Relation of Non-invasively Measured Parameters to Clinical Outcomes in CHF Patients
Condition: Congestive Heart Failure
MeSH terms: Heart Failure
Study type: Observational

Summary: 
      Our aim is to assess whether changes in CO, CI and SVR as measured using the Biobeat
      wearable, wireless, non-invasive device during IV diuretic administration in an outpatient
      setting among CHF patients correlate with short-term clinical change measured using symptoms
      questionnaires, change in weight and urine output. We will also assess the correlation
      between baseline values of those parameters and long-term clinical outcomes, measured by HF
      hospitalizations and the change in disease perception and quality of life reported in
      questionnaires.
    

Detailed description: 
      Heart failure (HF) is a common clinical syndrome resulting from structural and/or functional
      cardiac abnormality. It affects 2.2% of American adults and over 12% of Americans ≥80 years
      of age, and its total cost in the US was estimated at $30.7 billion in 2012. As prevalence
      and overall cost are expected to considerably rise in the coming years, HF continues to
      constitute a major burden to global health.

      HF is characterized with a progressive course of disease with high hospital readmission
      rates, which account for a major portion of the economic burden. Improving the management of
      congestion has been a crucial component in the efforts to reduce hospitalizations. Congestion
      is a cardinal manifestation of HF, presenting with dyspnea, orthopnea, and edema due to
      volume overload. Diuretics remain a cornerstone in the management of congestion; however,
      there are no clear guidelines on how to adjust their administration. Guidelines recommend
      monitoring of daily weight changes, but efficacy is debatable. Thus, there is a pressing need
      to find reliable markers to promptly recognize deteriorations and help tailor diuretic
      treatment to prevent them. To date, European Society of Cardiology (ESC) guidelines recommend
      two invasive monitoring approaches to guide management, one based on invasive wireless
      pulmonary artery pressure monitoring and the other on utilizing data from Implantable
      Cardioverter Defibrillators (ICDs). Hemodynamic monitoring using invasive right heart
      catheterization has not shown benefit in management of HF decompensations, and nowadays is
      reserved only for specific clinical scenarios. In the field of non-invasive monitoring,
      research efforts have focused on analyzing lung impedance, ECG , and heart sounds with some
      promising results; a recent study utilized machine learning to generate a personalized alert
      system, but with a limited number of parameters monitored. Nevertheless, their algorithm's
      success in predicting hospitalizations reflects the importance of recognizing the
      heterogeneity of HF and the advantages of an individualized approach.

      In this study, we will examine the use of a non-invasive, user-friendly device (BB-613WP,
      Biobeat Technologies LTD, Petah Tikva, Israel), in advanced HF patients receiving IV diuresis
      in a hospital outpatient clinic. The device can derive measurements of several parameters,
      including cardiac output (CO), cardiac index (CI), blood pressure (BP) and systemic vascular
      resistance (SVR) using photoplethysmography (PPG) technology, and has been tested in several
      clinical trials. We wish to assess if CO, CI and SVR can be utilized as markers for HF
      clinical course, so they can ideally be used to intervene and modify treatment prior to a
      deterioration.

      The literature describing the effects of diuresis on CO and SVR is rather limited and
      archaic. Most studies found a reduction in CO and a rise in SVR after diuresis, but some
      describe the opposite, and some describe a response changing over time. This can be explained
      when considering that the pathophysiology underlying the effects of volume status on cardiac
      performance in HF is complex. The classically described Frank-Starling principle states that
      contractility peaks at a muscle length that allows for optimal overlap of actin and myosin
      filaments and maximal calcium ions sensitivity. Up to a certain point, the longer the muscle
      is (represented as larger EDV, end diastolic volume), the higher the force of contraction.
      But beyond that length, the contractile force decreases. Since different patients are
      characterized with different levels of cardiac filling, volume reduction induced by diuresis
      may have a different impact on CO, depending on the position on the Frank Starling curve. For
      instance, impaired ventricular filling in HF with preserved ejection fraction can reduce
      systolic function, due to less effective contraction in low EDV. Similarly, SVR, which is
      inversely proportional to CO, is likely to be affected differently. Our primary objective is
      to assess whether the changes in CO, CI and SVR during IV diuretic administration correlate
      with short-term clinical change measured using symptoms questionnaires, change in weight and
      urine output. Our secondary objective is to assess the correlation between baseline values of
      those parameters and long-term clinical outcomes, measured by HF hospitalizations and the
      change in disease perception and quality of life reported in questionnaires.
    

Intervention name(s): Short term monitoring
Intervention type(s): Device
Intervention description(s): By using the Biobeat monitoring device, we will monitor CHF patients during an outpatient visit and during treatment with diuretics.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        50 patients >18 years of age, diagnosed with heart failure, arriving to Hadassah Ein Kerem
        outpatient clinic to receive IV diuresis, will be enrolled in the study
      
Keywords: Congestive Heart Failure; Non-invasive monitoring; Remote Patient Monitoring