Search

Background: Left ventricular assist device (LVAD) malposition has been linked to hemocompatibility‐related adverse events (HRAEs). This study aimed to identify preoperative anatomical landmarks and postoperative pump position, associated with HRAEs during LVAD support. Methods: Pre‐ and postoperative chest X‐ray measures (≤14 days pre‐implantation, first postoperative standing, 6, 12, 18, and 24 months post‐implantation) were analyzed for their association with HRAEs over 24 months in 33 HeartMate 3 (HM3) patients (15.2% female, age 66 (9.5) years). Results: HM3 patients with any HRAE showed significantly lower preoperative distances between left ventricle and thoracic outline (dLVT) (25.3 ± 10.2 mm vs. 40.3 ± 15.5 mm, p = 0.004). A ROC‐derived cutoff dLVT ≤ 29.2 mm provided 85.7% sensitivity and 72.2% specificity predicting any HRAE during HM3 support (76.2% (>29.2 mm) vs. 16.7% (≤29.2 mm) freedom from HRAE, p < 0.001) and significant differences in cardiothoracic ratio (0.58 ± 0.04 vs. 0.62 ± 0.04, p = 0.045). Postoperative X‐rays indicated lower pump depths in patients with ischemic strokes (9.1 ± 16.2 mm vs. 38.0 ± 18.5 mm, p = 0.007), reduced freedom from any neurological event (pump depth ≤ 28.7 mm: 45.5% vs. 94.1%, p = 0.004), and a significant correlation between pump depth and inflow cannula angle (r = 0.66, p < 0.001). Longitudinal changes were observed in heart‐pump width (F(4,60) = 5.61, p < 0.001). Conclusion: Preoperative X‐ray markers are associated with postoperative HRAE occurrence. Applying this knowledge in clinical practice may enhance risk stratification, guide therapy optimization, and improve HM3 recipient management. [ABSTRACT FROM AUTHOR]

Background: Temporal trends of routinely obtained parameters may provide valuable information for predicting BSIs, but this association has not yet been established in LVAD patients. Methods: This retrospective analysis included data from 347 consecutive recipients of three rotary LVAD types. Study endpoints included the incidence of BSI, the association of temporal trends of routinely obtained blood biomarkers with the development of BSIs, the incidence of BSIs, and survival on LVAD support. Results: During follow‐up, 47.8% (n = 166) of the patients developed BSI. In multivariate analyses, the development of BSI was a significant predictor of mortality (HR 5.78, 95% CI 4.08–8.19, p < 0.0001). In univariate analyses, after adjusting for potential confounders, albumin (SHR 0.94, 95% CI 0.91–0.97, p < 0.00010), creatinine (SHR 1.49, 95% CI 1.03–2.15, p = 0.033), and C‐reactive protein (SHR 1.19, 95% CI 1.08–1.32, p = 0.0007) significantly predicted the development of BSIs during LVAD support. Notably, the strength of the association of parameter changes with the prediction of BSIs demonstrated a time‐dependent correlation in the cases of albumin (p = 0.045) and creatinine (p = 0.003). Conclusion: Bloodstream infections are highly prevalent among LVAD recipients and are independent predictors of mortality. Temporal biomarker trends significantly predict the development of BSIs. These findings suggest opportunities for interventions aiming to reduce the incidence of BSIs. [ABSTRACT FROM AUTHOR]

Background: A relation between the left ventricular assist device inflow cannula (IC) malposition and pump thrombus has been reported. This study aimed to investigate if the pump position, derived from chest X‐rays in HeartMate 3 (HM3) patients, correlates with neurological dysfunction (ND), ischemic stroke (IS), hemorrhagic stroke (HS) and survival. Methods: This analysis was performed on routinely acquired X‐rays of 42 patients implanted with a HM3 between 2014 and 2017. Device position was quantified in patients with and without ND from frontal and lateral X‐rays characterizing the IC and pump in relation to spine, diaphragm or horizontal line. The primary end‐point was freedom from stroke and survival one‐year after HM3 implantation stratified by pump position. Results: The analysis of X‐rays, 33.5 (41.0) days postoperative, revealed a significant smaller IC angle of HM3 patients with ND versus no ND (0.1° ± 14.0° vs. 12.9° ± 10.1°, p = 0.005). Additionally, the IC angle in the frontal view, IS: 4.1 (20.9)° versus no IS: 13.8 (7.5)°, p = 0.004 was significantly smaller for HM3 patients with IS. Using receiver operating characteristics derived cut‐off, IC angle <10° provided 75% sensitivity and 100% specificity (C‐statistic = 0.85) for predicting IS. Stratified by IC angle, freedom from IS at 12 months was 100% (>10°) and 60% (<10°) respectively (p = 0.002). No significant differences were found in any end‐point between patients with and without HS. One‐year survival was significantly higher in patients with IC angle >10° versus <10° (100% vs. 71.8%, p = 0.012). Conclusions: IC malposition derived from standard chest X‐rays serves as a risk factor for ND, IS and worse survival in HM3 patients. [ABSTRACT FROM AUTHOR]

Driveline infections (DLI) are common adverse events in left ventricular assist devices (LVADs), leading to severe complications and readmissions. The study aims to characterize risk factors for DLI readmission 2 years postimplant. This single‐center study included 183 LVAD patients (43 HeartMate II [HMII], 29 HeartMate 3 [HM3], 111 HVAD) following hospital discharge between 2013 and 2017. Demographics, clinical parameters, and outcomes were retrospectively analyzed and 12.6% of patients were readmitted for DLI, 14.8% experienced DLI but were treated in the outpatient setting, and 72.7% had no DLI. Mean C‐reactive protein (CRP), leukocytes and fibrinogen were higher in patients with DLI readmission (P <.02) than in outpatient DLI and patients without DLI, as early as 60 days before readmission. Freedom from DLI readmission was comparable for HMII and HVAD (98% vs. 87%; HR, 4.52; 95% CI, 0.58‐35.02; P =.15) but significantly lower for HM3 (72%; HR, 10.82; 95% CI, 1.26‐92.68; P =.03). DLI (HR, 1.001; 95% CI, 0.999‐1.002; P =.16) or device type had no effect on mortality. DLI readmission remains a serious problem following LVAD implantation, where CRP, leukocytes, and fibrinogen might serve as risk factors already 60 days before. HM3 patients had a higher risk for DLI readmissions compared to HVAD or HMII, possibly because of device‐specific driveline differences. [ABSTRACT FROM AUTHOR]

The use of left ventricular assist devices (LVADs) as a treatment method for heart failure patients has been steadily increasing; however, pathological studies showed presence of thrombi around the HeartWare ventricular assist device inflow cannula (IC) in more than 95% of patients after device explantation. Flow fields around the IC might trigger thrombus formation and require further investigation. In this study flow dynamics parameters were evaluated for different patient geometries using computational fluid dynamics (CFD) simulations. Left ventricular (LV) models of two LVAD patients were obtained from CT scans. The LV volumes of Patient 1 (P1) and Patient 2 (P2) were 264 and 114 cm3 with an IC angle of 20° and 9° from the mitral‐IC tip axis at the coronal plane. The IC insertion site at the apex was central for P1, whereas it was lateral for P2. Transient CFD simulations were performed over 9 cardiac cycles. The wedge area was defined from the cannula tip to the wall of the LV apex. Mean velocity magnitude and blood stagnation region (volume with mean velocity <5 mm/s) as well as the wall shear stress (WSS) at the IC surface were calculated. Cardiac support resulted in a flow mainly crossing the ventricle from the mitral valve to the LVAD cannula for P2, while the main inflow jet deviated toward the septal wall in P1. Lower WSS at the IC surface and consequently larger stagnation volumes were observed for P2 (P1: 0.17, P2: 0.77 cm3). Flow fields around an LVAD cannula can be influenced by many parameters such as LV size, IC angle, and implantation site. Careful consideration of influencing parameters is essential to get reliable evaluations of the apical flow field and its connection to apical thrombus formation. Higher blood washout and lower stagnation were observed for a central implantation of the IC at the apex. [ABSTRACT FROM AUTHOR]

Suction of the left ventricle can lead to potentially life‐threatening events in left ventricular assist device (LVAD) patients. With the resolution of currently available clinical LVAD monitoring healthcare professionals are unable to evaluate patients' suction occurrences in detail. This study investigates occurrences and durations of suction events and their associations with tachycardia in stable outpatients. Continuous high‐resolution LVAD data from HVAD patients were analyzed in the early outpatient period for 15 days. A validated suction detection from LVAD signals was used. Suction events were evaluated as suction rates, bursts of consecutive suction beats, and clusters of suction beats. The occurrence of tachycardia was analyzed before, during, and after suction clusters. Furthermore, blood work, implant strategy, LVAD speed setting, inflow cannula position, left ventricular diameters, and adverse events were evaluated in these patients. LVAD data of 10 patients was analyzed starting at 78 ± 22 postoperative days. Individuals' highest suction rates per hour resulted in a median of 11% (range 3%‐61%). Bursts categorized as consecutive suction beats with n = 2, n = 3‐5, n = 6‐15, and n > 15 beats were homogenously distributed with 10.3 ± 0.8% among all suction beats. Larger suction bursts were followed by shorter suction‐free periods. Tachycardia during suction occurred in 12% of all suction clusters. Significant differences in clinical parameters between individuals with high and low suction rates were only observed in left ventricular end‐diastolic and end‐systolic diameters (P <.02). Continuous high‐resolution LVAD monitoring sheds light on outpatient suction occurrences. Interindividual and intraindividual characteristics of longitudinal suction rates were observed. Longer suction clusters have higher probabilities of tachycardia within the cluster and more severe types of suction waveforms. This work shows the necessity of improved LVAD monitoring and the implementation of an LVAD speed control to reduce suction rates and their concomitant burden on the cardiovascular system. [ABSTRACT FROM AUTHOR]

Patients supported with a left ventricular assist device (LVAD) have impaired cardiovascular adaptations during exercise, resulting in reduced total cardiac output and exercise intolerance. The aim of this study is to report associations among these impaired cardiovascular parameters and exercise hemodynamics, and to identify in which conditions an LVAD speed increase can provide substantial benefits to exercise. A cardiorespiratory simulator was used to reproduce the average hemodynamics of LVAD patients at exercise. Then, a sensitivity study was conducted where cardiovascular parameters were changed individually ±20% of their baseline value at exercise (heart rate, left/right ventricular contractility, total peripheral resistance, and valve pathologies). Simulations were performed at a baseline LVAD speed of 2700 rpm and repeated at 3500 rpm to evaluate the benefits of a higher LVAD support on hemodynamics. Total cardiac output (TCO) was mostly impaired by a poor left ventricular contractility or vasodilation at exercise (−0.6 L/min), followed by a poor chronotropic response (−0.3 L/min) and by a poor right ventricular contractility (−0.2 L/min). LVAD speed increase better unloads the left ventricle and improves total cardiac output in all the simulated conditions. The most substantial benefits from LVAD speed increase were observed in case of poor left ventricular contractility (TCO + 1.6 L/min) and vascular dysfunction (TCO + 1.4 L/min) followed by lower heart rate (TCO + 1.3 L/min) and impaired right ventricular contractility (TCO + 1.1 L/min). Despite the presence of the LVAD, exercise hemodynamic is strongly depending on the ability of the cardiovascular system to adapt to exercise. A poor left ventricular inotropic response and a poor vascular function can strongly impair cardiac output at exercise. In these conditions, LVAD speed increase can be an effective strategy to augment total cardiac output and unload the left ventricle. These results evidence the need to design a physiological LVAD speed controller, tailored on specific patient's needs. [ABSTRACT FROM AUTHOR]

Left ventricular assist devices (LVADs) restore cardiovascular circulatory demand at rest with a spontaneous increase in pump flow to exercise. The relevant contribution of cardiac output provided by the LVAD and ejected through the aortic valve for exercises of different intensities has been barely investigated in patients. The hypothesis of this study was that different responses in continuous recorded pump parameters occur for maximal and submaximal intensity exercises and that the pump flow change has an impact on the oxygen uptake at peak exercise (pVO2). Cardiac and pump parameters such as LVAD flow rate (QLVAD), heart rate (HR), and aortic valve (AV) opening were analyzed from continuously recorded LVAD data during physical exercises of maximal (bicycle ergometer test) and submaximal intensities (6‐min walk test and regular trainings). During all exercise sessions, the LVAD speed was kept constant. Cardiac and pump parameter responses of 16 patients for maximal and submaximal intensity exercises were similar for QLVAD: +0.89 ± 0.52 versus +0.59 ± 0.38 L/min (P = 0.07) and different for HR: +20.4 ± 15.4 versus +7.7 ± 5.8 bpm (P < 0.0001) and AV‐opening with 71% versus 23% of patients (P < 0.0001). Multi‐regression analysis with pVO2 (R2 = 0.77) showed relation to workload normalized by bodyweight (P = 0.0002), HR response (P = 0.001), AV‐opening (P = 0.02), and age (P = 0.06) whereas the change in QLVAD was irrelevant. Constant speed LVADs provide inadequate support for maximum intensity exercises. AV‐opening and improvements in HR show an important role for higher exercise capacities and reflect exercise intensities. Changes in pump flow do not impact pVO2 and are independent of AV‐opening and response in HR. An LVAD speed control may lead to adequate left ventricular support during strenuous physical activities. [ABSTRACT FROM AUTHOR]

Ventricular assist devices (VADs) are an established therapeutic option for patients with chronic heart failure. Continuous monitoring of VAD parameters and their adherence to guidelines are crucial to detect problems in an early stage to optimize outcomes. A telephone intervention algorithm for VAD outpatients was developed, clinically implemented and evaluated. During the phone calls, a structured inquiry of pump parameters, alarms, blood pressure, INR, body weight and temperature, exit‐site status and heart failure symptoms was performed and electronically categorized by an algorithm into 5 levels of severity. VAD outpatient outcomes without (n = 71) and with bi‐weekly telephone interviews in their usual care (n = 25) were conducted using proportional hazard Cox regression, with risk adjustment based on a propensity score model computed from demographics and risk factors. From February 2015 through October 2017, 25 patients (n = 3 HeartMate II, n = 4 HeartMate 3 and n = 18 HeartWare HVAD) underwent 637 telephone interventions. In 57.5% of the calls no problems were identified, 3.9% were recalled on the next day because of alarms. In 26.5% (n = 169), the VAD Coordinator had to refer to the physician due to elevated blood pressure (n = 125, >85 mm Hg), INR < 2.0 or > 4.0 (n = 24) or edema (n = 10), 11.9% of the calls led to a follow‐up because of equipment or exit‐site problems. Propensity‐adjusted 2‐year survival (89% vs. 57%, P = 0.027) was significantly higher for the telephone intervention group. Continuous, standardized communication with VAD outpatients is important for early detection of upcoming problems and leads to significantly improved survival. [ABSTRACT FROM AUTHOR]

In daily life, the safe, intuitive use of ventricular assist devices ( VADs) and especially their peripheral components is not only a question of life quality, but also sometimes crucial for survival. To investigate the advantages and disadvantages of different systems and to get patient feedback on preferred features, a multicenter study was initiated. Based on previous single-center studies, a questionnaire was developed to ascertain patients' experiences, difficulties with, and desires concerning use of the system. This questionnaire was provided both to ongoing patients and to new VAD patients after a minimum hospital discharge time of 6 weeks, at a regular checkup. Additionally, the patients completed a standardized questionnaire on life quality ( Kansas City Cardiomyopathy Questionnaire). The centers that contributed to this study were Bad Oeynhausen, Berlin, Hannover, and Vienna. Three hundred fifty-two completed questionnaires on eight different pump types were obtained. An important result is that 42% of those questioned dropped their controller bag at least once. Depending on the device, between 2 and 55% disconnected it unintentionally. Confidence in safe use of the system decreased significantly with age, from 80% at age 20-30 years to 33% at 70-80 years. In devices with an LCD display, 94% considered the readability sufficient. Ninety-four percent considered the training adequate. Between 22 and 88% of the patients called the emergency telephone hotline, depending on the device, and 23-46% depending on the center. This first multicenter study on VAD usability reveals considerable differences among devices and centers. The comparative assessment aims to help optimize device design, patient management, and training. [ABSTRACT FROM AUTHOR]

With increasing support duration of cardiac assist devices, transcutaneous drivelines remain a weak point of the therapy. First, they can be an entry point for infections, and second, cable lesions and even electrical failures due to material fatigue and eventual carelessness can occur. We report a case of a damaged outer sheath of a ventricular assist device driveline cable directly at the exit site, where the standard repair procedure with self-fusing tape may lead to biocompatibility problems and irritation of the entrance through the skin. Therefore, a new procedure was developed using a special sleeve expander tool and a highly expandable latex tubing to stabilize the defect in a flexible and biocompatible manner. A patient experienced a fracture of the outer sheath of a HeartWare HVAD driveline directly at the skin entrance (approximately 15 mm long, 5 mm distal from the skin). The metal strands and the electrical functionality were yet not affected, therefore, a pump exchange was not indicated. After considering several conventional solutions for repair as not applicable, a new approach was developed: a sleeve expander tool was applied, which allowed radial stretching of the latex tubing. After preparations of the tool and the cable site, the pump was briefly disconnected, the tubing was moved over the connector and was released at the site of fracture. The problem could be solved by keeping the cable's flexibility and without additional risks to the skin. Within a still ongoing (5-month) follow-up, the skin entrance returned to perfect condition and no further intervention was necessary. In conclusion, this method allows a quick stabilization and repair of damaged driveline isolations even near the exit site, resulting in a biocompatible surface and consistent flexibility of the cable. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusion Cold atmospheric plasma (CAP) therapy has been recognized as effective treatment option for reducing bacterial load in chronic wounds, such as adult ventricular assist device (VAD) driveline exit‐site infections. Currently, there have been no reports on the safety and efficacy of CAP therapy for pediatric cannula infections and inflammations in paracorporeal pulsatile VADs.The mechanical strength of Berlin Heart EXCOR cannulas were tested both before and after CAP treatment (SteriPlas, Adtec Healthcare Limited, UK) to prove material safety. A ring tensile test of 20 untreated and 20 CAP‐treated (5 min) EXCOR cannulas (Ø12mm), assessed the force at the breaking point of the cannulas (Fmax), at 25% (F25%) and 50% (F50%) of the maximum displacement. Additionally, the scanning electron microscope (SEM) micrographs for both groups examined any surface changes. Finally, the case of a 13‐year‐old male EXCOR patient with cannula infections, treated with CAP over 100 days, is presented.The in vitro measurements revealed no statistically significant differences in mechanical strength between the control and CAP group for F25% (8.18 ± 0.36 N, vs. 8.02 ± 0.43 N, p = 0.21), F50% (16.87 ± 1.07 N vs. 16.38 ± 1.32 N, p = 0.21), and FMAX (44.55 ± 3.24 N vs. 42.83 ± 4.32 N, p = 0.16). No surface structure alterations were identified in the SEM micrographs. The patient's cannula exit‐sites showed a visible improvement in DESTINE wound staging, reduction in bacterial load and inflammatory parameters after CAP treatment without any side effects.Overall, CAP therapy proved to be a safe and effective for treating EXCOR cannula exit‐site wound healing disorders in one pediatric patient, but further studies should investigate this therapy in more detail. [ABSTRACT FROM AUTHOR]