Risk factor analysis of long-term support with left ventricular assist system

Severe hemolytic anemia caused by the NIPRO extracorporeal left ventricular assist device

A 56-year-old woman with dilated cardiomyopathy underwent mitral and tricuspid annuloplasty, and simultaneous deployment of an extracorporeal left ventricular assist device (LVAD). Subsequently, she developed hemolytic anemia. Although the LVAD system was repeatedly exchanged and the mitral annular ring was removed, her hemolytic anemia did not improve. Finally, the NIPRO LVAD was replaced with Gyro Pump^®, and her anemia was ameliorated. It appears important to consider the possibility of hemolytic anemia as a LVAD-related complication, although it would be rare.

Preliminary report on the cost effectiveness of ventricular assist devices

The aim of the present study was to perform a cost-effectiveness analysis (CEA) of ventricular assist devices (VAD) implantation surgery in the Japanese medical reimbursement system. The study group consisted of thirty-seven patients who had undergone VAD implantation surgery for dilated cardiomyopathy (n = 25; 67.6 %) or hypertrophic cardiomyopathy (n = 4; 10.8 %), and others (n = 8; 21.6 %). Quality-adjusted life years (QALYs) were calculated using the utility score and years of life. Medical reimbursement bills were chosen as cost indices. The observation period was the 12-month period after surgery. Then, the incremental cost-effectiveness ratio was calculated according to the VAD type. In addition, the prognosis after 36 months was estimated on the basis of the results obtained using the Markov chain model. The mean preoperative INTERMACS profile score was 2.35 ± 0.77. Our results showed that the utility score, which indicates the effectiveness of VAD implantation surgery, improved by 0.279 ± 0.188 (ΔQALY, p < 0.05). The cost of VAD implantation surgery was 313,282 ± 25,275 (ΔUS$/year) on the basis of medical reimbursement bills associated with therapeutic interventions. The calculated result of CEA was 364,501 ± 190,599 (ΔUS$/QALY). The improvement in the utility score was greater for implantable versus extracorporeal VADs (0.233 ± 0.534 vs. 0.371 ± 0.238) and ICER was 303,104 (ΔUS$/ΔQALY). Furthermore, when we estimated CEA for 36 months, the expected baseline value was 102,712 (US$/QALY). Therefore, VAD implantation surgery was cost effective considering the disease specificities.

Novel method of evaluating liver stiffness using transient elastography to evaluate perioperative status in severe heart failure

BACKGROUND

The aim of the present study was to assess the efficacy of a non-invasive method, transient elastography (FibroScan), in measuring liver stiffness (LS), and whether LS can be used as a marker of cardiac - and hence perioperative - status.

METHODS AND RESULTS

Perioperative LS was prospectively measured using a FibroScan in 30 patients (21 male; 42.2 ± 13.3 years old) who underwent left ventricular assist device (LVAD) implantation. LS was checked pre- and postoperatively, then analyzed in regard to perioperative status. Preoperative LS was 13.3 ± 13.0 kPa (normal, <5.5 kPa), and was abnormal in 77% of patients. Four required bilateral VAD. LS in patients with bilateral VAD tended to be higher than in LVAD patients (25.1 ± 22.7 vs. 11.5 ± 10.5 kPa, P=0.051). No patient with LS ≤ 7.0 kPa required a right VAD. The incidence of major adverse events was lower in patients with LS ≤ 12.5 kPa (25% vs. 80%, P<0.05). There were also no mortalities among patients with LS ≤ 12.5 kPa.

CONCLUSIONS

LS was correlated with preoperative severity in patients with severe heart failure and reflected liver congestion, and may be useful to predict the requirement of right VAD, as well as postoperative complications in patients with LVAD implantation. This novel modality may be a useful non-invasive assessment method for management of severe heart failure.

Outcomes and predictors of early mortality after continuous-flow left ventricular assist device implantation as a bridge to transplantation

Left ventricular assist devices (LVADs) are fast becoming standard of care for patients with advanced heart failure. However, despite continuous improvement in VAD technology, there remains a significant early postoperative morbidity and mortality in this extreme patient group. The aim of the current study was to explore the short-term outcomes and predictors for 90 day mortality in the patients after implantation of continuous-flow LVAD. Perioperative clinical, echocardiographic, hemodynamic, and laboratory data of 90 day survivors and nonsurvivors were collected and compared retrospectively. Multivariate logistic regression analysis was performed on univariate predictors for 90 day mortality with an entry criterion of p < 0.1. Between July 2006 and May 2012, 117 patients underwent implantation of a continuous-flow LVAD as a bridge to transplantation: 71 (60.7%) HeartMate II (Thoratec Corp, Pleasanton, CA) and 46 (39.3%) HVAD (HeartWare International, Framingham, MA). All-cause 90 day mortality was 17.1%. Multivariate analysis revealed higher preoperative central venous pressure (odds ratio [OR], 1.18; 95% confidence interval [CI], 1.014-1.378; p = 0.033) and higher age (OR, 1.14; 95% CI, 1.01-1.38; p = 0.045) as the only independent predictors for 90 day mortality. Optimization of preoperative volume status, preload, and right heart function as well as age-based selection of candidates for LVAD support are the critical factors influencing early outcome after continuous-flow LVAD implantation.

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.

Clinical Outcomes of Pediatric Ventricular Assist Device Implantation: A Single-Institute Report from Japan

Purpose

Numerous difficulties remain associated with pediatric heart transplantation. Therefore, the development of a ventricular assist device (VAD) specific to these cases is extremely important for therapeutic effectiveness. We present 5 cases of severe heart failure that were managed by ventricular assist device implantation, as a bridge to transplantation.

Methods

We examined the clinical course of 5 patients (4 boys, 1 girl; mean age, 10.6 ± 1.5 years; range, 8-12 years) who underwent implantation of a pneumatic extracorporeal ventricular assist device between February 2004 and May 2009. Four patients had dilated cardiomyopathy and one had corrected transposition of the great arteries.

Results

The mean period between onset of heart failure and ventricular assist device implantation was 594 ± 750 days (range, 94-1702 days), and the mean duration of ventricular assist support was 112 ± 98 days (range, 44-284 days). Four patients underwent heart transplantation overseas and one died of cerebral hemorrhage.

Conclusions

Careful management of pediatric VAD patients and development of a device designed specifically for pediatric patients are essential for improving clinical outcomes in the future.

Prediction of outcome in patients with liver dysfunction after left ventricular assist device implantation

Although postoperative liver dysfunction (LD) following left ventricular assist device (LVAD) implantation is associated with high mortality, outcome is difficult to predict in patients with liver dysfunction. We aimed to clarify factors affecting recovery from LD after VAD implantation. A total of 167 patients underwent LVAD implantation, of whom 101 developed early postoperative LD, defined as maximum total bilirubin (max T-bil) greater than 5.0 mg/dl within 2 weeks. We set two different end-points, unremitting LD, and 90-day mortality. The rates of early mortality (90 days) and recovery from LD were 36 % (36/101) and 72 % (73/101), respectively. Univariate analysis showed that preoperative body weight, preoperative mechanical support, preoperative T-bil and creatinine, left ventricular diastolic dimension, right VAD (RVAD) insertion, cardiopulmonary bypass time, postoperative cardiac index, and postoperative T-bil and central venous pressure (CVP) on postoperative day (POD) 3 (non-recovered vs recovered, 12.4 ± 4.5 vs 9.5 ± 3.6 mmHg) were higher in patients with unremitting LD. Preoperative T-bil, RVAD insertion, and T-bil and CVP on POD 3 (non-survivor vs survivor, 12.4 ± 4.4 vs 9.4 ± 3.6 mmHg) were also higher in non-survivors. Multivariate analysis demonstrated that CVP on POD 3 was predictive of recovery from postoperative LD (OR 0.730, P < 0.05) and 90-day mortality (OR 0.730, P < 0.05). A key outcome factor in patients who developed early postoperative LD after LVAD implantation was postoperative liver congestion with high CVP. To overcome postoperative LD, appropriate management of postoperative CVP level is important.

Endovascular treatment of cerebral hemorrhage in a patient with a left ventricular assist device: report of a case

Cerebral hemorrhage is a common lethal complication associated with left ventricular assist device (LVAD) management. We performed cerebral angiography on patients with LVAD who developed cerebral hemorrhage and determined that ruptured aneurysms were the cause in some cases. Endovascular management of patients with LVAD can be a therapeutically useful approach for cerebral hemorrhage caused by aneurysm rupture.

Combination evaluation of preoperative risk indices predicts requirement of biventricular assist device

BACKGROUND

Patients with biventricular assist device (BiVAD) placement have a poor prognosis, but preoperative risk factors for the necessity of BiVAD have not been fully elucidated.

METHODS AND RESULTS

Data from 79 patients who received left ventricular assist device (LVAD) between November 2002 and December 2011 were retrospectively reviewed. Overall, 9 patients (11.4%) required BiVAD, and the survival rate of BiVAD patients was significantly lower than that of LVAD patients (P<0.001). Multivariate analysis for BiVAD requirement showed left ventricular diastolic diameter (LVDd) ≤62 mm (odds ratio [OR], 10.97; P=0.009) to be significantly associated with BiVAD requirement. Preoperative central venous pressure (CVP)/pulmonary capillary wedge pressure (PCWP) ratio ≥0.5 (OR, 13.09; P=0.028) was also significantly associated with BiVAD requirement. A new scoring system for predicting BiVAD requirement was created from the combination of CVP/PCWP ratio (≥0.5), body surface area (≤1.4 m(2)), preoperative continuous hemodiafiltration use, B-type natriuretic peptide (≥1,200 pg/ml) and LVDd (≤62 mm), and this had a significantly larger area under the curve (0.909; P=0.003) than right ventricular stroke work index on receiver operating characteristic analysis. A score >20 using the new scoring method indicated significantly high probability of BiVAD requirement (OR, 16.00; P=0.019).

CONCLUSIONS

The new scoring method, which includes CVP/PCWP ratio, is a novel risk stratification tool for BiVAD therapy.

Early decision for a left ventricular assist device implantation is necessary for patients with modifier A

Refractory ventricular tachyarrhythmias are life threatening, especially in patients with stage D heart failure, and left ventricular assist device therapy is virtually the sole option to resolve the fatal conditions in many cases. The Interagency Registry for Mechanically Assisted Circulatory Support defines modifier A as complicating recurrent ventricular tachyarrhythmias. However, the optimal timing to implant a left ventricular assist device remains to be determined in less sick patients with modifier A. We experienced three patients with stage D heart failure with revised modifier A, i.e., at least two appropriate operations of implantable cardiac defibrillators within 2 weeks. Two of them were rescued by extracorporeal left ventricular assist device implantation, but one died because of an electrical storm before left ventricular assist device support was available. We would like to emphasize that we should consider implantable left ventricular assist device therapy as soon as possible for those who are assigned modifier A to prevent sudden arrhythmic death.

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

BACKGROUND

This report details experience of the conversion of the Toyobo left ventricular assist device (LVAD; Nipro, Osaka, Japan) to the DuraHeart LVAD (TerumoHeart, Ann Arbor, MI, USA) in patients awaiting heart transplantation.

METHODS AND RESULTS

Eight patients (4 male, 4 female) with Toyobo paracorporeal LVAD underwent conversion to the third-generation centrifugal (DuraHeart) LVAD. The apical cuff of the Toyobo was not exchanged because the size was the same as that of the DuraHeart. All conversion operations were performed safely, but 3 patients who had infection of the Toyobo LVAD cannulation site prior to conversion suffered later pocket infections and 1 patient died because of sepsis. One patient underwent heart transplantation and 6 of 8 patients were awaiting heart transplantation at home.

CONCLUSIONS

Conversions from the Toyobo LVAD to the DuraHeart LVAD were performed safely. Considering that implantable LVADs provide superior long-term survival and quality of life, conversion is a reasonable decision for Toyobo LVAD users in whom there are no infections.

Successful treatment of cerebral hemorrhage using computed tomography angiography in a patient with left-ventricular-assist device

Cerebral hemorrhage is one of the common complications associated with left-ventricular-assist device (LVAD) treatment and leads to a high mortality rate because of excessive bleeding due to frequently unknown causes. Cerebral angiography is used to diagnose cerebrovascular events and is well recognized as being very useful for this purpose. We performed a cerebral angiography for a patient with an LVAD who developed cerebral hemorrhage, and the hemorrhagic source was clearly identified. The patient underwent successful neurosurgical treatment, which was followed by heart transplantation.

Prolonged biventricular assist device support as a bridge to heart transplantation

We report a case in which long-term biventricular assist device (BiVAD) support enabled successful heart transplantation. The patient was diagnosed with dilated cardiomyopathy at age 11. She underwent implantation of a Toyobo LVAD, tricuspid valvuloplasty and annuloplasty at age 15. Right heart bypass (RHB) was established using a centrifugal pump. Right ventricular function showed no improvement during a ten-day period, and RHB was switched to a Toyobo RVAD on postoperative day (POD) 11. Because of poor oxygenation, veno-venous extracorporeal membrane oxygenation (V-V ECMO) was instituted. She was weaned from V-V ECMO on POD 14. She was brought to the United States on POD 189 under BiVAD support, and underwent heart transplantation on POD 199. She was discharged 4 months later. Two years after heart transplantation, she remained in New York Heart Association class one without rejection.

Less frequent opening of the aortic valve and a continuous flow pump are risk factors for postoperative onset of aortic insufficiency in patients with a left ventricular assist device

BACKGROUND

Postoperative development of aortic insufficiency (AI) after implantation of left ventricular assist devices (LVADs) has recently been recognized, but the devices in the previous reports have been limited to the HeartMate I or II. The purposes of this study were to determine whether AI develops with other types of LVADs and to elucidate the factors associated with the development of AI.

METHODS AND RESULTS

Thirty-seven patients receiving LVADs without evident abnormalities in native aortic valves were enrolled (pulsatile flow LVAD [TOYOBO]: 76%, continuous flow LVAD [EVAHEART, DuraHeart, Jarvik2000, HeartMate II]: 24%). Frequency of aortic valve opening and grade of AI were evaluated by the most recent echocardiography during LVAD support. None of the patients had more than trace AI preoperatively. During LVAD support AI >- grade 2 developed in 9 patients (24%) across all 5 types of devices. More severe grade of AI correlated with higher plasma B-type natriuretic peptide concentration (r = 0.53, P < 0.01) and with less frequent of the aortic valve (r = 0.45, P < 0.01). Multivariate analysis revealed that lower preoperative left ventricular ejection fraction and a continuous flow device type were independent risk factors for higher incidence of AI.

CONCLUSIONS

AI, which is hemodynamically significant, develops after implantation of various types of LVADs. Physicians need to be more alert to the development of AI particularly with continuous flow devices.

Biventricular support using implantable continuous-flow ventricular assist devices

A 34-year-old woman with fulminant myocarditis underwent emergent implant with the Toyobo (Nipro, Osaka, Japan) paracorporeal biventricular assist device (BiVAD). The patient had been stable for 6 months, until she started to develop heart failure symptoms due to severe pulmonary insufficiency. Pulmonary valve closure and BiVAD conversion to implantable rotary pumps was performed. A DuraHeart centrifugal pump (Terumo Heart Inc., Ann Arbor, MI) was used for left ventricular assist, and a Jarvik 2000 axial-flow pump (Jarvik Heart Inc., New York, NY) was used for right ventricular assist. Although strict management was required to balance the flow rates of the two different types of devices, her postoperative course was uneventful and she was discharged home.

Mechanical circulatory assistance

Although heart transplantation is the gold standard for the treatment of advanced stage heart failure, the implantation of mechanical circulatory support devices (MCSDs) has become a well-established therapy for this disease. As the population of patients with severe heart failure has grown, the utilization of MCSDs has increased considerably. That trend is expected to continue, especially in light of dramatic advances in MCSD technology. This review outlines the current status and future directions of mechanical circulatory support therapy in the setting of a constantly evolving field of supportive devices and adjuvant therapies.

Age and preoperative total bilirubin level can stratify prognosis after extracorporeal pulsatile left ventricular assist device implantation

BACKGROUND

In Japan, the TOYOBO left ventricular assist device (LVAD) has been commercially available for heart failure patients as of 2010, but clinical risk stratification before implantation has not been widely performed.

METHODS AND RESULTS

In the present study data from 47 patients (age 38.6 ± 14.6 [SD] years, male 74.5%, non-ischemic 74.5%) implanted with a TOYOBO LVAD between November 2002 and February 2010 were analyzed. Kaplan-Meier survival analysis showed significantly higher mortality in the patients who had cardiogenic shock preoperatively (P = 0.031). Multivariate analysis revealed that the preoperative total bilirubin level (odds ratio [OR] 1.312, P < 0.001) and age (OR 1.076, P = 0.013) were independent risk factors for death. Perioperative necessity of a right ventricular assist device was also an independent risk factor for poor prognosis.

CONCLUSIONS

LVAD implantation is preferable before the patient experiences hemodynamic collapse. The preoperative total bilirubin level can be used to predict prognosis after device implantation in end-stage heart failure patients.