**2. Patient selection for LVAD therapy**

The population of people living with advanced heart failure is growing along with the need for advanced therapies. From 2006 through 2017, there have been 25,000 durable LVADs implanted [8]. This boost in implantation was largely due to the advent of the superior continuous flow LVADs which tripled the volumes being recorded in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) registry [8]. Firstly, there are two major LVAD indications that are accepted by both payors and governing bodies in medicine alike, either as a bridge to heart transplant (BTT) or as a final destination therapy (DT) in the setting of refractory end-stage heart failure [8]. It is also worth noting a more recent and controversial indication that is not recognized by the FDA which is being called "bridge to candidacy (BTC)." In this patient population, the LVAD is implanted officially as a DT, however, the heart team is hoping later to improve the patient's candidacy for a heart transplant. One example is an obese patient who would otherwise be a good OHT candidate where the LVAD is implanted with the hope of having the patient improve their BMI through weight management and/or bariatric surgery in order to become an eligible OHT candidate later. The least common implantation indication is as a bridge-to-recovery (BTR). While this remains a rare occurrence, only accounting for less than 3% of all LVAD recipients, there is recent retrospective data demonstrating that 40% of patients with a NICM and duration of HF less than or equal to 5 years at the time of implantation were alive and still not requiring MCS or OHT at 1-year post-LVAD explantation [9]. In the United States, the Centers for Medicaid and Medicare Services officially recognize the terms "short-term" and "long-term" in regard to the intention of LVAD implantation [8]. Patients who do qualify for an LVAD must undergo a qualification process to optimize their success post-surgery [10]. Risk stratification begins by classifying the patient with an INTERMACS profile. INTERMACS profiles range from 1 to 7, with 1 being the most severely decompensated cases of cardiogenic shock that require mechanical circulatory support (MCS) and 7 being the most compensated patients (**Table 1**).

*LVAD Continuing Care: A Comprehensive Guide to Long-Term Support and Management DOI: http://dx.doi.org/10.5772/intechopen.114271*


#### **Table 1.**

*INTERMACS profile descriptions.*

The advanced heart failure team will typically try to evaluate candidacy while the patient is still in INTERMACS profiles 3–4 where the post-surgical outcomes typically fare better than INTERMACS profiles 1 and 2.

LVAD candidacy evaluation should include a heart failure specialist, cardiac surgeons, anesthesiology, palliative care, psychology, and social work [11]. Additionally, multiple risk factors including the patient's age, renal function, liver function, hyponatremia, pulmonary disease, glucose tolerance, dysrhythmias, functional capacity, and history of recurrent admissions are all assessed [12]. All patients being evaluated for a durable LVAD should have early consultation with a palliative care specialist to establish each individual patient's goals of care by improving symptom management, setting realistic expectations, and clearly defining end-of-life care preferences. Progressive renal dysfunction is associated with a poorer prognosis, so it is generally recommended to implant the LVAD before developing severe cardiorenal syndrome or to place a temporary MCS device and monitor for improvement. For pulmonary assessment, it is recommended that the patient have a baseline chest X-ray and undergo invasive hemodynamic assessment. Routine ABGs are not required and there is limited data to validate the benefit of routine pulmonary function testing, but both may be useful if occult disease, such as COPD, is suspected [13]. CT or MRI to evaluate the chest anatomy in patients with a prior history of cardiac surgery is a reasonable choice pre-implantation for surgical planning. All patients should have a comprehensive neurological physical exam and any significant findings, including dementia and severe neuromuscular disease warrant a neurological consultation as these patients may not be able to manage their equipment. A CT head or an MRI may be considered if there is a prior history of stroke to establish a baseline. All patients should also have peripheral vascular disease screening by carotid and vertebral Doppler examinations. All patients should have their PT, aPTT, and INR checked and if an abnormality is found then it needs to be investigated as thrombophilia could thrombose the LVAD. Patients with a history of cancer in long-term remission may be candidates for DT LVAD. Patients with active malignancy, but a life expectancy greater than 2 years may also be considered for DT LVAD therapy in consultation with an oncologist. DT LVAD is not recommended in patients with an active malignancy and a life expectancy of less than 2 years. All patients should be screened for diabetes and those with known diabetes should have their glycemic control optimized prior to surgery. Women of reproductive age should be screened for pregnancy as durable LVADs are contraindicated during active pregnancy. Endoscopy and colonoscopy are reasonable in patients with a history of gastrointestinal bleeding or premalignant polyps.

Right heart failure (RHF) can be a common post-LVAD implantation complication, therefore the right ventricle must be thoroughly evaluated by a multifaceted approach that incorporates physical exam findings, invasive hemodynamics, echocardiography, and other advanced imaging modalities [14]. The gold standard of RV function and structural assessment is the cardiac MRI. Unfortunately, the utilization of MR may be limited in this population by device incompatibility. Right heart strain and 3D echocardiography have improved the ability to identify right heart failure on echocardiography and may be considered. While there is no ideal individual risk assessment tool for right heart failure, there are several predictive models that may be considered: Michigan RCF, Penn RVAD, Heartmate II bridge-to-transplantation RVF analysis, Utah RVF, Pittsburgh decision tree, EuroMACS, and other similar ones have been noted in the literature [14].

Cardiopulmonary stress testing (CPET) can be useful with peak oxygen consumption levels ≤12 mL/kg/min on beta-blocker therapy or ≤ 14 mL/kg/min off of beta-blocker therapy warranting further evaluation for advanced therapies [15]. Additionally, the patient's home should be evaluated for safety (lack of clutter, grounded electrical outlets, reliable telephone access, and emergency medical service access). The patient's psychosocial status should be assessed to evaluate the patient's capabilities and decision-making capacity as well as to mitigate any barriers to the patient being able to care for them self and manage the device. Psychosocial assessment aids in the success of post-LVAD morbidity and mortality. The Stanford Integrated Psychosocial Assessment for Transplantation (SIPAT) is a tool that can be used to determine post-implantation healthcare needs and behaviors. It analyzes a patient's preparedness, social support system, psychosocial stability, and lifestyle effects [16]. Any patient with a significant psychiatric disorder should be evaluated by a psychiatrist. Patients with a history of tobacco and marijuana use should receive counseling on the importance of cessation. Implanting centers vary on their respective policies in regard to marijuana use given the changing legal climate. Patients with a history of alcohol or other substance abuse must be abstinent for a period of time determined by the implanting centers. Active users of alcohol or other substance abuse should not receive an LVAD. The presence of a caregiver and their ability to participate in equipment and driveline management should be evaluated. Lack of a caregiver or a significant burden on the caregiver they cannot handle is a relative contraindication to implantation. While still poorly understood, frailty is associated with poorer outcomes and it is reasonable to use an objective frailty assessment tool such as the Fried Frailty Phenotype, The Deficit Index, or Handgrip strength test [8]. CT Imaging has been used to measure muscle mass as a surrogate as well [17].

Further, all reversible causes of heart failure should be thoroughly investigated including, but not limited to: treatable coronary disease, arrhythmogenic cardiomyopathy, valvular heart disease, cardiotoxic agents, and infiltrative disorders. The patient's guideline-directed medical therapy should be at maximally tolerated doses and device therapy with cardiac resynchronization therapy (CRT) should be optimized. OHT candidacy should be evaluated. LVAD therapy in advanced heart failure can lead to a significant improvement in quality of life. Follow-up is extensive and complex, requiring a thorough pre-implantation evaluation. Appropriate follow-up requires physicians, nurse practitioners, physical and occupational therapists, as well as social workers [18].

*LVAD Continuing Care: A Comprehensive Guide to Long-Term Support and Management DOI: http://dx.doi.org/10.5772/intechopen.114271*
