Biosensors with left ventricular assist devices.

Heart failure imposes a significant global health burden, standing as a primary contributor to mortality. Various indicators and physiological shifts within the body may hint at distinct cardiac conditions. Specific biosensors have the capability to identify these changes. Integrating or embedding these biosensors into mechanical circulatory support devices (MCSDs), such as left ventricular assist devices (LVADs), becomes crucial for monitoring alterations in biochemical and physiological factors subsequent to an MCSD implantation. Detecting abnormal changes early in the course of disease progression will allow for improved patient outcomes and prognosis following an MCSD implantation. The aim of this review is to explore the available biosensors that may be coupled or implanted alongside LVADs to monitor biomarkers and changes in physiological parameters. Different fabrication materials for the biosensors are discussed, including their advantages and disadvantages. This review also examines the feasibility of integrating feedback control mechanisms into LVAD systems using data from the biosensors. Challenges facing this emerging technology and future directions for research and development are outlined as well. The overarching goal is to provide an overview of how implanted biosensors may improve the performance and outcomes of LVADs through continuous monitoring and closed-loop control.

Neutrophil Extracellular Trap Formation in Advanced Heart Failure Patients-Preliminary Report.

In end-stage heart failure, which is characterized by persistent or progressive ventricular dysfunction despite optimal medical therapy, a left ventricular assist device (LVAD) can be beneficial. Congestive heart failure provokes inflammatory and prothrombotic activation. The aim of this study was to evaluate the serum concentration of citrullinated histone 3 (CH3) representing neutrophil extracellular trap (NET) formation in patients referred for LVAD implantation. There were 10 patients with a median age of 61 (57-65) years enrolled in a prospective single-center analysis who underwent LVAD implantation. The CH3 plasma concentration was measured preoperatively and on the 1st and 7th postoperative days, followed by control measurements on the median (Q1-3) 88th (49-143) day. The preoperative CH3 concentration strongly correlated with brain natriuretic peptide (r = 0.879, p < 0.001). Significant differences in CH3 serum concentration were observed between pre- and postoperative measurements, including an increase on the first postoperative day (p < 0.001), as well as a decrease on the seventh day (p = 0.016) and in follow-up (p < 0.001). CH3 concentration, as a marker of NET formation, decreases after LVAD implantation.

Beyond Quadruple Therapy and Current Therapeutic Strategies in Heart Failure with Reduced Ejection Fraction: Medical Therapies with Potential to Become Part of the Therapeutic Armamentarium.

Heart failure with reduced ejection fraction (HFrEF) is a complex clinical syndrome with significant morbidity and mortality and seems to be responsible for approximately 50% of heart failure cases and hospitalizations worldwide. First-line treatments of patients with HFrEF, according to the ESC and AHA guidelines, include ß-blockers, angiotensin receptor/neprilysin inhibitors, sodium-glucose cotransporter 2 inhibitors, and mineralocorticoid receptor antagonists. This quadruple therapy should be initiated during hospital stay and uptitrated to maximum doses within 6 weeks after discharge according to large multicenter controlled trials. Quadruple therapy improves survival by approximately 8 years for a 55-year-old heart failure patient. Additional therapeutic strategies targeting other signaling pathways such as ivabradine, digoxin, and isosorbide dinitrate and hydralazine combination for African Americans, as well as adjunctive symptomatic therapies, seem to be necessary in the management of HFrEF. Although second-line medications have not achieved improvements in mortality, they seem to decrease heart failure hospitalizations. There are novel medical therapies including vericiguat, omecamtiv mecarbil, genetic and cellular therapies, and mitochondria-targeted therapies. Moreover, mitraclip for significant mitral valve regurgitation, ablation in specific atrial fibrillation cases, omecamtiv mecarbil are options under evaluation in clinical trials. Finally, the HeartMate 3 magnetically levitated centrifugal left ventricular assist device (LVAD) has extended 5-year survival for stage D HF patients who are candidates for an LVAD.

Healthcare consumption of patients with left ventricular assist device: real-world data.

BACKGROUND: A left ventricular assist device (LVAD) is a life-saving but intensive therapy for patients with end-stage heart failure. We evaluated the healthcare consumption in a cohort of LVAD patients in our centre over 6 years. METHODS: All patients with a primary LVAD implantation at the University Medical Centre Utrecht in Utrecht, the Netherlands from 2016 through 2021 were included in this analysis. Subsequent hospital stay, outpatient clinic visits, emergency department visits and readmissions were recorded. RESULTS: During the investigated period, 226 LVADs were implanted, ranging from 32 in 2016 to 45 in 2020. Most LVADs were implanted in patients aged 40-60 years, while they were supported by or sliding on inotropes (Interagency Registry for Mechanically Assisted Circulatory Support class 2 or 3). Around the time of LVAD implantation, the median total hospital stay was 41 days. As the size of the LVAD cohort increased over time, the total annual number of outpatient clinic visits also increased, from 124 in 2016 to 812 in 2021 (p = 0.003). The numbers of emergency department visits and readmissions significantly increased in the 6­year period as well, with a total number of 553 emergency department visits and 614 readmissions. Over the years, the annual number of outpatient clinic visits decreased by 1 per patient-year follow-up, while the annual numbers of emergency department visits and readmissions per patient-year remained stable. CONCLUSION: The number of patients supported by an LVAD has grown steadily over the last years, requiring a more specialised healthcare in this particular population.

Racial differences in clinical characteristics and readmission burden among patients with a left ventricular-assist device.

BACKGROUND: There are limited data regarding racial disparities in outcomes after left ventricular assist device (LVAD) implantation. The purpose of this study was to compare clinical characteristics and the burden of readmissions by race among patients with LVAD. METHODS: The study population included 461 patients implanted with LVADs at the University of Rochester Medical Center, NY from May 2008 to March 2020. Patients were stratified by race as White patients (N = 396 [86%]) and Black patients (N = 65 [14%]). The Anderson-Gill recurrent regression analysis was used to assess the independent association between race and the total number of admissions after LVAD implant during an average follow-up of 2.45 ± 2.30 years. RESULTS: Black patients displayed significant differences in baseline clinical characteristics compared to White patients, including a younger age, a lower frequency of ischemic etiology, and a higher baseline serum creatinine. Black patients had a significantly higher burden of readmissions after LVAD implantation as compared with White patients 10 versus 7 (average number of hospitalizations per patient at 5 years of follow-up, respectively) translated into a significant 39% increased risk of recurrent readmissions after multivariate adjustment (Hazard ratio 1.39, 95% CI; 1.07-1.82, p 0.013). CONCLUSION: Black LVAD patients experience an increased burden of readmissions compared with White patients, after adjustment for baseline differences in demographics and clinical characteristics. Future studies should assess the underlying mechanisms for this increased risk including the effect of social determinants of health on the risk of readmissions in LVAD recipients.

Vibrational characterization of cavitation in left ventricular assist device.

BACKGROUND: The left ventricular assist device (LVAD) is a mechanical circulatory support device for patients with severe heart failure. Microbubbles caused by cavitation in the LVAD can potentially lead to physiological and pump-related complications. The aim of this study is to characterize the vibrational patterns in the LVAD during cavitation. METHODS: The LVAD was integrated into an in vitro circuit and mounted with a high-frequency accelerometer. Accelerometry signals were acquired with different relative pump inlet pressures ranging from baseline (+20 mmHg) to -600 mmHg in order to induce cavitation. Microbubbles were monitored with dedicated sensors at the pump inlet and outlet to quantify the degree of cavitation. Acceleration signals were analyzed in the frequency domain to identify changes in the frequency patterns when cavitation occurred. RESULTS: Significant cavitation occurred at the low inlet pressure (-600 mmHg) and was detected in the frequency range between 1800 and 9000 Hz. Minor degrees of cavitation at higher inlet pressures (-300 to -500 mmHg) were detected in the frequency range between 500-700, 1600-1700 Hz, and around 12 000 Hz. The signal power of the dominating frequency ranges was statistically significantly different from baseline signals. CONCLUSION: Vibrational measurements in the LVAD can be used to detect cavitation. A significant degree of cavitation could be detected in a wide frequency range, while minor cavitation activity could only be detected in more narrow frequency ranges. Continuous vibrational LVAD monitoring can potentially be used to detect cavitation and minimize the damaging effect associated with cavitation.

Outcomes in Patients With Chronic Kidney Disease and End-stage Renal Disease and Durable Left Ventricular Assist Device: Insights From the United States Renal Data System Database.

BACKGROUND: There is paucity of data regarding durable left ventricular assist device (LVAD) outcomes in patients with chronic kidney disease (CKD) stages 3-5 and CKD stage 5 on dialysis (end-stage renal disease [ESRD]). METHODS AND RESULTS: We conducted a retrospective study of Medicare beneficiaries with ESRD and a 5% sample of patients with CKD with an LVAD (2006-2018) to determine 1-year outcomes using the United States Renal Data System database. The LVAD implantation, comorbidities, and outcomes were identified using appropriate International Classification of Diseases, 9th and 10th edition codes. We identified 496 patients with CKD and 95 patients with ESRD who underwent LVAD implantation. The patients with ESRD were younger (59 years vs 66 years; P < .001), had more Blacks (40% vs 24.6%, P = .009), compared with the CKD group. The 1-year mortality (49.5% vs 30.9%, P < .001) and index mortality (27.4% vs 16.7%, P = .014) rates were higher for patients with ESRD. A subgroup analysis showed significantly higher mortality in ESRD vs CKD 3 (49.5% vs 30.2%, adjusted P = .009), but no significant difference in mortality between stage 3 vs 4/5 (30.2% vs 30.8%, adjusted P = .941). There was no significant difference in secondary outcomes (bleeding, stroke, and sepsis/infection) during follow-up between the 2 groups. CONCLUSIONS: Patients with ESRD undergoing LVAD implantation had significantly higher index and 1-year mortality rates compared with patients with CKD.

Electromagnetic interference induced ventricular tachycardia in left ventricular assist device.

Left ventricular assist devices (LVAD) have been increasingly utilized end-stage heart failure despite guidelinedirected medical therapy (due to limited organ availability) as a bridge to transplant or destination therapy, with improved overall survival.Majority of patients undergoing LVAD implantation have pre-existing implantable cardioverter-defibrillator (ICD) in-situ.We present a case of device-device interaction resulting in EMI inducing recurrent inappropriate device therapies inducing ventricular arrhythmia followed by the inappropriate triggering of noise reversion mode, thereby inhibiting device therapies.With the increase in number of end-stage heart failure patients with ICDs in situ (and limited organ availability) undergoing LVAD implantation, it is imperative to recognize potential device-device interactions to avoid unwarranted invasive interventions.

Outcomes Among Patients With Left Ventricular Assist Devices Receiving Maintenance Outpatient Hemodialysis: A Case Series.

RATIONALE & OBJECTIVE: The incidence of left ventricular assist device (LVAD) implantation as destination therapy for heart failure is increasing and kidney failure requiring maintenance hemodialysis is a common complication. Because little is known about the safety or efficacy of outpatient hemodialysis among patients with LVADs, this study sought to describe their clinical course. STUDY DESIGN: Case series of patients with an LVAD undergoing maintenance outpatient hemodialysis whose clinical data were obtained from an electronic medical record. SETTING & PARTICIPANTS: Adults who received an LVAD, survived to hospital discharge, and were subsequently treated with maintenance hemodialysis by a not-for-profit dialysis provider between 2011 and 2019. RESULTS: 11 patients were included. 6 had a known history of chronic kidney disease. Patients underwent outpatient hemodialysis for a mean duration of 165.2 (range, 31-542) days, during which they were treated with 544 total dialysis sessions. 6 of these sessions were stopped early due to dialysis-related adverse events (1.1%). More than 80% of follow-up time was spent out of the hospital; however, 55% of patients were rehospitalized within 1 month of starting outpatient hemodialysis. The most common reason for hospitalization was infection (32%), followed by hypervolemia (14%), and cerebrovascular accident or transient ischemic attack (11%). 4 patients recovered kidney function, 1 underwent combined heart and kidney transplantation, 2 continued treatment, 2 died, and 2 were lost to follow-up. LIMITATIONS: Retrospective design, small number of cases, and lack of complete follow-up data. CONCLUSIONS: Approximately half the patients with complete follow-up either recovered kidney function or underwent combined heart and kidney transplantation. This case series demonstrates that outpatient hemodialysis centers, in partnership with LVAD treatment teams, can successfully provide hemodialysis to patients on LVAD support.

Secondary aortic valve replacement in continuous flow left ventricular assist device therapy.

The purpose of the study was to investigate the outcome of secondary surgical aortic valve replacement (sSAVR) in patients with severe aortic regurgitation (AR) in the context of ventricular assist device (VAD) therapy. From 2009 to 2020, 792 patients underwent cf-LVAD implantation [HVAD (Medtronic, USA), n = 585, and HM 3 (Abbott, USA), n = 207]. All cf-LVAD patients with severe AR requiring secondary AVR were enrolled in this study. A total of six patients (median, 40 years, IQR; 34-61 years, 50% male) underwent secondary surgical aortic valve replacement (sSAVR) after cf-LVAD implantation. Median time of previous LVAD support was 26 months (IQR: 21-29 months). Two patients required additional tricuspid valve repair (TVR) and one patient underwent SAVR after failed TAVR. Four patients needed temporary right ventricular assist device (RVAD) with a median of 30 days (IQR; 29-33 days). Three patients were bridged to urgent heart transplantation due to persevering right heart failure, whereas two destination therapy (DT) candidates survived without any associated complications. An additional DT patient died of pneumonia 1 month after sSAVR. Secondary surgical aortic valve replacement in ongoing LVAD patients is an advanced procedure for a complex cohort. In our series, sSAVR was safely performed and effective, but involved a high-risk for subsequent right heart failure, requiring urgent heart transplantation. In LVAD patients with severe AR requiring treatment where TAVR is not feasible, sSAVR can be evaluated as salvage option for bridge to transplant patients or selected destination therapy candidates.

Carotid artery structure and hemodynamics and their association with adverse vascular events in left ventricular assist device patients.

Left ventricular assist devices (LVADs) are associated with major vascular complications including stroke and gastrointestinal bleeding (GIB). These adverse vascular events may be the result of widespread vascular dysfunction resulting from pre-LVAD abnormalities or continuous flow during LVAD therapy. We hypothesized that pre-existing large artery atherosclerosis and/or abnormal blood flow as measured in carotid arteries using ultrasonography are associated with a post-implantation composite adverse outcome including stroke, GIB, or death. We retrospectively studied 141 adult HeartMate II patients who had carotid ultrasound duplex exams performed before and/or after LVAD surgery. Structural parameters examined included plaque burden and stenosis. Hemodynamic parameters included peak-systolic, end-diastolic, and mean velocity as well as pulsatility index. We examined the association of these measures with the composite outcome as well as individual subcomponents such as stroke. After adjusting for established risk factors, the composite adverse outcome was associated with pre-operative moderate-to-severe carotid plaque (OR 5.08, 95% CI 1.67-15.52) as well as pre-operative internal carotid artery stenosis (OR 9.02, 95% CI 1.06-76.56). In contrast, altered hemodynamics during LVAD support were not associated with the composite outcome. Our findings suggest that pre-existing atherosclerosis possibly in combination with LVAD hemodynamics may be an important contributor to adverse vascular events during mechanical support. This encourages greater awareness of carotid morphology pre-operatively and further study of the interaction between hemodynamics, pulsatility, and structural arterial disease during LVAD support.

A case of left ventricular assist device application for chemotherapy-related cardiomyopathy caused by trastuzumab and anthracycline.

Left ventricular assist device (LVAD) is an established therapy for patients with severe heart failure. Because the incidence of cardiotoxicity owing to anticancer agents is low, it is difficult to predict the recovery prospects when the cause of heart failure is due to anticancer agents. In this context, cancer patients who present with severe symptoms of heart failure and who fail medical therapy for heart failure may pose a dilemma, especially in countries such as Japan where implantable LVADs are not approved for purposes other than bridging to transplant. Recently, we encountered a 32-year-old woman with chemotherapy-related cardiomyopathy that developed after anticancer treatment using trastuzumab and anthracycline. LVAD therapy was the only option to save the young woman. The patient received an extracorporeal LVAD, her cardiac function gradually recovered while on support, and the device was successfully removed.

Cardiac resynchronization therapy and outcomes in patients with left ventricular assist devices: a systematic review and meta-analysis.

The impact of cardiac resynchronization therapy (CRT) on clinical outcome in patients with a continuous-flow left ventricular assist device (LVAD) is currently not well understood. We conducted a systematic literature review and meta-analysis with an intention to summarize all published clinical evidence. We searched MEDLINE and EMBASE databases through March 2018 for studies that compared the outcomes in patients with LVAD and CRT. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated using a random-effects model, inverse variance method. The between-study heterogeneity was assessed using the Q statistic and I2. A total of seven studies that included 1157 (575 CRT; 582 non-CRT) patients were identified. Our meta-analysis did not demonstrate a significant difference in the risk of mortality (pooled OR = 1.21, 95% CI 0.90-1.63, P = 0.21), ventricular arrhythmia incidence (pooled OR = 1.36, 95% CI 0.99-1.86, P = 0.06), hospitalization (pooled OR = 1.36, 95% CI 0.59-3.14, P = 0.48), or implantable cardioverter defibrillator therapies (pooled OR = 1.08, 95% CI 0.51-2.30, P = 0.84) among the CRT group compared with the non-CRT group. There was high heterogeneity with an I2 of 75% for ICD therapies. Among LVAD patients, CRT combined did not significantly affect mortality, re-hospitalization, ventricular arrhythmia incidence, and ICD therapies.

Implication of Preoperative Existence of Atrial Fibrillation on Hemocompatibility-Related Adverse Events During Left Ventricular Assist Device Support.

BACKGROUND: Hemocompatibility-related adverse events (HRAEs) are substantial issues in patients with left ventricular assist devices (LVADs). Atrial fibrillation (AF) is associated with worse prognosis in patients with heart failure (HF), but its effect on HRAEs following LVAD implantation remain uncertain.Methods and Results:Data from the Japanese Mechanically Assisted Circulatory Support registry of consecutive patients who received HeartMate II LVADs and were followed for 1 year were retrospectively reviewed. Among 190 patients, 23 had AF and 167 had sinus rhythm. The AF group had comparable baseline characteristics with the non-AF group except for their higher age (53 vs. 42 years, P<0.001). Following LVAD implantation, most cases of AF (73%) persisted. Antiplatelet therapy, anticoagulation therapy, and LVAD speed following LVAD implantation were comparable between groups (P>0.05 for all). The 1-year survival free from HRAEs was comparable between groups (83% vs. 76%, P=0.52). Event rates of the breakdown of HRAEs were comparable between groups except for a relatively higher rate of surgically managed pump thrombosis in the AF group (0.16 vs. 0.04, incidence rate ratio 3.75, 95% confidence interval 0.87-16.1, P=0.075). These trends still remained with propensity score-matched comparison. CONCLUSIONS: Existence of AF had no effect on the development of HRAEs following LVAD implantation. The need to aggressively treat AF before or after LVAD implantation needs further investigation.

Stroke Risk Following Infection in Patients with Continuous-Flow Left Ventricular Assist Device.

BACKGROUND: Infection has been associated with stroke in patients with left ventricular assist devices (LVAD); however, little data exist on the timing, type and mortality impact of infection-related stroke. METHODS: Prospectively collected data of HeartMate II (N = 332) and HeartWare (N = 70) LVAD patients from a single center were reviewed. Only strokes (ischemic or hemorrhagic) that occurred within 6 weeks following a LVAD infection were considered in analyses. The association between LVAD infections (wound, pump pocket, driveline and/or bloodstream infection [BSI]), specific pathogens and ischemic and hemorrhagic strokes was evaluated using multivariable logistic regression analysis. The impact of infection-related stroke on cumulative survival was assessed using Kaplan-Meier analysis. RESULTS: Of 402 patients, LVAD infection occurred in 158 (39%) including BSI in 107 (27%), driveline infection in 67 (17%), wound infection in 31 (8%) and pump pocket infection in 24 (6%). LVAD infection-related stroke occurred in 20/158 (13%) patients in a median of 4 days (0-36 days) from documented infection. In multivariable analysis, ischemic stroke was associated with wound infection (aOR 9.0, 95% CI 2.4-34.0, P = 0.001) and BSI (aOR 7.7, 95% CI 0.9-66.0, P = 0.064), and hemorrhagic stroke was associated with BSI in 100% of cases (P = 0.01). There was no association with driveline or pump pocket infection. The cumulative survival rate among patients with infection-related stroke was significantly lower compared to those with LVAD infection but no stroke (log-rank P < 0.001). There was a trend toward shorter stroke-free survival among patients with LVAD infection. CONCLUSIONS: LVAD infections, particularly BSI, are significantly associated with stroke, and infection-related stroke conferred significantly lower cumulative survival.

A real-life experience with HeartMate III.

BACKGROUND: The HeartMate III (HM3) left ventricular assist device (LVAD) is the most recent LVAD to receive CE Mark and the Food and Drug Administration approval. It is a fully magnetically levitated pump with no reported haemolysis, pump thrombosis or pump failure in the first in-man study (a previous stody). It has now received market approval in the European Union, United States of America, and Australia. We reviewed our real-life experience with the device, to assess outcomes over the medium term. METHODS: We conducted a retrospective review of prospectively collected data for 33 consecutive patients implanted with a HM3 LVAD between November 2014 and October 2018 at The Alfred Hospital, Melbourne, Australia. RESULTS: Of the 33 patients, 31 remained alive at the census date, with only two early deaths and 11 patients transplanted. There were no pump thromboses, but there were three cases of clot ingestion (two on the right and one on the left). Seven patients required permanent biventricular assist device support. The duration of HM3 support at the time of census was a median of 196 (interquartile range, 118-386) days. CONCLUSION: This series demonstrates excellent results of the HM3 LVAD in an uncensored, real-life, consecutive group of patients in a single institution.

Left Ventricular Assist Devices, Kidney Disease, and Dialysis.

Left ventricular assist devices (LVADs) improve survival in patients with advanced heart failure. As LVAD use increases, so do the number of patients with LVADs who also have kidney disease. However, there are only sparse data on how best to care for these patients. This review provides an overview of LVAD principles and indications, including blood pressure assessment and criteria for receipt of both destination and bridge to transplantation LVADs. Following LVAD implantation, kidney function may improve in the short term, particularly if cardiorenal physiology was present; in the longer term, data remain limited. Individuals with glomerular filtration rates chronically < 30mL/min/1.73m2, including those treated with maintenance dialysis, are generally ineligible for destination LVADs. However, select patients with advanced chronic kidney disease can be considered for LVADs as a bridge to heart or heart-kidney transplantation. Patients who develop acute kidney injury and require dialysis following LVAD implantation have high mortality rates. Although thrice-weekly hemodialysis is the most common modality for patients with LVADs, peritoneal dialysis and home hemodialysis are additional options. Peritoneal dialysis in particular may be associated with lower risk for bloodstream infection and fewer hemodynamic shifts. For those treated with hemodialysis, arteriovenous fistulas can successfully be used for vascular access. Many questions remain, including optimal anemia management and refinement of hemodialysis protocols for patients with an LVAD, and further research is needed in this field.

Therapeutic Strategy for Gastrointestinal Bleeding in Patients With Left Ventricular Assist Device.

Left ventricular assist device (LVAD) technology has improved the survival of advanced heart failure patients. However, readmission rates following LVAD implantation remain high and are an unsolved matter. Currently, gastrointestinal bleeding is one of the major causes of readmission and has recently been demonstrated to mainly result from increased angiogenesis. In addition to the conventional therapeutic strategies, including a reduction in antiplatelet and anticoagulation therapies and blood products administration, several therapeutic tools have recently been proposed: octreotide, thalidomide, hemodynamic optimization by the ramp test, and fish oil therapy. This review will update the therapeutic strategy for gastrointestinal bleeding in LVAD patients.

Relationship Between Bacteremia and Hemorrhagic Stroke in Patients With Continuous-Flow Left Ventricular Assist Device.

BACKGROUND: Blood stream infection is thought to increase the risk of hemorrhagic stroke, a major adverse event with devastating outcome, in patients with continuous-flow left ventricular assist devices (LVADs). We analyzed the risk factors of hemorrhagic stroke in LVAD patients, as well as the time relationship between systemic bacteremia and hemorrhagic stroke.Methods and Results:We evaluated the incidence of systemic bacteremia and stroke in 164 patients who underwent continuous-flow LVAD implantation between 2005 and 2016. At 1 and 2 years after implantation, the incidence of bacteremia was 29% and 36%, and the incidence of hemorrhagic stroke was 22% and 22% in patients without bacteremia, and 32% and 44% in those with bacteremia, respectively (P=0.035). This higher prevalence of hemorrhagic stroke in patients with bacteremia was notable particularly in the chronic phase (>90 days after implantation). Multivariate analysis revealed that bacteremia was an independent risk factor of hemorrhagic stroke in the chronic phase [hazard ratio, 2.36 (1.02-5.62); P=0.044]. The hazard rate was the highest immediately after the onset of bacteremia, and the risk steadily declined by 90 days after the last episode of bacteremia and flattened thereafter. CONCLUSIONS: Bacteremia was an independent risk factor of hemorrhagic stroke in patients in the chronic phase, with the highest risk seen in the early phase following an episode of bacteremia.

Effect of obesity on outcomes in patients undergoing implantation of continuous-flow left ventricular assist devices.

The purpose of this study was to analyze the effect of obesity on outcomes after continuous-flow left ventricular assist device (CF-LVAD) implantation. A single-center retrospective analysis was performed on 526 chronic heart failure patients who were implanted with the HeartMate II CF-LVAD (n = 403) or HeartWare HVAD (n = 123) between November 2003 and March 2016. Patients were stratified into 4 groups based on BMI: underweight (< 18.5 kg/m2, n = 18, 3.4%), normal-weight (18.5-25 kg/m2, n = 173, 32.9%), overweight (25-30 kg/m2, n = 182, 30.2%), and obese (> 30 kg/m2, n = 153, 33.5%). The underweight group was excluded because of its small sample size. Records were reviewed to determine the incidence of postoperative complications and survival. Survival at 1, 6, 12, and 24 months were similar among normal-weight (91.3, 84.4, 76.3, and 67.6%), overweight (90.4, 80.8, 76.5, and 69.6%), and obese patients (90.7, 74.7, 65.3, and 61.3%, p = 0.24). Additionally, obesity was not a significant predictor of mortality in Cox proportional hazard models (hazard ratio 0.98, 95% confidence interval 0.766-1.277, p = 0.13). These findings suggest that appropriately selected obese patients receive similar survival benefit from CF-LVADs compared to non-obese patients, and obesity should not serve as a contraindication to CF-LVAD implantation.