined as >4 days; odds ratio [OR]: 1.30; 95% confidence interval [CI]: 1.22-1.40). This was also the case in volume overload/weight gain (OR: 1.32; 95% CI: 1.20-1.46), worsening renal failure (OR: 1.19; 95% CI: 1.08-1.30), arrhythmia (OR: 1.10; 95%: 1.02-1.18), and acute pulmonary edema (OR: 1.28; 95% CI: 1.05-1.57). In contrast, the presence of dyspnea was associated with a decreased length of stay in all EF subgroups.

In patients with borderline EF, pneumonia was associated with a longer hospital stay (OR: 1.31; 95% CI: 1.18-1.45), but dietary and medication noncompliance was associated with a shorter length of stay.

In the overall population, 3059 in-hospital deaths occurred during the study, with a slightly higher unadjusted death rate observed in the group with reduced EF (3.2%) vs those with borderline EF (2.6%) or preserved EF (3.0%).

Interestingly, dyspnea was associated with a lower mortality rate in patients with reduced EF (OR: 0.78; 95% CI: 0.68-0.89), and dietary noncompliance was also associated with lower mortality rates in both subgroups of reduced EF (OR: 0.65; 95% CI: 0.46-0.91) and preserved EF (OR: 0.52; 95% CI: 0.33-0.83). However, among the same subgroups, patients who presented with ischemia had a higher mortality rate (OR: 1.31; 95% CI: 1.02-1.69 and 1.72; 95% CI: 1.27-2.33, respectively).

The authors noted that the large size of the study, as well as the geographic variation (from 305 hospitals across the country), make the results highly generalizable. A lack of follow-up, however, did not allow them to conduct long-term outcome evaluations. Other potential limitations include accuracy of medical records, the incompleteness of the precipitating factors list, and differences between hospital care patterns or patient characteristics.

“Future studies should focus on testing interventions that target these contributing factors in patients with HF,” researchers concluded. “Such evaluations should examine interventions individually and also combined, as may occur through disease management or other types of comprehensive care structures.”

Reference

Kapoor JR, Kapoor R, Ju C, et al. Precipitating clinical factors, heart failure characterization, and outcomes in patients hospitalized with heart failure with reduced, borderline, and preserved ejection fraction. JACC Heart Fail. 2016;4(6):464-472. doi: 10.1016/j.jchf.2016.02.017.