Indications for Mechanical Circulatory Support Devices and Patient Selection...

MCS therapy is reserved for patients with advanced heart failure and can be used as a bridge to heart transplantation, bridge to decision or recovery, or destination therapy for patients who are not transplant candidates. Bridge-to-decision patients are those in which transplant eligibility is dependent on the patient’s condition after implantation. Indications for use may change as the patient’s condition changes. For example, a bridge-to-transplant candidate may become ineligible for transplant following the MCS implantations or a destination therapy patient may become transplant eligible after MCS implantation.

Advanced heart failure patients are symptomatic at rest or with minimal exertion and have difficulty with daily activities; their life expectancy is less than 2 years without intervention. Advanced symptoms of hyponatremia, hypotension, renal dysfunction, and frequent hospitalizations lead to poorer outcomes.

Devices may be extracorporeal, implantable or percutaneous; temporary or durable, long-term. Short-term non-durable devices include intra-aortic balloon pump (IABP), extracorporeal membrane oxygenation (ECMO), extracorporeal MCS devices (BVS5000 or AB5000), and percutaneous MCS devices such as Thoratec pVAD, Centrimag, Tandem Heart and the Impella. Devices designed for long-term use include Thoratec pVAD, Novacor, Heartmate XVE, Heartmate II, AbioMed TAH, Cardiowest TAH, Berlin EXCOR for pediatric patients, and DeBakey Child device. Several devices are currently under clinical investigation. The type of device chosen depends on the patient’s clinical condition, indication for use, and information provided by expert multidisciplinary teams for patient and family to provide informed consent.

Identifying the patient for MCS therapy is an intricate process requiring expertise of trained heart failure specialists. An evaluation is warranted to determine surgical risk, psychosocial status, and the ability to perform device self-care. The implanting or transplant center ultimately determines patient suitability.

The Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) has developed an assessment of severity tool that classifies patients into one of seven clinical profiles ranging from 1=”crash and burn” indicating the need for immediate implantation to 7=”placeholder” indicating that MCS is not currently indicated.

Several conditions may be contraindications for implantation or complicate MCS recovery, including right ventricular failure, structural heart disease, hepatic and renal dysfunction, coagulopathy, malnutrition and debilitation, obesity, and psychosocial and behavioral issues. This guideline paper specifically discusses each condition. Cautious assessment of right ventricular failure, nutritional status, and psychosocial and environmental assessment is recommended as part of the MCS evaluation. For patients with irreversible renal dysfunction, long-term MCS is not recommended.

Key take-away points from this guideline paper include 1) Referral to a MCS device center should be early; 2) Implantation should take place before the development of advanced heart failure symptoms such as hyponatremia, hypotension, and frequent hospitalizations; 3) Potential candidates should be evaluated by a multidisciplinary team expert in MCS; and 4) Morbidity and mortality are increased with co-morbid conditions.

Currently, in order to receive reimbursement, implanting centers are mandated by the Centers for Medicare and Medicaid (CMS) to participate in a disease-specific certification from the Joint Commission.