Initial experience of conversion of Toyobo paracorporeal left ventricular assist device to DuraHeart left ventricular assist device

Clinical Outcomes of Left Ventricular Assist Device Pump Infection

Few studies have focused on the clinical outcomes and risk factors of left ventricular assist device (LVAD) pump infection, and no standard treatment for LVAD pump infection has been established. Therefore, we used a therapeutic flowchart to manage LVAD pump infections. We retrospectively evaluated 220 patients who underwent continuous-flow LVAD implantation between January 2005 and March 2021 at Osaka University, Japan. First, we performed wound debridement, negative-pressure wound therapy, antibiotic treatment, and omental flap transposition. Subsequently, we administered conservative treatment, scheduled implantable LVAD exchange, or emergent removal of the implantable LVAD and exchange for extracorporeal LVAD or percutaneous LVAD (IMPELLA). Pump infections occurred in 32 patients. The survival rates of patients with pump infections during LVAD support were 93%, 74%, and 61% at 180 days, 1 year, and 2 years after LVAD pump infection, respectively. Fifteen patients underwent successful heart transplantation. Bridge-to-bridge surgery, preoperative use of venoarterial extracorporeal membrane oxygenation or percutaneous LVAD, high lactate dehydrogenase levels, and driveline infection were significantly associated with pump infection. Our study reveals that poor preoperative condition and driveline infection were significant risk factors for LVAD pump infection.

Impact of Different Therapeutic Strategies With Left Ventricular Assist Devices on Health-Related Quality of Life During Prolonged Device-Based Support

Background: Left ventricular assist device (LVAD) implantation improves survival and health-related quality of life (HRQoL) of patients with heart failure. However, the impact of LVADs or different LVAD-based therapeutic strategies on long-term HRQoL has not been investigated. We evaluated the long-term HRQoL of Japanese patients who were treated with different LVAD-based therapeutic strategies. Methods and Results: Patients whose data were recorded in the Japanese Registry for Mechanical Assisted Circulatory Support between January 2010 and December 2018 were divided into 3 groups: primary implantable LVAD (G-iLVAD; n=483), primary paracorporeal LVAD (n=33), and bridge-to-bridge from paracorporeal to implantable LVAD (n=65). HRQoL was evaluated using the EuroQoL 5-dimension 3-level (EQ-5D-3L) before and 3 and 12 months after LVAD implantation; the mean EQ-5D-3L visual analog scale (VAS) score in the G-iLVAD group at these time points was 47.4, 71.1, and 72.9, respectively (where scores of 0 and 100 indicate worst and best imaginable health state, respectively). Changes in the least squares means of the VAS scores at 3 and 12 months after implantation differed significantly among the 3 groups. Social function, disability, and physical and mental problems were significantly lower in the G-iLVAD than other groups. Conclusions: HRQoL improved significantly at 3 and 12 months after LVAD implantation in all groups. Physical function showed a stronger improvement than did social function, disability, and mental function.

Clinical determinants of successful weaning from extracorporeal membrane oxygenation in patients with fulminant myocarditis

Aims

Patients with fulminant myocarditis (FM) often present with cardiogenic shock and require mechanical circulatory support, including extracorporeal membrane oxygenation (ECMO) and ventricular assist device (VAD) implantation. This study sought to clarify the determinants of successful weaning from ECMO in FM patients.

Methods and results

We studied 37 consecutive FM patients supported by ECMO as the initial form of mechanical circulatory support between January 1995 and December 2014 in our hospital. Twenty‐two (59%) patients were successfully weaned from ECMO, while 15 (41%) were not. There were significant differences in levels of peak creatine kinase and those of its MB isoform (CK‐MB), left ventricular posterior wall thickness (LVPWT), and prevalence of cardiac rhythm disturbances. Receiver operating characteristic curve analysis revealed that a peak CK‐MB level of 185 IU/L and LVPWT of 11 mm were the optimal cut‐off values for predicting successful weaning from ECMO (areas under the curve, 0.89 and 0.85, respectively). During the follow‐up [median 48 (interquartile range 8–147) months], 83% of FM patients who were weaned from ECMO survived, with preserved fractional shortening based on echocardiography. Of the 15 FM patients who were not weaned from ECMO, nine bridged to VAD, and only two were successfully weaned from VAD and survived.

Conclusions

These results indicate that myocardial injury, as evidenced by CK‐MB and LVPWT, and prolonged presence of cardiac rhythm disturbances are important clinical determinants of successful weaning from ECMO.

Successful left ventricular assist device re-implantation with omental covering for MDRP device infection

We present a case of paracorporeal left ventricular assist device (p-LVAD)-related infection, caused by multi-drug resistant Pseudomonas aeruginosae (MDRP), and successfully treated by p-LVAD re-implantation with omental covering. A 59-year-old man underwent p-LVAD implantation and coronary artery bypass grafting after percutaneous cardiopulmonary support and intra-aortic balloon pumping for cardiogenic shock due to acute myocardial infarction. Then, he was registered for heart transplantation. He suffered from blood stream infection causative organism of Pseudomonas aeruginosa, 2 months after that operation. He underwent re-median sternotomy and open drainage, 15 months after the p-LVAD implantation. However, he suffered from septic shock due to MDRP. He underwent p-LVAD re-implantation under hypothermic circulatory arrest and iodine gauze packing, followed by omental covering of the all artificial materials in his body 10 days after that operation. Soon after that, the infection was well controlled and the intravenous antibiotics could be discontinued 2 months after that operation. He successfully underwent heart transplantation, 17 months after that procedure. We concluded that p-LVAD re-implantation with omental covering is seemed to be useful in the treatment of massive device infection. This procedure might be a novel treatment for severe VAD-related infection until heart transplantation.

Nipro extra-corporeal left ventricular assist device fitting after left ventricular reconstruction with mitral valve plasty

Both left ventricular assist device and left ventricular reconstruction are treatment choices for severe heart failure conditions. Our institution performed a left ventricular assist device installation following a left ventricular reconstruction procedure on a 42-year-old male patient who presented with dilated cardiomyopathy and low cardiac output syndrome. A mitral valve plasty was used to correct the acute mitral valve regurgitation and we performed a Nipro extra-corporeal left ventricular assist device installation on post-operative day 14. Due to the left ventricular reconstruction that the patient had in a previous operation, we needed to attach an apical cuff on posterior apex, insert the inflow cannula with a large curve, and shift the skin insertion site laterally to the left. We assessed the angle between the cardiac longitudinal axis and the inflow cannula using computed tomography. The patient did not complain of any subjective symptoms of heart failure. Although Nipro extra-corporeal left ventricular assist device installation after left ventricular reconstruction has several difficulties historically, we have experienced a successful case.

Midterm outcome of implantable left ventricular assist devices as a bridge to transplantation: Single-center experience in Japan

BACKGROUND

Two implantable continuous-flow left ventricular assist devices (LVADs), DuraHeart (Terumo Heart, Ann Arbor, MI, USA) and EVAHEART (Sun Medical, Nagano, Japan), were approved in Japan in April 2011. We analyzed the midterm outcome of patients implanted with these implantable LVADs at the University of Tokyo Hospital.

METHODS AND RESULTS

A total of 31 patients who underwent implantation of LVADs (10 DuraHeart, 21 EVAHEART) as a bridge to transplantation at our institution between April 2011 and August 2013 were retrospectively reviewed. All patients were followed up through December 2013. Seven patients underwent conversions from NIPRO paracorporeal LVAD (Nipro, Osaka, Japan) to an implantable LVAD. The mean observation period was 483±239 days (41.0 patient years). Eight patients were transplanted and one patient showed functional recovery with subsequent LVAD explantation. Four patients died due to cerebrovascular accident, empyema, or device malfunction due to pump thrombosis after cerebral bleeding. Kaplan-Meier analysis revealed 6-, 12-, and 24-month survival rates of 93%, 86%, and 86%, respectively. The rates of freedom from cerebrovascular accidents and device-related infections at 1 year after LVAD implantation were 65% and 36%, respectively. Twenty-nine patients were discharged home after LVAD implantation. During the period of this study, there were 59 readmissions (53 urgent, 6 elective) among 22 patients (76%). The overall and urgent readmission rates were 1.66 and 1.49 per patient year, respectively. The common reason for readmission was device-related infection (31%), followed by cerebrovascular accidents (17%). The total out-of-hospital time after the primary discharge was 90%.

CONCLUSIONS

Our midterm survival rate after LVAD implantation is satisfactory. However, patients undergoing LVAD support were often readmitted with adverse events.

Current status of extracorporeal ventricular assist devices in Japan

Extracorporeal VADs are less expensive, their prices reimbursable by the health insurance being about one-sixth of those of implantable VADs in Japan. However, a disadvantage is that, in Japan, their use is restricted to hospitals, necessitating prolonged hospitalization, reducing the patients' quality of life. According to the Japanese registry for Mechanically Assisted Circulatory Support, the survival rate does not differ significantly between patients with extracorporeal and implantable VADs. As in Europe and North America, extracorporeal VADs in Japan are commonly used as Bridge to Decision or Bridge to Recovery. Extracorporeal VADs are switched to implantable VADs as a Bridge-to-Bridge strategy after stabilization or when cardiac function recovery fails. They are also used as right ventricular assist devices (RVADs) in patients with right heart failure. A special characteristic of extracorporeal VADs in Japan is their frequent use as a Bridge to Candidacy. In Japan, indications for implantable VADs are restricted to patients registered for heart transplantation. Therefore, in patients who cannot be registered for transplantation because of transient renal dysfunction, etc., due to heart failure, extracorporeal VADs are used first, and then replaced by implantable VADs after transplant registry is done. Here, we describe the current status of extracorporeal VADs in Japan, focusing on the environmental backgrounds, along with a review of the relevant literature.

Operative modification for the prevention of device-related infection during NIPRO extracorporeal left ventricular assist device implantation

An operative modification in which the NIPRO left ventricular assist device (LVAD) cannulas are passed through the intraperitoneal cavity is performed as the first-choice standard technique in our institution. Eighteen consecutive patients who underwent NIPRO LVAD implantation as heart transplantation candidates were enrolled in this study. The cannulas were passed through the intraperitoneal cavity in 11 patients (Group IP) and the extraperitoneal space in 7 patients (Group EP). A device-related major infection was defined as bloodstream infection and/or abscess formation in the deep tissue space. Device-related major infection occurred in 6 patients in Group IP and in 6 patients in Group EP. Of these patients, 3 patients in Group IP and 5 patients in Group EP suffered from uncontrollable bloodstream infection and finally died of development into multiple organ failure and/or cerebrovascular accidents. The actuarial rates of freedom from device-related major infection at 6 months after LVAD implantation were 100 % in Group IP and 38 % in Group EP, respectively (p = 0.02). Moreover, the actuarial survival rates after the initial device-related major infection in Group IP could be significantly higher than in Group EP (83 and 67 % at 6 months, p = 0.03). We demonstrated that this operative modification can contribute to prevention of progression of superficial skin infection to critical infection and to extension of the survival duration after the initial device-related major infection.

Initial experience in Japan with HeartWare ventricular assist system

We describe the first clinical experiences in Japan with the HeartWare ventricular assist device (HVAD: HeartWare Inc., Miami Lakes, FL, USA) in patients awaiting heart transplantation. Nine patients (6 males, 3 females; mean 33.5 ± 7.8 years; New York Heart Association class III or IV) received the HVAD as a bridge to transplantation between 2011 and 2012. Six had dilated cardiomyopathy, 2 secondary cardiomyopathy, and 1 dilated phase hypertrophic cardiomyopathy. All operations were uneventful, with a mean operation time of 269 ± 77 min and cardiopulmonary bypass time of 121 ± 40 min. One required a temporary right ventricular assist device and was weaned on postoperative day 20, while another required pump exchange due to foreign tissue in the inflow. Mean support duration was 245 ± 162 days (range: 50-535 days) and mean pump blood flow at 1 month postoperatively was 4.8 ± 0.8 l/min. There was no mortality after 30 days, though 1 patient died during support due to cerebral hemorrhage. Presently, the others are waiting for heart transplantation without problems, except 1 who suffered from an active infection. There was no pump mechanical failure in any case. The HeartWare pump enables quick implantation with acceptable morbidity and mortality. Our preliminary results indicate that this left ventricular assist device is safe for circulatory assistance for heart transplant candidates in Japan.

Preoperative beta-blocker treatment is a key for deciding left ventricular assist device implantation strategy as a bridge to recovery

To date, there have been few reports demonstrating preoperative predictors for left ventricular reverse remodeling (LVRR) after LV assist device (LVAD) implantation, especially among patients with dilated cardiomyopathy (DCM). We retrospectively analyzed 60 patients with stage D heart failure due to DCM who had received LVAD treatment [pulsatile flow (PF) type, 26; continuous flow type, 34]. Data were evaluated at 6 months or just before explantation of the LVAD. We defined "LV reverse remodeling" (LVRR) by the achievement of an LV ejection fraction (LVEF) of ≥ 35 % after 6 months of LVAD support or explantation of LVAD within 6 months. LVRR occurred in 16 of our patients (26.7 %). Uni/multivariate logistic regression analyses for LVRR demonstrated that of the preoperative variables evaluated, PF LVAD usage and insufficient preoperative β-blocker treatment were independent predictors for LVRR. Patients who accomplished LVRR had a better clinical course, including lower levels of aortic valve insufficiency and lower levels of plasma B-type natriuretic peptide. Of the six patients (10.0 %) in whom LVADs were eventually explanted, all had an LVEF of ≥ 35 % before explantation or at 6 months. Based on these results, we conclude that DCM patients with insufficient preoperative β-blocker treatment have a chance to achieve LVRR under LVAD support as a bridge to recovery.

Destination therapy: the new gold standard treatment for heart failure patients with left ventricular assist devices

Heart failure continues to be a growing health problem, eluding large-scale improvement and treatment. Cardiac transplantation has been the gold standard treatment with high post-transplant survival rates and relatively good quality of life. However, there has been an extreme shortage of organ donations, limiting transplants to only a very small portion of patients with the condition. This led to a growing interest in alternative options for the increasing population of patients who are waitlisted or ineligible for transplantation. In recent years, ventricular assist device (VAD) technologies have advanced from pulsatile blood pumps to continuous-flow pumps that have demonstrated unprecedented post-implantation survival rates. The HeartMate II, the only commercially available, continuous flow left ventricular assist device (LVAD) in the United States and Europe, has been implanted in over 10,000 patients worldwide, setting a benchmark for biomedical modalities of advanced heart failure treatment. Thanks to the successes of contemporary LVADs, patients are able to enjoy a better lifestyle, with a significantly prolonged life span and the ability to regularly partake in physical activities. In this new biomedical generation, the usage of LVADs has begun to expand towards the treatment for a wider range of heart conditions, including earlier stages of heart failure. In fact, LVAD implantations have surpassed the number of transplants taken place annually. An increasing number of patients are considering the permanent, circulatory support with an LVAD, namely destination therapy, as a promising option for treating heart failure.