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    Ottawa Heart Failure Risk Scale (OHFRS)

    Identifies ED patients with heart failure at high risk for serious adverse events.
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    INSTRUCTIONS

    Use in patients presenting to the emergency department with acute dyspnea secondary to new-onset or chronic heart failure (HF), after initial intervention. Do not use prior to ED intervention. Do not use in patients who are hemodynamically unstable (see When to Use for full exclusion criteria).

    When to Use
    Pearls/Pitfalls
    Why Use
    • Patients presenting to the ED with HF exacerbation who have responded to treatment.
    • Do not use if:
      • Resting O₂ sat <85% on room air on normal home O₂ for >20 minutes.
      • Heart rate >120 on arrival.
      • Systolic BP <85 mmHg on arrival.
      • Confusion, disorientation, or dementia.
      • Ischemic chest pain requiring nitrates on arrival.
      • ST segment elevation on EKG.
      • Death expected within weeks from chronic illness.
      • Nursing home or chronic care facility resident.
      • On chronic hemodialysis.
    • The Ottawa Heart Failure Risk Scale (OHFRS) identifies ED patients with HF at high risk for serious adverse events (SAE), including death, MI, need for ICU/intubation.
    • Best suited for ED patients presenting with HF exacerbation who have responded to treatment in the ED.
    • Not intended to be used in determining disposition until after ED intervention (in the study, OHFRS was assessed 2-8 hours after initial ED treatment).
    • Can be used even if NT-proBNP is unavailable without sacrificing accuracy significantly.
    • Derivation study was conducted in Canada, where only 38% of patients presenting to EDs with acute HF are admitted, compared with 80% in the US (citation). Regional practice patterns should be considered in applying this score.
    • Patients presenting with acute HF or exacerbations of chronic HF are at high risk for adverse events. Even with appropriate ED management, many require admission for further evaluation and treatment. This score helps identify both:

      • Patients at low risk for adverse events and thus potentially safe for discharge with close follow-up.
      • Patients who are at higher risk and require admission and close monitoring.
    • More widely validated than the Emergency Heart Failure Mortality Risk Grade (EHMRG), but with stricter inclusion/exclusion criteria (see When to Use).
    History
    Examination
    Investigations

    Result:

    Please fill out required fields.

    Next Steps
    Evidence
    Creator Insights

    Advice

    Interpreting medium risk scores can be the most difficult part of the OHFRS. Using scores >1 as an admission threshold increases sensitivity for serious adverse events (SAE) and increases admission rates, but a threshold of scores >2 leads to similar sensitivity to previous practice with a notable reduction in admission rates.

    • Consider patient-specific factors to help determine disposition for patients with scores 1–2, e.g. access to medical care and timely follow-up, comorbidities, living conditions, frequency of HF exacerbations.
    • As with all risk scores, use clinician judgment and shared decision-making model to ensure the patient is informed of the benefits and risks associated with their disposition regardless of whether they are admitted or discharged.  
    • Patients being discharged should receive thorough return precautions, as heart failure patients are at higher risk for severe complications than the general population.

    Management

    • For patients with higher OHFRS (>1 or 2 depending on preference) or a concerning clinical presentation after initial intervention, consider admission for monitoring and further treatment.
    • Patients with OHFRS <2, good response to ED intervention, and encouraging clinical presentation may be safe for discharge with close follow-up.

    Critical Actions

    High or worsening score should trigger consideration of a higher level of care, including early involvement of intensivists, cardiologists, and other specialists.

    Formula

    Addition of the selected points:

     

    No

    Yes

    History

    Stroke or TIA

    0

    +1

    Intubation for respiratory distress

    0

    +2

    Examination

    HR ≥110 on ED arrival

    0

    +2

    SaO2 <90% on arrival

    0

    +1

    Heart rate ≥110 during 3-minutes walk test (or too ill to perform walk test)

    0

    +1

    Investigations

    New ischemic changes on EKG

    0

    +2

    Urea ≥12 mmol/L

    0

    +1

    Serum CO2 ≥35 mmol/L (mEq/L)

    0

    +2

    Troponin I or T elevated to MI level

    0

    +2

    NT-proBNP ≥5,000 ng/L (pg/mL)

    0

    +1

    Facts & Figures

    Interpretation:

    Total Score

    Risk of Serious Adverse Event (SAE)*

    Category

    0

    2.8%

    Low

    1

    5.1%

    Medium

    2

    9.2%

    Medium

    3

    15.9%

    High

    4

    26.1%

    High

    5

    39.8%

    Very high

    6

    55.3%

    Very high

    7

    69.8%

    Very high

    8

    81.2%

    Very high

    9

    89.0%

    Very high

    >9

    >89.0%

    Very high

     *Serious adverse events were defined as:

    • 30-day all cause mortality, or
    • Any of the following within 14 days of the index ED visit, regardless of whether initially admitted:
      • Admission to critical care or acute monitoring unit (excluding ambulatory telemetry units).
      • Endotracheal intubation or need for noninvasive ventilation after hospital admission (unless on noninvasive ventilation at home).
      • MI, as defined by international consensus standards. Either one of the following criteria satisfies the diagnosis for an acute, evolving, or recent MI:
        • Typical rise and gradual fall of troponin with at least one of the following:
          • Ischemic symptoms.
          • Pathologic Q waves on EKG.
          • EKG changes indicative of ischemia.
          • Coronary artery intervention (e.g., coronary angioplasty).
        • Pathologic findings of an acute MI.
      • Major procedure, defined as CABG, PCI, other cardiac surgery, or new hemodialysis.
      • Relapse and hospital admission for patients discharged on the initial ED visit, defined as a return to the ED for any related medical problem within 14 days followed by admission to hospital (relapse to the ED without associated admission was not considered a SAE).

    Evidence Appraisal

    The OHFRS was derived from a prospective cohort study at six large Canadian EDs by Stiell et al (2013). A total of 559 patient visits were evaluated to determine the rates of admission and serious adverse events (SAE, defined as death, MI, or need for ICU or intubation). Variables from history, physical exam, imaging, ECG, and laboratory studies were assessed with univariate analysis. Statistically significant variables associated with SAE were included in a multivariate logistic regression model to determine independent predictors for SAE.

    Using the predictors identified, the performance of the score was validated in the study population for sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio across 1,000 replications using the bootstrap method. 52% of patients admitted from their first ER visit had documented SAE. Using OHFRS values of 1, 2, or 3 as a threshold for admission had higher sensitivity for identifying and admitting patients who had an SAE within 14 days of initial encounter (95.2, 80.6, and 64.5%, respectively).  

    The OHFRS was prospectively validated by Stiell et al (2017) in an observational cohort study including 1,100 patients who were enrolled and followed for occurrence of an SAE within 30 days of initial presentation. Similar inclusion and exclusion criteria were used for the validation study as the primary study. They found that an admission threshold of OHFRS >1 improved sensitivity compared to previous practice. OHFRS >2 had equivocal sensitivity for SAE as previous practice, but reduced admission rates substantially.  

    The study authors also compared sensitivity with and without the use of NT-proBNP and found results to be similar in improved sensitivity compared to previous practice.  The use of NT-proBNP in the score improved sensitivity of the OHFRS compared to omitting the laboratory study from the score.

    Dr. Ian Stiell

    About the Creator

    Ian Stiell, MD, MSc, FRCPC, is Professor and Chair, Department of Emergency Medicine, University of Ottawa; Distinguished Professor and University Health Research Chair, University of Ottawa; Senior Scientist, Ottawa Hospital Research Institute; and Emergency Physician, The Ottawa Hospital. He is internationally recognized for his research in emergency medicine with a focus on the development of clinical decision rules and the conduct of clinical trials involving acutely ill and injured patients treated by prehospital services and in emergency departments. He is best known for the development of the Ottawa Ankle Rule, the Canadian C-Spine Rule, and Canadian CT Head Rule and as the Principal Investigator for the landmark OPALS Studies for prehospital care. Dr. Stiell is the Principal Investigator for 1 of 3 Canadian sites in the Resuscitation Outcomes Consortium (ROC) which is funded by CIHR, NIH, HSFC, AHA, and National Defence Canada. Dr. Stiell is a Member of the Institute of Medicine of the U.S. National Academies of Science.

    To read more about Dr. Stiell's work, visit his website.

    To view Dr. Ian Stiell's publications, visit PubMed

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