Mechanical circulatory support after heart transplantation

Abstract

Objective: Mechanical circulatory support (MCS) may be used for severe graft failure after heart transplantation, but the degree to which it is lifesaving is uncertain.

Methods: Between June 1990 and December 2009, 53 patients after 1417 heart transplants (3.7%) required post-transplant MCS for acute rejection (n=17), biventricular failure (n=16), right ventricular failure (n=16), left ventricular failure (n=1), or respiratory failure (n=3). Although support was occasionally instituted remotely post-transplant (5>1 year), in 39 (73%) instances it was required within 1 week. Initial mode of support was extracorporeal membrane oxygenation in 43 patients (81%), biventricular assist device in 4 (7.5%), and right ventricular assist device in 6 (11%).

Results: Risk of requiring respiratory support was highest in those with restrictive cardiomyopathy as indication for transplant, women, and those with elevated pulmonary pressure or renal failure. Complications of support, which increased progressively with its duration, included stroke in two patients (3.8%), infection in two (3.8%), and reoperation for bleeding (seven instances) in four (7.0%). Nineteen patients (36%) recovered and were removed from support, five (9.4%) underwent retransplantation (four after biventricular failure and one after acute rejection), and 29 died while on support (55%). Overall survival after initiating support was 94%, 83%, 66%, and 43% at 1, 3, 7, and 30 days, respectively. Patients requiring support for biventricular failure had better survival than those having acute rejection or other indications (P=0.03). Survival after retransplantation or removal from support following recovery was 88% at 1 year and 61% at 10 years.

Conclusion: Severe refractory heart failure after transplantation is a rare catastrophic event for which MCS offers the possibility of recovery or bridge to retransplantation, particularly for patients with biventricular failure in the absence of rejection. Early retransplantation should be considered in patients who show no evidence of graft recovery on MCS.

Figure 1:

Sequence of mechanical circulatory support. The volume of each sphere is proportional to the number of patients who received that support device.

Figure 2:

Competing risks during mechanical circulatory support (MCS): death before MCS removal/retransplant (red), MCS removal for recovery (yellow), and retransplant (blue). Green line represents patients alive on MCS at any given time. (A) Percent of patients in each category. Each symbol represents an event and vertical bars 68% confidence limits equivalent to ±1 standard error. Numbers in parentheses represent patients remaining at risk. (B) Instantaneous risk of transition from ‘alive on MCS’ to each end-state category. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of the article.)

Figure 3:

All-cause mortality at any time after instituting mechanical circulatory support. (A) Survival at 0–15 months. Each circle represents a death, vertical bars 68% confidence limits, solid line parametric survival estimate, and dashed line 68% confidence limits around parametric estimate. Numbers in parentheses represent patients remaining at risk. (B) Survival at 0–12 years. Format is as in part (A).

Figure 4:

Survival after instituting mechanical circulatory support according to indication. Each symbol represents a death and vertical bars 68% confidence limits. Numbers in parentheses are patients remaining at risk.

Figure 5:

Survival after removal from mechanical circulatory support (MCS). Format is as in Fig. 3.