Impact of Mechanical Circulatory Support on Posttransplant Outcomes

Impact of duration of mechanical support on heart transplantation: Hasty transplantation may not have a good long-term outcome

BACKGROUND

Mechanical circulatory support (MCS) has been widely utilized in critically ill cardiac transplant candidates. Few studies have investigated the impact of duration of MCS before heart transplantation (HTx) on long-term patient survival.

METHODS

A retrospective HTx database was reviewed between 2009 and 2019. Patients who did not or did undergo MCS before HTx were categorized into two groups: (1) A (did not) and (2) B (did), respectively. A receiver operating characteristic (ROC) curve was plotted to assess the cutoff level of MCS duration before HTx in evaluating 5-year survival.

RESULT

A total of 270 HTx patients (group A: 120, group B: 150) were analyzed. Group B patients had a higher percentage of blood type O, a higher incidence of resuscitation, a shorter listing duration, and a higher likelihood of having United Network for Organ Sharing (UNOS) 1A status than group A. The ROC curve revealed 24 days as a good cut-off level for determining the best MCS before HTx timing. Group B was categorized into two subgroups: (1) B1 (MCS < 24 days, n = 65) and (2) B2 (MCS > 24 days, n = 85). B2 had a higher incidence of cardiopulmonary resuscitation (CPR), hemodialysis, longer waiting time after MCS, and better ventricular assist device implantation than B1. However, the survival curves showed that B1 outcomes were significantly worse than in groups A and B2. Groups A and B2 had similar survival curves without an increased incidence of infection.

CONCLUSION

The preliminary data demonstrated that a longer duration of MCS may be associated with better outcomes than urgent HTx.

Vasoplegia following heart transplantation and left ventricular assist device explant is not associated with inferior outcomes

Background

Vasoplegia has been associated with inferior outcomes following heart transplantation (HTx). This observational study was designed to investigate outcomes in recipients with vasoplegia following left ventricular assist device (LVAD) explant HTx.

Methods

Patients undergoing LVAD explant followed by HTx from 01/2013–12/2018 at our centre were included. Vasoplegia was defined as the requirement for high dose vasopressor [noradrenaline (>0.5 μg/kg/min) and vasopressin (>1 U/h)] over the first 24 hours following HTx. Demographic and outcome data were retrieved from the transplant unit database.

Results

During the study period 24 patients underwent LVAD explant HTx. Of these, 13 (54.2%) developed vasoplegia. Both groups had similar duration of LVAD support (median 684 vs. 620 days P=0.62). There was a higher incidence of driveline infection in patients developing vasoplegia (69.2% vs. 18.2% P=0.02). HTx following donation after circulatory death (DCD) occurred in 9 (37.5%) patients and was not associated with a higher incidence of vasoplegia (P=0.21). Vasoplegia developed early following reperfusion and intensive care unit admission vasopressor-inotrope scores were significantly higher in patients with vasoplegia (P=0.002). Patients developing vasoplegia had similar ICU (P=0.79) and hospital (P=0.93) lengths of stay. Survival was equivalent both at 30-day (92.3% vs. 100% P=0.99) and 1-year (67.7% vs. 74.7% P=0.70). Our overall HTx 1-year survival was 89.3% over this period.

Conclusions

Vasoplegia is seen with a high incidence in HTx recipients bridged with an LVAD. This appears to be associated with the presence of driveline infections. Early aggressive management is advocated, resulting in equivalent 1-year survival to those patients not developing vasoplegia.

The Man with 2 Hearts: 25 Years from Heterotopic to Orthotopic Heart Transplantation

Substantial technological advances in mechanical circulatory support have caused a shift in the management of end-stage heart failure. From the 1970s through the 1990s, heterotopic heart transplantation was routinely performed in patients in whom orthotopic transplantation was likely to fail. Heterotopic heart transplantation is now performed less often because modern mechanical circulatory assist devices are routinely used as bridges to orthotopic transplantation; regardless, the operation has helped numerous patients who would not otherwise have received adequate allografts. We describe the case of a man with idiopathic nonischemic cardiomyopathy who, at age 17, was given an ABO- and size-matched heterotopic allograft that was a complete human leukocyte antigen mismatch. The graft functioned normally for 20 years until the patient had a myocardial infarction that necessitated placement of a coronary artery stent. Subsequent treatments involved many interventions, including insertion of an intra-aortic balloon pump, medical therapy for heart failure, implantation of a total artificial heart, and, ultimately, orthotopic transplantation. To our knowledge, our patient is the longest surviving recipient of a heterotopic heart transplant, with a remarkable 25-year graft survival despite poor histocompatibility and an almost complete lack of native heart function. The strategies used for his treatment make him a living case study that can add valuable information to the history of cardiac support.