Outcomes and Predictors of Mortality Among Cardiac Intensive Care Unit Patients With Heart Failure

https://doi.org/10.1016/j.cardfail.2022.02.015Get rights and content

Highlights

  • Cardiac intensive care unit patients with heart failure present a broad spectrum of illness severity and mortality risk, with the magnitude of critical illness being the dominant determinant of outcomes.

  • Those patients who do not have critical care diagnoses or require critical care therapies are low risk and might not require cardiac intensive care unit care in all cases.

  • The left ventricular ejection fraction is not an important determinant of prognosis in this population, and providers should focus on other established risk factors.

Abstract

Background

Little is known regarding the causes of critical illness and determinants of prognosis of patients with heart failure (HF) admitted to the modern cardiac intensive care unit (CICU). We sought to describe the epidemiology and outcomes of patients with HF admitted to the contemporary CICU.

Methods and Results

Retrospective cohort analysis of Mayo Clinic CICU patients admitted with HF from 2007 to 2018 who had left ventricular ejection fraction (LVEF) data. HF with reduced LVEF (HFrEF) was defined as a LVEF of less than 50%, and HF with preserved LVEF (HFpEF) as a LVEF of 50% or greater. In-hospital mortality was analyzed using multivariable logistic regression. Survival to 1 year was analyzed using a Kaplan–Meier analysis. We included 4012 patients, including 67.8% with HFrEF and 32.2% with HFpEF. Patients with HFrEF and HFpEF were comparable and had equivalent severity of illness. Critical care therapies were used in 59.4%, with a slight preponderance in patients with HFrEF. In-hospital mortality occurred in 12.5% of patients and was similar in HFrEF vs HFpEF. Shock and cardiac arrest were the strongest predictors of adjusted in-hospital mortality, followed by Braden skin score and serum chloride level; patients with HFrEF and HFpEF had similar adjusted mortality rates. The 1-year survival after hospital discharge was 74.5% and was slightly lower for patients with HFpEF. All-cause rehospitalization occurred in 36.6%, and 52.8% of hospital survivors died or were readmitted within 1 year.

Conclusions

CICU patients with HF have a substantial burden of critical illness, high use of critical care therapies, and poor outcomes regardless of LVEF. This finding emphasizes the potential unmet care needs in this cohort.

Lay summary

Patients with heart failure who require admission to the cardiac intensive care unit have high severity of illness and are at significant risk of death during and after hospitalization. These patients often require specialized critical care therapies to treat manifestations of critical illness. Patients who are admitted with cardiac arrest or shock, including those who require mechanical ventilation or vasopressors, are at particularly high risk of death. Patients’ left ventricular ejection fraction is not strongly associated with the risk of death when accounting for other major predictors including frailty and laboratory abnormalities.

Section snippets

Methods

This study was approved by the Institutional Review Board of the Mayo Clinic as minimal risk and was performed under a waiver of informed consent. We retrospectively analyzed a previously constructed cohort including data from the index CICU admission of adults who were admitted to the CICU at Mayo Clinic St. Mary's Hospital (Rochester, MN) from January 2007 to April 2018.12,16 We included only patients with an admission diagnosis of HF, defined as any International Classification of Diseases,

Study Population

Out of a database of 12,322 unique CICU patient admissions with available admission diagnosis data, 6008 (48.8%) had an admission diagnosis of HF. Among these patients, 4272 (71.1%) had a TTE within 1 day of hospitalization and the 4012 of these patients with data for LVEF were included in the final study population. The final study population had a median age of 71.9 years (IQR, 61.7–81.1 years), and 60.8% were men (Table 1). Concomitant admission diagnoses (in addition to HF) included acute

Discussion

In this study of more than 4000 CICU patients admitted with HF, we observed a substantial risk of in-hospital and postdischarge mortality such that one-third of all patients with HF admitted to the CICU died within 1 year after CICU admission. Approximately one-third of patients with HF had HFpEF, and the remainder had HFrEF (including those with HFmrEF). Although these 2 groups differed slightly, including a greater prevalence of critical care diagnoses and slightly more use of critical care

Conclusions

CICU patients admitted with HF are not restricted to those with severe systolic dysfunction, with approximately one-third of patients displaying HFpEF. Within the CICU HF cohort, there is a high proportion of patients with HF with critical illness requiring intensive therapies regardless of LVEF. This cohort demonstrated a high incidence of short- and long-term mortality and rehospitalization in patients with HFrEF and patients with HFpEF, although patients without critical illness were at a

Declaration of Competing Interest

None of the authors has a relevant financial disclosure or conflict of interest pertinent to this research.

Funding

No funding was involved in the conduct of this research.

References (29)

  • O Miro et al.

    Comparative analysis of short-term outcomes of patients with heart failure with a mid-range ejection fraction after acute decompensation

    Am J Cardiol

    (2019)
  • E Akintoye et al.

    National trends in admission and in-hospital mortality of patients with heart failure in the United States (2001-2014)

    J Am Heart Assoc

    (2017)
  • KE Bergethon et al.

    Trends in 30-day readmission rates for patients hospitalized with heart failure: findings from the Get With The Guidelines-Heart Failure Registry

    Circ Heart Fail

    (2016)
  • MS Nieminen et al.

    EuroHeart Failure Survey II (EHFS II): a survey on hospitalized acute heart failure patients: description of population

    Eur Heart J

    (2006)
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