New experimental model of hind limb ischemia in pot-bellied pigs.

BACKGROUND: The simulation of limb ischemia in large laboratory animals is a complex and currently topical task in experimental medicine. Meanwhile, there is a demand for a reliable and effective model of limb ischemia for further testing of medicines to stimulate circulation and induce angiogenesis, gene medicines in particular. Aim of this study was to develop and experimentally test an effective method of simulation of hind limb ischemia. METHODS: Female Vietnamese pot-bellied pigs were chosen as biological models. The reproduction of the pathology was evaluated using the following methods: laser doppler flowmetry, laboratory test of venous blood, immunohistochemical reaction with antibodies against CD31, a specific marker of endothelial cells, Van Gieson's staining of muscles for presence of connective tissue and clinical observation to detect the presence of lameness in pigs. RESULTS: Laser doppler flowmetry recorded a significant decrease in the intensity of the blood circulation and a marked decrease in temperate in the operated limb. Increased lactate and creatine kinase were registered immediately after the surgery and were absent 3 or more days later. Clinical observation demonstrated presence of walking lameness. Histological and immunohistochemical methods revealed a credible increase in connective tissue area and a reduction in the number of blood vessels in the muscles, confirming the presence of ischemia. CONCLUSIONS: An effective approach to modeling limb ischemia has been developed and experimentally tested. The proposed model may be used in cardiovascular surgery and will allow further testing of new medications designed to treat ischemia of hind limbs.

Predictors of acute kidney injury in patients after extracorporeal cardiopulmonary resuscitation.

OBJECTIVES: Extracorporeal cardiopulmonary resuscitation (eCPR) is increasingly used due to its beneficial outcomes and results compared with conventional CPR. Data after eCPR for acute kidney injury (AKI) are lacking. We sought to investigate factors predicting AKI in patients who underwent eCPR. METHODS: From January 2016 until December 2020, patients who underwent eCPR at our institution were retrospectively analyzed and divided into two groups: patients who developed AKI (n = 60) and patients who did not develop AKI (n = 35) and analyzed for outcome parameters. RESULTS: Overall, 63% of patients suffered AKI after eCPR and 45% of patients who developed AKI needed subsequent dialysis. Patients who developed AKI showed higher values of creatinine (1.1 mg/dL vs 1.5 mg/dL, p ⩽ 0.01), urea (34 mg/dL vs 42 mg/dL, p = 0.04), CK (creatine kinase) (923 U/L vs 1707 U/L, p = 0.07) on admission, and CK after 24 hours of ECMO support (1705 U/L vs 4430 U/L, p = 0.01). ECMO explantation was significantly more often performed in patients who suffered AKI (24% vs 48%, p = 0.01). In-hospital mortality (86% vs 70%; p = 0.07) did not differ significantly. CONCLUSION: Patients after eCPR are at high risk for AKI, comparable to those after conventional CPR. Baseline urea levels predict the development of AKI during the hospital stay.

Risk factors associated with in-hospital mortality for patients with ECLS due to postcardiotomy cardiogenic shock after isolated coronary surgery.

OBJECTIVES: Extracorporeal membrane oxygenation or extracorporeal life support (ECLS) in patients after cardiac surgery and postcardiotomy cardiogenic shock (PCS) is known to be associated with high mortality. Especially in patients after coronary artery bypass grafting (CABG) and PCS, ECLS is frequently established. The aim of this analysis was to evaluate factors associated with in-hospital mortality in patients treated with ECLS due to PCS after CABG. METHODS: Between August 2006 and January 2017, 92 consecutive patients with V-A ECLS due to PCS after isolated CABG were identified and included in this retrospective analysis. Patients were divided into survivors (S) and non-survivors (NS) and analyzed with risk factors of in-hospital mortality. RESULTS: In-hospital mortality added up to 61 patients (66%). Non-survivors were significantly older (60 ± 812 (S) vs. 67 ± 10 (NS); p = 0.013). Bilateral internal mammary artery graft was significantly more frequently used in S (23% (S) vs. 2% (NS); p = 0.001). After 24 h of ECLS support, median lactate levels were significantly higher in NS (1.9 (1.3; 3.5) mmol/L (S) vs. 3.5 (2.1; 6.3) mmol/L (NS); p = 0.001). NS suffered more often acute kidney injury requiring dialysis (42% (S) vs. 74% (NS); p = 0.002). CONCLUSION: Mortality in patients with refractory PCS after CABG and consecutive ECLS support remains high. Failing end-organ recovery under ECLS despite optimized concomitant medical therapy is an indicator of adverse outcomes in this specific patient cohort. Moreover, total-arterial revascularization might be beneficial for cardiac recovery in patients suffering PCS after CABG and following ECLS.

Gender-related propensity score match analysis of ECMO therapy in postcardiotomy cardiogenic shock in patients after myocardial revascularization.

BACKGROUND: Gender is known to influence the pathophysiology and pathogenesis of the coronary vascular disease. Data on gender-related differences in patients with veno-arterial extracorporeal membrane oxygenation due to postcardiotomy cardiogenic shock is lacking in current literature. We aimed to analyze the impact of gender on intraoperative and short-term outcomes of vaECMO patients after coronary surgery and postcardiotomy cardiogenic shock. METHODS: Between 2006 and 2017, a total of 92 patients with PCS after CABG underwent vaECMO-implantation at our institution. After a 1:1 propensity score match (PSM) for relevant preoperative data, we identified a cohort of 32 patients, 16 males, and 16 females. Periprocedural and short-term outcome data were analyzed with respect to sex differences. RESULTS: The mean age was 64 ± 11 years, and 79% (n = 73) were male patients. Clinical outcomes showed a 30-day all-cause mortality of 64% (n = 59). After PSM, male patients showed a significantly smaller number of arterial grafts (0.4 ± 0.53 male vs 1.1 ± 0.7 female; p = 0.037). Thirty-day all-cause mortality did not differ between the groups (56% male vs 75% female; p = 0.262). In general, short-term outcome data were comparable without significant differences for the matched groups. CONCLUSION: Gender has no impact on patients with vaECMO therapy due to PCS in isolated coronary surgery.

Extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest: first results and outcomes of a newly established ECPR program in a large population area.

OBJECTIVES: Out-of-hospital cardiac arrest (OHCA) is associated with excessively high mortality rates. Recent studies suggest benefits from extracorporeal cardiopulmonary resuscitation (ECPR) performed in selected patients. We sought to present the first results from our interdisciplinary ECPR program with a particular focus on early outcomes and potential risk factors associated with in-hospital mortality. METHODS: Between January 2016 and December 2019, 44 patients who underwent ECPR selected according to our institutional ECPR protocol were retrospectively analyzed regarding pre-hospital, in-hospital, and early outcome parameters. Patients were divided into survivors (S) and non-survivors (NS). Statistical analysis of risk factors regarding in-hospital mortality of the patient cohort analyzed was performed. RESULTS: The mean age of the population was 53 ± 12 years, with most patients being male (n = 40). The leading cause of cardiac arrest (CA) was myocardial infarction (n = 24, 55%). The median hospital stay was 1 (1;13) day. Twenty-three percent of patients (n = 10) were discharged from hospital including eight patients (18%) with CPC 1-2. Survivors showed a trend toward shorter pre-hospital CPR duration (60 (59;60) min (S) vs 60 (55;90) min (NS), p = 0.07). CONCLUSION: Establishing ECPR programs in large population areas offers the option to improve survival rates for OHCA patients. Stringent compliance of institutional criteria (mainly age, witnessed arrest, and time of pre-hospital resuscitation) and providing ECPR to strictly selected patients seems to be a vital factor for such programs' success. Pre-clinical settings and therapeutic measures must be adjusted in this regard to improve outcomes for this highly demanding patient cohort.

The outcome of patients with peripartum cardiomyopathy and consecutive implantation of a left ventricular assist device.

OBJECTIVES: Peripartum cardiomyopathy (PPCM) is a form of systolic heart failure occurring toward the end of pregnancy or in the period after delivery. Lack of myocardial recovery or therapy-refractory cardiogenic shock are rare complications and left ventricular assist device (LVAD) systems might be used as a life-saving option. The aim of this study was to investigate outcomes of PPCM patients supported with LVAD, registered in the European Registry for Patients with Mechanical Circulatory Support (EUROMACS). METHODS: All patients registered in EUROMACS with a primary diagnosis of PPCM were included in this study. Demographic, preoperative, intraoperative, postoperative, and follow-up data were collected and patients analysed concerning their outcome after initiation of LVAD therapy. RESULTS: Between May 2011 and September 2018, 16 patients with PPCM and consecutive LVAD implantation were enrolled into EUROMACS. The median age of the patient population was 31 (26;41) years with a mean left ventricular ejection fraction (LV-EF) of 15% ± 6%. In-hospital mortality after LVAD implantation was 6% (n = 1). One-year mortality accounted for 13% (n = 2). Six patients (40%) were transplanted with a median support time of 769 (193;1529) days. Weaning of LVAD support due to ventricular recovery was feasible in 3 (20%) patients. CONCLUSION: In patients with severe PPCM, LVAD therapy is associated with considerably low in-hospital mortality, potentially allowing bridging to heart transplantation, or left ventricular recovery. Therefore, durable mechanical support should be considered as a treatment option in this, by nature, young and often otherwise healthy patient population.

Concomitant ECMO And IABP Support in Postcardiotomy Cardiogenic Shock Patients.

OBJECTIVES: Simultaneous mechanical circulatory support (MCS) with intra-aortic balloon pump (IABP) to extracorporeal membrane oxygenation (ECMO) is common in postcardiotomy cardiogenic shock (PCS). This study aimed to analyse the effect of concomitant ECMO and IABP therapy on the short-term outcomes of patients with PCS. METHODS: Between March 2006 and March 2017, 172 consecutive patients with central (c) or peripheral (p) veno-arterial ECMO therapy due to PCS were identified at the current institution and included in this retrospective analysis. Patients were divided into ECMO+IABP and ECMO alone groups. Further, the impact of ECMO flow direction was analysed for the groups. RESULTS: A total of 129 patients received ECMO+IABP support and 43 patients were treated with ECMO alone. Median ECMO duration did not differ between the groups (68 [34; 95] hours ECMO+IABP vs 44 [20; 103] hours ECMO; p=0.151). However, a trend toward a higher weaning rate was evident in ECMO+IABP patients (75 [58%] ECMO+IABP vs 18 [42%] ECMO; p=0.078). Concomitant IABP support with either cECMO (73% [n=24] cECMO+IABP vs 50% [n=11] ECMO; p=0.098) or pECMO (57% [n=55] ECMO+IABP vs 33% [n=7] ECMO; p=0.056) was also associated with a trend toward a higher weaning rate off ECMO. In-hospital mortality did not differ between the groups. CONCLUSION: This analysis found that, independent of ECMO type, additional IABP support might increase ECMO weaning; however, it did not influence survival in PCS patients. Larger studies are necessary to further analyse the impact of this concomitant MSC therapy on clinical outcomes.

Higher incidence of perivalvular abscess determines perioperative clinical outcome in patients undergoing surgery for prosthetic valve endocarditis.

BACKGROUND: Cardiac surgery for prosthetic valve endocarditis (PVE) is associated with substantial mortality. We aimed to analyze 30-day and 1-year outcome in patients undergoing surgery for PVE and sought to identify preoperative risk factors for mortality with special regard to perivalvular infection. METHODS: We retrospectively analyzed data of 418 patients undergoing valve surgery for infective endocarditis between January 2009 and July 2018. After 1:1 propensity matching 158 patients (79 PVE/79 NVE) were analyzed with regard to postoperative 30-day and 1-year outcomes. Univariate and multivariable analyses were performed to identify potential risk factors for mortality. RESULTS: 315 patients (75.4%) underwent surgery for NVE and 103 (24.6%) for PVE. After propensity matching groups were comparable with regard to preoperative characteristics, clinical presentation and microbiological findings, except a higher incidence of perivalvular infection in patients with PVE (51.9%) compared to NVE (26.6%) (p = 0.001), longer cardiopulmonary bypass (166 [76-130] vs. 97 [71-125] min; p < 0.001) and crossclamp time (95 [71-125] vs. 68 [55-85] min; p < 0.001). Matched patients with PVE showed a 4-fold increased 30-day mortality (20.3%) in comparison with NVE patients (5.1%) (p = 0.004) and 2-fold increased 1-year mortality (PVE 29.1% vs. NVE 13.9%; p = 0.020). Multivariable analysis revealed perivalvular abscess, sepsis, preoperative AKI and PVE as independent risk factors for mortality. Patients with perivalvular abscess had a significantly higher 30-day mortality (17.7%) compared to patients without perivalvular abscess (8.0%) (p = 0.003) and a higher rate of perioperative complications (need for postoperative pacemaker implantation, postoperative cerebrovascular events, postoperative AKI). However, perivalvular abscess did not influence 1-year mortality (20.9% vs. 22.3%; p = 0.806), or long-term complications such as readmission rate or relapse of IE. CONCLUSIONS: Patients undergoing surgery for PVE had a significantly higher 30-day and 1-year mortality compared to NVE. After propensity-matching 30-day mortality was still 4-fold increased in PVE compared to NVE. Patients with perivalvular abscess showed a significantly higher 30-day mortality and perioperative complications, whereas perivalvular abscess seems to have no relevant impact on 1-year mortality, the rate of readmission or relapse of IE.

Levosimendan Reduces Mortality and Low Cardiac Output Syndrome in Cardiac Surgery.

BACKGROUND: There has been conflicting evidence concerning the effect of levosimendan on clinical outcomes in patients undergoing cardiac surgery. Therefore, we performed a systematic review and conducted this meta-analysis to provide evidence for/against the administration of levosimendan in cardiac surgery patients. METHODS: We performed a meta-analysis from literature search in PubMed, EMBASE, and Cochrane Library. Only randomized controlled trials comparing the administration of levosimendan in cardiac surgery patients with a control group (other inotrope, standard therapy/placebo, or an intra-aortic balloon pump) were included. In addition, at least one clinical outcome had to be mentioned: mortality, myocardial infarction, low cardiac output syndrome (LCOS), acute kidney injury, renal replacement therapy, atrial fibrillation, prolonged inotropic support, length of intensive care unit, and hospital stay. The pooled treatment effects (odds ratio [OR], 95% confidence intervals [CI]) were assessed using a fixed or random effects model. RESULTS: The literature search retrieved 27 randomized, controlled trials involving a total of 3,198 patients. Levosimendan led to a significant reduction in mortality (OR: 0.67; 95% CI: 0.49-0.91; p = 0.0087). Furthermore, the incidence of LCOS (OR: 0.56, 95% CI: 0.42-0.75; p < 0.0001), acute kidney injury (OR: 0.63; 95% CI: 0.46-0.86; p = 0.0039), and renal replacement therapy (OR: 0.70; 95% CI: 0.50-0.98; p = 0.0332) was significantly decreased in the levosimendan group. CONCLUSION: Our meta-analysis suggests beneficial effects for the prophylactic use of levosimendan in patients with severely impaired left ventricular function undergoing cardiac surgery. The administration of levosimendan was associated with a reduced mortality, less LCOS, and restored adequate organ perfusion reflected in less acute kidney injury.

Treatment of cardiogenic shock in peripartum cardiomyopathy: Case series from a tertiary ECMO center.

Peripartum cardiomyopathy (PPCM) occurs toward the end of pregnancy or in the months after delivery without previously known structural heart disease. Development of therapy-refractory cardiogenic shock is described in the literature with a limited number of overall presented cases in this young patient cohort. To provide differences and key points in the therapy of end-stage PPCM patients, we present a case series of four young women with PPCM referred to our department for potential VA ECMO support.