Advanced heart failure patients supported with ambulatory inotropic therapy: What defines success of therapy?

Objective

The objective of this study was to describe the profiles and outcomes of a cohort of advanced heart failure patients on ambulatory inotropic therapy (AIT).

Background

With the growing burden of patients with end-stage heart failure, AIT is an increasingly common short or long-term option, for use as bridge to heart transplant (BTT), bridge to ventricular assist device (BTVAD), bridge to decision regarding advanced therapies (BTD) or as palliative care. AIT may be preferred by some patients and physicians to facilitate hospital discharge. However, counseling patients on risks and benefits is critically important in the modern era of defibrillators, durable mechanical support and palliative care.

Methods

We retrospectively studied a cohort of 241 patients on AIT. End points included transplant, VAD implantation, weaning of inotropes, or death. The primary outcomes were survival on AIT and ability to reach intended goal if planned as BTT or BTVAD. We also evaluated recurrent heart failure hospitalizations, incidence of ventricular arrhythmias (VT/VF) and indwelling line infections. Unintended consequences of AIT, such reaching unintended end point (e.g. VAD implantation in BTT patient) or worse than expected outcome after LVAD or HT, were recorded.

Results

Mean age of the cohort was 60.7 ± 13.2 years, 71% male, with Class III-IV heart failure (56% non-ischemic). Average ejection fraction was 19.4 ± 10.2%, pre-AIT cardiac index was 1.5 ± 0.4 L/min/m² and 24% had prior ventricular arrhythmias. Overall on-AIT 1-year survival was 83%. Hospitalizations occurred in 51.9% (125) of patients a total of 174 times for worsening heart failure, line complication or ventricular arrhythmia. In the BTT cohort, only 42% were transplanted by the end of follow-up, with a 14.8% risk of death or delisting for clinical deterioration. For the patients who were transplanted, 1-year post HT survival was 96.7%. In the BTVAD cohort, 1-year survival after LVAD was 90%, but with 61.7% of patients undergoing LVAD as INTERMACS 1-2. In the palliative care cohort, only 24.5% of patients had a formal palliative care consult prior to AIT.

Conclusions

AIT is a strategy to discharge advanced heart failure patients from the hospital. It may be useful as bridge to transplant or ventricular assist device, but may be limited by complications such as hospitalizations, infections, and ventricular arrhythmias. Of particular note, it appears more challenging to bridge to transplant on AIT in the new allocation system. It is important to clarify the goals of AIT therapy upfront and continue to counsel patients on risks and benefits of the therapy itself and potential unintended consequences. Formalized, multi-disciplinary care planning is essential to clearly define individualized patient, as well as programmatic goals of AIT.

Introduction

As a result of improvements in medical and surgical therapy for heart failure (HF), a growing number of patients are living with end-stage disease. As a result, the demand for advanced therapies such as heart transplant (HT) and left ventricular assist device (LVAD) continues to increase. In step with this, inotropic infusion is increasingly used as a short-term therapy for in-hospital stabilization of cardiogenic shock or less severe decompensation, and ambulatory inotropic therapy (AIT) has broad use in palliative care and/or as a bridge to surgical therapies for advanced heart failure.^1,2 From 2010-2014 alone, Medicare data suggests a marked increase in the use of AIT, with spending that totaled nearly $250 million.³ For hospitalized patients who are deemed “inotrope-dependent,” AIT offers the opportunity for patients to go home - to consider or prepare for HT or LVAD - or to accept AIT as part of a palliative care plan or try for slow cross-titration to oral guideline-directed heart failure medications. AIT also aligns patient preference to go home with a hospital goal of decreased length of stay.

The American College of Cardiology/American Heart Association (ACC/AHA) assigns a Class IIa recommendation to AIT as Bridge to Transplant (BTT), and a Class IIb for palliative care.⁴ Critical to assessing the safety and efficacy of AIT is understanding whether the goal of AIT was achieved and if so, at what cost with regard to type and frequency of complications and unintended consequences. In the contemporary era, there remain insufficient data describing outcomes of AIT, specifically with regard to intention-to-treat outcomes, rates of rehospitalization and complications of therapy. Furthermore, in the era of mechanical circulatory support, few studies have examined the safety and efficacy of AIT as bridge to HT, specifically to avoid the “LVAD step” as bridge to transplant.

Thus, the objectives of the current study were to (1) describe the experience of AIT at a large volume, tertiary care heart failure center, (2) assess overall survival of patients on AIT, (3) assess intention-to-treat outcomes of AIT as bridge to advanced therapies and as palliation, with a specific focus on HT candidates, and (4) describe complications associated with AIT such as rates of rehospitalization, ventricular arrhythmias and indwelling line infections.