Clinical management of continuous-flow left ventricular assist devices in advanced heart failure

The dual prevalence of advanced degrees of obesity and heart failure: a study from the National Inpatient Sample database

BACKGROUND

National prevalence rates for obesity and heart failure (HF) have been steadily increasing, which predisposes patients to higher morbidity and mortality rates.

OBJECTIVES

The purpose of this study was to evaluate the prevalence of HF stages in hospitalized patients according to their body mass index (BMI).

SETTING

Academic institution.

METHODS

National Inpatient Sample data from 2016 to 2018 were examined to identify patients with obesity, HF (presence or absence of advanced HF [AHF]), and cardiogenic shock (CS). The proportion of hospital admissions was determined for each category on the basis of the presence of AHF with/without CS. A comparative analysis was performed between patients with and without AHF, and multivariate logistic regression analysis was performed for the event of AHF. The same analyses were performed for the event of CS.

RESULTS

A total of 3,354,970 hospital admissions were identified. The prevalence of hospital admissions with a diagnosis of AHF and class III obesity and a diagnosis of CS and class III obesity was 21% and .5%, respectively. The prevalence of AHF and other classes of BMI and CS and other classes of BMI was 17% and .5%, respectively. The univariate analysis showed that there were significant variations in 10 factors between hospital admissions with/without the diagnosis of both AHF and CS. Statistical analyses indicated the following findings: Hospitalized patients in higher obesity groups are more likely to have AHF, and they are less likely to have CS compared with those with a BMI of ≤29.9.

CONCLUSIONS

This study revealed that the prevalence of AHF was significantly higher in hospitalized patients with class III obesity. These findings have implications for clinical management, and it can be inferred that these patients are less likely to receive advanced cardiac replacement therapies and might benefit from innovative approaches to address severe dual morbidity.

Dynamic modeling of variable speed left ventricular assist devices coupled to the cardiovascular system

BACKGROUND

Most of the modeling of the Left Ventricular Assist Devices (LVADs) coupled with the cardiovascular system is based on the assumption of constant rotational speed. Compared with the traditional inertial model, the validated hysteresis model can take into account the unsteady characteristics of LVADs, but it fails to work under the condition of variable speed modulation.

METHOD

This study takes into consideration the impact of speed variations on the unsteady hysteresis effects. The time constant in the hysteresis model is treated as a time-varying parameter, thereby developing a new model applicable to variable speed modulation. Under sinusoidal speed modulation at various phases, a comparative analysis was undertaken among the steady-state model, inertial model, and the new model. Transient Computational Fluid Dynamics (CFD) simulations and existing experimental results are used for validation.

RESULTS

The new model provides a more accurate method for the predicting the characteristics of LVAD in the coupled model under varying pump speeds, and exhibits higher linearity in the work done by the left ventricle and the blood pump, and R 2 = 0 . 9998 , which is aligning closely with the experimental results. This enhancement renders it applicable for proactive control predictions and passive control validations.

Turbulent flow field in maglev centrifugal blood pumps of CH-VAD and HeartMate III: secondary flow and its effects on pump performance

Secondary flow path is one of the crucial aspects during the design of centrifugal blood pumps. Small clearance size increases stress level and blood damage, while large clearance size can improve blood washout and reduce stress level. Nonetheless, large clearance also leads to strong secondary flows, causing further blood damage. Maglev blood pumps rely on magnetic force to achieve rotor suspension and allow more design freedom of clearance size. This study aims to characterize turbulent flow field and secondary flow as well as its effects on the primary flow and pump performance, in two representative commercial maglev blood pumps of CH-VAD and HeartMate III, which feature distinct designs of secondary flow path. The narrow and long secondary flow path of CH-VAD resulted in low secondary flow rates and low disturbance to the primary flow. The flow loss and blood damage potential of the CH-VAD mainly occurred at the secondary flow path, as well as the blade clearances. By contrast, the wide clearances in HeartMate III induced significant disturbance to the primary flow, resulting in large incidence angle, strong secondary flows and high flow loss. At higher flow rates, the incidence angle was even larger, causing larger separation, leading to a significant decrease of efficiency and steeper performance curve compared with CH-VAD. This study shows that maglev bearings do not guarantee good blood compatibility, and more attention should be paid to the influence of secondary flows on pump performance when designing centrifugal blood pumps.

Patient management important for long-term support beyond 5 years in the BTT: republication of the article published in the Japanese Journal of Artificial Organs

Heart transplantation is considered to be the best treatment for severe heart failure refractory to medical therapy, improving patients' survival and quality of life (QOL). However, the number of donors is smaller than the number of registered applicants for heart transplantation, which increases every year, and the waiting period for heart transplantation has been extended to more than 1700 days by 2022. Since 2011, reimbursement for the implantable left ventricular assist device (iLVAD) was established. The numbers of the iLVAD patients have been increasing year by year. Patients are managed at home with an iLVAD and can live with their families and even return to work, depending on the situation. On the other hand, self-management at home, including caregivers, is important for a safe life. Home management beyond 5 years is becoming more common due to long waiting time for transplant. This article outlines the important aspects of patient management for long-term support. This review was created based on a translation of the Japanese review written in the Japanese Journal of Artificial Organs in 2023 (Vol. 52, No. 1, pp. 62-66), with some modifications.

Antithrombotic Strategies With Left Ventricular Assist Devices

Long-term outcomes of patients with advanced heart failure treated with durable left ventricular assist devices (LVADs) have been augmented due to improved durability and hemocompatibility on the backbone of pump engineering enhancements. The incidence of hemocompatibility-related adverse events (pump thrombosis, stroke and nonsurgical bleeding events) are device specific and vary by type of engineered pump. A fully magnetically levitated rotor containing LVAD in concert with use of antithrombotic therapy has successfully overcome an increased risk of pump thrombosis and stroke-risk, albeit with only modest reduction in bleeding events. Modifications to antithrombotic strategies have focused on reduced-dose vitamin K antagonist use or use of direct oral anticoagulants with demonstration of safety and progress in reduction of mucosal bleeding episodes with elimination of antiplatelet agents. This review outlines the current landscape of advances in anticoagulation management in LVAD patients, highlighting the need for ongoing research and cautious application of emerging therapies and technologies.

Oral amiodarone and propranolol in maintenance therapy of postimplantation tachycardia: An observational study

Left ventricular assist devices (LVADs) are widely used as end-stage therapy in patients with advanced heart failure, whereas implantation increases the risks of development of sustained ventricular tachycardia at the later postimplantation stage. Therefore, this study aimed to evaluate the clinical efficacy of orally administered amiodarone and propranolol in 3 patients with ventricular tachycardia (VT) after LVAD implantation who were resistant to initial anti-antiarrhythmic drugs. This retrospective cohort study consisted of the initial evaluation of the clinical data of 14 adult patients who underwent implantation of LVAD between January 2019 and March 2021. A total of 3 patients with resistant VT were finally included. In all cases, the patients were initially administered amiodarone in the different doses intravenously to stabilize the critical condition, whereas its oral form along with that of propranolol was used as maintenance therapy in the first 2 cases. In the third case, amiodarone was withdrawn because of the risk of development of hyperthyroidism, while oral propranolol was used in the treatment. The assessment in the 16-month follow-up period after discharge did not show presence of non-sustained and sustained VT in all 3 cases. In the ventricular arrhythmia-free group, the total mortality rate within the follow-up period was 11.1 ± 7.78 months in the 3 patients. We suggest that maintenance oral therapy of propranolol and amiodarone can significantly decrease the risks of complications in patients with VT after implantation of ventricular assist device in the long term.

Right heart failure with left ventricular assist devices: Preoperative, perioperative and postoperative management strategies. A clinical consensus statement of the Heart Failure Association (HFA) of the ESC

Right heart failure (RHF) following implantation of a left ventricular assist device (LVAD) is a common and potentially serious condition with a wide spectrum of clinical presentations with an unfavourable effect on patient outcomes. Clinical scores that predict the occurrence of right ventricular (RV) failure have included multiple clinical, biochemical, imaging and haemodynamic parameters. However, unless the right ventricle is overtly dysfunctional with end-organ involvement, prediction of RHF post-LVAD implantation is, in most cases, difficult and inaccurate. For these reasons optimization of RV function in every patient is a reasonable practice aiming at preparing the right ventricle for a new and challenging haemodynamic environment after LVAD implantation. To this end, the institution of diuretics, inotropes and even temporary mechanical circulatory support may improve RV function, thereby preparing it for a better adaptation post-LVAD implantation. Furthermore, meticulous management of patients during the perioperative and immediate postoperative period should facilitate identification of RV failure refractory to medication. When RHF occurs late during chronic LVAD support, this is associated with worse long-term outcomes. Careful monitoring of RV function and characterization of the origination deficit should therefore continue throughout the patient's entire follow-up. Despite the useful information provided by the echocardiogram with respect to RV function, right heart catheterization frequently offers additional support for the assessment and optimization of RV function in LVAD-supported patients. In any patient candidate for LVAD therapy, evaluation and treatment of RV function and failure should be assessed in a multidimensional and multidisciplinary manner.

A Computational Investigation of the Effects of Temporal Synchronization of Left Ventricular Assist Device Speed Modulation with the Cardiac Cycle on Intraventricular Hemodynamics

Patients with advanced heart failure are implanted with a left ventricular assist device (LVAD) as a bridge-to-transplantation or destination therapy. Despite advances in pump design, the risk of stroke remains high. LVAD implantation significantly alters intraventricular hemodynamics, where regions of stagnation or elevated shear stresses promote thrombus formation. Third generation pumps incorporate a pulsatility mode that modulates rotational speed of the pump to enhance in-pump washout. We investigated how the timing of the pulsatility mode with the cardiac cycle affects intraventricular hemodynamic factors linked to thrombus formation. Computational fluid dynamics simulations with Lagrangian particle tracking to model platelet behavior in a patient-specific left ventricle captured altered intraventricular hemodynamics due to LVAD implantation. HeartMate 3 incorporates a pulsatility mode that modulates the speed of the pump every two seconds. Four different timings of this pulsatility mode with respect to the cardiac cycle were investigated. A strong jet formed between the mitral valve and inflow cannula. Blood stagnated in the left ventricular outflow tract beneath a closed aortic valve, in the near-wall regions off-axis of the jet, and in a large counterrotating vortex near the anterior wall. Computational results showed good agreement with particle image velocimetry results. Synchronization of the pulsatility mode with peak systole decreased stasis, reflected in the intraventricular washout of virtual contrast and Lagrangian particles over time. Temporal synchronization of HeartMate 3 pulsatility with the cardiac cycle reduces intraventricular stasis and could be beneficial for decreasing thrombogenicity.

Left ventricular assist devices: yesterday, today, and tomorrow

The shortcomings of expense, power requirements, infection, durability, size, and blood trauma of current durable LVADs have been recognized for many years. The LVADs of tomorrow aspire to be fully implantable, durable, mitigate infectious risk, mimic the pulsatile nature of the native cardiac cycle, as well as minimize bleeding and thrombosis. Power draw, battery cycle lifespan and trans-cutaneous energy transmission remain barriers to completely implantable systems. Potential solutions include decreases in pump electrical draw, improving battery lifecycle technology and better trans-cutaneous energy transmission, potentially from Free-range Resonant Electrical Energy Delivery. In this review, we briefly discuss the history of LVADs and summarize the LVAD devices in the development pipeline seeking to address these issues.

Tricuspid transcatheter edge-to-edge repair in a 72-year-old patient with a left ventricular assist device and prior mitral edge-to-edge repair: a case report

Background

We report a case of a 72-year-old patient developing a significant tricuspid regurgitation (TR) 6 years after a left ventricular assist device (LVAD) implantation. The aim of this case is to demonstrate the feasibility of transcatheter edge-to-edge repair (TEER) of the tricuspid valve and the excellent clinical benefit in long-term follow-up in an LVAD patient.

Case summary

Our patient presented with recurrent acute heart failure syndrome. After a fulminant myocarditis in 2005, his previous treatment consisted of cardiac resynchronization therapy, TEER of the mitral valve, and LVAD (HeartMate III) implantation. At that point in time, his TR was only mild to moderate. Due to recurrent hospitalization despite optimized heart failure medication, we decided to treat the patient with a tricuspid TEER. His immediate post-interventional result and 1-year follow-up showed an excellent outcome with only minimal TR on transoesophageal echocardiogram.

Discussion

In general, TR improves after LVAD implantation. However, there are two possible pathophysiological mechanisms, which result in an increasing TR: firstly, supporting LV dysfunction may lead to a leftward shift of the interventricular septum with restriction of the tricuspid leaflets. Secondly, the increase of venous preload with LVAD support may result in an annular dilatation with secondary TR, particularly in patients with pre-existing right ventricular dysfunction. According to the data currently available, the unpredictable course of developing TR necessitates regular clinical examination and echocardiographic investigation. Treatment with TEER appears to be feasible and safe, with excellent 1-year results in patients with previously implanted LVADs.

Advanced Heart Failure: Therapeutic Options and Challenges in the Evolving Field of Left Ventricular Assist Devices

Heart Failure is a chronic and progressively deteriorating syndrome that has reached epidemic proportions worldwide. Improved outcomes have been achieved with novel drugs and devices. However, the number of patients refractory to conventional medical therapy is growing. These advanced heart failure patients suffer from severe symptoms and frequent hospitalizations and have a dismal prognosis, with a significant socioeconomic burden in health care systems. Patients in this group may be eligible for advanced heart failure therapies, including heart transplantation and chronic mechanical circulatory support with left ventricular assist devices (LVADs). Heart transplantation remains the treatment of choice for eligible candidates, but the number of transplants worldwide has reached a plateau and is limited by the shortage of donor organs and prolonged wait times. Therefore, LVADs have emerged as an effective and durable form of therapy, and they are currently being used as a bridge to heart transplant, destination lifetime therapy, and cardiac recovery in selected patients. Although this field is evolving rapidly, LVADs are not free of complications, making appropriate patient selection and management by experienced centers imperative for successful therapy. Here, we review current LVAD technology, indications for durable MCS therapy, and strategies for timely referral to advanced heart failure centers before irreversible end-organ abnormalities.

Warfarin and aspirin versus warfarin alone for prevention of bleeding and thrombotic events in patients with a HeartMate 3™ left ventricular assist device

BACKGROUND

We conducted a single-center, retrospective comparison of adult patients who received warfarin and ASA or warfarin alone after HeartMate 3 (HM3) LVAD placement.

METHODS

The primary outcome was a composite of bleeding and thrombotic events.

RESULTS

Of 81 patients, 53 patients received warfarin and ASA, and 28 patients received warfarin alone. A primary outcome event occurred in 22 of 53 patients (41.4%) in the warfarin and ASA group and in 2 of 28 patients (7.1%) in the warfarin alone group (p = 0.0533). The odds of a bleeding event occurring were higher in the warfarin and ASA group (32.1% vs. 7.1%, p = 0.01309). The odds of a thrombotic event occurring were not significantly different between the warfarin and ASA group and the warfarin alone group (9.4% vs. 0%, respectively, p = 0.1582).

CONCLUSION

The complete omission of ASA from the antithrombotic regimen of patients with a HM3 LVAD was associated with less bleeding events without an increase in thrombotic events.

Comparing the Efficacy and Safety of Warfarin Monotherapy vs. Warfarin and Aspirin for Adult Patients With Left Ventricular Assist Devices: A Meta-Analysis

The aim of this meta-analysis was to assess the safety and efficacy of warfarin plus aspirin versus warfarin monotherapy in patients with left ventricular assist devices (LVAD). The present meta-analysis was conducted using the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Two authors systematically searched online databases, including PubMed, EMBASE, the Cochrane Library, and Web of Science from inception to December 31, 2023. Outcomes assessed in this meta-analysis included any thrombotic event, bleeding events, and all-cause mortality. A total of five articles were included in the meta-analysis, enrolling a pooled sample size of 876 patients, including 405 in the warfarin monotherapy group and 471 in the warfarin plus aspirin group. Pooled analysis showed that the risk of thrombotic events was not significantly different between the two groups (risk ratio (RR): 0.46, 95% confidence interval (CI): 0.15-1.37). The risk of bleeding events was significantly lower in patients receiving warfarin alone compared to patients receiving aspirin plus warfarin (RR: 0.67, 95% CI: 0.53-0.85). The risk of all-cause mortality was not significantly different between patients receiving warfarin alone and patients receiving aspirin plus warfarin (RR: 0.92, 95% CI: 0.65-1.30). Despite the potential benefits of discontinuing aspirin, the decision should be approached cautiously, considering the undefined risks of discontinuing anticoagulation in LVAD patients.

A case of progressive right ventricular failure with ventricular arrhythmia and aortic insufficiency after implantable left ventricular assist device implantation

Right ventricular failure (RVF) is a serious complication after left ventricular assist device (LVAD) implantation. In this report, a case of RVF that developed over two years after LVAD implantation is presented. The patient was a 12-year-old male with dilated phase of hypertrophic cardiomyopathy. He had no risk factors for early or late-onset RVF. However, his right ventricular function worsened after he developed ventricular arrhythmia (VA), and right ventricular dysfunction became exacerbated with an increasing frequency of VAs. He also developed moderate aortic insufficiency (AI), which became severe. Two years after implantation, he was admitted for treatment of recurrent ventricular tachycardia and became inotropic-dependent during hospitalization. Finally, he underwent successful heart transplantation 2 years and 9 months after LVAD implantation. This case suggests that vicious cycle of RV dysfunction, recurrent VAs and severe AI could lead to RVF in patients without known risk factors for RVF, even long after LVAD implantation.

Learning objective

This report shows a progressive right ventricular failure (RVF) two years after left ventricular assist device (LVAD) implantation. Although the patient had no known risk factor, vicious circle of RV dysfunction, ventricular arrhythmias (VAs) and aortic insufficiency (AI) lead to RVF. Patients with LVAD as destination therapy will increase and require long-term LVAD management. We should recognize that these patients could develop RVF even years after LVAD implantation in association with VAs and AI.

Less Invasive Left Ventricular Assist Device Implantation Is Safe and Feasible in Patients With Smaller Body Surface Area

OBJECTIVE

Smaller body surface area (BSA) frequently precludes patients from left ventricular assist device (LVAD) therapy. We sought to investigate the clinical outcomes in patients with small BSA undergoing less invasive LVAD implantation.

METHODS

We conducted a retrospective review of 216 patients implanted with HeartMate 3 LVAD (Abbott, Chicago, IL) via less invasive surgery at our institution. Patients were dichotomized based on their preimplant BSA for comparison between small BSA (≤1.8 m2) and normal/large BSA (>1.8 m2). We analyzed patient perioperative characteristics and outcomes.

RESULTS

In our study, small BSA was found in 32 patients (14.8%), while 184 patients (85.2%) had normal/large BSA. Women were more prevalent in the small BSA group (50.0% vs 13.0%, P < 0.001). Preoperative and intraoperative data showed comparable results. Major complications and hospital length of stay did not differ by BSA group. Patients with smaller BSA had significantly decreased pump parameters at discharge, including LVAD flow (4.11 ± 0.49 vs 4.60 ± 0.54 L/min, P < 0.001) and pump speed (5,200 vs 5,400 rpm, P < 0.001). Survival to discharge and within 6 months after implantation were similar between the groups.

CONCLUSIONS

Our study results suggest that less invasive HeartMate 3 implantation can be safely performed and demonstrates equivalent outcomes in patients with smaller body habitus. Randomized trials are required to confirm our data.

Native Arteriovenous Fistula Creation in Patients With Continuous Flow Left Ventricular Assist Devices: A Case Report and a Narrative Review

Worsening of kidney function after left ventricular assist device (LVAD) implantation is common, and many patients reaching end-stage kidney disease require long-term dialysis. Permanent vascular access in a patient with LVAD remains a clinical dilemma. There is a theoretical concern about the maturation of the arteriovenous fistula in a patient with LVAD due to the absence of a pulsatile flow in these patients. We described a case of successful creation of a left brachial-cephalic AVF in a patient with continuous flow LVAD (Abbott's HeartMate 3TM), which was used for dialysis without issue.

Management of hypertension in patients supported with continuous flow left ventricular assist devices

PURPOSE OF REVIEW

Hypertension remains one of the most common clinical problems leading to devastating postleft ventricular assist device (LVAD) implant complications. This study reviews the pathophysiology of hypertension in the setting of continuous flow LVAD support and provides an update on currently available antihypertensive therapies for LVAD patients.

RECENT FINDINGS

The true prevalence of hypertension in the LVAD population remains unknown. Effective blood pressure (BP) control and standardization of BP measurement are key to prevent suboptimal left ventricular unloading, pump malfunction and worsening aortic regurgitation. Angiotensin-converting enzyme inhibitors (ACEI), angiotensin receptor blockers (ARB), beta blockers and mineralocorticoid receptor antagonists (MRA) are the preferred antihypertensive agents because of their additional potential benefits, including optimization of haemodynamics, prevention of stroke, gastrointestinal bleed and in some patients myocardial recovery. Angiotensin receptor-neprilysin inhibition (ARNI) may be a well tolerated and effective therapy for BP control especially among CF-LVAD patients with resistant hypertension. Similarly, sodium glucose co-transporter 2 inhibitors (SGLT2i) should be considered in the absence of contraindications.

SUMMARY

Hypertension is very common post-LVAD implant. Heart failure guideline directed medical therapies, including ACEI, ARB, beta blockers and MRA, are the preferred antihypertensive agents to improve post-LVAD outcomes.

Short-term outcomes of heart transplant patients bridged with Impella 5.5 ventricular assist device

AIMS

We sought to investigate the outcomes of heart transplant patients supported with Impella 5.5 temporary mechanical circulatory support.

METHODS AND RESULTS

Patient demographics, perioperative data, hospital timeline, and haemodynamic parameters were followed during initial admission, Impella support, and post-transplant period. Vasoactive-inotropic score, primary graft failure, and complications were recorded. Between March 2020 and March 2021, 16 advanced heart failure patients underwent Impella 5.5 temporary left ventricular assist device support through axillary approach. Subsequently, all these patients had heart transplantation. All patients were either ambulatory or chair bound during their temporary mechanical circulatory support until heart transplantation. Patients were kept on Impella support median of 19 days (3-31) with the median lactate dehydrogenase level of 220 (149-430). All Impella devices were removed during heart transplantation. During Impella support, patients had improved renal function with median creatinine serum level of 1.55 mg/dL decreased to 1.25 (P = 0.007), pulmonary artery pulsatility index scores increased from 2.56 (0.86-10) to 4.2 (1.3-10) (P = 0.048), and right ventricular function improved (P = 0.003). Patients maintained improved renal function and favourable haemodynamics after their heart transplantation as well. All patients survived without any significant morbidity after their heart transplantation.

CONCLUSIONS

Impella 5.5 temporary left ventricular assist device optimizes care of heart transplant recipients providing superior haemodynamic support, mobility, improved renal function, pulmonary haemodynamics, and right ventricular function. Utilizing Impella 5.5 as a direct bridging strategy to heart transplantation resulted in excellent outcomes.

Transcatheter valvular therapies in patients with left ventricular assist devices

Aortic, mitral and tricuspid valve regurgitation are commonly encountered in patients with continuous-flow left ventricular assist devices (CF-LVADs). These valvular heart conditions either develop prior to CF-LVAD implantation or are induced by the pump itself. They can all have significant detrimental effects on patients' survival and quality of life. With the improved durability of CF-LVADs and the overall rise in their volume of implants, an increasing number of patients will likely require a valvular heart intervention at some point during CF-LVAD therapy. However, these patients are often considered poor reoperative candidates. In this context, percutaneous approaches have emerged as an attractive "off-label" option for this patient population. Recent data show promising results, with high device success rates and rapid symptomatic improvements. However, the occurrence of distinct complications such as device migration, valve thrombosis or hemolysis remain of concern. In this review, we will present the pathophysiology of valvular heart disease in the setting of CF-LVAD support to help us understand the underlying rationale of these potential complications. We will then outline the current recommendations for the management of valvular heart disease in patients with CF-LVAD and discuss their limitations. Lastly, we will summarize the evidence related to transcatheter heart valve interventions in this patient population.

Outcomes of concomitant aortic valve procedures and left ventricular assist device implantation: A systematic review and meta-analysis

BACKGROUND

Left ventricular assist device (LVAD) implantation is frequently employed in patients with end-stage heart failure. The outcomes of addressing the repair of all substantial aortic valvular disease at the time of LVAD implantation remain unclear. We sought to assess the clinical outcomes in patients undergoing LVAD implantation concomitant with aortic valve procedures (AVPs) compared with isolated LVAD implantation.

METHODS

A literature search was performed using PubMed, Embase, and Cochrane library from inception till June 2022. Primary outcomes included short-term mortality and long-term survival. Random effects models were used to compute mean differences and odds ratios with 95% confidence intervals (CIs).

RESULTS

A total of 14 observational studies (N = 52 693) met our inclusion criteria. Concomitant LVAD implantation and AVPs were associated with higher short-term mortality (OR = 1.61 [95% CI, 1.06-2.42]; p = 0.02) and mean CPBt (MD = 43.25 [95% CI, 22.95-63.56]; p < 0.0001), and reduced long-term survival (OR = 0.70 [95% CI, 0.55-0.88]; p = 0.003) compared with isolated LVAD implantation. No difference in the odds of cerebrovascular accident (OR = 1.05 [95% CI, 0.79-1.39]; p = 0.74) and mean length of hospital stay (MD = 2.89 [95% CI, -4.04 to 9.82]; p = 0.41) was observed between the two groups. On adjusted analysis, short-term mortality was significantly higher in the LVAD group with concurrent AVPs when compared with the isolated LVAD group (aHR = 1.50 [95% CI, 1.20-1.87]; p = 0.0004).

CONCLUSIONS

Concurrent AVPs were associated with higher short-term mortality and reduced long-term survival in patients undergoing LVAD implantation compared with isolated LVAD implantation.

Impact of preoperative mitral regurgitation on left ventricular assist device patients: propensity score-matched analysis of the EUROMACS dataset

OBJECTIVES

Mitral regurgitation (MR) is frequently observed in patients undergoing left ventricular assist device implantation. We investigated the impact of preoperative MR on left ventricular assist device patients.

METHODS

A retrospective propensity score-matched analysis of adult patients enrolled in the EUROMACS registry between 1 January 2011 and 30 November 2021 was performed. Patients were divided into 2 groups according to the grade of preoperative MR: none-to-mild (MR 0-II) or moderate-to-severe (MR III-IV).

RESULTS

Following 1:1 propensity score matching, each group consisted of 914 patients. Incidence of postoperative temporary right ventricular support, reoperation for bleeding and dialysis was similar. MR III-IV demonstrated shorter median intensive care unit stay [14 days (6; 27.8) vs 10 days (5; 22), P = 0.004] and ventilation time [72 h (22, 320) vs 31 h (18, 150), P < 0.001]. Mortality was lower for MR III-IV patients [subdistribution hazard ratio: 0.66, 95% confidence interval (CI): 0.59-0.73, P < 0.001]. The 1-year survival was 68.1% (95% CI: 65.1-71.3%) in MR 0-II and 75% (95% CI: 72.1-78%) in MR III-IV. A lower incidence of total complications [odds ratio (OR): 0.93 (0.89-0.98), P = 0.003] and trend towards a lower risk of neurological dysfunction (subdistribution hazard ratio: 0.79; 95% CI: 0.61-1.01, P = 0.063) and sustained ventricular tachycardia [OR: 0.93 (0.54-1.03), P = 0.074] were demonstrated for MR III-IV. The risk of fatal stroke and pump thrombosis was similar.

CONCLUSIONS

Moderate-to-severe MR in patients undergoing left ventricular assist device implantation is associated with better mid-term survival and lower incidence of total major adverse events and complications. The incidence of severe postoperative complications including fatal stroke and device thrombosis was similar.

Considerations of valvular heart disease in children with ventricular assist devices

Ventricular assist devices have become a valuable tool in the treatment of heart failure in children. The use of ventricular assist devices has decreased mortality in children with end-stage heart failure awaiting transplant. It is not uncommon for children with end-stage heart failure associated with cardiomyopathy or congenital heart disease to have significant systemic semilunar and atrioventricular valve regurgitation, which can impact the efficiency and efficacy of hemodynamic support provided by a ventricular assist device. Therefore, implanting clinicians should carefully assess for valve abnormalities that may need repair and impact device selection and cannulation strategy to effectively support this diverse population. The purpose of this review is to provide an overview of this important and relevant topic and to discuss strategies for managing these patients.

Selection and management considerations to enhance outcomes in patients supported by left ventricular assist devices

PURPOSE OF REVIEW

Left ventricular assist devices (LVADs) are life-saving therapies for patients in end-stage heart failure (HF) with reduced ejection fraction regardless of candidacy for heart transplantation. Multiple clinical trials have demonstrated improved morbidity and mortality with LVADs when compared to medical therapy alone. However, the uptake of LVADs as a therapeutic option in a larger section of end-stage HF patients remains limited, partly due to associated adverse events and re-hospitalization.

RECENT FINDINGS

Accurate assessment and staging of HF patients is crucial to guide appropriate use of LVADs. Innovative methods to risk stratify patients and manage cardiac and noncardiac comorbidities can translate to improved outcomes in LVAD recipients. Inclusion of quality of life metrics and measurements of adverse events can better inform heart failure cardiologists to help identify ideal LVAD candidates. Addition of machine learning algorithms to this process may guide patient selection to improve outcomes.

SUMMARY

Patient selection and assessment of reversible medical comorbidities are critical to the postoperative success of LVAD implantation. Identifying patients most likely to benefit and least likely to experience adverse events should be a priority.

Clinical and Prognostic Role of Noninvasive Hemodynamic Assessment in Left Ventricular Assist Device Carriers

Persistence of heart failure symptoms or suboptimal hemodynamic is a frequent condition in LVAD carriers, associated with adverse outcome. Invasive hemodynamic optimization was associated with a better outcome. Our group recently validated an echocardiographic protocol to noninvasively assess hemodynamics of LVAD patients. Aim of this prospective study was to investigate its utility in clinical practice and its prognostic role. From February 2016 to February 2019 fifty-five LVAD carriers (HVAD/HM3 34/21; age 61 ± 10 years, 89% males; INTERMACS profile at LVAD implantation ≤3 68%). A two-phased protocol was performed. First, the patient underwent clinical evaluation. Second, an echo-Doppler blinded to clinical data was performed. Clinical and echo-Doppler evaluation both identified patients with "optimal hemodynamic profile" (normal left and right estimated atrial pressures) versus other profiles. clinical evaluation overestimated the presence of an optimal profile compared with echo-Doppler (83% vs. 59%). The presence of overt heart failure identified patients with the highest risk of adverse outcomes (death or hospitalization for HF at 6 months: HR 15, 95% CI, 5.5-39, P < 0.001). An optimal profile by echo-Doppler was associated with a better outcome among patients without overt heart failure (death or hospitalization for HF at 6 months: HR 0.08, 95% CI, 0.01.5-0.64, P < 0.02). After echo-Doppler, the clinician modified treatment in 46 cases (37%). Noninvasive evaluation of hemodynamics by echo-Doppler adds significant prognostic information in LVAD patients without overt HF and is a valuable tool to tailor treatment in the outpatient follow-up of LVAD carriers. Visual abstract: http://links.lww.com/ASAIO/A783.

Right heart failure after left ventricular assist device: From mechanisms to treatments

Left ventricular assist device (LVAD) therapy is a lifesaving option for patients with medical therapy-refractory advanced heart failure. Depending on the definition, 5-44% of people supported with an LVAD develop right heart failure (RHF), which is associated with worse outcomes. The mechanisms related to RHF include patient, surgical, and hemodynamic factors. Despite significant progress in understanding the roles of these factors and improvements in surgical techniques and LVAD technology, this complication is still a substantial cause of morbidity and mortality among LVAD patients. Additionally, specific medical therapies for this complication still are lacking, leaving cardiac transplantation or supportive management as the only options for LVAD patients who develop RHF. While significant effort has been made to create algorithms aimed at stratifying risk for RHF in patients undergoing LVAD implantation, the predictive value of these algorithms has been limited, especially when attempts at external validation have been undertaken. Perhaps one of the reasons for poor performance in external validation is related to differing definitions of RHF in external cohorts. Additionally, most research in this field has focused on RHF occurring in the early phase (i.e., ≤1 month) post LVAD implantation. However, there is emerging recognition of late-onset RHF (i.e., > 1 month post-surgery) as a significant cause of morbidity and mortality. Late-onset RHF, which likely has a unique physiology and pathogenic mechanisms, remains poorly characterized. In this review of the literature, we will describe the unique right ventricular physiology and changes elicited by LVADs that might cause both early- and late-onset RHF. Finally, we will analyze the currently available treatments for RHF, including mechanical circulatory support options and medical therapies.

Impact of Mechanical Circulatory Support on Exercise Capacity in Patients With Advanced Heart Failure

Approximately 6 million individuals have heart failure in the United States alone and 15 million in Europe. Left ventricular assist devices (LVAD) improve survival in these patients, but functional capacity may not fully improve. This article examines the hypothesis that patients supported by LVAD experience persistent reductions in functional capacity and explores mechanisms accounting for abnormalities in exercise tolerance.

Noninvasive blood pressure measurement in patients with continuous-flow left ventricular assist devices

Oscillatory blood pressure (OBP) with a slow cuff-deflation system has been proposed as noninvasive measurement of mean arterial pressure (MAP) in patients with continuous-flow left ventricular assist devices (LVADs). However, the challenge is that the measurement is not obtainable in certain patients. We hypothesized that the combined use of color Doppler imaging during OBP measurement (CDBP) could derive MAP accurately. We conducted a prospective observational study in critically ill patients (30 patients with continuous-flow LVADs and 30 control patients without LVADs). Triplicate OBP and CDBP measurements were performed and invasive blood pressure (IBP) was recorded. The overall success rate of OBP was 63.3% in the LVAD group and 98.9% in the control group. The CDBP was successfully obtained in 100% of all study patients. The CDBP in the LVAD group was closest to the MAP of measured IBP, while that in the control group was closest to the systolic IBP. The mean absolute differences in OBP and CDBP from the closest IBP were similar in both the control and LVAD groups. In nonpulsatile LVAD patients with a pulse pressure IBP < 10 mmHg, the success rate of OBP measurement was only 10.0%, and CDBP showed significantly reduced error in MAP measurement (mean absolute difference: OBP 23.2 ± 8.7 vs CDBP 5.2 ± 3.6 mmHg, p < 0.001). The validity of OBP measurement with a slow cuff-deflation system limited particularly in nonpulsatile LVAD patients. The concurrent use of color Doppler imaging is encouraged for more accurate measurement of MAP in patients with continuous-flow LVADs.

Management of patients with the Intravascular Ventricular Assist System (iVAS) for non-cardiac surgery

Intravascular ventricular assist system (iVAS) is an investigative device in clinical trials for the management of advanced heart failure. It works on the principle of counterpulsation, similar to the classic intra-aortic balloon counterpulsation (IABP). We present a case of a 66-year-old man with iVAS in situ who required emergency laparotomy for a strangulated umbilical hernia. Patients with mechanical circulatory devices (MCD) are presenting more frequently for emergency and even elective noncardiac operations. Managing such patients poses significant challenges to the perioperative team due to its novelty and paucity of management recommendations.

The hemodynamics and blood trauma in axial blood pump under different operating model

Speed modulation of blood pump has been proved to help restore vascular pulsatility and implemented clinically during treatment for cardiac failure. However, its effect on blood trauma has not been studied thoroughly. In this paper, we study the flow field of an axial pump FW-X under the modes of co-pulse, counter pulse and constant speed to evaluate the blood trauma. Based on the coupling model of cardiovascular system and axial blood pump, aortic pressure and the pump flow were obtained and applied as the boundary conditions at the pump outlet and inlet. The level of shear stress and hemolysis index were derived from computational fluid dynamics (CFD) simulation. Results showed the constant speed mode had the lowest shear stress level and hemolytic index at the expense of diminished pulsatility. Compared with the constant speed mode, the hemolysis index of co-pulse and counter pulse mode was higher, but it was helpful to restore vascular pulsatility. This method can be easily incorporated in the in vitro testing phase to analyze and decrease a pump's trauma before animal experimentation, thereby reducing the cost of blood pump development.

Models of Shear-Induced Platelet Activation and Numerical Implementation With Computational Fluid Dynamics Approaches

Shear-induced platelet activation is one of the critical outcomes when blood is exposed to elevated shear stress. Excessively activated platelets in the circulation can lead to thrombus formation and platelet consumption, resulting in serious adverse events such as thromboembolism and bleeding. While experimental observations reveal that it is related to the shear stress level and exposure time, the underlying mechanism of shear-induced platelet activation is not fully understood. Various models have been proposed to relate shear stress levels to platelet activation, yet most are modified from the empirically calibrated power-law model. Newly developed multiscale platelet models are tested as a promising approach to capture a single platelet's dynamic shape during activation, but it would be computationally expensive to employ it for a large-scale analysis. This paper summarizes the current numerical models used to study the shear-induced platelet activation and their computational applications in the risk assessment of a particular flow pattern and clot formation prediction.

Prognostic Implications of Ambulatory N-Terminal Pro-B-Type Natriuretic Peptide Changes in Patients with Continuous-Flow Left Ventricular Assist Devices

Data regarding the role of N-terminal Pro-B-type natriuretic peptide (NT-pro BNP) in patients with a continuous-flow left ventricular assist device (CFLVAD) is scarce. To evaluate the prognostic implications of measuring both absolute values and changes in NT-pro BNP concentrations in ambulatory patients with a CFLVAD, we performed a retrospective study of 168 consecutive patients who had an LVAD implantation at our institution and survived beyond their index hospitalization. Of these, 127 patients (56.2 ± 12.5 years, 21.2% female) had NT-pro BNP measured at 1 and 3 months postdischarge in ambulatory settings. Compared to the NT-pro BNP concentration at 1 month, 94 patients (74%) had a decline, and 33 patients (26%) had an increase in concentrations, from their 1 month baseline. After a median follow-up of 17 months, a total of 53 (41.7%) adverse events occurred. Of these, 37 (69.8%) were heart failure (HF) hospitalizations, and 16 (30.2%) were deaths. For each 1,000 unit increase in NT-pro BNP concentration at 3 months, there was a 17% increase in the risk of HF hospitalization or death (hazard ratio [HR] = 1.17, 95% confidence interval [CI] = 1.04-1.32, p = 0.007). Conversely, each 1000 unit decline during the same time, was associated with an 11% decrease in the risk of HF hospitalization or death (HR = 0.89, 95% CI = 0.77-0.98, p = 0.04). In conclusion, in patients with a CFLAD, an increase in NT-pro BNP concentration from 1 to 3 months is associated with an increased risk of HF hospitalization and death. In contrast, a decline is associated with a reduction in the risk of HF hospitalization and death.

Analysis of Trends and Outcomes of 90 and 180 Day Readmissions After Left Ventricular Assist Device Implantation

Despite decreasing morbidity and mortality in left ventricular assist device (LVAD) recipients, readmission after implantation remains a major problem. Our aim was to investigate the trends and outcomes of 90 and 180 day readmission in this population. The National Readmission Database from 2012 to 2017 was queried to identify LVAD recipients. A total of 5,907 adults (90 day readmissions) and 3,653 adults (180 day readmissions) who survived LVAD implantation during the index admission were included in our analysis. Readmissions occurred in 45.6% and 65.1% by 90 and 180 days, respectively, with most readmissions occurring within the first 20 days. During the study period, mortality at index admission and readmission rate after discharge from index admission remained stable, whereas mortality during the readmission declined overtime both at 90 and 180 days. Heart failure was the most common cause for readmission (both 90 and 180 days), while its incidence also increased over the years. Among the reasons for readmission, intracranial bleeding, ischemic stroke, and device thrombosis were associated with highest mortality and gastrointestinal bleeding with the lowest. Intracranial bleeding, device thrombosis, and device infection were associated with longer length of stay. Multivariate logistic regression models identified gastrointestinal bleeding, length of stay during index admission, and end-stage renal disease requiring hemodialysis as risk factors of readmissions. Our study has unveiled several important factors associated with readmission and mortality. Approaches to identify and prevent readmissions early after LVAD implantation by addressing these factors may lead to lower morbidity, healthcare cost related to readmission, and improved quality of life.

Nephrology Considerations in the Management of Durable and Temporary Mechanical Circulatory Support

Durable and temporary mechanical circulatory support (MCS) use is growing for a range of cardiovascular indications. Kidney dysfunction is common in people evaluated for or receiving durable or temporary MCS and portends worse outcomes. This kidney dysfunction can be due to preexisting kidney chronic kidney disease (CKD), acute kidney injury (AKI) related to acute cardiovascular disease necessitating MCS, AKI due to cardiac procedures, and acute and chronic MCS effects and complications. Durable MCS, with implantable continuous flow pumps, is used for long-term support in advanced heart failure refractory to guideline-directed medical and device therapy, either permanently or as a bridge to heart transplantation. Temporary MCS-encompassing in this review intra-aortic balloon pumps (IABP), axial flow pumps, centrifugal flow pumps, and venoarterial ECMO-is used for diverse situations: high-risk percutaneous coronary interventions (PCI), acute decompensated heart failure, cardiogenic shock, and resuscitation after cardiac arrest. The wide adoption of MCS makes it imperative to improve understanding of the effects of MCS on kidney health/function and of kidney health/function on MCS outcomes. The complex structure and functions of the kidney, and the complex health states of individuals receiving MCS, makes investigations in this area challenging, and current knowledge is limited. Fortunately, the increasing nephrology toolbox of noninvasive kidney health/function assessments may enable development and testing of individualized management strategies and therapeutics in the future. We review technology, epidemiology, pathophysiology, clinical considerations, and future directions in MCS and nephrology.

Diagnostic Evaluation and Cervical Spine Surgery in the Setting of a Cardiac Left Ventricular Assist Device: Challenges and a Case Illustration

Due to incompatibility with magnetic resonance imaging, patients with left ventricular assist devices (LVADs) presenting with pathologies of the spinal soft tissues or neural elements represent diagnostically complex cases. We present a case of a patient undergoing a CT (computed tomography) myelogram and subsequent successful cervical posterior laminectomy. A C1-C2 lateral puncture approach CT myelogram revealed nearly a complete block of contrast movement at the level of the C2-C3 vertebrae concerning a compressive etiology. The cervical lateral approach was chosen based on patient symptomology and concern that contrast dye injected in the lumbar spine would not travel to the region of interest due to altered CSF pulsatility caused by the LVAD device. A C3-C7 posterior laminectomy was then successfully performed. Intra-operatively, however, there was no sign of a compressive lesion, and ultrasound confirmed a decompressed spinal cord. This case highlights the diagnostic challenges of pre-operative evaluation in patients with LVADs in which the efficacy of performing CT myelograms is also questionable due to potential alterations in cerebrospinal fluid movement due to variations in arterial pulsatility due to LVAD physiology.

Exercise in patients with left ventricular devices: The interaction between the device and the patient

Advances in the engineering of surgically implanted, durable left ventricular assist devices (LVAD) has led to improvements in the two-year survival of patients on LVAD support, which is now comparable to that of heart transplant (HT) recipients. And with the advent of magnetic levitation technology, both the survival rate and average time on LVAD support are expected to improve even further. However, despite these advances, the functional capacity of patients on LVAD support remains reduced compared to those who received a HT. A few small clinical trials have shown improvement in functional capacity with exercise training. Peak oxygen uptake improves modestly (10%-20%) with exercise training, suggesting a possible celling-effect linked to the ability of the LVAD to increase flow during exercise. This paper reviews both (a) the effect of the LVAD on the cardiorespiratory responses during a single, acute bout of exercise up to maximum and (b) the central and peripheral adaptations that occur among patients with an LVAD who undergo an exercise training regimen. We also address the tenets of the exercise prescription that are unique to patients with a durable LVAD.

Development of Mechanical Circulatory Support Devices: 55 Years and Counting

Heart failure is a leading cause of morbidity and mortality in the United States. Treatment of this condition increasingly involves mechanical circulatory support devices. Even with optimal medical therapy and use of simple cardiac devices, heart failure often leads to reduced quality of life and a shortened life span, prompting exploration of more advanced treatment approaches. Left ventricular assist devices constitute an effective alternative to cardiac transplantation. These devices are not without complications, however, and their use requires careful cooperative management by the patient's cardiology team and primary care provider. Left ventricular assist devices have undergone many technological advancements since they were first introduced, and they will continue to evolve. This article reviews the history of different types of left ventricular assist devices, appropriate patient selection, and common complications in order to increase health professionals' familiarity with these treatment options.

Contrast-Enhanced Ultrasound of Muscle Perfusion May Indicate Patient Response to Left Ventricular Assist Device Therapy

PURPOSE

Left ventricular assist device (LVAD) support is associated with peripheral vascular abnormalities beyond those associated with heart failure (HF). These abnormalities are associated with persistent functional impairments that adversely impact quality of life (QoL). Methods for measuring peripheral vascular function in this population are needed.

METHODS

This pilot study investigated the use of contrast-enhanced ultrasound (CEUS) using standardized protocols to estimate changes in peripheral (quadriceps) muscle perfusion among patients with HF (INTERMACS profile 3) undergoing LVAD implantation (n = 7). Patients were then stratified by those who did ("responders", n = 4) and did not ("nonresponders", n = 3) report QoL improvement with LVAD support.

RESULTS

Serial measurements obtained preoperatively and 3 months following LVAD implantation showed no significant change (P > .23) in muscle perfusion by all CEUS-based measures at rest or with an exercise stimulus for the overall population. Responders exhibited improved muscle perfusion at rest (P = .043) and decreased time to peak contrast enhancement (P = .010) at 3 months compared with baseline, suggesting improved delivery of blood to the extremities post-LVAD. Nonresponders showed unchanged resting muscle perfusion (P > .99), time to peak contrast enhancement (P = .59), and response to exercise stimulus (P > .99) following LVAD therapy.

CONCLUSION

Our findings suggest that CEUS evaluation is a promising noninvasive, quantitative modality for real-time assessment of peripheral vasculature and muscle perfusion as an indication of treatment response in LVAD recipients and that this modality may capture perfusion measures important to QoL following LVAD implantation.

Alarms and Their Outcomes in Left Ventricular Assist Device Patients

Low flow and suction alarms are provided to alert caregivers of changes in left ventricular assist device pump function but may be reset in clinical practice. We investigated the incidence and underlying causes of these alarms as well as their prognostic significance. HeartWare ventricular assist device patients (n = 113) were divided into quartiles based on their frequency of low flow and suction alarms. Survival and adverse events (thrombus, stroke, bleeding, and right heart failure) were compared between quartiles. Low flow alarms peaked in the first few months of pump support before dropping down to near negligible levels. Suction alarm frequency remained relatively constant throughout pump support. Although pump speeds (p < 0.001) and flow (p = 0.01) decreased over time, there was an increase in suction alarm frequency (p = 0.018), with no changes in low flow alarms. Patients with smaller body size (p = 0.016) and lower pump flows (p = 0.008) had higher frequencies of low flow alarms on multiple regression (p < 0.001). Patients with the highest low flow alarm frequency demonstrated poorer survival (p = 0.026). There was no relationship between suction alarm frequency and survival. There was also no relationship between either low flow or suction alarm frequency with strokes, gastrointestinal bleeds, pump thrombus, or right ventricular failure. Duration of alarm and intervention in response to the alarm was not assessed in this study. Further studies examining alarm duration and responses may inform future pump alarm algorithms.

Rethinking Rehabilitation: A REVIEW OF PATIENT POPULATIONS WHO CAN BENEFIT FROM CARDIAC REHABILITATION

Although cardiac rehabilitation (CR) is safe and highly effective for individuals with various cardiovascular health conditions, to date there are only seven diagnoses or procedures identified by the Centers for Medicare & Medicaid Services that qualify for referral. When considering the growing number of individuals with cardiovascular disease (CVD), or other health conditions that increase the risk for CVD, it is important to determine the extent for which CR could benefit these populations. Furthermore, there are some patients who may currently be eligible for CR (spontaneous coronary artery dissection, left ventricular assistant device) but make up a relatively small proportion of the populations that are regularly attending and participating. Thus, these patient populations and special considerations for exercise might be less familiar to professionals who are supervising their programs. The purpose of this review is to summarize the current literature surrounding exercise testing and programming among four specific patient populations that either do not currently qualify for (chronic and end-stage renal disease, breast cancer survivor) or who are eligible but less commonly seen in CR (sudden coronary artery dissection, left ventricular assist device). While current evidence suggests that individuals with these health conditions can safely participate in and may benefit from supervised exercise programming, there is an immediate need for high-quality, multisite clinical trials to develop more specific exercise recommendations and support the inclusion of these populations in future CR programs.

Recommendations for Psychosocial Evaluation of VAD candidates: Adoption, completion, and barriers to implementation

BACKGROUND

Recommendations exist to guide clinicians on a comprehensive psychosocial (PS) evaluation prior to Mechanical Circulatory Support (MCS) implantation.

OBJECTIVES

Assess adoption, beliefs, methodologies, and barriers to completion of the 2018 ISHLT/APM/AST/ICCAC/STSW Recommendations for Psychosocial evaluation of adult cardiothoracic transplant and long term mechanical circulatory support.

METHODS

Cross-sectional survey distributed to all 183 implanting LVAD centers in North America via mail and email.

RESULTS

Total of 58 Programs (35.6% response rate) representing 29 states and all regions of the United States responded. Respondents reported implanting 1,183 adults (range 0 - 85; mean = 21.5, SD = 18) in 2018. A majority (n = 55, 94.8%) reported that the 2018 Recommendations were consistent with their clinical practice and most (n = 51, 87.9%) had adopted the recommendations. The Stanford Integrated Psychosocial Assessment for Transplant (SIPAT) (n = 25, 47.1%) was the most commonly cited assessment tool in the use, although 15 centers reported utilizing more than one tool during the assessment process. Most common barriers influencing completion of the PS evaluation include patient too ill (total responses = 104), lack of time (total responses = 89), patient poor candidate (total responses = 44), and lack of Insurance coverage/reimbursement (total responses = 41).

CONCLUSION

The 2018 ISHLT Recommendations for PS evaluation of LVAD Candidates are widely adopted by respondents in clinical practice, although barriers are still reported to their implementation. Additional research is needed to understand strategies to reduce barriers to implementation and maintenance of the recommendations in clinical practice.

Carbon Monoxide Diffusing Capacity Predicts Cardiac Readmission in Patients Undergoing Left Ventricular Assist Device Implantation in Japan

Carbon monoxide diffusion capacity (DLCO) is impaired in heart failure patients; however, its clinical impact has not been well investigated in the left ventricular assist device (LVAD) population. We explored the predictive value of preoperative DLCO in the survival and cardiac readmission rates after LVAD implantation. Seventy-six patients who received continuous-flow LVAD as bridge-to-transplant therapy from November 2007 to September 2018 and underwent pulmonary function test before LVAD implantation were included. The primary study endpoints were death and readmission for heart failure or arrhythmia (cardiac readmission). Patients were stratified into two groups according to the percent of predicted DLCO (%DLCO). Pulmonary vascular resistance (PVR) was equivocal between the groups preoperatively, whereas the low DLCO group (%DLCO < 80%) showed significantly high PVR postoperatively. The mortality rate was not different between the groups. The 2 year cardiac readmission rate was 33.5% in the low DLCO group and 8.7% in the high DLCO group (%DLCO ≥ 80%) (P = 0.028). The %DLCO was associated with cardiac readmission in univariate and multivariate analyses (hazard ratio: 4.32; 95% CI: 1.50-15.9; P = 0.005). Low %DLCO was associated with high PVR postoperatively and was a risk factor for cardiac readmission after LVAD implantation.

Evaluation of aspirin platelet inhibition in left ventricular assist device population

INTRODUCTION

Aspirin therapy is recommended in durable left ventricular assist device (LVAD) patients to prevent thromboembolic complications. Up to 30% of patients treated with aspirin may demonstrate aspirin resistance, which has been related to thrombotic complications. However, it is unknown whether individual patients exhibit temporal alterations in aspirin sensitivity during LVAD support. We hypothesized that aspirin platelet inhibition would wane after the initial postimplant period.

METHODS

This was a retrospective, observational, single center study conducted at an academic medical center. This study evaluated changes in aspirin platelet inhibition over the first 6 months of LVAD support. Patients who underwent placement of centrifugal LVAD with aspirin platelet sensitivity assays were included for analysis. Aspirin responsiveness was assessed postimplant after 5 days, 3 months, and 6 months.

RESULTS

A total of 28 patients were included for analysis of which 7% of patients were aspirin resistant initially. At 3 months, 32% (odds ratio [OR], 6.1, p = .03) of patients were aspirin resistant and 28% (OR, 4.1, p = .1) at 6 months. Over the first 3 months postimplant, the odds of aspirin resistance increased sixfold and remained relatively constant at 6 months. Patients who were aspirin resistant and received an increase in aspirin dose at 3 months subsequently had a sensitive ARU at 6 months.

CONCLUSION

Aspirin responsiveness not only varies between patients but can significantly wane within individual LVAD patients over time. Additional study is needed to determine if monitoring aspirin resistance may prevent thrombotic complications after LVAD implantation.

Association of thrombophilia prospective detection with hemocompatibility related outcomes in left ventricular assist device patients

INTRODUCTION

Inherited thrombophilias represent a concerning risk factor due to a proclivity to an aberrant clot formation. However, in patients with left ventricular assist device (LVAD), their impact on bleeding and thrombotic complications remains still poorly understood. The aim of the present study was to evaluate the effect of thrombophilic mutation directed anticoagulation therapy on adverse clinical outcomes in LVAD patients.

MATERIALS AND METHODS

About 138 consecutive patients indicated for LVAD implant (HeartMate II, Abbott, Plymouth, USA) were prospectively screened for three major thrombophilic mutations: factor II (prothrombin), factor V Leiden, and homozygous methylenetetrahydrofolate reductase (MTHFR). Subsequently, discordant individualized anticoagulation targets of INR 2.5-3.0 in thrombophilia positive and INR 1.8-2.2 in negative patients were established; notably without anti-platelet agents given the center standard of care.

RESULTS

Mean age was 50 ± 12.7 years, 83% male. Mean duration of support was 464.5 days (SD 482.9; SEM 41.1) and median of 310 days (IQR 162; 546). Full thrombophilia positive cohort analysis has not revealed any significant impact on event free survival. In contrast, detailed analysis of specific thrombophilias subsets has revealed Factor II prothrombin mutation as a significant predisposition for the pump thrombosis risk (SHR 10.48; p = 0.001) despite more aggressive prespecified anticoagulation target. Moreover, the incidence of bleeding events in prothrombin group was also significantly increased (SHR 6.0; p = 0.03).

CONCLUSIONS

Our observations suggest that specific thrombophilias in LVAD patients may pose different intensity predisposition for thrombotic complications. Factor II (prothrombin) positive mutation was identified as significant risk factor associated with the pump thrombosis.