Peripheral extracorporeal membrane oxygenation system as salvage treatment of patients with refractory cardiogenic shock: preliminary outcome evaluation

The interaction of thrombocytopenia, hemorrhage, and platelet transfusion in venoarterial extracorporeal membrane oxygenation: a multicenter observational study

BACKGROUND

Thrombocytopenia, hemorrhage and platelet transfusion are common in patients supported with venoarterial extracorporeal membrane oxygenation (VA ECMO). However, current literature is limited to small single-center experiences with high degrees of heterogeneity. Therefore, we aimed to ascertain in a multicenter study the course and occurrence rate of thrombocytopenia, and to assess the association between thrombocytopenia, hemorrhage and platelet transfusion during VA ECMO.

METHODS

This was a sub-study of a multicenter (N = 16) study on transfusion practices in patients on VA ECMO, in which a retrospective cohort (Jan-2018-Jul-2019) focusing on platelets was selected. The primary outcome was thrombocytopenia during VA ECMO, defined as mild (100-150·109/L), moderate (50-100·109/L) and severe (< 50·109/L). Secondary outcomes included the occurrence rate of platelet transfusion, and the association between thrombocytopenia, hemorrhage and platelet transfusion, assessed through mixed-effect models.

RESULTS

Of the 419 patients included, median platelet count at admission was 179·109/L. During VA ECMO, almost all (N = 398, 95%) patients developed a thrombocytopenia, of which a significant part severe (N = 179, 45%). One or more platelet transfusions were administered in 226 patients (54%), whereas 207 patients (49%) suffered a hemorrhagic event during VA ECMO. In non-bleeding patients, still one in three patients received a platelet transfusion. The strongest association to receive a platelet transfusion was found in the presence of severe thrombocytopenia (adjusted OR 31.8, 95% CI 17.9-56.5). After including an interaction term of hemorrhage and thrombocytopenia, this even increased up to an OR of 110 (95% CI 34-360).

CONCLUSIONS

Thrombocytopenia has a higher occurrence than is currently recognized. Severe thrombocytopenia is strongly associated with platelet transfusion. Future studies should focus on the etiology of severe thrombocytopenia during ECMO, as well as identifying indications and platelet thresholds for transfusion in the absence of bleeding.

TRIAL REGISTRATION

This study was registered at the Netherlands Trial Registry at February 26th, 2020 with number NL8413 and can currently be found at https://trialsearch.who.int/Trial2.aspx?TrialID=NL8413.

Use of fondaparinux in patients with heparin-induced thrombocytopenia on veno-venous extracorporeal membrane oxygenation: A three-patient case series report

Heparin-induced thrombocytopenia is a life-threatening immune-mediated complication of unfractionated heparin therapy. Fondaparinux is a therapeutic alternative, but it has limited evidence for its use in patients on extracorporeal membrane oxygenation (ECMO). We present a series of three adult patients with COVID-19 on ECMO who were diagnosed with heparin-induced thrombocytopenia after 7-12 days of unfractionated heparin treatment and were switched to fondaparinux. Fondaparinux was initiated with an intravenous loading dose of 5 mg, followed by a dose of 2.5 mg subcutaneously every 8-12 h. Dosage was adjusted according to daily measured anti-Xa concentration with a target range of 0.4-0.7 mg/L. The total duration of treatment with fondaparinux and ECMO ranged from 13 to 26 days. One major bleeding episode unrelated to fondaparinux therapy was observed, and the transfusions requirement was also low in all patients. The ECMO circuit was changed once in each patient. This series provides a deep insight into the use of fondaparinux over an extended period of time in patients on ECMO. Based on the presented data, fondaparinux can be considered a reasonable and affordable anticoagulant in patients without a high risk of bleeding.

Risk of Stroke with Impella Placement Is Not Associated with Access Vessel

Objective: The Impella heart pump is an intravascular microaxial device that provides short-term mechanical circulatory support and can be placed through the femoral, axillary, or central vessels. One of the most feared complications is stroke. It is unclear if patient stroke risk varies based on access vessel. Methods: A retrospective review of consecutive patients who underwent Impella placement at an academic institution from January 1, 2007, through September 15, 2018, was performed. Four groups were compared: (1) minimally invasive Impella (femoral or axillary access), (2) minimally invasive Impella upgraded to another minimally invasive Impella, (3) minimally invasive Impella upgraded to a central Impella (ascending aorta), and (4) central Impella. Patient charts were reviewed to identify baseline characteristics. Outcome measures included length of stay, stroke, and mortality. Results: A total of 349 patients (or 407 Impellas) were identified, and the majority of the devices were inserted through a minimally invasive approach (n = 248, 60.9%), while the remainder were implanted via central access (n = 159, 39.1%). Minimally invasive Impellas were upgraded in 44 patients. The risk of stroke for the entire cohort was 10.3% (n = 36), with no difference observed in any particular group. Overall mortality was 44.4% (n = 155). Of the patients who initially received a minimally invasive Impella, those who were upgraded had higher rates of mortality (56.8% vs 39.4%, P = 0.03), postoperative dialysis (50.0% vs 27.4%, P < 0.01), and sepsis (43.2% vs 20.0%, P < 0.01). Conclusions: This study found no statistically significant difference in rates of postoperative stroke based on initial access vessel.

A Systematic Literature Review of Packed Red Cell Transfusion Usage in Adult Extracorporeal Membrane Oxygenation

Background: Blood product administration plays a major role in the management of patients treated with extracorporeal membrane oxygenation (ECMO) and may be a contributor to morbidity and mortality. Methods: We performed a systematic review of the published literature to determine the current usage of packed red cell transfusions. Predefined search criteria were used to identify journal articles reporting transfusion practice in ECMO by interrogating EMBASE and Medline databases and following the PRISMA statement. Results: Out of 1579 abstracts screened, articles reporting ECMO usage in a minimum of 10 adult patients were included. Full texts of 331 articles were obtained, and 54 were included in the final analysis. All studies were observational (2 were designed prospectively, and two were multicentre). A total of 3808 patients were reported (range 10–517). Mean exposure to ECMO was 8.2 days (95% confidence interval (CI) 7.0–9.4). A median of 5.6% was not transfused (interquartile range (IQR) 0–11.3%, 19 studies). The mean red cell transfusion per ECMO run was 17.7 units (CI 14.2–21.2, from 52 studies) or 2.60 units per day (CI 1.93–3.27, from 49 studies). The median survival to discharge was 50.8% (IQR 40.0–64.9%). Conclusion: Current evidence on transfusion practice in ECMO is mainly drawn from single-centre observational trials and varies widely. The need for transfusions is highly variable. Confounding factors influencing transfusion practice need to be identified in prospective multicentre studies to mitigate potential harmful effects and generate hypotheses for interventional trials.

Outcomes of extracorporeal membrane oxygenation in adults with active hematologic and nonhematologic malignancy

Although the number of cancer patients admitted to the intensive care unit is increasing, the data on the use of extracorporeal membrane oxygenation in patients with malignancy are limited. We applied extracorporeal membrane oxygenation to carefully selected patients with active hematologic malignancy or nonhematologic malignancy who experienced respiratory or cardiac failure despite maximal conventional therapy. Patients with active malignancy who underwent extracorporeal membrane oxygenation in our institution between January 2012 and December 2016 were included in this study. The primary outcome of this study was defined as survival to hospital discharge. We also investigated the factors associated with survival to hospital discharge. There were 30 (30.6%) and 68 (69.4%) patients in the hematologic malignancy group and the nonhematologic malignancy group, respectively. Patients in the hematologic malignancy group were younger, more neutropenic, more hypotensive, had a lower Charlson Comorbidity Index, higher sequential organ failure assessment score, and lower platelet count than those in the nonhematologic malignancy group. Forty-six (46.9%) patients were successfully weaned off extracorporeal membrane oxygenation, and 30 (30.6%) patients survived until hospital discharge. Hospital survival rate and survival status 6 months after hospital discharge were significantly lower in patients with hematologic malignancy than in those with nonhematologic malignancy (13.3% vs. 38.2%, P = .026 and 3.3% vs. 26.5%, P = .017, respectively). Multivariate analysis identified an active hematologic malignancy, older age, acidosis, thrombocytopenia, high vasoactive-inotrope score, and respiratory failure as the risk factors for in-hospital death. Patients with hematologic malignancy requiring extracorporeal membrane oxygenation support had significantly lower rates of hospital survival and 6-month survival after discharge than patients with nonhematologic malignancy. Therefore, extracorporeal membrane oxygenation for treating cardiac or respiratory failure should only be considered in highly selected patients with hematologic malignancy.

Outcomes of left ventricular unloading with a transseptal cannula during extracorporeal membrane oxygenation in adults

We evaluated the benefit of left ventricular (LV) unloading using a percutaneous transseptal left atrial (LA) drain catheter via femoral vein incorporated into the ECMO venous circuit. This single-center retrospective observational study analyzed clinical outcomes of the LA venting group (N = 62) who underwent percutaneous transseptal LA drain placement comparing with the conventionally treated control group (N = 62) with an arterial pulse pressure below 10 mm Hg for at least 24 hours from December 2012 to August 2018. The ECMO weaning rate (61.3% vs. 38.7%, P = .012) and cardiac transplantation rate (29.0% vs. 11.3%, P = .014) were higher in the LA venting group than in the control group. Inhospital mortality was not significantly different (56.5% vs. 69.4%, P = .191). Pulmonary congestion mostly improved after LA decompression (61.3%, P = .003). A serum lactate level at 24 hours after LA venting of more than 2.2 mmol/L was associated with poor outcomes. LA venting via transseptal cannula reduced pulmonary venous congestion and achieved higher rates of successful ECMO weaning and cardiac transplantation. Placement of a transseptal venous drain cannula should be considered in patients with uncontrolled pulmonary edema secondary to severe LV loading undergoing VA-ECMO.

The science of safety: complications associated with the use of mechanical circulatory support in cardiogenic shock and best practices to maximize safety

Acute mechanical circulatory support (MCS) devices are widely used in cardiogenic shock (CS) despite a lack of high-quality clinical evidence to guide their use. Multiple devices exist across a spectrum from modest to complete support, and each is associated with unique risks. In this review, we summarize existing data on complications associated with the three most widely used acute MCS platforms: the intra-aortic balloon pump (IABP), Impella systems, and veno-arterial extracorporeal membrane oxygenation (VA-ECMO). We review evidence from available randomized trials and highlight challenges comparing complication rates from case series and comparative observational studies where a lack of granular data precludes appropriate matching of patients by CS severity. We further offer a series of best practices to help shock practitioners minimize the risk of MCS-associated complications and ensure the best possible outcomes for patients.

Platelets and extra-corporeal membrane oxygenation in adult patients: a systematic review and meta-analysis

Despite increasing improvement in extracorporeal membrane oxygenation (ECMO) technology and knowledge, thrombocytopenia and impaired platelet function are usual findings in ECMO patients and the underlying mechanisms are only partially elucidated. The purpose of this meta-analysis and systematic review was to thoroughly summarize and discuss the existing knowledge of platelet profile in adult ECMO population. All studies meeting the inclusion criteria (detailed data about platelet count and function) were selected, after screening literature from July 1975 to August 2019. Twenty-one studies from 1.742 abstracts were selected. The pooled prevalence of thrombocytopenia in ECMO patients was 21% (95% CI 12.9-29.0; 14 studies). Thrombocytopenia prevalence was 25.4% (95% CI 10.6-61.4; 4 studies) in veno-venous ECMO, whereas it was 23.2% (95% CI 11.8-34.5; 6 studies) in veno-arterial ECMO. Heparin-induced thrombocytopenia prevalence was 3.7% (95% CI 1.8-5.5; 12 studies). Meta-regression revealed no significant association between ECMO duration and thrombocytopenia. Platelet function impairment was described in 7 studies. Impaired aggregation was shown in 5 studies, whereas loss of platelet receptors was found in one trial, and platelet activation was described in 2 studies. Platelet transfusions were needed in up to 50% of the patients. Red blood cell transfusions were administered from 46 to 100% of the ECMO patients. Bleeding events varied from 16.6 to 50.7%, although the cause and type of haemorrhage was not consistently reported. Thrombocytopenia and platelet dysfunction are common in ECMO patients, regardless the type of ECMO mode. The underlying mechanisms are multifactorial, and understanding and management are still limited. Further research to design appropriate strategies and protocols for its monitoring, management, or prevention should be matter of thorough investigations.

Optimal Strategy and Timing of Left Ventricular Venting During Veno-Arterial Extracorporeal Life Support for Adults in Cardiogenic Shock

Background:

Veno-arterial extracorporeal life support (VA-ECLS) is widely used to treat refractory cardiogenic shock. However, increased left ventricular (LV) afterload in VA-ECLS can worsen pulmonary congestion and compromise myocardial recovery. Our objectives were to explore the efficacy, safety, and optimal timing of adjunctive LV venting strategies.

Methods:

A systematic search was performed on Medline, EMBASE, PubMed, CDSR, CCRCT, CINAHL, ClinicalTrials.Gov, and WHO ICTRP from inception until January 2019 for all relevant studies, including LV venting. Data were analyzed for mortality and weaning from VA-ECLS on the basis of timing of LV venting, along with adverse complications.

Results:

A total of 7995 patients were included from 62 observational studies, wherein 3458 patients had LV venting during VA-ECLS. LV venting significantly improved weaning from VA-ECLS (odds ratio, 0.62 [95% CI, 0.47–0.83]; P =0.001) and reduced short-term (30 day; risk ratio [RR], 0.86 [95% CI, 0.77–0.96]; P =0.008) but not in-hospital (RR, 0.92 [95% CI, 0.83–1.01] P =0.09) or long-term (6 months; RR, 0.96 [95% CI, 0.90–1.03]; P =0.27) mortality. Early (<12 hours; RR, 0.86 [95% CI, 0.75–0.99]; P =0.03) but not late (≥12 hours; RR, 0.99 [95% CI, 0.71–1.38]; P =0.93) LV venting significantly reduced short-term mortality. Patients with LV venting spent more time on VA-ECLS (3.6 versus 2.8 days, P <0.001), and mechanical ventilation (7.1 versus 4.6 days, P =0.013). With the exception of hemolysis (RR, 2.18 [95% CI, 1.58–3.01]; P <0.00001), overall adverse events did not differ.

Conclusions:

LV venting, especially if done early (<12 hours), appears to be associated with an increased success of weaning and reduced short-term mortality. Future studies are required to delineate the importance of any or early LV venting adjuncts on mortality and morbidity outcomes.

Extracorporeal Life Support Enhances the Forward Pressure Wave to Cause a Mismatch between Cardiac Oxygen Demand and Supply

Extracorporeal life support (ECLS) is a world-famous life-saving method. Until now, changes in arterial wave properties due to ECLS have remained unexamined. In this study, we determined the effects of ECLS on arterial wave properties and ventricular/arterial coupling in male Wistar rats with the measured aortic pressure alone. Ascending aortic pressure signals were measured before ECLS and at 30, 60, and 90 min after weaned off. The aortic pressure signal then calculated by fourth-order derivative to obtain an assumed triangular flow wave. The ratio of mean systolic pressure to mean diastolic pressure (P_ms/P_md), a parameter for evaluating the matching condition between myocardial oxygen demand and supply, was significantly higher after ECLS. The magnitude of forward pressure (|P_f|) augmented by ECLS prevailed over the backward pressure (|P_b|), leading to a decline in wave reflection factor. P_ms/P_md was positively linearly correlated with |P_f| (P_ms/P_md = 0.9177 + 0.0078 × |P_f|, r = 0.8677; P < 0.0001). These findings suggest that |P_f| was a predominant factor responsible for the mismatch between the myocardial oxygen demand and supply in rats after ECLS phase of experiment.

Incidence and Impact of Acute Kidney Injury in Patients Receiving Extracorporeal Membrane Oxygenation: A Meta-Analysis

BACKGROUND

Although acute kidney injury (AKI) is a frequent complication in patients receiving extracorporeal membrane oxygenation (ECMO), the incidence and impact of AKI on mortality among patients on ECMO remain unclear. We conducted this systematic review to summarize the incidence and impact of AKI on mortality risk among adult patients on ECMO.

METHODS

A literature search was performed using EMBASE, Ovid MEDLINE, and Cochrane Databases from inception until March 2019 to identify studies assessing the incidence of AKI (using a standard AKI definition), severe AKI requiring renal replacement therapy (RRT), and the impact of AKI among adult patients on ECMO. Effect estimates from the individual studies were obtained and combined utilizing random-effects, generic inverse variance method of DerSimonian-Laird. The protocol for this systematic review is registered with PROSPERO (no. CRD42018103527).

RESULTS

41 cohort studies with a total of 10,282 adult patients receiving ECMO were enrolled. Overall, the pooled estimated incidence of AKI and severe AKI requiring RRT were 62.8% (95%CI: 52.1%-72.4%) and 44.9% (95%CI: 40.8%-49.0%), respectively. Meta-regression showed that the year of study did not significantly affect the incidence of AKI (p = 0.67) or AKI requiring RRT (p = 0.83). The pooled odds ratio (OR) of hospital mortality among patients receiving ECMO with AKI on RRT was 3.73 (95% CI, 2.87-4.85). When the analysis was limited to studies with confounder-adjusted analysis, increased hospital mortality remained significant among patients receiving ECMO with AKI requiring RRT with pooled OR of 3.32 (95% CI, 2.21-4.99). There was no publication bias as evaluated by the funnel plot and Egger's regression asymmetry test with p = 0.62 and p = 0.17 for the incidence of AKI and severe AKI requiring RRT, respectively.

CONCLUSION

Among patients receiving ECMO, the incidence rates of AKI and severe AKI requiring RRT are high, which has not changed over time. Patients who develop AKI requiring RRT while on ECMO carry 3.7-fold higher hospital mortality.

An audit of mortality by using ECMO specific scores and APACHE II scoring system in patients receiving extracorporeal membrane oxygenation in a tertiary intensive care unit in Hong Kong

Background

Outcomes of patients receiving extracorporeal membrane oxygenation (ECMO) therapies risk-adjusted by ECMO specific scores have rarely been reported. Our primary aim was to determine the risk adjusted outcome of these patients by the use of Respiratory Extracorporeal Membrane Oxygenation Survival Prediction (RESP), Survival After Veno-Arterial-ECMO (SAVE) and APACHE II scores. The differences in predicted mortality between these scoring systems were analyzed.

Methods

This is a single-center retrospective study reviewing 62 patients who received venous-venous ECMO (VV-ECMO) and venous-arterial ECMO (VA-ECMO) between 2009 and 2017 in a tertiary ICU. Demographic, clinical, laboratory, imaging data were analyzed. Primary outcome measures were the crude mortality and standardized mortality ratio (SMR), expressed as observed mortality divided by expected mortality predicted from RESP, SAVE and APACHE II scores, respectively. We also examined the difference in predicted mortality derived from RESP, SAVE, and APACHE II by using Bland Altman plots.

Results

Twenty and Forty-two patients received VV-ECMO (20 runs) and VA-ECMO (43 runs) respectively. For VV-ECMO, the mean RESP was 0.6 [standard deviation (SD) 4.86] with RESP-SMR of 1.16 [95% confidence interval (95% CI) =0.44-1.88]. For VA-ECMO, the mean SAVE score was -7.8 (SD 5.6), with SAVE-SMR of 0.69 (95% CI =0.39-0.98). In the Bland Altman plot for VA-ECMO, mean difference in predicted mortality between SAVE and APACHE II was 17.6% (95% CI: 7.6% to 27.6%, P<0.0001), with 95% limit of agreement of -30.2% to 65.5% and beta coefficient of -1.04. APACHE II predicted mortality for VA-ECMO was lower than that for SAVE until it crossed SAVE prediction at about 80% mortality. After this point, it becomes progressively higher than that for SAVE.

Conclusions

The mortality outcome of our patients on VV-ECMO and VA-ECMO compares favorably with predicted mortality based on RESP and SAVE, respectively. In our cohort of patients receiving VA-ECMO, APACHE II tends to underestimate mortality in lower risk patients, and overestimate the mortality in patients at high risk of death.

Outcomes of venoarterial extracorporeal membrane oxygenation for refractory cardiogenic shock: systematic review and meta-analysis

Background

Despite advances in management techniques and medical therapy, refractory cardiogenic shock remains a life-threatening condition with high mortality rates. The present systematic review and meta-analysis aims to explore the outcomes associated with venoarterial extracorporeal membrane oxygenation (VA-ECMO) use in the setting of refractory cardiogenic shock, stratified per survivorship.

Methods

A literature search was performed using three electronic databases from the date of their inception up to June 2018. The literature search and subsequent data extraction were performed by two independent reviewers. Digitized survival data were extracted from Kaplan-Meier curves in order to re-create the original patient data using an iterative algorithm and were subsequently aggregated for analysis.

Results

Fifty-two studies were included, with 44 undergoing quantitative analysis. A total of 17,515 patients were identified, with a mean age of 58.4±9.4 years and a mean duration of ECMO support of 5.1±2.6 days; 68.7% of the patients were male. Aggregated survival rates at 1, 2, 3 and 5 years were 36.7%, 34.8%, 33.8% and 29.9%, respectively.

Conclusions

The present systematic review illustrates the expected survival results for VA-ECMO in the intermediate- to long-term. Extended follow-up and standardized reporting measures are urgently needed in order to carry out more definitive subgroup analyses.

Clinical complications during veno-arterial extracorporeal membrane oxigenation in post-cardiotomy and non post-cardiotomy shock: still the achille's heel

Extracorporeal membrane oxygenation (ECMO) is life-saving for potentially reversible heart failure and respiratory injuries not responsive to conventional therapies. Technological innovations have produced over the years significant improvements in ECMO devices (pump, cannula design and oxygenator) and have allowed a better risk/benefit profile. Alongside with recognized advantages in the treatment of very sick patients, ECMO remains an invasive procedure for mechanical circulatory support (MCS) and it is associated with complications that strongly influence the prognosis. Current review was designed to provide a comprehensive outline on ECMO complications, analyzing risk factors and strategies of management, focusing on adult population undergoing veno-arterial ECMO (VA-ECMO) therapy.

Protracted aortic valve closure during peripheral veno-arterial extracorporeal life support: is intra-aortic balloon pump an effective solution?

Background:

Left ventricular (LV) afterload increase with protracted aortic valve (AV) closure may represent a complication of veno-arterial extracorporeal membrane oxygenation (V-A ECMO). The aim of the present study was to assess the effects of an intra-aortic balloon pump (IABP) to overcome such a hemodynamic shortcoming in patients submitted to peripheral V-A ECMO.

Methods:

Among 184 adult patients who were treated with peripheral V-A ECMO support at Medical University Center Maastricht Hospital between 2007 and 2018, patients submitted to IABP implant for protracted AV closure after V-A ECMO implant were retrospectively identified. All clinical and hemodynamic data, including echocardiographic monitoring, were collected and analyzed.

Results:

During the study period, 10 subjects (mean age 60 years old, 80% males) underwent IABP implant after peripheral V-A ECMO positioning due to the diagnosis of protracted AV closure and inefficient LV unloading as assessed by echocardiography and an absence of pulsation in the arterial pressure wave.

Recovery of blood pressure pulsatility and enhanced LV unloading were observed in 8 patients after IABP placement, with no significant differences in the main hemodynamic parameters, inotropic therapy or in the ECMO flow (p=0.48). The weaning rate in this patient subgroup (mean ECMO duration 8 days), however, was only 10%, with another patient finally transplanted, leading to a 20% survival-to-hospital discharge.

Conclusion:

IABP placement was an effective solution in order to reverse the protracted AV closure and impaired LV unloading observed during peripheral V-A ECMO support. However, the impact on the weaning rate and survival needs further investigations.

CD163 as a novel target gene of STAT3 is a potential therapeutic target for gastric cancer

CD163 is a member of the scavenger receptor cysteine-rich superfamily, and has been widely used to identify M2 type macrophage. However, the expression of CD163 in gastric cancer and its regulatory mechanism are still unclear. Here we show that CD163 is elevated in gastric cancer tissues. High expression of CD163 is a potential indicator to evaluate the status of tumor associated macrophages (TAMs), regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs) and cancer associated fibroblasts (Cafs). Besides, more CD163 positive macrophages and CD163 expressing gastric cancer cells are associated with tumor invasion and poor prognosis. Knocking-down CD163 in cancer cells could inhibit tumor growth in vivo. We also find various immune molecules which are correlated with CD163 in gastric cancer tissues and cell lines have positive staining in the cancer cells of clinical sample. Finally, we confirm CD163 is a novel target gene of STAT3 (signal transducer and activator of transcription 3) in gastric cancer. Our data indicate that CD163 may be a potential poor prognostic marker and therapeutic target for gastric cancer.

Advanced Age as a Predictor of Survival and Weaning in Venoarterial Extracorporeal Oxygenation: A Retrospective Observational Study

Background. In most reports on ECMO treatment, advanced age is classified as a contraindication to VA ECMO. We attempted to investigate whether advanced age would be a main risk factor deciding VA ECMO application and performing VA ECMO support. We determined whether advanced age should be regarded as an absolute or relative contraindication to VA ECMO and could affect weaning and survival rates of VA ECMO patients. Methods. VA ECMO was performed on 135 adult patients with primary cardiogenic shock between January 2010 and December 2014. Successful weaning was defined as weaning from ECMO followed by survival for more than 48 hours. Results. Among the 135 patients, 35 survived and were discharged uneventfully, and the remaining 100 did not survive. There were significant differences in survival between age groups, and older age showed a lower survival rate with statistical significance (P = .01). By multivariate logistic regression analysis, age was not significantly associated with in-hospital mortality (P = .83) and was not significantly associated with VA ECMO weaning (P = .11). Conclusions. Advanced age is an undeniable risk factor for VA ECMO; however, patients of advanced age should not be excluded from the chance of recovery after VA ECMO treatment.

Role of Intra-Aortic Balloon Pump and Extracorporeal Membrane Oxygenation in Early Graft Failure After Cardiac Transplantation

Early graft failure (EGF) is a major risk factor for death after heart transplantation (Htx). We investigated the predictive risk factors for moderate-to-severe EGF requiring an intra-aortic balloon pump (IABP) or extracorporeal membrane oxygenation (ECMO) circulatory support as treatment after Htx. Between January 2000 and December 2014, 412 consecutive adult patients underwent isolated Htx at our institution. Moderate and severe EGF were defined as the need for IABP and ECMO support, respectively, within 24 h after Htx. All available recipient and donor variables were analyzed to assess the risk of EGF occurrence. Overall, moderate-to-severe EGF occurred in 46 (11.1%) patients. Twenty-nine (63.04%) patients required peripheral or central ECMO support in the treatment of severe EGF and 17 (36.9%) patients required IABP support for the treatment of moderate EGF. The predictive risk factors for moderate-to-severe EGF in recipients, as assessed by logistic regression analysis, were a preoperative transpulmonary gradient > 12 mm Hg (odds ratio [OR] 5.2; P = 0.023), a preoperative inotropic score > 10 (OR 8.5; P = 0.0001), and preoperative ECMO support (OR 4.2; P = 0.012). For donors, the predictive risk factor was a donor score ≥ 17 (OR 8.3; P = 0.006). The absence of EGF was correlated with improved long-term survival: 94% at 1 year and 81% at 5 years without EGF versus 76% and 36% at 1 year (P < 0.001), and 70% and 28% at 5 years (P < 0.001) with EGF requiring IABP and ECMO support, respectively. In-hospital weaned and survived patients after IABP or ECMO treatment for moderate-to-severe EGF had a similar 5-year conditional survival rate as transplant patients who had not suffered EGF: 88% without EGF versus 84% with EGF treated with mechanical circulatory support devices (P = 0.08). The occurrence of EGF is a multifactorial deleterious event that depends on donor and recipient profiles. IABP and ECMO support are reliable treatment strategies, depending on the grade of EGF. Furthermore, surviving patients treated with IABP or ECMO have the same long-term conditional survival rate as patients who have not suffered EGF.

Contemporary Outcomes of Venoarterial Extracorporeal Membrane Oxygenation for Refractory Cardiogenic Shock at a Large Tertiary Care Center

Refractory cardiogenic shock (RCS) is associated with significant morbidity and mortality, and current mainstays of medical therapy appear inadequate. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) represents an increasingly accepted therapy for RCS. Demographics, past medical history, preoperative characteristics, outcomes, and adverse events were collected for consecutive patients who received VA-ECMO support for RCS at our institution from March 2007 to December 2013. One hundred and seventy-nine patients with a mean age of 56.9 ± 16.1 years were included. Etiologies of RCS included postcardiotomy shock in 70 patients (39%), acute myocardial infarction in 46 patients (26%), primary graft failure in 17 patients (10%), and acute decompensated heart failure in 24 patients (13%). Mean arterial pressure before VA-ECMO support was 59.4 ± 22.8 mm Hg and 30.7% (n = 55) were undergoing active cardiopulmonary resuscitation at the time of cannulation. Overall, 38.6% of patients (n = 69) survived to discharge and 44.7% of patients (n = 80) survived to 30 days. Myocardial recovery was achieved in 79.7% of survivors (n = 55) and 39.1% were transitioned to a more durable device. Univariate analysis identified age (p = 0.002) and etiology of RCS (p = 0.041) as the most significant predictors of in-hospital mortality. Venoarterial extracorporeal membrane oxygenation for RCS appears successful as salvage therapy. Age and etiology should be considered when evaluating patients for VA-ECMO.

Clinical Features and outcomes in adults with cardiogenic shock supported by extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is an increasingly used supportive measure for patients with refractory cardiogenic shock (CS). Despite its increasing use, there remain minimal data regarding which patients with refractory CS are most likely to benefit from ECMO. We retrospectively studied all patients (n = 123) who underwent initiation of ECMO for CS from February 2009 to September 2014 at a single center. Baseline patient characteristics, including demographics, co-morbid illness, cause of CS, available laboratory values, and patient outcomes were analyzed. Overall, 69 patients (56%) were weaned from ECMO, with 48 patients (39%) surviving to discharge. Survivors were younger (50 vs 60 years; p ≤0.0001), had a lower rate of previous smoking (27 vs 56%; p = 0.01) and chronic kidney disease (2% vs 13%; p = 0.03), and had lower lactate measured soon after ECMO initiation (3.1 vs 10.2 mmol/l; p = 0.01). Patients with pulmonary embolism (odds ratio 8.0, 95% confidence interval 2.00 to 31.99; p = 0.01) and acute cardiomyopathy (odds ratio 7.5, 95% confidence interval 1.69 to 33.27; p = 0.01) had a higher rate of survival than acute myocardial infarction, chronic cardiomyopathy, and miscellaneous etiologies compared to postcardiotomy CS as a referent. In conclusion, survival after ECMO initiation differs based on underlying cause of CS. Survival may be lower in older patients and those with early evidence of persistent hypoperfusion after initiation of ECMO for CS.

The contemporary role of Impella in a comprehensive mechanical circulatory support program: a single institutional experience

Background

The treatment of cardiogenic shock with percutaneous mechanical circulatory support (MCS) is attractive: however, at present it is not clear which is the best strategy, as no survival benefit has been demonstrated for any device as single therapy. Aim of this study is to describe the role of percutaneous Impella in a comprehensive MCS program.

Methods

Observational study on 22 patients supported with the Impella device in our hospital from May 2013 to June 2014.

Results

Four patients (18 %) were treated with Impella alone, 8 patients (36 %) were treated with Impella and IABP, 6 patients (27 %) with Impella and VA ECMO, and 4 patients (18 %) with Impella, IABP and VA ECMO.

The cause of cardiogenic shock was myocardial infarction (CSMI) in 9 patients (41 %), postcardiotomic cardiogenic shock in 5 (23 %), and a miscellaneous of other causes in the remaining 8 (36 %). Eight Impella devices (36 %) were placed under transesophageal echocardiographic guidance, while 14 (64 %) under fluoroscopy. The device was removed with manual compression at bedside and no vascular complications were observed.

Duration of Impella support was 107 (54–141) hours and duration of ventilation was 48 (14–92) hours. Hemolysis occurred in 6 patients (27 %), while major bleeding in 4 patients (18 %). Survival was 73 %: 13 patients (58 %) showed recovery of cardiac function; 1 patient (5 %) was bridged to left ventricular assist device (LVAD) implantation, 1 patient (5 %) to heart transplantation (HTx) and 1 patient (5 %) received a BiVAD and was eventually bridged to HTx.

Conclusions

Our data suggest that a multi-device approach, encompassing active LV support with Impella, is safe and can significantly improve survival in patients with cardiogenic shock.

Management and outcome of patients supported with Impella 5.0 for refractory cardiogenic shock

Introduction

Cardiogenic shock refractory to standard therapy with inotropes and/or intra-aortic balloon pump is accompanied with an unacceptable high mortality. Percutaneous left ventricular assist devices may provide a survival benefit for these very sick patients. In this study, we describe our experience with the Impella 5.0 device used in the setting of refractory cardiogenic shock.

Methods

In this observational, retrospective, single-center study we included all the consecutive patients supported with Impella 5.0, between May 2008 and December 2013, for refractory cardiogenic shock. Patients’ baseline and procedural characteristics, hemodynamics and outcome to the first 48 h of support, to ICU discharge and day-28 visit were collected.

Results

A total of 40 patients were included in the study. Median age was 57 years and 87.5 % were male. Cardiogenic shock resulted from acute myocardial infarction in 17 patients (43 %), dilated cardiomyopathy in 12 (30 %) and postcardiotomy cardiac failure in 7 (18 %). In 15 patients Impella 5.0 was added to an ECMO to unload the left ventricle. The median SOFA score for the entire cohort prior to circulatory support was 12 [10–14] and the duration of Impella support was 7 [5–10] days. We observed a significant decrease of the inotrope score (10 [1–17] vs. 1 [0–9]; p = 0.04) and the lactate values (3.8 [1.7–5.9] mmol/L vs. 2.5 [1.5–3.4] mmol/L; p = 0.01) after 6 h of support with Impella 5.0. Furthermore, at Impella removal the patients’ left ventricular ejection fraction improved significantly (p < 0.001) when compared to baseline. Cardiac recovery, bridge to left ventricular assist device or heart transplantation was possible in 28 patients (70 %). Twenty-six patients (65 %) survived at day 28. A multivariate analysis showed a higher risk of mortality for patients with acute myocardial infarction (hazard ratio = 4.1 (1.2–14.2); p = 0.02).

Conclusions

Impella 5.0 allowed fast weaning of inotropes and might facilitate myocardial recovery. Despite high severity scores at admission, day-28 mortality rate was better than predicated.

Veno-arterial extracorporeal membrane oxygenation for adult cardiovascular failure

PURPOSE OF REVIEW

To examine the utility and technical challenges of applying veno-arterial extracorporeal membrane oxygenation for acute cardiovascular failure in adults with acute and chronic causes of heart failure.

RECENT FINDINGS

The role of mechanical circulatory support in acute cardiovascular continues to evolve as technology and clinical experience develop. There is increasing interest in the role of veno-arterial extracorporeal membrane oxygenation as a bridging therapy and as an adjunct to conventional cardiopulmonary resuscitation.

SUMMARY

Veno-arterial extracorporeal membrane oxygenation is an expensive, complex, resource intensive support. It is essential that its future use be guided by evidence obtained from centres that have demonstrated timely, safe support.

Extracorporeal cardiopulmonary resuscitation

PURPOSE OF REVIEW

To discuss the role of extracorporeal membrane oxygenation (ECMO) in patients with cardiac arrest.

RECENT FINDINGS

Return to spontaneous circulation dramatically decreases with the duration of cardiopulmonary resuscitation (CPR). In this context, it has been proposed to implement venoarterial ECMO in order to assist CPR (ECPR) both in inhospital cardiac arrest (IHCA) and in out-of-hospital cardiac arrest (OHCA).

SUMMARY

This review highlights that ECPR is feasible for both IHCA and OHCA. In the recent series, the outcome of ECPR in IHCA is satisfactory, with survival rates good with neurologic outcome reaching the 40-50% range. All series converge in highlighting that time from cardiac arrest to ECMO flow is a critical determinant of outcome, with survival rates of 50% when initiated within 30 min of IHCA, 30% between 30 and 60 min, and 18% after 60 min. Results of ECPR in OHCA are more challenging. Recent series suggest that good outcome can be obtained in 15-20% of the patients, provided that time from arrest to ECMO is shorter than 60 min. Duration of cardiac arrest seems to be more important than location of cardiac arrest. ECPR thus seems to be a valuable option in selected cases.

Mechanical circulatory support in advanced heart failure: single-center experience

BACKGROUND

Currently, ventricular assist device (VAD) or total artificial heart (TAH) mechanical support provides an effective treatment of unstable patients with advanced heart failure. We report our single-center experience with mechanical circulatory support therapy.

METHODS

From March 2002 to December 2012, 107 adult patients (mean age, 56.8 ± 9.9 y; range, 31-76 y) were primarly supported on temporary or long-term VAD or TAH support as treatment for refractory heart failure at our institution. Temporary extracorporeal radial VAD support (group A) was established in 49 patients (45.7%), and long-term paracorporeal and intracorporeal VAD or TAH (group B) in 58 patients (54.2%). Left ventricular (LVAD) support was established in 55 patients (51.4%; n = 33, Heartmate II; n = 6, Heartmate I XVE; n = 4, Heartware HVAD; and n = 12, Centrimag) and biventricular (BVAD/TAH) support (group B) in 28 patients (26.1%; n = 10, Thoratec paracorporeal; n = 2, Heartware HVAD, n = 1, Thoratec implantable; n = 1, Syncardia TAH; and n = 14, Centrimag). The temporary Centrimag was the only device adopted as isolated right ventricular (RVAD) support, and it was inserted in 24 patients (22.4%).

RESULTS

In group A, overall mean support time was 10.2 ± 6.6 days (range, 3-43 d). In group B, LVAD mean support time was 357 ± 352.3 days (range, 1-902 d) and BVAD/TAH support time was 98 ± 82.6 days (range, 8-832 d). In group A, the overall success rate was 55.1% (27 patients). In group B, LVAD overall success rate was 74.4% (32 patients) and BVAD/TAH success rate was 50% (7 patients). Overall heart transplantation rate for both groups was 27.1% (n = 2, group A; n = 27, group B). Overall 1-year and 5-year survivals after heart transplantation were 72.4% (n = 21) and 58.6% (n = 17), respectively.

CONCLUSIONS

Mechanical circulatory support is an effective strategy even in cases of end-stage heart failure according to our experience. Further improvement of VAD and TAH technologies may support their adoption as an encouraging alternative to heart transplantation in the near future.

Clinical impact of intra-aortic balloon pump during extracorporeal life support in patients with acute myocardial infarction complicated by cardiogenic shock

Background

There is no available data on clinical outcome in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock who are supported by an intra-aortic balloon pump (IABP) in combination with extracorporeal life support (ECLS).

Methods

We analysed 96 consecutive patients with AMI and complicating cardiogenic shock who were assisted by an ECLS system between January 2004 and December 2011. The primary outcome was in-hospital mortality. The secondary outcomes were the success rate of weaning from ECLS and the lactate clearance for 48 hours (%).

Results

A combination of IABP and ECLS was used in 41 (42.7%) patients. In-hospital mortality occurred for 51 patients (ECLS with IABP versus ECLS alone; 51.2% vs. 54.5%, p = 0.747). The success rate of weaning from ECLS was similar between the two groups (63.4% vs. 58.2%, p = 0.604). Complications such as ischemia of a lower extremity or bleeding at the ECLS insertion site (p = 0.521 and p = 0.667, respectively) did not increase when ECLS was combined with IABP. Among patients who survived for 24 hours after intervention, lactate clearance was not significantly different between patients who received ECLS alone and those who received ECLS with IABP (p = 0.918).

Conclusions

The combined use of ECLS and IABP did not improve in-hospital survival in patients with AMI complicated by cardiogenic shock.

The Impella device for acute mechanical circulatory support in patients in cardiogenic shock

BACKGROUND

Acute cardiogenic shock is associated with high mortality rates. Mechanical circulatory devices have been increasingly used in this setting for hemodynamic support. The Impella device (Abiomed Inc, Danvers, MA) is a microaxial left ventricular assist device that can be inserted using a less invasive technique. This study was conducted to determine the outcome of patients who have undergone placement of the Impella device for acute cardiogenic shock in our institution.

METHODS

A retrospective record review of 47 patients who underwent placement of the Impella device was performed from January 1, 2006, to December 31, 2011. Records were evaluated for demographics, operative details, and postoperative outcomes. Operative mortality was defined as death within 30 days of the operation.

RESULTS

The patients (33 male) were an average age of 60.23 ± 13 years. The indication for placement of the Impella device included cardiogenic shock in 15 patients (32%) and postcardiotomy cardiogenic shock in 32 (68%). Of the 47 patients, 38 (80%) received the Impella 5.0 and the rest the 2.5 device. Ventricular function recovered in 34 of 47 patients (72%), and the device was removed, with 4 patients (8%) transitioned to long-term ventricular assist devices. The 30-day mortality was 25% (12 of 47 patients). Complications occurred in 14 patients (30%), consisting of device malfunction, high purge pressures, tube fracture, and groin hematoma.

CONCLUSIONS

This is one of the largest series of patients undergoing placement of the Impella device for acute cardiogenic shock. Our outcomes showed improved results compared with historical data. Myocardial recovery was accomplished in most patients. Finally, the 30-day mortality and complication rate was acceptable in these critical patients. These benefits were all achieved with the Impella device in a less invasive method.

Neuron-specific enolase serum levels predict severe neuronal injury after extracorporeal life support in resuscitation

OBJECTIVES

Extracorporeal life support (ECLS) is a rescue option in critically ill patients. Since fast available and appropriate for respiratory and circulatory failure, it is frequently applied in resuscitation scenarios. Neurological injury is a complication common in ECLS patients limiting outcome, particularly after resuscitation. In this study, the institutional ECLS database was used to correlate neuron-specific enolase (NSE) serum peak values with outcome of patients supported with venoarterial (VA) ECLS during cardiopulmonary resuscitation (CPR).

METHODS

From January 2011 to August 2012, 31 patients were provided with a VA ECLS during CPR (external cardiac massage). Serum NSE peaks were monitored and correlated with neurological outcome and hospital mortality. Patients were divided into two groups with mild-to-moderate and high NSE levels (cut-off value 100 μg/l).

RESULTS

High NSE levels were seen in 7 patients (mean 218 ± 155 μg/l) and mild-to-moderate levels in 24 patients (50 ± 23 μg/l, P = 0.0001). Duration of extracoporeal support was comparable in both groups (6.3 ± 7.5 vs 5.0 ± 4.5 days, P = n.s.). Patients with mild-to-moderate NSE levels were significantly older than those with high NSE levels (58 ± 16 vs 44 ± 15 years, P = 0.02). Six patients with high NSE levels (86%) developed severe neurological complications. Though 4 patients could be weaned from extracorporeal support, hospital mortality was 86% (6 patients). In contrast, patients with mild-to-moderate NSE levels had a hospital mortality of 46% (11 patients). Eighteen patients (75%) could be weaned from the device, and incidence of major neurological events was 29% (6 patients) only. Serum pH and lactate levels before ECLS implantation were significantly lower in patients with mild-to-moderate NSE values (pH: 7.23 ± 0.04 vs 6.93 ± 0.12, P = 0.039; lactate: 106 ± 11 vs 161 ± 16 mg/l, P = 0.023).

CONCLUSIONS

High NSE serum levels after ECLS correspond to poor neurological outcome and considerable mortality. Therefore, early neuroimaging is reasonable for determining therapeutic strategies in patients with high NSE peaks after resuscitation and extracorporeal support.

Cardiogenic Shock and the ICU Patient

Cardiogenic shock is one of the most important complications of acute myocardial infarction (MI) and acute left ventricular failure (LVF). It threatens the life of 5–10% of patients with ST-segment elevation myocardial infarction (STEMI) particularly in the presence of inappropriately low peripheral vascular resistance. Cardiogenic shock results in poor tissue perfusion, end-organ damage and carries a high mortality risk. The goal of therapy is to prevent end-organ dysfunction and severe metabolic derangement by raising mean arterial blood pressure, which is achieved with the use of inotropes and vasopressors, often at the expense of tachycardia, elevated myocardial oxygen consumption and extended myocardial ischaemia. Current therapeutic approaches include early coronary artery revascularisation (which has significantly improved the survival rate), fluid resuscitation, inotropic support and mechanical circulatory support using intra-aortic balloon pumps or ventricular assist devices. In this article, we review the pathophysiology, diagnosis and management of cardiogenic shock.

Mechanical circulatory support for cardiogenic shock

Cardiogenic shock (CS) is a syndrome of progressive depression of myocardial function with systemic hypoperfusion. It occurs due to various aetiologies such as acute myocardial infarction, myocarditis, acute decompensated heart failure and postcardiotomy. Cardiogenic shock carries poor prognosis, and medical therapy alone is not effective. Mechanical circulatory support is required to unload the ventricles, decrease the myocardial demand, prevent further injury, improve the coronary perfusion, stabilise the haemodynamics and maintain the end-organ perfusion before definitive interventions such as coronary reperfusion can take place. Currently, there are several methods of mechanical circulatory support. These include extracorporeal life support, paracorporeal or extracorporeal ventricular-assist devices, percutaneous ventricular assist devices, intra-aortic balloon counterpulsation and total artificial heart. In this review, we discuss the role of each of these circulatory support devices in the management of acute cardiac failure.

Outcome of the Impella Device for Acute Mechanical Circulatory Support

Objective

The contribution of cardiogenic shock to in-hospital mortality has not decreased significantly despite prompt revascularization, advances in medical therapy, and mechanical circulatory support. For patients in cardiogenic shock, mechanical circulatory support has been provided by a variety of devices. We report the outcome of the Impella device for acute mechanical circulatory support in cardiogenic shock in a setting of a large-volume single institution. The primary end points include survival to 30 days and recovery of native heart function and survival to 90 days and 1 year. The secondary end points include device complications.

Methods

We performed a retrospective chart review of 36 consecutive patients who underwent placement of the Impella device from February 6, 2006, to December 31, 2010. The charts were evaluated for data relative to the patients’ demographics, hemodynamics, operative details, 30-day outcome including the patients’ native heart function recovery, and 90-day and 1-year survival.

Results

Thirty-six consecutive patients were included in our study. The mean ± SD age was 60.3 ± 13 years, and 69% were men. The indication for placement of the Impella device included postcardiotomy cardiogenic shock in 23 patients (64%), acute myocardial infarction complicated with cardiogenic shock in 10 patients (28%), acute decompensated ischemic cardiomyopathy in 2 patients (6%), and myocarditis with cardiogenic shock in 1 patient (3%). The mean ± SD duration of the Impella support was 4.5 ± 3.9 days (range, 1–18). The 30-day survival rate was 72% (26/36), and, of those, 96% (25/26) recovered their native heart function and one (4%) was bridged to long-term left ventricular assist device (HeartMate II; Thoratec, Inc, Pleasanton, CA USA). The 90-day and 1-year survival was 64% and 61%, respectively.

Conclusions

The Impella devices yielded a very favorable outcome in patients with cardiogenic shock.