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Heart Transplantation for Advanced Heart Failure


Heart failure (HF) continues to be a leading cause of morbidity and mortality in the United States. Approximately 5.7 million Americans are currently living with HF; that number is expected to increase to more than 8 million by 2030. For the 915,000 new cases of HF diagnosed each year, 5-year mortality remains at approximately 50%. The gross annual cost for managing HF is approximately $30.7 billion and is expected to reach $70 billion by 2030. Strategies to avert these costs should focus on prevention considering that 75% of new HF cases are preceded by a history of hypertension. Technologic advances continue to improve therapeutic options and outcomes for patients living with advanced HF (AHF). Ultimately, heart transplantation provides the best long-term outcomes for AHF patients.

Identifying Advanced Heart Failure

The cardiac intensivist must be adept at identifying, stabilizing, and treating the AHF patient. Depending on the practice environment and patient population, proficiency begins with:

  • 1.

    Identifying AHF patients ( Box 48.1 )

    Box 48.1
    Modified from Yancy CW, Jessup M, Bozkurt B, et al. 2013 ACCF/AHA Guideline for the Management of heart failure: A Report of the American College of Cardiology Foundation/American Heart Association Task Force on practice guidelines. Circulation 2013;128(16):e240-327; and Metra M, Ponikowski P, Dickstein K, et al. Advanced chronic heart failure: a position statement from the Study Group on Advanced Heart Failure of the Heart Failure Association of the European Society of Cardiology. Eur J Heart Fail. 2007;9(6-7):684–694.
    Diagnostic Criteria and Clinical Events Identifying Patients With Advanced Heart Failure

    • 1.

      Diagnostic criteria

      • a.

        Advanced NYHA functional class (NYHA class III-IV)

      • b.

        Episodes of HF decompensation, characterized by either volume overload or reduced cardiac output

      • c.

        Objective evidence of severe cardiac dysfunction shown by one of the following:

        • i.

          LVEF <30%

        • ii.

          Pseudo-normal or restrictive mitral inflow pattern

        • iii.

          PCWP >16 mm Hg and/or RAP >12 mm Hg

        • iv.

          Elevated BNP or NT-proBNP plasma levels in the absence of noncardiac causes

      • d.

        Severe impairment of functional capacity shown by one of the following:

        • i.

          Inability to exercise

        • ii.

          Distance walked in 6 minutes ≤300 m

        • iii.

          Peak oxygen consumption (VO 2 ) <12–14 mL•kg•min

      • e.

        History of ≥1 HF hospitalizations in the past 6 months

      • f.

        Presence of all of the previous features despite “attempts to optimize” therapy, unless these are poorly tolerated or contraindicated, and cardiac resynchronization therapy when indicated

    • 2.

      Clinical events that suggest AHF

      • a.

        Frequent (≥2) HF hospitalizations or ED visits in the past 12 months

      • b.

        Progressive decline in renal function

      • c.

        Cardiac cachexia

      • d.

        Intolerance to ACE inhibitors because of hypotension or worsening renal function

      • e.

        Intolerance to β-blockers because of hypotension or worsening HF

      • f.

        Frequent systolic blood pressure <90 mm Hg

      • g.

        Persistent dyspnea with dressing or bathing requiring rest

      • h.

        Inability to walk 1 block on the level ground because of dyspnea or fatigue

      • i.

        Escalation of diuretics to maintain euvolemia (furosemide dose >160 mg/day or use of metolazone)

      • j.

        Progressive decline in serum sodium levels (<133 mEq/L)

      • k.

        Frequent ICD shocks

    ACE, Angiotensin-converting enzyme; BNP, B-type natriuretic peptide; ED , emergency department; ICD , implantable cardioverter-defibrillator; LVEF, left ventricular ejection fraction; NT-proBNP , N-terminal pro-B-type natriuretic peptide; NYHA, New York Heart Association; PWCP, pulmonary capillary wedge pressure; RAP, right atrial pressure: VO 2 , oxygen consumption.

  • 2.

    Determining which patients with AHF are potential heart transplant candidates

  • 3.

    Managing critically ill heart transplant candidates, which includes:

    • Intensification of intravenous diuretics, vasodilators, and inotropes

    • Interpretation of hemodynamics to guide therapy

    • Identification of optimal timing for mechanical circulatory support (MCS)

  • 4.

    Proficiency in the immediate postoperative care following heart transplantation

  • 5.

    Competency in the management of longer-term posttransplant complications that require cardiac intensive care unit (CICU) support;

    • Primary graft dysfunction

    • Acute and chronic rejection

    • Managing the denervated heart

    • Cardiac allograft vasculopathy

    • Complications of immunosuppression

Epidemiology

Of the almost 6 million Americans living with HF, approximately 200,000 patients have AHF or American College of Cardiology/American Heart Association (ACC/AHA) stage D heart failure. Once an AHF or stage D patient is identified and determined to be high risk for rehospitalization, heart transplant or mechanical circulatory support candidacy should be determined. Critical to optimal patient outcomes is timely selection of the right intervention for the right patient. The limited supply of donor hearts warrants strict selection criteria, ensuring that those who are listed for heart transplantation are most likely to benefit. Box 48.2 outlines common elements used for evaluation of potential cardiac transplant candidates.

Box 48.2
Evaluation of Potential Cardiac Transplant Candidates

  • 1.

    Detailed medical history and thorough physical examination

  • 2.

    Laboratory evaluation

    • Complete blood count

    • Renal function tests

      • Blood urea nitrogen/creatinine

      • Creatinine clearance

      • Glomerular filtration rate

    • Liver function tests

      • Alkaline phosphatase

      • Bilirubin

      • Albumin

      • Transaminases

    • ABO blood type and antibody screen

    • Serologies for:

      • Hepatitis A, B, C

      • HIV (human immunodeficiency virus)

      • Cytomegalovirus

      • Epstein-Barr virus

      • Herpes simplex viruses I, II

      • Toxoplasma gondii

      • Syphilis

    • Skin test for tuberculosis with controls

    • Right heart catheterization

    • Left heart catheterization/coronary angiography, if indicated

    • Echocardiogram or other form of ventriculography, if indicated

    • Electrocardiogram

    • Chest radiograph

    • Carotid ultrasound, if indicated

    • Pulmonary function tests

    • Exercise testing with measured oxygen consumption, VO 2

    • Histocompatibility leukocyte antigen typing/panel reactive antibody

  • 3.

    Psychosocial/financial consultation

Heart Transplantation Indications/Contraindication

Box 48.3 outlines common indications for heart transplantation. It is important to have a solid background in these indications to ensure that necessary treatment is not delayed and that unnecessary testing and treatment is not performed. In addition, the intensivist must recognize that severe HF or suboptimally treated HF is an insufficient indication for heart transplantation. Many patients considered for advanced therapies may still have stage C HF and require only medical optimization.

Box 48.3
Commonly Accepted Indications for Heart Transplantation

  • Cardiogenic shock with low probability of recovery

    • Refractory volume overload and inability to wean ventilator

    • Inability to wean temporary mechanical circulatory support

    • Intraaortic balloon pump, ventricular assist device, ECMO

    • Inability to wean continuous inotropic support

  • NYHA class IIIb or IV despite maximal medical and surgical therapy

    • Including hypertrophic and restrictive cardiomyopathies

    • Complex congenital heart disease not amenable to surgical or procedural intervention

  • Severe functional limitations secondary to underlying cardiac condition

    • Peak oxygen consumption VO 2 ≤1214 mL/kg/min, or marked serial decline over time in the context of age appropriate controls

    • 6-minute walk test <300 m

  • Ischemic heart disease with refractory CCS class III or IV angina pectoris despite optimal medical, surgical, and/or interventional therapy

  • Recurrent life-threatening ventricular arrhythmias despite optimal medical, electrophysiologic, and surgical therapy

  • Localized cardiac tumors with low likelihood of metastasis

CCS, Canadian Cardiovascular Society; ECMO, extracorporeal membrane oxygenation; NYHA, New York Heart Association.

Furthermore, the HF team must understand when heart transplantation is not an option or unlikely to be successful for a patient. Absolute and relative contraindications exist ( Box 48.4 ); practice varies among transplant centers.

Box 48.4
Modified from Mancini D, Lietz K. Selection of cardiac transplantation candidates in 2010. Circulation. 2010;122:173–183.
Commonly Accepted Contraindications for Heart Transplantation

Absolute Contraindications

  • Systemic illness with a life expectancy of <2 years despite HT, including

    • Active or recent solid organ or blood malignancy within 5 years (e.g., leukemia, low-grade neoplasms of prostate with persistently elevated prostate-specific antigen)

    • AIDS with frequent opportunistic infections

    • Systemic lupus erythematosus, sarcoid, or amyloidosis that has multisystem involvement and is still active and not amenable to treatment

    • Irreversible renal or hepatic dysfunction in patients considered for only HT

    • Significant obstructive pulmonary disease (FEV 1 <1 L/min)

    • Fixed pulmonary hypertension

    • Pulmonary artery systolic pressure >60 mm Hg

    • Mean transpulmonary gradient >15 mm Hg

    • Pulmonary vascular resistance >6 Wood units

Relative Contraindications

  • Age >72 years

  • Any active infection (with exception of device-related infection in VAD recipients)

  • Active peptic ulcer disease

  • Severe diabetes mellitus with end-organ damage (neuropathy, nephropathy, or retinopathy)

  • Severe peripheral vascular or cerebrovascular disease

    • Peripheral vascular disease not amenable to surgical or percutaneous therapy

    • Symptomatic carotid stenosis

    • Ankle brachial index <0.7

    • Uncorrected abdominal aortic aneurysm >6 cm

  • Morbid obesity (body mass index >35 kg/m 2 ) or cachexia (body mass index <18 kg/m 2 )

  • Creatinine >2.5 mg/dL or creatinine clearance <25 mL/min a

    a May be suitable for HT if inotropic support and hemodynamic management produce a creatinine <2 mg/dL and creatinine clearance >50 mL/min. Transplantation may also be advisable as combined heart-kidney transplantation.

  • Bilirubin >2.5 mg/dL, serum transaminases >3×, INR >1.5 off warfarin

  • Severe pulmonary dysfunction with FEV 1 <40% normal

  • Recent pulmonary infarction within 6–8 weeks

  • Difficult-to-control hypertension

  • Irreversible neurologic or neuromuscular disorder

  • Active mental illness or psychosocial instability

  • Drug, tobacco, or alcohol abuse within 6 months

  • Heparin-induced thrombocytopenia within 100 days

FEV 1 , Forced expiratory volume in 1 second; HT, heart transplantation; INR, international normalized ratio; VAD, ventricular assist device.

Recognizing risk factors and comorbidities helps determine the safety and appropriateness of transplantation for AHF patients and is critical to optimizing posttransplant outcomes. Members of every transplant center must work through their individual policies and determine what is an acceptable amount of risk while maintaining optimal outcomes.

Age

Age greater than 72 years is considered a relative contraindication to heart transplantation, based on work by Mancini and Lietz. There are limited data on septuagenarians, but Goldstein et al. reviewed 332 patients older than 70 years who underwent heart transplantation and demonstrated median unadjusted survival of 8.5 years compared to 9.8 years in over 5800 sexagenarians. They concluded that select heart transplant candidates over the age of 70 years still derive great benefit from cardiac transplantation. It is generally accepted that heart transplant programs develop specific donor and recipient criteria in the context of their local organ availability and quality to ensure optimal outcomes and a high probability of transplantation for all patients listed.

Weight

There continues to be worse outcomes in patients at the extremes of the body mass index (BMI) spectrum, BMI less than 18.5 kg/m 2 and greater than 35 kg/m 2 . It is a class IIa recommendation that patients achieve BMI less than 35 kg/m 2 before listing for heart transplantation. Additionally, there is a growing body of literature demonstrating safety and improved long-term outcomes in morbidly obese AHF patients who undergo bariatric surgery, some of whom are able to then go onto heart transplantation.

Diabetes Mellitus

Patients with diabetes mellitus (DM) who have no or minimal end-organ damage have excellent short- and intermediate-term outcomes with heart transplantation. Steroids will cause postprandial hyperglycemia, leading to worsened blood glucose control. Tacrolimus and cyclosporine will likely lead to end-organ damage, most commonly nephrotoxicity and/or neurotoxicity. The guidelines have adopted a class IIa recommendation stating a relative contraindication to heart transplantation in patients with DM and end-organ damage or persistent HbA1c levels greater than 7.5%.

Renal and Hepatic Impairment

AHF often leads to worsening renal and hepatic function. Cardiorenal syndrome and hepatic congestion can rapidly progress to irreversible stages. While no single test is an optimal predictor of recovery following heart transplantation, current guidelines recommend assessing renal function using estimated glomerular filtration rate (eGFR) or creatinine clearance. Evaluation often includes 24-hour proteinuria assessment, renal ultrasonography, and consultation with a nephrologist. The liver is more challenging than the kidney to predict degree of irreversible damage. Screening tools such as assessment of hepatic synthetic function (e.g., international normalized ratio [INR], platelets, albumin) are often misleading. Imaging of the liver, including abdominal ultrasound and abdominal computed tomography (CT), can often yield inconsistent results. The liver biopsy is being debated as a gold standard. Optimal liver biopsy specimens still have up to a 25% rate of discordance for fibrosis staging and an inherent risk of sampling bias. Newer imaging techniques—such as ultrasound elastography/fibroscan, perfusion imaging with CT, and magnetic resonance elastography (MRE) may improve disease assessment. Transplantation candidates with marginal hepatic and renal function are not only at risk during the perioperative period but have higher long-term morbidity and mortality.

Pulmonary Function

Severe chronic lung disease increases the risk of complications during the perioperative period and, independently, decreases the patient's functional capacity and chance for survival following transplantation. Patients with pulmonary dysfunction on immunosuppressive therapy demonstrate an increased incidence of pulmonary infection. Data are limited, but a single-center review of over 600 heart transplant patients demonstrated patients with FEV 1 (forced expiratory volume in one second)/FVC (forced vital capacity) ratio of 70% or less had significant prolongation of intubation and a significant reduction in 3-year survival compared to patients with FEV 1 /FVC ratio greater than 70%. Similar outcomes were seen in patients with a diffusing capacity of the lungs for carbon monoxide (DLCO) less than 60%. Caution should be exercised when evaluating patients with abnormal pulmonary function tests for heart transplantation.

Pulmonary Hypertension

Left ventricular (LV) dysfunction is the most common cause of pulmonary hypertension worldwide. Pulmonary hypertension increases the risk for right ventricular failure during the perioperative period and significantly worsens mortality. Patients under consideration for heart transplantation should undergo right heart catheterization (RHC). Several key parameters are determined at the time of RHC, including pulmonary vascular resistance (PVR), transpulmonary gradient (TPG), and the diastolic pulmonary gradient. Pulmonary artery (PA) systolic pressure greater than 50 mm Hg and a TPG greater than 15 mm Hg or a PVR greater than 3 Wood units is a class I recommendation to perform a vasodilator challenge. If these parameters can be corrected during initial hemodynamic measurement (e.g., with the administration of intravenous nitroprusside or an inotropic agent), it can safely be assumed that these abnormalities are secondary to the marked degree of cardiac dysfunction. Many AHF centers use indwelling PA catheters to allow for inpatient hemodynamic optimization. Select patients with severe cardiac dysfunction may require temporary MCS (tMCS) to fully unload the LV and allow for optimization of hemodynamics. This strategy may improve patient selection for durable MCS and, ultimately, patient outcomes. Durable MCS has been successful in lowering LV filling pressures over months, leading to negative remodeling. This strategy may provide marginal candidates the opportunity to become acceptable for heart transplantation. RHC should be routinely performed on patients based on risk factors and the clinical severity of disease in those who are being considered for heart transplantation. During episodes of decompensation or if patients are found to have unacceptably high PA pressures, admission to the CICU with PA catheter placement for medical optimization can be very helpful prior to transplantation. Young donor hearts with a naïve right ventricle (RV) have limited exposure to elevated pulmonary pressures and are at high risk for acute RV failure when transplanted into individuals with pulmonary hypertension. Patients with irreversible pulmonary hypertension may be considered for combined heart-lung transplantation.

Peripheral Vascular Disease and Cerebrovascular Disease

Severe symptomatic cerebrovascular or peripheral vascular disease can significantly hinder recovery and cardiac rehabilitation following heart transplantation. Registry data of over 1000 transplant patients with a history of symptomatic cerebrovascular disease document an increased risk of stroke and functional decline following transplantation. As part of the routine pretransplant evaluation, carotid Doppler ultrasound should be performed in patients with coronary artery disease or in patients older than 40 to 50 years. If significant carotid occlusive disease is identified, surgical correction should be strongly considered before transplantation. History and/or clinical signs or symptoms of peripheral vascular disease (PVD) should warrant appropriate screening and assessment, which may include lower extremity arterial Doppler evaluation and assessment of ankle-brachial indexes.

Infection

Transplanting in an individual with active infection is extremely high risk. The critical importance of immunosuppression immediately postoperatively leaves little room for error. It is routine to consult with an infectious disease specialist prior to transplantation if there are any active infectious concerns. Inpatient transplant candidates are particularly at risk for the development of a nosocomial infection. Meticulous attention to ongoing indications for indwelling lines or Foley catheters can help to avoid preventable infections. Practicing consistent sterile precautions while performing line maintenance can help prevent catheter-related infections. Using a very low threshold at the first sign of fever or leukocytosis to initiate a thorough investigation is recommended. At times, it is necessary to defer a patient's candidacy or downgrade a patient's listing status. An extensive infectious workup is performed on all potential transplant candidates. Finally, a thorough dental examination should be conducted before listing to identify patients with poor dentition and subclinical sources of infection. It is also important to recognize that patients who test positive for cytomegalovirus, Toxoplasma gondii , Epstein-Barr virus, hepatitis, human immunodeficiency virus (HIV), or prior tuberculosis (TB) infections can still be considered for heart transplantation. A transplant infectious disease physician can be instrumental in guiding therapy for this patient population, especially after the initiation of immunosuppression.

Malignancy

Transplantation significantly increases the incidence of malignancy, largely related to the effects of chronic immunosuppression. The prognosis, rate of progression, type of malignancy, response to treatment, and likelihood of widespread metastases must be thoroughly discussed and considered prior to proceeding with heart transplantation. Ongoing studies are needed to guide this decision process, especially for individuals with chemotherapy-induced cardiomyopathy.

Frailty

With an increasingly older population undergoing heart transplantation, accurate assessment of frailty is a growing area of interest. Frailty is a clinically recognized syndrome of decreased physiologic reserve that is often unmasked with only minor stressors. It is defined as a positive response to three or more of the following five components: weak grip strength, slowed walking speed, poor appetite, physical inactivity, and exhaustion. Frailty is an independent predictor of increased all-cause mortality in patients with AHF who are referred for heart transplantation. The difficulty with evaluating frailty is a lack of standardization. Flint et al. raise concern that not all frailty can be considered the same. They suggest that some frail patients may be appropriately treated with advanced therapy while others may not; therefore the current definition needs additional refinement and further study.

Psychosocial Issues

A comprehensive team evaluating all aspects of transplant candidacy, including psychosocial factors, is critical to optimizing patient outcomes and appropriate patient selection. A robust social support system is essential to the success of any patient undergoing heart transplantation. The vital nature of medication adherence, consistent follow-up, and early recognition of abnormal signs or symptoms are paramount to quality of life and long-term survival. The International Society for Heart and Lung Transplantation (ISHLT) guidelines provide a class IIa recommendation that “any patient for whom social supports are deemed insufficient to achieve compliant care in the outpatient setting may be regarded as having a relative contraindication to transplant.” Every heart transplant candidate should receive a careful and thorough evaluation by qualified professionals. Psychiatric conditions, including active substance abuse or prior substance abuse without clearly documented abstinence, may profoundly increase the risk of posttransplant complications. Tobacco use and alcohol abuse should be categorized with illicit drugs in estimating the scope of substance abuse. Marijuana has gained increasing attention as individual states have passed laws legalizing its use. The psychological stress of heart transplantation and its long-term sequela demand patient investment and commitment. Therefore it is important that psychosocial issues be addressed prior to heart transplantation.

Finances

The financial burden of heart transplantation varies significantly by region and insurance coverage. The estimated average 2014 billed charges associated with heart transplant in the United States are as follows:

  • 30 days pretransplant: $50,900

  • Procurement: $97,200

  • Hospital transplant admission: $771,500

  • Physician during transplant: $88,600

  • 180 days posttransplant discharge: $198,400

  • Immunosuppressants and other medications: $35,600

  • Total: $ 1,242,200

These figures do not include the nonmedical costs associated with food, lodging, transportation to and from a transplant center, need for child care and lost wages for the patient and family member who may be required to leave work to function as a primary caretaker. While most insurers cover the expenses incurred in the transplant procedure itself, coverage varies dramatically for medications and long-term care. A comprehensive transplant team will have dedicated financial specialists who can assess the costs of future care based on an individual's insurance coverage. The goal of the financial team is to ensure that the family is prepared and capable of dealing with the financial burden of heart transplantation. Undergoing heart transplantation is physically, emotionally, and psychologically challenging. The burdensome financial strains add to the complexity and, ultimately, can lead to nonadherence to treatment plans and protocols, resulting in poor outcomes.

Overview of Heart Transplantation

Heart transplantation remains the most effective treatment for selected patients with AHF. Once transplanted, survival is significantly improved, as shown in Fig. 48.1 .

Fig. 48.1, Kaplan-Meier long-term survival for adult heart transplants performed between January 1982 and June 2013. Recipient survival improves with each successive 5 to 10 years; however, the major gains in survival are limited to the first 6 to 12 months, with the long-term attrition rate being unchanged.

Survival at 1, 10, and 20 years is nearly 90%, 50%, and 20%, respectively. This is a dramatic improvement for AHF patients living with New York Heart Association (NYHA) class IV, stage D heart failure whose 5-year survival approaches zero. Heart transplantation is limited primarily by a worsening supply-demand mismatch. As recently as 2012, nearly 2000 heart transplants were performed nationwide, yet over 3300 patients were on the waiting list with a 1- to 2-year survival of 50%.

Patients with AHF awaiting heart transplantation face not only the challenges of their disease process but the limitations of donor availability, regional differences in wait times ( Fig. 48.2 and Table 48.1 ), and an increasingly complex donor allocation system. Since 2004, the annual number of cardiac transplants performed in the United States has slowly increased to approximately 2600 per year.

Fig. 48.2, Map of the 11 United Network for Organ Sharing regions in the United States.

TABLE 48.1
Median Wait Time by Region for Status 1A Patients Awaiting Heart Transplantation and Mean Heart Transplant Volume Relative to a Region's Population
Modified from Quader M, Wolfe L, Katlaps G, Kasirajan V. Donor heart utilization following cardiopulmonary arrest and resuscitation: influence of donor characteristics and wait times in transplant regions. J Transplant. 2014;2014:519401.
Region Total Population HTx Population Mean HTx Volume/y Median 1A Wait Time (d)
1 13,936,692 158,371 88 59.6
2 30,917,426 110,026 281 74.3
3 48,262,570 165,851 291 40.0
4 29,874,023 140,915 212 47.6
5 52,294,441 115,176 337 34.6
6 15,521,147 242,517 64 72.6
7 25,513,744 125,683 203 90.3
8 19,601,598 141,018 139 80.3
9 20,196,272 133,750 151 58.3
10 27,974,919 136,463 205 68.6
11 33,498,321 140,160 239 67.6
HTx, Heart transplantation.

The median wait time for a patient listed as status 1A in Region 7 is approximately 90 days. The criteria required for patients to become listed as status 1A are presented in Table 48.2 . It has been nearly a decade since the last revision of the heart allocation policy in the United States. Although during that time advances in medical therapy and drastic improvements in MCS options have helped to prolong survival, the status 1A mortality rate remains unacceptably high. An updated heart allocation policy with a six-tier system has been accepted and implemented in 2018.

TABLE 48.2
United Network for Organ Sharing (UNOS) Heart Allocation Algorithm
Modified from Kilic A, Emani S, Sai-Sudhakar C, Higgins R, Whitson B. Donor selection in heart transplantation. J Thorac Dis. 2014;6(8):1097–1104.
Status Level Category
Status 1A Transplant candidate must be admitted to listing transplant center hospital and have at least one of the following devices or therapies in place

  • I.

    Mechanical circulatory support for acute hemodynamic decompensation that includes at least one of the following:

    • a.

      Candidates with implanted left and/or right ventricular assist device may be listed for 30 days under this criterion at any point after being implanted if treating physicians determine they are clinically stable—admittance to hospital not required.

    • b.

      Total artificial heart

    • c.

      Intraaortic balloon pump

    • d.

      Extracorporeal membrane oxygenator (ECMO)

  • II.

    Mechanical circulatory support with objective medical evidence of significant device-related complications

  • III.

    Continuous mechanical ventilation

  • IV.

    Continuous infusion of a single high-dose intravenous inotrope or multiple intravenous inotropes in addition to continuous hemodynamic monitoring of left ventricular filling pressures

Status 1B Transplant candidate listed must have at least one of the following devices or therapies in place:
I. Left and/or right ventricular assist device implanted
II. Continuous infusion of intravenous inotropes
Status 2 A transplant candidate who does not meet the criteria for status 1A or 1B
Status 7 A transplant candidate who is considered temporarily unsuitable to receive a heart transplant

The wait for heart transplantation is becoming longer for candidates due to several factors: a surge in the number of candidates, an increase in survival with the use of MCS as a bridge to transplant, and a plateau of acceptable donor hearts. The allocation of such a scarce resource warrants an investment in research and technology to help expand the donor pool.

In an effort to deliver the best outcomes with the highest quality of life to patients, intensivists must recognize the role of the multidisciplinary cardiovascular care team ( Fig. 48.3 ), which includes cardiothoracic surgeons, mechanical circulatory support teams, interventional/structural cardiologists, critical care teams, AHF cardiologists, and supportive/palliative care physicians. Such a collaborative approach is fundamental for optimal patient care. Several randomized controlled trials have demonstrated that multidisciplinary team-based care for patients with AHF can reduce mortality by 25% to 46%, HF hospitalization by 25%, and all-cause hospitalizations by 20% to 30%. Additional studies have confirmed that the implementation of team-based care for AHF decreases length of stay and improves quality of life.

Fig. 48.3, An integrated model of team-based care for advanced heart failure patients incorporating multidisciplines while maintaining the patient at the center of the care plan. HTx, Heart transplant; MCS, mechanical circulatory support; PCI, percutaneous coronary intervention.

Pretransplant Patient Care

Pretransplant patient management starts with early recognition of patients with AHF. There are several levels of care that a patient with AHF awaiting heart transplantation may require; the physician must determine which will be sufficient. Many patients can be managed in the outpatient setting and remain listed as status 2. Frequent outpatient visits and assessment of adequate metabolic, cellular, and nutritional health are critical in preventing irreversible end-organ damage. The common symptoms, physical signs, and objective measures of cardiopulmonary status are listed in Box 48.5 .

Box 48.5
Indications of Intolerance of Current Medical Management

Worsening Cardiovascular Symptoms

  • Easy fatigability

  • Increasing frequency and severity of angina

  • Exertional dyspnea/shortness of breath at rest

  • Orthopnea/paroxysmal nocturnal dyspnea

  • Dysrhythmia (tachycardia, palpitations)

Worsening Cardiovascular Physical Signs

  • Hypotension/narrow pulse pressure

  • Resting tachycardia/frequent ventricular ectopy/atrial fibrillation

  • Elevated jugular venous pressure

  • Prominent S 3 /S 4

  • Loud murmur of mitral/tricuspid regurgitation

  • Hepatomegaly/ascites/hepatojugular reflux

  • Edema/anasarca

  • Diminished peripheral perfusion (cyanosis/delayed capillary refill)

Worsening Objective Measures of Cardiac Performance

  • Diminished renal perfusion (prerenal azotemia/rising serum creatinine)

  • Hepatic congestion (elevated liver function tests)

  • Decreased end-organ perfusion (metabolic acidosis/elevated serum lactate)

  • Deteriorating left ventricular function by echocardiogram

  • Decreased left ventricular ejection fraction by radionuclide ventriculography

  • Worsened cardiomegaly/pulmonary edema on chest radiograph

  • Diminished maximal oxygen consumption VO 2 on exercise testing

  • Abnormal parameters on right heart catheterization

  • Elevated central venous pressure

  • Worsening pulmonary arterial hypertension/pulmonary vascular resistance

  • Declining cardiac output/cardiac index

  • Increasing arteriovenous oxygen difference (A – VO 2 )

There is no single parameter that identifies an individual who would benefit from heart transplantation. LV ejection fraction (LVEF) was previously thought to be the primary indicator of worsening prognosis and survival, but we now know that LVEF fails to consistently predict outcomes and, alone, is an inadequate indication for heart transplantation. Nearly 50% of HF patients have HF with preserved ejection fraction (HFpEF). The field of AHF must find better ways of predicting outcomes and obtaining objective data points that can assist in predicting outcomes for this patient population. Two diagnostic tests, RHC and cardiopulmonary exercise testing (CPET), provide reliable, objective data that are helpful in evaluating patients with AHF.

RHC has a class I recommendation for all adult candidates in preparation for listing for heart transplantation. In addition, an RHC should periodically be performed on candidates awaiting heart transplantation at a frequency that is personalized to each individual situation. With the development of ambulatory PA pressure monitoring systems, such as the CardioMEMS (Abbott) device, future guidelines may need to consider alternatives to recurrent invasive procedures.

Recent trials have built upon the foundational work of Mancini and colleagues on the use of CPET as a tool for predicting outcomes in AHF patients. They found that a peak VO 2 of less than 14 mL/kg per minute can be used to predict a 1-year mortality benefit with heart transplantation in patients with AHF. CPET has been integrated into recent scientific statements. Multiple studies have demonstrated the utility of measuring exercise capacity and oxygen consumption to assist in determining the degree of cardiac dysfunction and prognosis. As our knowledge and understanding of the pathophysiology of AHF have matured, we have developed a better understanding of why the functional reserve capacity in AHF patients is limited. Exercise capacity in AHF patients is impaired by abnormal O 2 uptake in the lungs, progressive anemia limiting O 2 transport to skeletal muscle, reduced cardiac output in the setting of chronotropic and inotropic incompetence, and impaired vasoreactivity. The careful measurement of both ventilatory and peripheral O 2 uptake patterns can provide both prognostic value and quantification of disease severity.

The use of HF prognosis scores such as the Heart Failure Survival Score (HFSS) or the Seattle Heart Failure Model (SHFM) may be used to predict morbidity and mortality in ambulatory AHF patients and assist in discriminating patients who should be listed for transplantation. Predicted patient survival of less than 80% at 1 year by the SHFM or in the medium- to high-risk range by the HFSS is considered a reasonable threshold for listing for cardiac transplantation. Risk calculators such as the SHFM were developed for predicting events in outpatient cohorts, which limits their applicability to hospitalized AHF patients. While survival scores can be helpful in prognostication, listing patients for heart transplantation based only on survival risk scores is a class III recommendation and should be avoided.

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