HeartMate II Left Ventricular Assist Device Pump Exchange: A Single-Institution Experience

Clinical Outcomes in Patients With Bacteremia and Concomitant Left Ventricular Assist Devices and Cardiac Implantable Electronic Devices

Infection remains a common cause of morbidity and mortality in patients with both left ventricular assist devices (LVADs) and cardiac implanted electronic devices (CIEDs) with limited data describing outcomes in patients who have both devices implanted. We performed a single-center, retrospective, observational cohort study of patients with both a transvenous CIED and LVAD who developed bacteremia. Ninety-one patients were evaluated. Eighty-one patients (89.0%) were treated medically and nine patients (9.9%) underwent surgical management. A multivariable logistic regression showed that blood culture positivity for >72 hours was associated with inpatient death, when controlled for age and management strategy (odds ratio [OR] = 3.73 [95% confidence interval {CI} = 1.34-10.4], p = 0.012). In patients who survived the initial hospitalization, the use of long-term suppressive antibiotics was not associated with the composite outcome of death or infection recurrence within 1 year, when controlled for age and management strategy (OR = 2.31 [95% CI = 0.88-2.62], p = 0.09). A Cox proportional hazards model showed that blood culture positivity for >72 hours was associated with a trend toward increased mortality in the first year, when controlled for age, management strategy, and staphylococcal infection (hazard ratio = 1.72 [95% CI = 0.88-3.37], p = 0.11). Surgical management was associated with a trend toward decreased mortality (hazard ratio = 0.23 [95% CI = 0.05-1.00], p = 0.05).

Left ventricular assist device exchange: a review of indications, operative procedure, and outcomes

The use of left ventricular assist devices (LVADs) is intended to treat patients with end-stage heart failure. Owing to technological advances, these devices are becoming more durable. However, LVADs may need to be exchanged when complications arise and heart transplantation is not possible. Indications for LVAD exchange (LVADE) include device thrombosis, device infections, and pump component failure. LVADE has historically been associated with a high risk of morbidity and mortality. In this review, we discuss the indications of LVADE, the decisional and technical aspects during surgery, and outcomes.

Interventional Microbubble Enhanced Sonothrombolysis on Left Ventricular Assist Devices

The left ventricular assist device (LVAD) is often used in the treatment of heart failure. However, 4% to 9% implanted LVAD will have thrombosis problem in one year, which is fatal to the patient's life. In this work, an interventional sonothrombolysis (IST) method is developed to realize the thrombolysis on LVAD. A pair of ultrasound transducer rings is installed on the shell of LVAD, and drug-loaded microbubbles are injected into the LVAD through the interventional method. The microbubbles are adhere on the thrombus with the coated thrombus-targeted drugs, and the thrombolytic drugs carried by the bubbles are brought into the thrombus by the cavitation of bubbles under the ultrasound. In a proof-of-concept experiment in a live sheep model, the thrombus on LVAD is dissolved in 30 min, without damages on LVADs and organs. This IST exhibits to be more efficient and safer compared with other thrombolysis methods on LVAD.

Long-term ungrounded cable support for short-to-shield syndrome

Short-to-shield (STS) is a potential complication for left ventricular assist device (LVAD) patients supported by the HeartMate II (HMII) pump. This phenomenon occurs when a damaged internal wire within the driveline makes contact with the surrounding sheath, resulting in insufficient power delivery to the motor when connected to a grounded power base unit (PBU). An ungrounded cable can be used to negate these effects, but the long-term safety of this treatment strategy is unknown. In this case series, we present our institutional experience treating 17 STS patients with an ungrounded cable. In total, we present 4922 patient-days (13.4 patient-years) of ungrounded cable support after primary STS treatment. There were no deaths or complications related to STS. These data suggest that the long-term use of an ungrounded cable is a reasonable treatment option for patients who cannot or do not wish to undergo pump exchange or splice repair.

Outcomes following left ventricular assist device exchange

INTRODUCTION

Left ventricular assist device (LVAD) exchange has been historically associated with a significant risk of morbidity and mortality. It is unknown, however, whether these outcomes have improved. We aimed to compare clinical outcomes following LVAD exchange to those following initial LVAD implant in a contemporary patient cohort.

METHODS

A total of 115 LVAD patients were enrolled between 2014 and 2017 and followed for 1 year. Of these, 15 patients (54.5 ± 13.3 years old, 87% male) underwent LVAD exchange at 277 (IQR 191-597) days following LVAD implantation and 100 patients (57.5 ± 12.3 years old, 76% male) did not undergo an LVAD exchange (non-exchange group).

RESULTS

One-year survival rate following LVAD exchange tended to be higher than the non-exchange patients (93% vs 76%, P = .15). Readmission rates for each comorbidity did not significantly differ between the two groups (P > .05 for all) except for the higher rate of pump thrombosis in the LVAD exchange group (P < .05).

DISCUSSION

LVAD exchange cohorts seem to have comparable clinical outcome with the non-exchange cohorts.

CONCLUSION

LVAD exchange might be an increasingly appropriate therapeutic option for the management of pump thrombosis, although careful monitoring for recurrent pump thrombosis is required.

Recurrent pump thrombosis is common after axial continuous-flow left ventricular assist device exchange

In selected patients with left ventricular assist device-associated infection or malfunction, pump exchange may become necessary after conservative treatment options fail and heart transplantation is not readily available. We examined the survival and complication rate in patients (⩾19 years of age) who underwent HeartMate II to HeartMate II exchange at our institution from 1 January 2010 to 28 February 2018. Clinical outcomes were analyzed and compared for patients who underwent exchange for pump thrombosis (14 patients), breach of driveline integrity (5 patients), and device-associated infection (2 patients). There were no differences in 30-day mortality (p = 0.58), need for temporary renal replacement therapy (p = 0.58), right ventricular mechanical support (p = 0.11), and postoperative stroke (p = 0.80) among groups. Survival at 1 year was 90% ± 7% for the whole cohort and 85% ± 10% for those who underwent exchange for pump thrombosis. In patients exchanged for device thrombosis, freedom from re-thrombosis and survival free from pump re-thrombosis at 1 year were 49% ± 16% and 42% ± 15%, respectively. No association of demographic and clinical variables with the risk of recurrent pump thrombosis after the first exchange was identified. Survival after left ventricular assist device exchange compares well with published results after primary left ventricular assist device implantation. However, recurrence of thrombosis was common among patients who required a left ventricular assist device exchange due to pump thrombosis. In this sub-group, consideration should be given to alternative strategies to improve the outcomes.