Early detection of HVAD pump thrombosis based on technical analysis and power consumption measurements.

BACKGROUND: Continuous-flow left ventricular assist devices (LVADs) have been extensively used in a strategy of bridge to orthotopic heart transplant and destination therapy. The usage of LVAD, however, is not free from limitations such as device-related adverse events, including pump thrombosis (PT). We aimed to develop an algorithm of early PT detection based on the maintenance parameters monitored by the implanted device. METHODS: We analyzed log files of 101 patients implanted with HeartWare pump (HVAD) with 18 PT events among them. For signal processing, we used the open-high-low-close format transformation and typical price (TP) technical analysis indicator. Model parameters were tuned with 5-fold cross-validation, and the final performance was measured on a separate group of patients. RESULTS: Our algorithm achieved 100% sensitivity and 100% specificity of indications. In the final evaluation, alarms preceded the clinical acknowledgement of events by 2 days and 20 h on average. In the worst-case scenario, an alarm was raised 1 day and 8 h prior to the event. CONCLUSIONS: The proposed algorithm could be installed to work directly with the device controller and provide clinicians with automatic readings analysis, raising an alarm when there is a high probability of thromboembolism. Early event detection could enable better thrombosis management and improve prognosis in patients implanted with HVAD.

Oxidative Stress Markers and Modified Model for End-Stage Liver Disease Are Associated with Outcomes in Patients with Advanced Heart Failure Receiving Bridged Therapy with Continuous-Flow Left Ventricular Assist Devices.

Left ventricular assist device (LVAD) is well established as an alternative treatment for end-stage heart failure (HF) patients. The aim of the study was to determine the prognostic value of oxidative stress markers and the modified Model for End-Stage Liver Disease (modMELD) in patients receiving bridged therapy with continuous-flow LVAD. We prospectively analyzed 36 end-stage HF patients who received LVAD therapy between 2015 and 2018. The total antioxidant capacity (TAC) and total oxidant status (TOS) were measured by the methods described by Erel. The oxidative stress index (OSI) was defined as the ratio of the TOS to TAC levels. The modMELD scores were calculated based on the serum bilirubin, creatinine, and albumin levels. The patients' median age was 58 (50-63.0) years. During the 1.5-years follow-up, a major adverse cardiac event-MACE (death, stroke, or pump thrombosis) was observed in 17 patients (47.2%). The area under the receiver operating characteristics curves (AUCs) indicated a good prognostic power of TAC (AUC 0.7183 (0.5417-0.8948)), TOS (AUC 0.9149 (0.8205-0.9298)), OSI (AUC 0.9628 (0.9030-0.9821)), and modMELD (AUC 0.87 (0.7494-0.9905)) to predict a MACE. Oxidative stress markers serum concentrations, as well as the modMELD score, allow the identification of patients with a risk of MACE.

Oxidative Stress Markers in Hypertrophic Cardiomyopathy.

Background and Objectives: Hypertrophic cardiomyopathy (HCM) depends on the primary impairment of sarcomeres, but it can also be associated with secondary alterations in the heart related to oxidative stress. The present study aimed to examine oxidative-antioxidant disturbances in patients with HCM compared with control individuals. Materials and Methods: We enrolled 52 consecutive HCM patients and 97 controls without HCM. The groups were matched for age, body mass index, and sex. Peripheral blood was collected from all patients to determine the total antioxidant capacity (TAC), total oxidant status (TOS), lipid hydroperoxide (LPH), and malondialdehyde (MDA). The oxidative stress index (OSI) was defined as the ratio of the TOS level to the TAC level. Results: The median age was 52 years, and 58.4% were female. The area under the curve (AUC) indicated good predictive power for the TAC and TOS [AUC 0.77 (0.69-0.84) and 0.83 (0.76-0.90), respectively], as well as excellent predictive power for the OSI [AUC 0.87 (0.81-0.93)] for HCM detection. Lipid peroxidation markers also demonstrated good predictive power to detect HCM patients [AUCLPH = 0.73, AUCMDA = 0.79]. Conclusions: The TOS, the TAC, LPH levels, and MDA levels have good predictive power for HCM detection. The holistic assessment of oxidative stress by the OSI had excellent power and could identify patients with HCM.

A systematic approach to transoesophageal echocardiography in the intensive care unit - a practical guide for intensivists.

Transoesophageal echocardiography (TOE) has become a useful diagnostic and monitoring tool in critical care settings, especially when transthoracic echocardiography is difficult to perform. It gives valuable information in mechanical ventilation, especially in the prone position, in obese patients, and in patients with surgical dressings and chest tubes. Transthoracic echocardiography allows visualization of deep cardiac structures and their pathologies. It has extensive diagnostic implications. This article describes the systematic approach to critical care TOE examination with a detailed description of the views necessary for rapid haemodynamic assessment in critical care patients. It is concordant with European Diploma in Advanced Echocardiography (EDEC) requirements, and its structural approach is based on the author's experience acquired in the EDEC examination process. Performing TOE in an organized fashion can help to pinpoint most of the pathologies and monitor the treatment process in the intensive care unit.

Mechanical circulatory support restores eligibility for heart transplant in patients with significant pulmonary hypertension.

BACKGROUND: An increasing number of patients with end­stage heart failure implies a wider use of left ventricular assist devices (LVADs). Irreversible pulmonary hypertension (PH) is a predictor of unfavorable prognosis and a contraindication to orthotopic heart transplant (OHT). AIMS: The aim of this study was to evaluate the effect of continuous­flow LVAD (CF­LVAD) support on pulmonary pressure and pulmonary vascular resistance (PVR) as well as the impact of pre­LVAD hemodynamic parameters on survival during LVAD support. METHODS: Data collected from 106 patients who underwent CF­LVAD implantation in the years 2009 to 2018 (men, 95.3%; mean [SD] age, 51.8 [12] years; mean [SD] INTERMACS profile, 2.9 [1.6]; mean [SD] LVAD support time, 661 [520] days; follow­up until May 2019) were retrospectively analyzed. RESULTS: Right heart catheterization was performed before LVAD implantation in 94 patients (88.7%), after implantation-in 31 (29.2%), and before and after implantation-in 28 (26.4%). We observed mean pulmonary artery pressure (mPAP) >25 mm Hg in 65 patients (61.3%) and PVR >2.5 Wood units in 33 patients (31.1%) before LVAD implantation. A significant improvement after CF­LVAD implantation was noted in mPAP, pulmonary capillary wedge pressure, transpulmonary gradient, PVR, cardiac output (P <0.001 for all parameters), and cardiac index (P = 0.003). All patients with initially irreversible PH became eligible for OHT during LVAD support. Survival during LVAD support did not depend on initial mPAP and PVR. CONCLUSIONS: In patients with end­stage heart failure, CF­LVAD support leads to a significant reduction of pre­ and postcapillary PH. Survival on CF­LVAD support is independent of elevated mPAP and PVR before implantation, which suggests that LVADs decrease the risk associated with PH.

Short- and long-term outcomes of continuous-flow left ventricular assist device therapy in 79 patients with end-stage heart failure.

INTRODUCTION: An increasing number of patients with end­stage heart failure, along with a shortage of heart donors, necessitates the use of mechanical circulatory support. OBJECTIVES: This single­center retrospective study evaluated short- and long term outcomes of continuous­flow left ventricular assist device (CF LVAD) therapy in patients with end stage heart failure. PATIENTS AND METHODS: We collected and assessed data of 79 patients (77 men, 2 women; mean age, 50.3 years; mean INTERMACS profile, 3.1) implanted with a CF­LVAD between 2009 and 2017 (HeartMate 3 in 19 patients [24%]; HeartMate 2 in 9 [11.4%]; and HeartWare in 51 [64.6%]). RESULTS: The mean time on CF-LVAD support was 604 days (range, 1­1758 days). There were 2 device exchanges due to pump thrombosis and 1 explantation due to heart regeneration; 9 patients (11.4%) underwent heart transplant. Stroke (nondisabling, 48%) occurred in 27.8% of patients (ischemic in 9 patients; hemorrhagic, in 14; both types, in 1) despite the standardized anticoagulation regimen. Major gastrointestinal bleeding and pump thrombosis were reported in 13 patients (16.5%), while 18 patients (22.8%) developed driveline infections (recurrent in 15 patients [19%]). Hemorrhagic stroke and bacteremia had a negative impact on survival. Hemorrhagic stroke was the main cause of death. Survival probability was 0.9 at 1 month and 0.81, 0.71, 0.61, and 0.53 at 1, 2, 3, and 4 years, respectively. CONCLUSIONS: Although CF­LVAD support is associated with substantial adverse events, they do not significantly affect mortality (except hemorrhagic stroke and bacteremia). Novel devices seem to overcome these limitations, but larger studies are needed to support these findings.