LVAD implantation involves open heart surgery (Figure , and additional file 1
: videos of HeartMate XVE and Thoratec ventricular assist devices implantation procedures). Surgery to implant the LVAD has a hospital (30- to 90-day) mortality of 14% to 27%, depending on the recipient's age and preexisting disease and comorbid conditions [11
]. In a prospective, randomized, controlled trial (Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure [REMATCH]) conducted between May 1998 and July 2001, 129 patients with chronic end-stage heart failure who were ineligible for cardiac transplantation were randomly assigned to receive LVAD-DT (n = 68) or optimal medical management (OMM) (n = 61) [11
]. In this trial, the HeartMate XVE (Thoratec Corporation, Pleasanton, California) was implanted as LVAD-DT (Figure ) [1
]. The LVAD-DT group had superior survival over OMM at 1 year follow-up (52% vs 25%, P
= 0.002) and at 2-year (23% vs 8%, P
= 0.09). However, the preponderance of male patients enrolled in the REMATCH trial (82% and 78% male patients treated with OMM and LVAD-DT, respectively) made it difficult to generalize the survival benefits to female patients [11
]. In spite of this limitation of the REMATCH trial, the US Food and Drug Administration and the US Centers for Medicare & Medicaid Services approved LVAD-DT in 2003 for men and women Medicare beneficiaries with chronic end-stage heart failure [17
Figure 1 The left ventricular assist device (LVAD). The LVAD from Thoratec Corporation (Pleasanton, California), the HeartMate LVAS (left ventricular assist system) XVE, helps the left ventricle of the heart pump blood throughout the body. A median sternotomy (more ...)
The Centers for Medicare & Medicaid Services guidelines for LVAD-DT eligibility in patients with chronic end-stage heart failure (New York Heart Association class IV end-stage left ventricular failure for ≤ 90 days with a life expectancy of < 2 years) and are not candidates for heart transplantation, mandate that they must meet all of the following conditions:
(1) The patient's class IV heart failure symptoms have failed to respond to OMM, including dietary salt restriction, diuretics, digitalis, β-adrenergic receptor-blocking agents, and angiotensin-converting enzyme inhibitors (if tolerated) for at least 60 of the past 90 days.
(2) The patient has a left ventricular ejection fraction of less than 25%.
(3) The patient has demonstrated functional limitation, with a peak oxygen consumption of less than 12 mL/kg per minute or the patient has continued need for intravenously administered inotropic therapy because of symptomatic hypotension, decreasing renal function, or worsening pulmonary congestion.
(4) The patient has the appropriate body surface area or size (≥ 1.5 m2
) to support implantation of the ventricular assist device [17
Notably, these coverage criteria do not address or stipulate several factors (e.g., cachexia, right ventricular heart failure, pulmonary hypertension, concurrent end-organ disease, malignancy or psychosocial factors) that are critical to patient outcome and QOL. Nevertheless, considering these factors is important in order to avoid, in some cases, reaching an ethically complex end-point sometimes referred to as "destination nowhere." [20
In the INTrEPID trial (Chronic Mechanical Circulatory Support for Inotrope-Dependent Heart Failure Patients Who Are Not Transplant Candidates) conducted between March 2000 and May 2003, the Novacor device (World Heart Corp, Oakland, California) was used in LVAD-DT patients [12
]. The survival rates for LVAD-DT (n = 37) and OMM (n = 18) were (46% vs 22%; P
= .03) at 6 months and (27% vs 11%; P
= .02) at 12 months.
In the post-REMATCH study conducted between November 2001 and December 2005, the in-hospital mortality rate was 27% for 280 patients who underwent HeartMate XVE implantation as DT [13
]. The causes of death were infections with sepsis, right ventricular heart failure, and multiorgan failure. The overall 1-year, 2-year and 3-year survival rates were 56%, 31% and 17%, respectively. The predictors of poor 1-year survival were cachexia, poor nutrition, hematologic abnormalities, end-organ or right ventricular dysfunction, and lack of inotropic support in LVAD-DT. Stratification of LVAD-DT patients as having low (n = 65), medium (n = 111), high (n = 28), or very high (n = 18) risk on the basis of these predictors corresponded with 1-year survival rates of 81%, 62%, 28%, and 11%, respectively [13
The post-REMATCH study used a case-series design; therefore, it did not validate the survival advantage attributed to LVAD in the subgroup analysis because it did not compare 1-year survival with comparable low-risk or medium-risk groups on OMM. Nonetheless, the excellent survival rate attributed to LVAD-DT in the low-risk subgroup can be similar to the survival rate with OMM in a similar group of low-risk patients (i.e., clinical equipoise). There has been an improvement in the overall survival rate after the onset of heart failure of 12% per decade during the past 5 decades [21
]. The largest increase in survival is most noticeable in low-risk heart failure patients because of clinically significant advances in the development and utilization of multiple-drug regimens for OMM. Currently, the actual 3-year survival rate of risk-adjusted heart failure patients is 71% on OMM [22
] and compares favorably with the survival rate of carefully selected low risk patients after LVAD implantation [14
Advances in medical technology have enabled rapid and temporary application of short-term mechanical circulatory devices in emergency situations. Short-term mechanical circulatory devices include, but are not limited to, extracorporeal membrane oxygenation, percutaneous cardiopulmonary bypass or percutaneous ventricular assist devices. The short-term mechanical circulatory devices are initiated as a bridge to long-term (also called bridge to bridge) or a bridge to permanent surgical implantation of LVAD [16
]. Idelchik et al. reported a series of 18 patients with chronic end-stage heart failure who experienced terminal hemodynamic collapse and underwent emergency placement of a percutaneous ventricular assist device (pVAD) (TandemHeart CardiacAssist Inc, Pittsburgh, Pennsylvania) as a bridge to long-term or permanent surgical implantation of an LVAD [16
]. In Idelchik et al. study, patients survived pVAD and were successfully bridged to a permanent LVAD: 4 patients received a HeartMate XVE, 6 received a HeartMate II (Thoratec Corporation), 3 received a Jarvik 2000 (Jarvik Heart, Inc, New York, New York), and 2 received a Novacor device. The rate of survival with LVAD-DT was 73% at 30 days and 67% at 6 months. Gregoric et al. also reported emergent placement of pVAD in a series of 9 end-stage heart-failure patients [23
]. The pVAD was a bridge to permanent surgical implantation of HeartMate II devices in 6 patients.