Clinical experience with HeartWare left ventricular assist device in patients with end-stage heart failure

Recovery after acute kidney injury requiring kidney replacement therapy in patients with left ventricular assist device: A meta-analysis

BACKGROUND

Acute kidney injury (AKI) is a common and severe complication after left ventricular assist device (LVAD) implantation with an incidence of 37%; 13% of which require kidney replacement therapy (KRT). Severe AKI requiring KRT (AKI-KRT) in LVAD patients is associated with high short and long-term mortality compared with AKI without KRT. While kidney function recovery is associated with better outcomes, its incidence is unclear among LVAD patients with severe AKI requiring KRT.

AIM

To identify studies evaluating the recovery rates from severe AKI-KRT after LVAD placement, which is defined by regained kidney function resulting in the discontinuation of KRT. Random-effects and generic inverse variance method of DerSimonian-Laird were used to combine the effect estimates obtained from individual studies.

METHODS

A total of 268 patients from 14 cohort studies that reported severe AKI-KRT after LVAD were included. Follow-up time ranged anywhere from two weeks of LVAD implantation to 12 mo. Kidney recovery occurred in 78% of enrollees at the time of hospital discharge or within 30 d. Overall, the pooled estimated AKI recovery rate among patients with severe AKI-KRT was 50.5% (95%CI: 34.0%-67.0%) at 12 mo follow up. Majority (85%) of patients used continuous-flow LVAD. While the data on pulsatile-flow LVAD was limited, subgroup analysis of continuous-flow LVAD demonstrated that pooled estimated AKI recovery rate among patients with severe AKI-KRT was 52.1% (95%CI: 36.8%-67.0%). Meta-regression analysis did not show a significant association between study year and AKI recovery rate (P = 0.08). There was no publication bias as assessed by the funnel plot and Egger's regression asymmetry test in all analyses.

RESULTS

A total of 268 patients from 14 cohort studies that reported severe AKI-KRT after LVAD were included. Follow-up time ranged anywhere from two weeks of LVAD implantation to 12 mo. Kidney recovery occurred in 78% of enrollees at the time of hospital discharge or within 30 d. Overall, the pooled estimated AKI recovery rate among patients with severe AKI-KRT was 50.5% (95%CI: 34.0%-67.0%) at 12 mo follow up. Majority (85%) of patients used continuous-flow LVAD. While the data on pulsatile-flow LVAD was limited, subgroup analysis of continuous-flow LVAD demonstrated that pooled estimated AKI recovery rate among patients with severe AKI-KRT was 52.1% (95%CI: 36.8%-67.0%). Meta-regression analysis did not show a significant association between study year and AKI recovery rate (P = 0.08). There was no publication bias as assessed by the funnel plot and Egger's regression asymmetry test in all analyses.

CONCLUSION

Recovery from severe AKI-KRT after LVAD occurs approximately 50.5%, and it has not significantly changed over the years despite advances in medicine.

Incidence and impact of acute kidney injury on patients with implantable left ventricular assist devices: a Meta-analysis

Background: We aimed to evaluate the acute kidney injury (AKI) incidence and its associated risk of mortality in patients with implantable left ventricular assist devices (LVAD).Methods: A systematic literature search in Ovid MEDLINE, EMBASE, and Cochrane Databases was conducted through January 2020 to identify studies that provided data on the AKI incidence and AKI-associated mortality risk in adult patients with implantable LVADs. Pooled effect estimates were examined using random-effects, generic inverse variance method of DerSimonian-Laird.Results: Fifty-six cohort studies with 63,663 LVAD patients were enrolled in this meta-analysis. The pooled incidence of reported AKI was 24.9% (95%CI: 20.1%-30.4%) but rose to 36.9% (95%CI: 31.1%-43.1%) when applying the standard definition of AKI per RIFLE, AKIN, and KDIGO criteria. The pooled incidence of severe AKI requiring renal replacement therapy (RRT) was 12.6% (95%CI: 10.5%-15.0%). AKI incidence did not differ significantly between types of LVAD (p = .35) or indication for LVAD use (p = .62). While meta-regression analysis did not demonstrate a significant association between study year and overall AKI incidence (p = .55), the study year was negatively correlated with the incidence of severe AKI requiring RRT (slope = -0.068, p < .001). The pooled odds ratios (ORs) of mortality at 30 days and one year in AKI patients were 3.66 (95% CI, 2.00-6.70) and 2.22 (95% CI, 1.62-3.04), respectively. The pooled ORs of mortality at 30 days and one year in severe AKI patients requiring RRT were 7.52 (95% CI, 4.58-12.33) and 5.41 (95% CI, 3.63-8.06), respectively.Conclusion: We found that more than one-third of LVAD patients develop AKI based on standard definitions, and 13% develop severe AKI requiring RRT. There has been a potential improvement in the incidence of severe AKI requiring RRT for LVAD patients. AKI in LVAD patients was associated with increased 30-day and 1 year mortality.

Is it Safe for Patients with Left Ventricular Assist Devices to Undergo Non-Cardiac Surgery?

Background and Objectives: Since the first use of ventricular assist devices (VADs) as bridge to recovery and bridge to cardiac transplantation in the early 1990s, significant technological advances have transformed VAD implantation into a routine destination therapy. With improved survival, many patients present for cardiac surgery for conditions not directly related to their permanent mechanical circulatory support. The aim of this study was to analyze the indications and outcomes of non-cardiac surgeries (NCSs) of left ventricular assist device (LVAD) patients in tertiary center. Material and Methods: We present a single-center experience after 151 LVAD implantations in 138 consecutive patients between 2012–2019 who had to undergo NCS during a follow-up period of 37 +/− 23.4 months on left ventricular assist device (LVAD). Results: A total of 105 procedures was performed in 63 LVAD recipients, resulting in peri-operative mortality of 3.8%. Twenty-five (39.7%) of patients underwent multiple surgeries. We found no significant difference in cumulative survival associated with the performed surgical interventions (p = 0.469). Conclusion: We demonstrated good overall clinical outcomes in LVAD patients undergoing NCS. With acceptable peri-operative mortality, NCS can be safely performed in LVAD patients on long-term support.

Independent risk factors for ICU mortality after left ventricular assist device implantation

Left ventricular assist devices (LVADs) are used as an alternative therapy for heart transplantation in patients with advanced heart failure. However, the mortality rate of these patients remains relatively high. A large proportion of deaths after LVAD implantation occur during intensive care unit (ICU) stay. We conducted a retrospective study to identify the risk factors for all-cause ICU mortality in patients with an implanted LVAD. Between January 1, 2008 and December 31, 2016, 70 consecutive patients who had received an LVAD were analyzed. The median ICU length of stay was 14 days (IQR: 8-31) and 16 patients (22.9% [95%CI: 13.1-32.7]) died in the ICU. The 90-day mortality rate was 25.7% (95%CI: 15.5-35.9). The main causes of ICU mortality were: multiple organ failure, stroke, and hemorrhagic events. The univariate analysis identified the following perioperative risk factors for all-cause ICU mortality: hypertension, preoperative platelet count, preoperative white cell count, inotropic support before LVAD implantation, mechanical ventilation before LVAD implantation, renal replacement therapy before LVAD implantation, short-term mechanical support before LVAD implantation, INTERMACS class 1 to 2, low intraoperative platelet count, low early postoperative hemoglobin level, low early postoperative platelet count, low early postoperative pH, and massive perioperative blood transfusion. In the multivariate logistic regression analysis, only mechanical ventilation before LVAD implantation was retained as an independent risk factor for ICU mortality (OR = 11.96 [95%CI: 2.67-53.45], P < .01). These findings confirm that most deaths after LVAD implantation occur in the ICU. Patients that receive mechanical ventilation preoperatively have the highest risk of death. This confirms the need to actively treat respiratory failure and to wean patients from respiratory support before LVAD implantation. Such a strategy offers the best opportunity to initiate active rehabilitation.

Impact of preoperative extracorporeal life support on left ventricular assist device outcomes: A comparative study

Background:

To investigate whether preoperative short-term extracorporeal life support therapy in patients undergoing continuous-flow left ventricular assist device implantation has an impact on the outcome regarding survival and adverse events.

Methods:

Between January 2011 and May 2018, 100 consecutive patients received HeartMate II, HeartWare, or HeartMate III for end-stage heart failure. Mean age was 64.2 ± 10.3 years. Three patient groups were identified: without preoperative extracorporeal life support (non-extracorporeal life support group, n = 80), with preoperative extracorporeal life support due to postcardiotomy shock after conventional cardiac surgery (postcardiotomy shock group, n = 9), and with preoperative extracorporeal life support without previous surgery (non-postcardiotomy shock group, n = 11). The primary endpoint was overall survival after device implantation. Secondary endpoints were adverse events during the follow-up period.

Results:

Survival was significantly different between the groups (p < 0.05): 30-day, 6-month, and 1-year survival rates were 85%, 68%, and 61% for non-extracorporeal life support group; 44%, 22%, and 22% for postcardiotomy shock group; and 45%, 27%, and 24% for non-postcardiotomy shock group, respectively. Furthermore, in both extracorporeal life support groups (postcardiotomy shock and non-postcardiotomy shock), there were a higher incidence (p < 0.05) of postoperative right heart failure (30% vs 66.7% vs 54.5%), acute renal failure requiring dialysis (20% vs 77.8% vs 54.5%), and respiratory failure (31.3% vs 88.9% vs 81.8%).

Conclusion:

Continuous-flow left ventricular assist device implantation with prior extracorporeal life support appears to have a worse outcome regarding survival, right heart failure, renal and respiratory dysfunction (p < 0.05). Future studies have to be done to evaluate the outcome after extracorporeal life support bridge pre-left ventricular assist device, especially as ultima ratio in postcardiotomy shock patients.

Left Ventricular Assist Device Infections: A Systematic Review

Left ventricular assist devices (LVADs) are becoming a more frequent life-support intervention. Gaining an understanding of risk factors for infection and management strategies is important for treating these patients. We conducted a systematic review and meta-analysis of studies describing infections in continuous-flow LVADs. We evaluated incidence, risk factors, associated microorganisms, and outcomes by type of device and patient characteristics. Our search identified 90 distinct studies that reported LVAD infections and outcomes. Younger age and higher body mass index were associated with higher rates of LVAD infections. Driveline infections were the most common infection reported and the easiest to treat with fewest long-term consequences. Bloodstream infections were not reported as often, but they were associated with stroke and mortality. Treatment strategies varied and did not show a consistent best approach. LVAD infections are a significant cause of morbidity and mortality in LVAD patients. Most research comes from secondary analyses of other LVAD studies. The lack of infection-oriented research leaves several areas understudied. In particular, bloodstream infections in this population merit further research. Providers need more research studies to make evidence-based decisions about the prevention and treatment of LVAD infections.

It keeps on turning: Effects of prolonged long-term left ventricular assist device support as a bridge to heart transplantation

OBJECTIVES:

Increasing incidence of end-stage heart failure has moved the therapy with left ventricular assist devices to the forefront of surgical treatment. Moreover, continuous sophistication in this technology has resulted in increasing proportion of patients on prolonged support. Early and late complications after left ventricular assist device as a bridge to transplantation and present factors associated with long-term support and long-term outcomes of patients supported for at least 1 year were compared.

METHODS:

A total of 163 consecutive patients who underwent left ventricular assist device implantation as bridge to transplantation were included. A total of 79 patients were supported for at least 1 year (long-term support), whereas 84 patients were supported for less than 1 year (short-term group).

RESULTS:

Factors associated with a successful long-term support were male gender (p < 0.001), cessation of smoking at least 6 months prior to surgery (p = 0.045), previous implantation of implantable cardioverter defibrillator (p = 0.001) and rapid postoperative extubation (p = 0.018). Regarding echocardiographic parameters, higher left ventricular mass (p = 0.013) and larger left ventricular-end systolic (p = 0.008) and diastolic (p = 0.005) diameters prior to left ventricular assist device implantation were associated with long-term support. Short-term group showed higher mortality and higher proportion of patients who underwent device exchange due to device failure, and left ventricular assist device explantation for myocardial recovery was less frequent in the long-term support (p < 0.001). In addition, patients from the long-term support had significantly higher incidence of higher-grade aortic regurgitation (p = 0.005).

CONCLUSION:

Prolonged left ventricular assist device support as bridge to transplantation is associated with lower mortality and lower incidence of device failure requiring device exchange. However, long-term support reduces the chance of device explantation for myocardial recovery and increases the incidence of higher-grade aortic regurgitation in the follow-up.

A Bayesian Model to Predict Survival After Left Ventricular Assist Device Implantation

OBJECTIVES

This study investigates the use of a Bayesian statistical models to predict survival at various time points in patients undergoing left ventricular assist device (LVAD) implantation.

BACKGROUND

LVADs are being increasingly used in patients with end-stage heart failure. Appropriate patient selection continues to be key in optimizing post-LVAD outcomes.

METHODS

Data used for this study were derived from 10,277 adult patients from the INTERMACS (Inter-Agency Registry for Mechanically Assisted Circulatory Support) who had a primary LVAD implanted between January 2012 and December 2015. Risk for mortality was calculated retrospectively for various time points (1, 3, and 12 months) after LVAD implantation, using multiple pre-implantation variables. For each of these endpoints, a separate tree-augmented naïve Bayes model was constructed using the most predictive variables.

RESULTS

A set of 29, 26, and 31 pre-LVAD variables were found to be predictive at 1, 3, and 12 months, respectively. Predictors of 1-month mortality included low Inter-Agency Registry for Mechanically Assisted Circulatory Support profile, number of acute events in the 48 h before surgery, temporary mechanical circulatory support, and renal and hepatic dysfunction. Variables predicting 12-month mortality included advanced age, frailty, device strategy, and chronic renal disease. The accuracy of all Bayesian models was between 76% and 87%, with an area under the receiver operative characteristics curve of between 0.70 and 0.71.

CONCLUSIONS

A Bayesian prognostic model for predicting survival based on the comprehensive INTERMACS registry provided highly accurate predictions of mortality based on pre-operative variables. These models may facilitate clinical decision-making while screening candidates for LVAD therapy.

Levitronix bilateral ventricular assist device, a bridge to recovery in a patient with acute fulminant myocarditis and concomitant cerebellar infarction

We report on the case of a 27-year-old male who presented to our emergency room with chest tightness, dyspnoea and cold sweats. The 12-lead electrocardiogram showed diffuse ventricular tachycardia with wide QRS complexes. Troponin-I level was elevated to 100 ng/ml. The coronary angiogram showed good patency of all three coronary vessels, and acute fulminant myocarditis was suspected. The patient underwent cardiopulmonary resuscitation in the catheter room and high-dose inotropic support was initiated to stabilise his haemodynamic status. After resuscitation, the patient was in a coma and acute stroke was highly suspected. In addition, deteriorating cardiogenic shock with acute renal failure and pulmonary oedema were also detected. Due to haemodynamic compromise despite high-dose inotropic support, a Levitronix® bilateral ventricular assist device (Bi-VAD) was implanted on an emergency basis for circulatory support. Postoperative brain computed tomography revealed acute left cerebellar infarction. Because the patient had left cerebellar infarction with right hemiplegia, heart transplantation was contraindicated. Eventually, cardiac systolic function recovered well and the patient underwent successful Bi-VAD removal after a total of 18 days on Levitronix® haemodynamic support. He was weaned from the ventilator two weeks later and was discharged 10 days later.

Is there a difference in bleeding after left ventricular assist device implant: centrifugal versus axial?

BACKGROUND

Continuous-flow left ventricular assist devices (CF-LVAD) have become the standard of care for patients with end stage heart failure. Device reliability has increased, bringing the potential for VAD, compared to transplant, into debate. However, complications continue to limit VADs as first line therapy. Bleeding is a major morbidity. A debate exists as to the difference in bleeding profile between the major centrifugal and axial flow devices. We hypothesized that there would be similar adverse bleeding event profiles between the 2 major CF-LVADs.

METHODS

We retrospectively investigated isolated CF LVADs performed at our institution between July 2010 and July 2015: HeartMateII (HMII, n = 105) and HeartWare (HVAD, n = 34). We reviewed demographic, perioperative and short- and long-term outcomes.

RESULTS

There was no significant difference in demographics or comorbidities. There was a low incidence of gastrointestinal (GI) bleed 3.9% in HMII and 2.9% in HVAD (p = 0.78). Preoperatively, the cohorts did not differ in coagulation measures (p = 0.95). Within the post-operative period, there was no difference in product transfusion: red blood cells (p = 0.10), fresh frozen plasma (p = 0.19), and platelets (p = 0.89). Post-operatively, a higher but not significantly different number of HMII patients returned to the operating room for bleeding (n = 27) compared to HVAD (n = 6, p = 0.35). There was no difference in rates of stroke (p = 0.65), re-intubation (p = 0.60), driveline infection (p = 0.05), and GI bleeding (p = 0.31). The patients had equivalent ICU LOS (p = 0.86) and index hospitalization LOS (p = 0.59).

CONCLUSION

We found no difference in the rate of bleeding complications between the current commercially available axial and centrifugal flow devices.

Thrombosis in Left Ventricular Assistance Device with Centrifugal Technology: Is Early Thrombolysis a Better Solution?

Background

Continuous flow left ventricular assistance devices (CF-LVADs) have revolutionized the treatment of advanced heart failure. Pump replacement for thrombosis is a high-risk procedure with a high perioperative mortality rate with possible recurrence. We aim to summarize our experience using a conservative approach with medical therapy.

Methods

We retrospectively reviewed records of patients who experienced pump thrombosis after LVAD implantation with HeartWare HVAD at our institution, from November 2010 to March 2016. Device thrombosis (DT) was divided into suspected (SDT) and confirmed (CDT). A conservative approach using thrombolysis and heparin was used in all patients.

Results

A total of 32 HeartWare HVAD pumps were implanted. Mean age was 59 ± 10 years and the mean time on mechanical support was 19.29 months (± 14.06). Pump thrombosis occurred in 7 patients (0.14 patients/year) after a mean time of 733 (231–1,606) days after LVAD implantation. Three out of 7 cases had thrombosis recurrence (43%). Overall 19 episodes were recorded (0.38 event per patient/year). Eighteen out of 19 thrombolytic treatments were successful (94.7%). No patient required LVAD replacement or transfusion of blood products. There was no significant difference in terms of survival between patients who experienced thrombotic events and patients who did not. No major complications related to thrombolysis were recorded.

Conclusions

Systemic thrombolysis plus heparin was an excellent therapeutic option. Early intervention in clinically stable patients without signs of heart failure but with indirect signs of device thrombosis has led to better outcomes.

In Vitro PET Imaging of a Miniature Ventricular Assist Device

Interactions between the life-sustaining ventricular assist devices and diagnostic therapies must be carefully considered to decrease the risk of inaccurate diagnostic imaging or pump failure.

METHODS

The MVAD(®) pump, currently under investigational use, was tested for interaction with radiotracers in an in vitro flow-loop study. The radiotracers (18)F-sodium fluoride and (18)F-FDG were injected into a closed loop to determine the feasibility of direct imaging of the MVAD(®) pump in a PET scanner.

RESULTS

No real-time changes were observed in pump operation, and there were no statistical differences in pump parameters (power consumption, speed, and estimated flow rate) between the baseline and circulation conditions. In addition, no effect was observed on any external components, including the permissive-action-link controller and the batteries powering the device. Imaging of the internal pump components was possible, with obscuration observed only in the portion of the pump where the spinning impeller is located. Retention of radiotracer in the pump components after circulation was minimal (<1%).

CONCLUSION

PET imaging is an attractive diagnostic tool for patients with a ventricular assist device and may have additional utility outside its current use, detection of infection.

Fully Magnetically Levitated Left Ventricular Assist System for Treating Advanced HF: A Multicenter Study

BACKGROUND

The HeartMate 3 left ventricular assist system (LVAS) is intended to provide long-term support to patients with advanced heart failure. The centrifugal flow pump is designed for enhanced hemocompatibility by incorporating a magnetically levitated rotor with wide blood-flow paths and an artificial pulse.

OBJECTIVES

The aim of this single-arm, prospective, multicenter study was to evaluate the performance and safety of this LVAS.

METHODS

The primary endpoint was 6-month survival compared with INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support)-derived performance goal. Patients were adults with ejection fraction ≤ 25%, cardiac index ≤ 2.2 l/min/m(2) without inotropes or were inotrope-dependent on optimal medical management, or listed for transplant.

RESULTS

Fifty patients were enrolled at 10 centers. The indications for LVAS support were bridge to transplantation (54%) or destination therapy (46%). At 6 months, 88% of patients continued on support, 4% received transplants, and 8% died. Thirty-day mortality was 2% and 6-month survival 92%, which exceeded the 88% performance goal. Support with the fully magnetically levitated LVAS significantly reduced mortality risk by 66% compared with the Seattle Heart Failure Model-predicted survival of 78% (p = 0.0093). Key adverse events included reoperation for bleeding (14%), driveline infection (10%), gastrointestinal bleeding (8%), and debilitating stroke (modified Rankin Score > 3) (8%). There were no pump exchanges, pump malfunctions, pump thrombosis, or hemolysis events. New York Heart Association classification, 6-min walk test, and quality-of-life scores showed progressive and sustained improvement.

CONCLUSIONS

The results show that the fully magnetically levitated centrifugal-flow chronic LVAS is safe, with high 30-day and 6-month survival rates, a favorable adverse event profile, and improved quality of life and functional status. (HeartMate 3™ CE Mark Clinical Investigation Plan [HM3 CE Mark]; NCT02170363).

Short and long term outcomes of 200 patients supported by continuous-flow left ventricular assist devices

AIM: To study the institutional experience over 8 years with 200 continuous-flow (CF) - left ventricular assist devices (LVAD).

METHODS: We evaluated our institution’s LVAD database and analyzed all patients who received a CF LVAD as a bridge to transplant (BTT) or destination therapy from March 2006 until June 2014. We identified 200 patients, of which 179 were implanted with a HeartMate II device (Thoratec Corp., Pleasanton, CA) and 21 received a Heartware HVAD (HeartWare Inc., Framingham, MA).

RESULTS: The mean age of our LVAD recipients was 59.3 years (range 17-81), 76% (152/200) were males, and 49% were implanted for the indication of BTT. The survival rate for our LVAD patients at 30 d, 6 mo, 12 mo, 2 years, 3 years, and 4 years was 94%, 86%, 78%, 71%, 62% and 45% respectively. The mean duration of LVAD support was 581 d (range 2-2595 d). Gastrointestinal bleeding (was the most common adverse event (43/200, 21%), followed by right ventricular failure (38/200, 19%), stroke (31/200, 15%), re exploration for bleeding (31/200, 15%), ventilator dependent respiratory failure (19/200, 9%) and pneumonia (15/200, 7%). Our driveline infection rate was 7%. Pump thrombosis occurred in 6% of patients. Device exchanged was needed in 6% of patients. On multivariate analysis, preoperative liver dysfunction, ventilator dependent respiratory failure, tracheostomy and right ventricular failure requiring right ventricular assist device support were significant predictors of post LVAD survival.

CONCLUSION: Short and long term survival for patients on LVAD support are excellent, although outcomes still remain inferior compared to heart transplantation. The incidence of driveline infections, pump thrombosis and pump exchange have declined significantly in recent years.

Neurologic aspects of cardiac emergencies

In this review, cardiac arrest is discussed, with a focus on neuroprognostication and the emerging data, with regard to identifying more accurate predictors of neurologic outcomes in the era of therapeutic hypothermia. Topics discussed include recent controversies with regard to targeted temperature management in comatose survivors of cardiac arrest; neurologic complications associated with surgical disease and procedures, namely aortic dissection, infective endocarditis, left ventricular assist devices, and coronary artery bypass grafting; and the cause, pathogenesis, and management of neurogenic stunned myocardium.

Long term biventricular support with Berlin Heart Excor in a Septuagenarian with giant-cell myocarditis

Giant-cell myocarditis (GCM) is known as a rare, rapidly progressive, and frequently fatal myocardial disease in young and middle-aged adults. We report about a 76 year old male patient who underwent implantation with a biventricular Berlin Heart Excor system at the age of 74 due to acute biventricular heart failure caused by giant-cell myocarditis. The implantation was without any surgical problems; however, a difficulty was the immunosuppressive therapy after implantation. Meanwhile the patient is 76 years old and lives with circulatory support for about 3 years without major adverse events. Also, in terms of mobility in old age there are no major limitations. It seems that in even selected elderly patients an implantation of a long term support with the biventricular Berlin Heart Excor is a useful therapeutic option with an acceptable outcome.

Does CircuLite Synergy assist device as partial ventricular support have a place in modern management of advanced heart failure?

The discrepancy between the number of patients on the waiting list and available donor hearts has led to the successful development of left ventricular assist devices (LVAD) as a bridge to transplantation. The conventional LVADs are designed to provide full hemodynamic support for the end-stage failing heart. However, full-support LVAD implantation requires major surgery, sternotomy and cardiopulmonary bypass in majority of cases. The Synergy Micro-pump is the smallest implantable LVAD and provides partial flow support up to 3 l/min. It was shown that early intervention with this device can provide substantial benefits to patients with severe heart failure not yet sick enough for a full-support LVAD. Due the small dimensions it can be implanted without cardiopulmonary bypass or a sternotomy. The purpose of this article is to review the clinical use of the Synergy Micro-pump as partial hemodynamic support.

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.

Outcomes after implantation of 139 full-support continuous-flow left ventricular assist devices as a bridge to transplantation

OBJECTIVES

Left ventricular assist devices (LVADs) are a routine treatment for patients with advanced heart failure as a bridge to transplantation. The aim of this study was to present our institutional experience and mid-term outcomes after implantation of 139 continuous-flow (cf) LVADs as a bridge to transplantation.

METHODS

One hundred and thirty-nine consecutive LVAD implantations were performed in our institution between July 2007 and August 2013. The mean age of the population was 44.0 ± 13.7 years and 24 (17%) of the patients were female. A substantial number of the patients were on preoperative mechanical support: 35 (25%) with an intra-aortic balloon pump, 9 (6.5%) with an extracorporeal membrane oxygenator and 25 (18%) with previous LVAD, for LVAD exchange.

RESULTS

The mean support duration was 514 ± 481 days, whereas the longest support duration was 2493 days (>6 years). The overall cumulative survival rate following cfLVAD implantation was 89% at 30 days, 76% at 1 year and 66% at 2 years (Fig. 1). There was a statistically significant difference in survival in favour of first LVAD implantation compared with VAD exchange: 91 vs 80% at 30 days, 79 vs 57% at 1 year and 70 vs 43% at 2 years (log-rank P = 0.010). Postoperatively, patients had a significant improvement in end-organ function 1 month after LVAD implantation. In addition, comparison of two different devices [HeartMate II (HM II) and HeartWare] using propensity score matching showed no significant differences in survival and most postoperative adverse events. However, patients supported with HM II required significantly more units of fresh frozen plasma (P = 0.020) with a trend towards a higher use of red blood cells (P = 0.094), and were also more likely to develop percutaneous site infections (P = 0.022).

CONCLUSIONS

HM II and HeartWare cfLVADs have excellent early postoperative outcomes and good mid-term survival, despite a considerable number of patients needing VAD exchange.

Clinical experience of combined HeartWare ventricular assist device and implantable cardioverter defibrillator therapy

INTRODUCTION

The HeartWare continuous flow ventricular assist device (HVAD) is used in an increasing number of heart failure patients. In those patients, ventricular arrhythmias (VAs) are common and, consequently, many patients already have an implanted implantable cardioverter defibrillator (ICD) in place or receive ICD implantation after left ventricular assist device implantation. However, limited data on feasibility and necessity of combined ICD and HVAD therapy are available. In this study we present our technical and clinical experience.

METHODS AND RESULTS

Between 01/2010 and 06/2013, 41 patients received HVAD implantation. Twenty-six HVAD patients who already had an ICD device placed prior to HVAD implantation or received ICD implantation afterwards were enrolled in this study. Peri- and postoperative complications as well as ICD interrogations were documented and analyzed retrospectively. Mean patients age was 58.4 ± 12.6 years; 88.5% of patients were male. During mean follow-up of 12.2 ± 8.9 months, appropriate ICD interventions occurred in 9 patients (34.6%) due to ventricular tachyarrhythmia (n = 7) or ventricular fibrillation (n = 2). An inappropriate ICD intervention was seen in 1 patient (3.9%) due to tachycardic atrial fibrillation. Patients on HVAD with a history of VAs (n = 13) had a significantly higher incidence of ICD interventions compared to patients with primary prophylactic indication for ICD (n = 13; 53.8% vs. 7.7%; P = 0.015). No disturbance of ICD function was seen after HVAD implantation.

CONCLUSION

Combined ICD and HVAD therapy was safe and feasible, without electromagnetic interference between ICD and ventricular assist device. The incidence of ICD interventions was high in patients with a history of VAs, but low in patients with ICD implantation for primary prevention.

Outcomes after implantation of partial-support left ventricular assist devices in inotropic-dependent patients: Do we still need full-support assist devices?

OBJECTIVES

Partial-support left ventricular assist devices (LVADs) represent a novel strategy for heart failure treatment. The Synergy Pocket Micro-pump (HeartWare Inc, Framingham, Mass), the smallest surgically implanted long-term LVAD, provides partial flow up to 4.25 L/min and was primarily designed for "less sick" patients with severe heart failure. This device is implanted minimally invasively without sternotomy or cardiopulmonary bypass. Early implantation in patients with Interagency Registry for Mechanically Assisted Circulatory Support class 4 and higher was shown to be feasible and associated with significantly improved hemodynamics and quality of life. The aim of this study was to present our experience with implementation of long-term partial circulatory support as a bridge to transplantation in patients with more advanced heart failure who were dependent preoperatively on inotropic support or intra-aortic balloon pump.

METHODS

In this observational study, only inotropic or intra-aortic balloon pump-dependent patients with end-stage heart failure were included (n = 12). These patients underwent Synergy device implantation between February 2012 and August 2013.

RESULTS

The mean preoperative Interagency Registry for Mechanically Assisted Circulatory Support class was 2.17 ± 0.84 (class 1, 25%; class 2, 33%; class 3, 42%). The mean age was 46 ± 15 years, and 33% were female. Preoperatively, 4 patients (33%) had at least 1 previous sternotomy, 3 patients (25%) were supported with a balloon pump, 1 patient (8%) had a previous full-support LVAD, and 4 patients (33%) had cerebrovascular events in the past. After device implantation, there were no right ventricular failures, device-related infections, hemorrhagic strokes, arterial or venous thromboembolisms, or worsenings of aortic and mitral regurgitation observed over the follow-up. The mean follow up was 174 ± 171 days (range, 5-764 days; cumulative, 3199 days). One patient (8%) died, 3 patients (25%) successfully underwent transplantation, 1 device (8%) was explanted after myocardial recovery, and 5 patients (42%) are still on ongoing support. Two patients (17%) were upgraded to a full-support LVAD after 65 days of mean support. A total of 11 of 12 patients (92%) were discharged from the hospital and are presently alive. Left ventricular end-diastolic diameter was significantly reduced 3 months after device implantation.

CONCLUSIONS

Partial LVAD support may be clinically efficacious in inotropic and intra-aortic balloon pump-dependent patients. On the basis of our experience and evidence of previous research, such patients may benefit from minimally invasive access, no need for sternotomy and cardiopulmonary bypass, a short implantation time, an easy exchange if necessary, and a lower risk of subsequent heart transplantation. Because the implantation is performed without sternotomy, device upgrade is feasible with a comparatively low operative risk and good clinical outcome. Our preliminary results show that partial-support devices may have the potential to replace full-support LVADs in the near future.

Use of Foley catheter for insertion of ventricular assist device inflow cannula

Ventricular assist devices are fast becoming an accepted alternative to treat end-stage heart failure, and are being implemented as a bridge to myocardial recovery, a bridge to heart transplantation, or as destination therapy. Positioning of the inflow cannula into the apex of the ventricle is a crucial step due to the risk of sucking in air. We describe an improved method of preparing the insertion site for the ventricular assist device inflow cannula, to minimize the chances of air embolism and blood spillage, which we applied in a 34-year-old man, as a bridge to transplantation.

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.

Successful bridge to recovery using two-stage HeartWare LVAD explantation approach after embolic stroke

A two-stage explantation of a left ventricular assist device (LVAD) was performed on 47 year old afro-american gentlemen with non-ischemic dilated cardiomyopathy (DCM) who was successfully bridged to recovery. After he suffered a stroke caused by a VAD thrombosis with embolisation, the VAD outflow graft was first ligated using minimally-invasive approach. Two months later, the device was explanted and a manufactured titanium plug was placed into the sewing ring. This stepwise procedure might be beneficial in cases of high thromboembolic risk and in patients who suffered a thromboembolic event previously.

Isolation of outflow graft of a clotted ventricular assist device with recovery of cardiac function

Ventricular assist device (VAD) thrombosis, though uncommon, is a well-known complication. A HeartWare VAD implanted 2 years ago in a middle-aged man stopped because of thrombosis in the VAD. Because the patient's left ventricular function was recovered by the time of intervention, only the outflow graft was isolated and cut, leaving the pump in place.

Ventricular assist devices (VAD) therapy: new technology, new hope?

Ventricular assist devices are commonly utilized in the treatment of end-stage heart failure. Advances in continuous flow technology have improved efficiency, size, implantability, extended support, and overall patient outcomes. This has led to an expanded role of left ventricular assist device (LVAD) clinical use and applications. This review describes the advances and current state of LVAD devices and provides a future outlook for this technology.

Should eligibility for heart transplantation be a requirement for left ventricular assist device use? Recommendations based on a systematic review

Left ventricular assist devices (LVADs) are used in chronic end-stage heart failure as "bridge to transplantation" (BTT) and, more recently, for transplant-ineligible patients as "destination therapy" (DT). We reviewed the evidence on clinical effects and cost-effectiveness of 2 types of continuous-flow LVADs (HeartMate II [HM II] and HeartWare), for BTT and DT patients. We systematically searched the scientific literature (January 2008-June 2012) and identified 14 clinical studies (approximately 2900 HM II and approximately 200 HeartWare patients), and 3 economic evaluations (HM II) using simulation models. Data were, however, limited to 2-3 studies per outcome. We made policy recommendations on the basis of our systematic review. Although complications after implantation are frequent, LVAD therapy is often highly effective across transplantation eligibility status and device, with 1-year survival reaching 86% for BTT and 78% for DT (compared with 25% for medical therapy). Neither BTT nor DT currently meet traditional cost-effectiveness limits in models using historical data, although BTT is standard practice for a limited number of patients in many regions. We found that BTT and DT as implantation strategies tend to be no longer mutually exclusive. We conclude that evidence is sufficient to support LVAD use, regardless of transplantation eligibility status, as long as patients are carefully selected and program infrastructure and budget are adequate. However, evidence gaps, limitations in economic models, and the lack of Canadian data point to the importance of mandatory, systematic monitoring of LVAD use and outcomes.