Low INTERMACS Profiles: One-Stage Durable LVAD Implantation for INTERMACS Level 1: Indications and Contraindications

Abstract

Left ventricular assist devices (LVADs) have become the standard of care for patients with end-stage heart failure as a bridge-to-transplant (BTT) therapy [1] and as a destination therapy (DT) [2]. Over the past decade, numbers of LVAD implants in North America have grown exponentially, with over 15,000 patients undergoing LVAD implantation with continuous-flow LVAD. Approval of DT and other studies have accelerated the shift of timing of LVAD implantation to more ambulatory patients with heart failure in several years [3]. However, in the seventh annual Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) report, about 15% of all patients with INTERMACS profile 1 underwent LVAD implantation, and this rate has not changed in the past several years [4]. Therefore, it is important to discuss about the treatment strategy for patients at the INTERMACS level 1. The major problems of patients at the INTERMACS level 1 include not only decompensated hemodynamic condition but also other organ dysfunction or uncertified neurological status. At the first encounter for patients with cardiogenic shock, candidacy for DT or BTT LVAD is often unclear. In addition, because of the severity of their illness, the time to make a decision is very limited. Therefore, an alternative approach instead of primary implantable LVAD insertion may be considered using short-term mechanical circulatory support (MCS) for patients at the INTERMACS level 1. This treatment strategy is considered as a bridge-to-decision therapy. The merit of this strategy is that stabilization of hemodynamics and improvement of organ function can be achieved before long-term durable LVAD implantation. We reported favorable outcomes with CentriMag (Thoratec Co., Pleasanton, CA) VAD usage in patients with cardiogenic shock [5]. Moreover, recent advances in technology enable us to implant percutaneous short-term VADs such as extracorporeal membrane oxygenation (ECMO) and Impella (Abiomed, Danvers, MA). Percutaneous MCS devices can be less invasively implanted and are especially applicable for salvage treatment in critically ill cases [6]. This staged procedure has potential benefits to restore hemodynamic instability and end-organ function and may improve outcomes following definitive surgeries [7]. On the other hand, there remain several concerns in the bridge-to-decision strategy. Patients require a second intervention in cases which require subsequent implantable LVAD insertion. The second surgery after surgical short-term VAD requires adhesive dissection and more transfusions. Moreover, bridge-to-bridge surgery imposes increasing risk of device infection on patients [8]. In addition, bridging strategy using multiple MCS devices could increase medical cost and impose prolonged hospital stay. Thus, one-stage durable LVAD implantation is possibly advantageous with regards to cost and adverse consequences associated by multiple interventions. No studies have been conducted comparing outcomes between two strategies in INTERMACS 1 patients. Nonetheless, utmost careful attention must be paid for appropriate patient selection.