Stroke in Ventricular Assist Device Patients: Reducing Complications and Improving Outcomes No abstract available

Extracorporeal Membrane Oxygenation for Adults With Refractory Septic Shock Because of a severe dysregulation of the host response to infection, septic shock may induce a profound imbalance between oxygen consumption and delivery, which in some cases may be refractory to conventional support measures. In this setting, extracorporeal membrane oxygenation (ECMO) may help to restore this ratio. Indeed, in neonates and children, this technique is already established as a valid salvage therapy. In spite of the rapid growth in the use of ECMO in recent years, the evidence of its benefits in adult patients is weak, particularly in cases of refractory septic shock. Nevertheless, several case series have reported good outcomes in selected cases with specific management. Here we explore the links between sepsis and ECMO, starting with the basic biology underlying the two entities. We then review the published literature on the use of extracorporeal support in adult patients with septic shock and finally conclude with a review of the key points of management that can optimize the results after this critical situation.

Preoperative Predictors of Mortality in Short-Term Continuous-Flow Ventricular Assist Devices Short-term continuous-flow ventricular assist devices (STCF-VADs) are increasingly being utilized to support critically ill patients, despite limited information regarding overall outcomes. All adult patients supported with an STCF-VAD between June 2009 and December 2015 were included in this retrospective single-center study. Associations between preoperative characteristics and unsuccessful bridge (death on device or within 30 days postdecannulation) were assessed using logistic regression. A total of 61 patients (77% male) were identified with a median age at implant of 54.6 years. Left VADs were implanted in 51%, right VADs in 21%, and both VADs in 28%, and patients were supported for a median of 11 days. Overall, 23% were weaned to recovery, 13% underwent heart transplantation, 16% converted to long-term VADs, and 48% had an unsuccessful bridge. In multivariable analysis, only renal insufficiency or dialysis (odds ratio = 7.53; p = 0.002) remained a significant independent predictor of an unsuccessful bridge. Short-term continuous-flow VADs can successfully bridge adult patients with mortality around 50%. Preimplant renal insufficiency or dialysis is correlated with an unsuccessful bridge in our patient population, likely reflecting the severity of illness preimplant. Further studies are required to determine whether this factor remains significant in a larger patient population.

Meet the Authors No abstract available

What Causes LVAD-Associated Ischemic Stroke? Surgery, Pump Thrombosis, Antithrombotics, and Infection Acute ischemic stroke (AIS) is a major complication in left ventricular assist device (LVAD) population. A better understanding of clinical risk factors associated with AIS may help mitigate risk of stroke. We reviewed prospectively collected data of 477 LVAD patients from a tertiary center from October 1, 2004 to December 31, 2016. Supplemental data abstraction was performed on patients with AIS. Fifty-seven (12%) developed 61 AIS. Of 61, 17 (28%) AIS occurred perioperatively. The median time from implant to perioperative AIS was 5 days (interquartile range: 3–9). Pump thrombosis accounted for 19 (31%) of 61 AIS, and 7 (37%) presented initially with AIS before the pump thrombosis. The median lactate dehydrogenase (LDH) at the time of AIS in the pump thrombosis group (806) was higher than LDH at 1 month (437, P = 0.27) at 3 months (334, P = 0.01), and 6 months (286, P = 0.001) before AIS. Thirty-three (54%) AIS occurred while receiving inadequate antithrombotic therapy. Acute infections were common (31, 51%) in AIS and 12 (20%) were associated with acute bloodstream infection. All AIS were explained by a combination of four clinical risk factors. All LVAD-associated AIS occurred perioperatively or in conjunction with pump thrombosis, subtherapeutic anticoagulation, and bloodstream infection. The common underlying thread is occurrence of a prothrombotic state. The results of this study underscore the potential consequences of disruption of delicate hemostatic balance in patients with LVAD.

Predictors of Survival for Patients with Acute Decompensated Heart Failure Requiring Extra-Corporeal Membrane Oxygenation Therapy Chronic systolic heart failure (HF) with acute decompensation can result in cardiogenic shock (CS) requiring short-term mechanical circulatory support. We sought to identify predictors of survival for acute decompensated HF (ADHF) patients requiring veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Patients >18 years old treated at our institution with VA-ECMO from 2009 to 2018 for ADHF with CS were studied. Demographic, hemodynamic, and echocardiographic data were collected. The primary outcome was survival to discharge. Fifty-two patients received VA-ECMO for ADHF with CS; 24 (46.2%) survived. Seventeen (32.7%) had suffered cardiac arrest, and 37 (71.2%) were mechanically ventilated. Mean lactate was 4.33 ± 3.45 mmol/L, and patients were receiving 2.7 ± 1.2 vasopressor/inotropic infusions at ECMO initiation; these did not differ significantly between survivors and nonsurvivors. Pre-ECMO cardiac index was 1.84 ± 0.56L/min/m2 and 1.94 ± 0.63L/min/m2 in survivors and nonsurvivors, respectively (p = 0.57). In multivariable analysis, only diabetes mellitus (DM; OR, 13.25; CI, 1.42–123.40; p = 0.02) and mineralocorticoid receptor antagonist use (OR, 0.12; CI, 0.02–0.78; p = 0.03) were independent predictors of mortality. Nineteen (79.2%) survivors required durable ventricular assist device. Among ADHF patients receiving VA-ECMO, DM is a powerful predictor of outcomes while markers of clinical acuity including hemodynamics, vasopressor/inotrope use, and lactate are not. The vast majority of survivors required durable left-ventricular assist devices.

Development and Validation of a Life-Sized Mock Circulatory Loop of the Human Circulation for Fluid-Mechanical Studies Mock circulatory loops (MCLs) are usually developed for assessment of ventricular assist devices and consist of abstracted anatomical structures represented by connecting tubing pipes and controllable actuators which could mimic oscillating flow processes. However, with increasing use of short-term peripheral mechanical support (extracorporeal life support [ECLS]) and the upcoming evidence of even counteracting flow processes between the failing native circulation and ECLS, MCLs incorporating the peripheral vascular system and preserved anatomical structures are becoming more important for systematic assessment of these processes. For reproducible and standardized fluid-mechanical studies using magnetic resonance imaging, Doppler ultrasound, and computational fluid dynamics measurements, we developed a MCL of the human circulation. Silicon-based life-sized dummies of the human aorta and vena cava (vascular module) were driven by paracorporeal pneumatic assist devices. The vascular module is placed in a housing with all arterial branches merging into peripheral resistance and compliances modules, and blood-mimicking fluid returns to the heart module through the venous dummy. Compliance and resistance chambers provide for an adequate simulation of the capillary system. Extracorporeal life support cannulation can be performed in the femoral and subclavian arteries and in the femoral and jugular veins. After adjusting vessel diameters using variable Hoffmann clamps, physiologic flow rates were achieved in the supraaortic branches, the renal and mesenteric arteries, and the limb arteries with physiologic blood pressure and cardiac output (4 L/min). This MCL provides a virtually physiologic platform beyond conventional abstracted MCLs for simulation of flow interactions between the human circulation and external circulation generated by ECLS.

Bloodstream Infections in Continuous Flow Left Ventricular Assist Device Recipients: Diagnostic and Clinical Implications Bloodstream infection (BSI) is a common complication of left ventricular assist device (LVAD) support and particularly difficult to treat. The presentation is often variable because of altered physiology and augmentation of cardiac output by the device. We studied LVAD recipients at a single institution. Multivariate logistic and Cox (with time-varying parameters) regression were implemented. Of 212 patients, 58% experienced infections. Driveline infection (DLI) affected 31%, with 60% of them having deep-tissue involvement. Sixty-six patients (31%) suffered from 135 BSIs. Systemic inflammatory response syndrome (SIRS) was present in 47% of BSIs at presentation and associated with increased mortality. Right heart failure, destination therapy, Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile, morbid obesity, and deep-DLI were independent risk factors for BSI. The BSI was independently associated with mortality. Bridge-to-transplantation (BTT) patients were more likely to receive transplant if they did not have BSIs. Among 104 BTT patients who received heart transplantation, development of BSI was associated with shorter time-to-transplantation. Diagnosis of BSI poses diagnostic and prognostic challenges because of the hemodynamic profile of LVAD patients who may not mount the expected physiologic response to sepsis. Although SIRS criteria lack sensitivity in the LVAD population, SIRS signifies increased risk for death. Deep DLI was the strongest predictor of BSI. Despite the upgrade in listing status of BTT-LVADs with BSIs and shorter time-to-transplantation, BSI remain a major cause of mortality. BSIs are associated with significant mortality and should be regarded as a serious complication, similar to pump thrombosis and stroke.

Adverse Event Profile Associated with Prolonged Use of CentriMag Ventricular Assist Device for Refractory Cardiogenic Shock Several studies have investigated early outcomes with a surgical short-term ventricular assist device (VAD), but little is known about adverse event profile during prolonged support with a surgical short-term VAD. This is a retrospective analysis of 161 patients who received a CentriMag ventricular assist system (Abbott Laboratories, Abbott Park, IL) at our institution between January 2007 and June 2014. Device-related adverse events include major bleeding, infection, and stroke incidents occurring during CentriMag support. Cumulative frequency of adverse events was estimated by Nelson’s nonparametric method. One hundred and forty-three (88.8%) patients had biventricular VAD and 18 (11.2%) had isolated left VAD. Median duration of support was 16 days (interquartile range [IQR]: 10–29). Mortality was 24.8% and 1 year overall survival is 51.8% (95% CI: 43.3–59.5%). The most common adverse event during support was major bleeding (n = 121, 75.1%). Ninety-five (59.0%) developed major infections such as pneumonia and urinary tract infection. Sixteen patients (10%) experienced stroke. Cumulative data analysis showed that stroke and reoperation caused by bleeding were rare beyond 30 days, whereas infection and nonsurgical bleeding events were directly related to support time. In conclusion, temporary VAD with CentriMag support is an effective treatment for patients in refractory cardiogenic shock. Despite its side effect, profile including a high rate of blood transfusion early in the immediate postoperative period of CentriMag support, aggressive use of the CentriMag support device has acceptable survival to discharge and 1 year survival.

Yellow Means Caution: Correlations Between Liver Injury and Mortality with the Use of VA-ECMO Abnormalities in markers of liver injury after venoarterial extracorporeal membrane oxygenation (VA-ECMO) initiation are of unclear distribution and clinical significance. This study included all consecutive adult patients from a single institution who underwent VA-ECMO cannulation between May 2012 and September 2016 and had liver function panels drawn during their admission (n = 223). Data points include: age, sex, body mass index, diagnosis, duration of ECMO cannulation, duration of hospitalization, pre-ECMO cardiac arrest, central nervous system (CNS) injury, the presence of chronic kidney disease or acute renal failure, renal replacement therapy utilization, lactate levels, duration of pre-ECMO intubation, admission and peak bilirubin/aspartate aminotransferase (AST)/alanine aminotransferase (ALT)/alkaline phosphatase (ALP) levels, and time to peak bilirubin/AST/ALT/ALP in relation to cannulation. Multivariate Poisson regression analyses were performed to determine associations with mortality. In-hospital mortality was 66%. Serum bilirubin elevation appeared to significantly correlate continuously with mortality. Other markers of liver injury were not significant in final multivariate models. As a univariate factor, no patient survived with a total serum bilirubin greater than 30 mg/dl, and specificity for 90% mortality was crossed at 11 mg/dl. Mortality was also significantly associated with the presence of CNS injury and elevation of lactic acid levels. Postcannulation liver injury is significantly associated with increased mortality and total serum bilirubin appears to be a biomarker of considerable clinical significance.