Implementation of an epicardial implantable MEMS sensor for continuous and real-time postoperative assessment of left ventricular activity in adult minipigs over a short- and long-term period

The sensing of left ventricular (LV) activity is fundamental in the diagnosis and monitoring of cardiovascular health in high-risk patients after cardiac surgery to achieve better short- and long-term outcome. Conventional approaches rely on noninvasive measurements even if, in the latest years, invasive microelectromechanical systems (MEMS) sensors have emerged as a valuable approach for precise and continuous monitoring of cardiac activity. The main challenges in designing cardiac MEMS sensors are represented by miniaturization, biocompatibility, and long-term stability. Here, we present a MEMS piezoresistive cardiac sensor capable of continuous monitoring of LV activity over time following epicardial implantation with a pericardial patch graft in adult minipigs. In acute and chronic scenarios, the sensor was able to compute heart rate with a root mean square error lower than 2 BPM. Early after up to 1 month of implantation, the device was able to record the heart activity during the most important phases of the cardiac cycle (systole and diastole peaks). The sensor signal waveform, in addition, closely reflected the typical waveforms of pressure signal obtained via intraventricular catheters, offering a safer alternative to heart catheterization. Furthermore, histological analysis of the LV implantation site following sensor retrieval revealed no evidence of myocardial fibrosis. Our results suggest that the epicardial LV implantation of an MEMS sensor is a suitable and reliable approach for direct continuous monitoring of cardiac activity. This work envisions the use of this sensor as a cardiac sensing device in closed-loop applications for patients undergoing heart surgery.

Features and Outcomes of Females and Males Requiring Postcardiotomy Extracorporeal Life Support

BACKGROUND

Although cardiogenic shock requiring extracorporeal life support (ECLS) after cardiac surgery is associated with high mortality, the impact of sex on outcomes of post-cardiotomy ECLS remains unclear with conflicting results in literature. We compare patient characteristics, in-hospital outcomes, and overall survival between females and males requiring post-cardiotomy ECLS.

METHODS

This retrospective, multicentre (34 centres), observational study included adults requiring post-cardiotomy ECLS between 2000 and 2020. Pre-operative, procedural, and ECLS characteristics, complications, and survival were compared between females and males. Association between sex and in-hospital survival was investigated through mixed-Cox proportional hazards models.

RESULTS

This analysis included 1823 patients [females:40.8%; median age:66.0 (interquartile range:56.2-73.0 years)]. Females underwent more mitral (females:38.4%, males:33.1%, p=0.019) and tricuspid (females:18%, males:12.4%, p<0.001) valve surgery, while males had more coronary artery surgery (females:45.9%, males:52.4%, p=0.007). ECLS implantation was more common intra-operatively in females (females:64.1%, males:59.1%) and post-operatively in males (females:35.9%, males:40.9%, p=0.036). Ventricular unloading (females:25.1%, males:36.2%, p<0.001) and intra-aortic balloon pump (females: 25.8%, males:36.8%, p<0.001) were most frequently used in males. Females suffered more post-operative right ventricular failure (females:24.1%, males:19.1%, p=0.016) and limb ischemia (females:12.3%, males:8.8%, p=0.23). In-hospital mortality was 64.9% in females and 61.9% in males (p=0.199) with no differences in 5-year survival (females:20%, 95%CI:17-23; males:24%, 95%CI:21-28;p=0.069). Crude hazard ratio for in-hospital mortality in females was 1.12 (95%CI: 0.99-1.27,p=0.069) and did not change after adjustments.

CONCLUSIONS

This study demonstrates that females and males requiring post-cardiotomy ECLS have different pre-operative and ECLS characteristics, as well as complications, without a statistical difference in in-hospital and 5-year survival.

Age-Related Quality of Life in Cardiac Surgical Patients with Extracorporeal Life Support

BACKGROUND

 The rationale of the study was to analyze the impact of age on quality of life (QoL) in patients who had undergone cardiac surgery with consecutive extracorporeal life support (ECLS) treatment.

METHODS

 The study population consisted of 200 patients, operated upon between August 2006 and December 2018. The patient cohort was divided into two groups following an arbitrary cutoff age of 70 years. Comparative outcome analysis was calculated utilizing the European Quality of Life-5-Dimensions-5-Level Version (EQ-5D-5L).

RESULTS

 A total of 113 patients were 70 years or less old (group young), whereas 87 patients were older than 70 years (group old). In 45.7% of cases, the ECLS system was established during cardiogenic shock and external cardiac massage. The overall survival-to-discharge was 31.5% (n = 63), with a significantly better survival in the younger patient group (young = 38.9%; old = 21.8%, p = 0.01). Forty-two patients (66%) responded to the QoL survey after a median follow-up of 4.3 years. Older patients reported more problems with mobility (y = 52%; o = 88%, p = 0.02) and self-care (y = 24%; o = 76%, p = 0.01). However, the patients' self-rated health status utilizing the Visual Analogue Scale revealed no differences (y = 70% [50-80%]; o = 70% [60-80%], p = 0.38). Likewise, the comparison with an age-adjusted German reference population revealed similar QoL indices. There were no statistically significant differences in the EQ-5D-5L index values related to sex, number of comorbidities, and emergency procedures.

CONCLUSION

 Despite the limited sample size due to the high mortality rate especially in elderly, the present study suggests that QoL of elderly patients surviving ECLS treatment is almost comparable to younger patients.

Sleep-Disordered Breathing, Advanced Age, and Diabetes Mellitus Are Associated with De Novo Atrial Fibrillation after Cardiac Surgery

Background: Postoperative de novo atrial fibrillation (POAF) is one of the most frequently encountered complications following cardiac surgery. Despite the identification of several risk factors, the link between sleep-disordered breathing (SDB) and POAF has barely been examined. The objective of this prospective observational study was to determine whether severe SDB is associated with POAF in patients after elective coronary artery bypass grafting (CABG) surgery. Study design and methods: The incidence and preoperative predictors of in-hospital POAF were assessed in 272 patients undergoing CABG surgery at the University Medical Center Regensburg (Germany). In-hospital POAF was detected by continuous telemetry-ECG monitoring and 12-lead resting ECGs within the first seven postoperative days. POAF that occurred after hospital discharge within 60 days post CABG surgery was classified as post-hospital POAF and was ascertained by standardized phone interviews together with the patients' medical files, including routinely performed Holter-ECG monitoring at 60 days post CABG surgery. The night before surgery, portable SDB monitoring was used to assess the presence and type of severe SDB, defined by an apnea-hypopnea index ≥ 30/h. Results: The incidence of in-hospital POAF was significantly higher in patients with severe SDB compared to those without severe SDB (30% vs. 15%, p = 0.009). Patients with severe SDB suffered significantly more often from POAF at 60 days post CABG surgery compared to patients without severe SDB (14% vs. 5%, p = 0.042). Multivariable logistic regression analysis showed that severe SDB (odds ratio, OR [95% confidence interval, CI]: 2.23 [1.08; 4.61], p = 0.030), age ≥ 65 years (2.17 [1.04; 4.53], p = 0.038), and diabetes mellitus (2.27 [1.15; 4.48], p = 0.018) were significantly associated with in-hospital POAF. After additional adjustment for heart failure, the association between sleep apnea and postoperative atrial fibrillation was attenuated (1.99 [0.92; 4.31], p = 0.081). Conclusions: Amongst established risk factors, severe SDB was significantly associated with in-hospital POAF in patients undergoing CABG surgery. Whether SDB contributes to POAF independently of heart failure and whether risk for POAF may be alleviated by proper treatment of SDB merits further investigation.

The importance of timing in postcardiotomy venoarterial extracorporeal membrane oxygenation: A descriptive multicenter observational study

OBJECTIVES

Postcardiotomy extracorporeal membrane oxygenation (ECMO) can be initiated intraoperatively or postoperatively based on indications, settings, patient profile, and conditions. The topic of implantation timing only recently gained attention from the clinical community. We compare patient characteristics as well as in-hospital and long-term survival between intraoperative and postoperative ECMO.

METHODS

The retrospective, multicenter, observational Postcardiotomy Extracorporeal Life Support (PELS-1) study includes adults who required ECMO due to postcardiotomy shock between 2000 and 2020. We compared patients who received ECMO in the operating theater (intraoperative) with those in the intensive care unit (postoperative) on in-hospital and postdischarge outcomes.

RESULTS

We studied 2003 patients (women: 41.1%; median age: 65 years; interquartile range [IQR], 55.0-72.0). Intraoperative ECMO patients (n = 1287) compared with postoperative ECMO patients (n = 716) had worse preoperative risk profiles. Cardiogenic shock (45.3%), right ventricular failure (15.9%), and cardiac arrest (14.3%) were the main indications for postoperative ECMO initiation, with cannulation occurring after (median) 1 day (IQR, 1-3 days). Compared with intraoperative application, patients who received postoperative ECMO showed more complications, cardiac reoperations (intraoperative: 19.7%; postoperative: 24.8%, P = .011), percutaneous coronary interventions (intraoperative: 1.8%; postoperative: 3.6%, P = .026), and had greater in-hospital mortality (intraoperative: 57.5%; postoperative: 64.5%, P = .002). Among hospital survivors, ECMO duration was shorter after intraoperative ECMO (median, 104; IQR, 67.8-164.2 hours) compared with postoperative ECMO (median, 139.7; IQR, 95.8-192 hours, P < .001), whereas postdischarge long-term survival was similar between the 2 groups (P = .86).

CONCLUSIONS

Intraoperative and postoperative ECMO implantations are associated with different patient characteristics and outcomes, with greater complications and in-hospital mortality after postoperative ECMO. Strategies to identify the optimal location and timing of postcardiotomy ECMO in relation to specific patient characteristics are warranted to optimize in-hospital outcomes.

Mortality on extracorporeal membrane oxygenation: Evaluation of independent risk factors and causes of death during venoarterial and venovenous support

INTRODUCTION

Most patients on extracorporeal membrane oxygenation (ECMO) decease during therapy on the system. However, the actual causes of death have not been studied sufficiently. This study analyses the etiology, prevalence, and risk factors for the outcome variable death during ongoing ECMO for all patients and divided according to venoarterial (VA) or venovenous (VV) support.

METHODS

We retrospectively analysed all patients receiving ECMO support at our institution between March 2006 to January 2021. Only the patients deceased during ongoing support were included.

RESULTS

2016 patients were placed on VA (n = 1168; 58%) or VV (n = 848; 42%) ECMO; 759 patients (37.7%) deceased on support. The causes of death differed between the support types: VA ECMO patients mostly died from cerebral ischemia (34%), low-cardiac output (LCO; 24.1%) and multi-organ failure (MOF; 21.6%), whereas in VV ECMO cases, refractory respiratory failure (28.2%), and sepsis (20.4%) dominated. Multivariate regression analysis revealed cardiopulmonary resuscitation (CPR) and acidosis prior to ECMO as risk factors for dying on VA ECMO, while high inotropic doses pre-ECMO, a high fraction of inspired oxygen on day 1, elevated lactate dehydrogenase, and international normalized ratio levels lead to an unfavourable outcome in VV ECMO patients.

CONCLUSION

Even in highly experienced centers, ECMO mortality remains high and occurs mainly on support or 24 h after its termination. The causes of death differ between VV and VA ECMO, depending on the underlying diseases responsible for the need of extracorporeal support.

On-Support and Postweaning Mortality in Postcardiotomy Extracorporeal Membrane Oxygenation

BACKGROUND

Postcardiotomy venoarterial extracorporeal membrane oxygenation (VA ECMO) is characterized by discrepancies between weaning and survival-to-discharge rates. This study analyzes the differences between postcardiotomy VA ECMO patients who survived, died on ECMO, or died after ECMO weaning. Causes of death and variables associated with mortality at different time points are investigated.

METHODS

The retrospective, multicenter, observational Postcardiotomy Extracorporeal Life Support Study (PELS) includes adults requiring postcardiotomy VA ECMO between 2000 and 2020. Variables associated with on-ECMO mortality and postweaning mortality were modeled using mixed Cox proportional hazards, including random effects for center and year.

RESULTS

In 2058 patients (men, 59%; median age, 65 years; interquartile range [IQR], 55-72 years), weaning rate was 62.7%, and survival to discharge was 39.6%. Patients who died (n = 1244) included 754 on-ECMO deaths (36.6%; median support time, 79 hours; IQR, 24-192 hours), and 476 postweaning deaths (23.1%; median support time, 146 hours; IQR, 96-235.5 hours). Multiorgan (n = 431 of 1158 [37.2%]) and persistent heart failure (n = 423 of 1158 [36.5%]) were the main causes of death, followed by bleeding (n = 56 of 754 [7.4%]) for on-ECMO mortality and sepsis (n = 61 of 401 [15.4%]) for postweaning mortality. On-ECMO death was associated with emergency surgery, preoperative cardiac arrest, cardiogenic shock, right ventricular failure, cardiopulmonary bypass time, and ECMO implantation timing. Diabetes, postoperative bleeding, cardiac arrest, bowel ischemia, acute kidney injury, and septic shock were associated with postweaning mortality.

CONCLUSIONS

A discrepancy exists between weaning and discharge rate in postcardiotomy ECMO. Deaths occurred during ECMO support in 36.6% of patients, mostly associated with unstable preoperative hemodynamics. Another 23.1% of patients died after weaning in association with severe complications. This underscores the importance of postweaning care for postcardiotomy VA ECMO patients.

Predictors of Nocturnal Hypoxemic Burden in Patients Undergoing Elective Coronary Artery Bypass Grafting Surgery

Background: Nocturnal hypoxemia has been linked to increased cardiovascular morbidity and mortality. Several common diseases, such as sleep-disordered breathing (SDB), heart failure (HF), obesity, and pulmonary disease, coincide with an elevated nocturnal hypoxemic burden with and without repetitive desaturations. Research question: This study aimed to evaluate the association of relevant common diseases with distinctive metrics of nocturnal hypoxemic burden with and without repetitive desaturations in patients undergoing coronary artery bypass grafting surgery. Study design and methods: In this subanalysis of the prospective observational study, CONSIDER-AF (NCT02877745) portable SDB monitoring was performed on 429 patients with severe coronary artery disease the night before cardiac surgery. Pulse oximetry was used to determine nocturnal hypoxemic burden, as defined by total recording time spent with oxygen saturation levels < 90% (T90). T90 was further characterized as T90 due to intermittent hypoxemia (T90desaturation) and T90 due to nonspecific and noncyclic SpO2-drifts (T90non-specific). Results: Multivariable linear regression analysis identified SDB (apnea-hypopnea-index ≥ 15/h; B [95% CI]: 6.5 [0.4; 12.5], p = 0.036), obesity (8.2 [2.5; 13.9], p = 0.005), and mild-to-moderate chronic obstructive pulmonary disease (COPD, 16.7 [8.5; 25.0], p < 0.001) as significant predictors of an increased nocturnal hypoxemic burden. Diseases such as SDB, obesity and HF were significantly associated with elevated T90desaturation. In contrast, obesity and mild-to-moderate COPD were significant modulators of T90non-specific. Interpretation: SDB and leading causes for SDB, such as obesity and HF, are associated with an increased nocturnal hypoxemic burden with repetitive desaturations. Potential causes for hypoventilation syndromes, such as obesity and mild-to-moderate COPD, are linked to an increased hypoxemic burden without repetitive desaturations. Clinical Trial Registration: ClinicalTrials.gov identifier: NCT02877745.

Patient and Management Variables Associated With Survival After Postcardiotomy Extracorporeal Membrane Oxygenation in Adults: The PELS-1 Multicenter Cohort Study

Background Extracorporeal membrane oxygenation (ECMO) has been increasingly used for postcardiotomy cardiogenic shock, but without a concomitant reduction in observed in-hospital mortality. Long-term outcomes are unknown. This study describes patients' characteristics, in-hospital outcome, and 10-year survival after postcardiotomy ECMO. Variables associated with in-hospital and postdischarge mortality are investigated and reported. Methods and Results The retrospective international multicenter observational PELS-1 (Postcardiotomy Extracorporeal Life Support) study includes data on adults requiring ECMO for postcardiotomy cardiogenic shock between 2000 and 2020 from 34 centers. Variables associated with mortality were estimated preoperatively, intraoperatively, during ECMO, and after the occurrence of any complications, and then analyzed at different time points during a patient's clinical course, through mixed Cox proportional hazards models containing fixed and random effects. Follow-up was established by institutional chart review or contacting patients. This analysis included 2058 patients (59% were men; median [interquartile range] age, 65.0 [55.0-72.0] years). In-hospital mortality was 60.5%. Independent variables associated with in-hospital mortality were age (hazard ratio [HR], 1.02 [95% CI, 1.01-1.02]) and preoperative cardiac arrest (HR, 1.41 [95% CI, 1.15-1.73]). In the subgroup of hospital survivors, the overall 1-, 2-, 5-, and 10-year survival rates were 89.5% (95% CI, 87.0%-92.0%), 85.4% (95% CI, 82.5%-88.3%), 76.4% (95% CI, 72.5%-80.5%), and 65.9% (95% CI, 60.3%-72.0%), respectively. Variables associated with postdischarge mortality included older age, atrial fibrillation, emergency surgery, type of surgery, postoperative acute kidney injury, and postoperative septic shock. Conclusions In adults, in-hospital mortality after postcardiotomy ECMO remains high; however, two-thirds of those who are discharged from hospital survive up to 10 years. Patient selection, intraoperative decisions, and ECMO management remain key variables associated with survival in this cohort. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03857217.

The Relation Between Obesity and Mortality in Postcardiotomy Venoarterial Membrane Oxygenation

BACKGROUND

Obesity is an important health problem in cardiac surgery and among patients requiring postcardiotomy venoarterial extracorporeal membrane oxygenation (V-A ECMO). Still, whether these patients are at risk for unfavorable outcomes after postcardiotomy V-A ECMO remains unclear. The current study evaluated the association between body mass index (BMI) and in-hospital outcomes in this setting.

METHODS

The Post-cardiotomy Extracorporeal Life Support (PELS-1) study is an international, multicenter study. Patients requiring postcardiotomy V-A ECMO in 36 centers from 16 countries between 2000 and 2020 were included. Patients were divided in 6 BMI categories (underweight, normal weight, overweight, class I, class II, and class III obesity) according to international recommendations. Primary outcome was in-hospital mortality, and secondary outcomes included major adverse events. Mixed logistic regression models were applied to evaluate associations between BMI and mortality.

RESULTS

The study cohort included 2046 patients (median age, 65 years; 838 women [41.0%]). In-hospital mortality was 60.3%, without statistically significant differences among BMI classes for in-hospital mortality (P = .225) or major adverse events (P = .126). The crude association between BMI and in-hospital mortality was not statistically significant after adjustment for comorbidities and intraoperative variables (class I: odds ratio [OR], 1.21; 95% CI, 0.88-1.65; class II: OR, 1.45; 95% CI, 0.86-2.45; class III: OR, 1.43; 95% CI, 0.62-3.33), which was confirmed in multiple sensitivity analyses.

CONCLUSIONS

BMI is not associated to in-hospital outcomes after adjustment for confounders in patients undergoing postcardiotomy V-A ECMO. Therefore, BMI itself should not be incorporated in the risk stratification for postcardiotomy V-A ECMO.

Long-Term Results of Patch Repair in Destructive Valve Endocarditis

OBJECTIVES

Treatment of destructive endocarditis with abscess formation is a surgical challenge and associated with significant morbidity and mortality. A root replacement is often performed in case of an annular abscess. This retrospective study was designed to assess the long-term outcome of extensive debridement and patch reconstruction as an alternative approach.

METHODS

Between November 2007 and November 2016, a selected group of 79 patients (29.6% of all surgical endocarditis cases) with native valve endocarditis (NVE, 53.2%) or prosthetic valve endocarditis (PVE, 46.8%) valve endocarditis underwent surgical therapy with extensive annular debridement and patch reconstruction. Their postoperative course, freedom from recurrent endocarditis, and survival at 1, 5, and 7 years were evaluated.

RESULTS

About two-thirds of patients were in a stable condition, one-third of patients were in a critical state. The median logistic EuroSCORE I was 17%. Infected tissue was removed, and defect closure was performed, either with autologous pericardium for small defects, or with bovine pericardium for larger defects. Overall, in-hospital mortality was 11.3% (NVE: 9.7%, PVE: 13.2%; p = 0.412). In single valve endocarditis survival at 1, 5, and 7 years was 81, 72, 72%, respectively for NVE, and 80, 57, 57%, respectively for PVE (p = 0.589), whereas in multiple valve endocarditis survival at 1, 5, and 7 years was 82, 82, 82% for NVE, and 61, 61, and 31%, respectively for PVE (p = 0.132). Confirmed late reinfection was very low.

CONCLUSION

Surgical treatment of destructive endocarditis with abscess formation using patch repair techniques offers acceptable early and long-term results. The relapse rate was low. PVE and involvement of multiple valves were associated with worse outcomes.

Effects of Atrial Fibrillation on the Human Ventricle

RATIONALE

Atrial fibrillation (AF) and heart failure often coexist, but their interaction is poorly understood. Clinical data indicate that the arrhythmic component of AF may contribute to left ventricular (LV) dysfunction.

OBJECTIVE

This study investigates the effects and molecular mechanisms of AF on the human LV.

METHODS AND RESULTS

Ventricular myocardium from patients with aortic stenosis and preserved LV function with sinus rhythm or rate-controlled AF was studied. LV myocardium from patients with sinus rhythm and patients with AF showed no differences in fibrosis. In functional studies, systolic Ca2+ transient amplitude of LV cardiomyocytes was reduced in patients with AF, while diastolic Ca2+ levels and Ca2+ transient kinetics were not statistically different. These results were confirmed in LV cardiomyocytes from nonfailing donors with sinus rhythm or AF. Moreover, normofrequent AF was simulated in vitro using arrhythmic or rhythmic pacing (both at 60 bpm). After 24 hours of AF-simulation, human LV cardiomyocytes from nonfailing donors showed an impaired Ca2+ transient amplitude. For a standardized investigation of AF-simulation, human iPSC-cardiomyocytes were tested. Seven days of AF-simulation caused reduced systolic Ca2+ transient amplitude and sarcoplasmic reticulum Ca2+ load likely because of an increased diastolic sarcoplasmic reticulum Ca2+ leak. Moreover, cytosolic Na+ concentration was elevated and action potential duration was prolonged after AF-simulation. We detected an increased late Na+ current as a potential trigger for the detrimentally altered Ca2+/Na+-interplay. Mechanistically, reactive oxygen species were higher in the LV of patients with AF. CaMKII (Ca2+/calmodulin-dependent protein kinase IIδc) was found to be more oxidized at Met281/282 in the LV of patients with AF leading to an increased CaMKII activity and consequent increased RyR2 phosphorylation. CaMKII inhibition and ROS scavenging ameliorated impaired systolic Ca2+ handling after AF-simulation.

CONCLUSIONS

AF causes distinct functional and molecular remodeling of the human LV. This translational study provides the first mechanistic characterization and the potential negative impact of AF in the absence of tachycardia on the human ventricle.

Long-term follow-up and quality of life in patients receiving extracorporeal membrane oxygenation for pulmonary embolism and cardiogenic shock

Background

Since 2019, European guidelines recommend considering extracorporeal life support as salvage strategy for the treatment of acute high-risk pulmonary embolism (PE) with circulatory collapse or cardiac arrest. However, data on long-term survival, quality of life (QoL) and cardiopulmonary function after extracorporeal membrane oxygenation (ECMO) are lacking.

Methods

One hundred and nineteen patients with acute PE and severe cardiogenic shock or in need of mechanical resuscitation (CPR) received venoarterial or venovenous ECMO from 2007 to 2020. Long-term data were obtained from survivors by phone contact and personal interviews. Follow-up included a QoL analysis using the EQ-5D-5L questionnaire, echocardiography, pulmonary function testing and cardiopulmonary exercise testing.

Results

The majority of patients (n = 80, 67%) were placed on ECMO during or after CPR with returned spontaneous circulation. Overall survival to hospital discharge was 45.4% (54/119). Nine patients died during follow-up. At a median follow-up of 54.5 months (25–73; 56 ± 38 months), 34 patients answered the QoL questionnaire. QoL differed largely and was slightly reduced compared to a German reference population (EQ5D5L index 0.7 ± 0.3 vs. 0.9 ± 0.04; p  < 0.01). 25 patients (73.5%) had no mobility limitations, 22 patients (65%) could handle their activities, while anxiety and depression were expressed by 10 patients (29.4%). Return-to-work status was 33.3% (average working hours: 36.2 ± 12.5 h/per week), 15 (45.4%) had retired from work early. 12 patients (35.3%) expressed limited exercise tolerance and dyspnea. 59% (20/34) received echocardiography and pulmonary function testing, 50% (17/34) cardiopulmonary exercise testing. No relevant impairment of right ventricular function and an only slightly reduced mean peak oxygen uptake (76.3% predicted) were noted.

Conclusions

Survivors from severe intractable PE in cardiogenic shock or even under CPR with ECMO seem to recover well with acceptable QoL and only minor cardiopulmonary limitations in the long term. To underline these results, further research with larger study cohorts must be obtained.

Sleep-disordered breathing is independently associated with reduced atrial connexin 43 expression

BACKGROUND

Patients with atrial fibrillation (AF) exhibit decreased atrial expression of connexin (Cx), which has been causally linked to a proarrhythmogenic substrate. Interestingly, patients with sleep-disordered breathing (SDB) are at increased risk of AF, but the mechanisms remain unclear.

OBJECTIVE

We tested the hypothesis that patients with SDB have reduced atrial Cx expression independent of important comorbidities.

METHODS

We analyzed right atrial appendage biopsies from 77 patients undergoing coronary artery bypass grafting. Patients were tested for SDB by polygraphy before surgery. Expression of Cx40 and Cx43 messenger RNA was quantified using real-time quantitative polymerase chain reaction and Western blot (Cx43). Structural atrial remodeling was investigated histologically and by quantitative polymerase chain reaction. Postoperative AF was assessed by 12-lead electrocardiography.

RESULTS

Patients were stratified according to apnea-hypopnea index (SDB if apnea-hypopnea index ≥15 per hour, n = 32 vs n = 45). Patients with SDB had significantly lower atrial Cx43 expression, which was negatively correlated with apnea-hypopnea index and oxygen desaturation index. No significant increase in atrial fibrosis or expression of hypertrophy and inflammatory markers was observed. Interestingly, SDB remained the strongest independent predictor of decreased atrial Cx43 expression in a multivariate logistic regression model including age, sex, diabetes, and heart failure with reduced ejection fraction (odds ratio 7.58; 95% confidence interval 1.891-30.375; P = .004). Moreover, reduced atrial Cx43 expression was strongly associated with the occurrence of postoperative AF (odds ratio 15.749; 95% confidence interval 1.072-231.472; P = .044).

CONCLUSION

Patients with SDB exhibited decreased atrial Cx43 expression, which correlated with the severity of SDB. This correlation was independent of several concomitant diseases and may be linked to an increased risk of AF after cardiac surgery.

Case report: Recovery after large intramyocardial dissecting haematoma of the ventricular septum-a rare complication of myocardial infarction

Background

Intramyocardial dissecting haematoma is a rare and potentially life-threatening complication of myocardial infarction (MI). Only a few isolated cases have been reported so far.

Case summary

We report the case of a patient with a large, obstructing intramyocardial haematoma of the ventricular septum following MI due to plaque rupture of the right coronary artery (RCA) and following successful coronary intervention. The clinically inapparent haematoma was discovered during routine echocardiography and confirmed by both computed tomography (CT) and magnetic resonance imaging (MRI). With non-surgical treatment, the patient remained clinically stable. Repeated echocardiography showed gradual regression of the haematoma. Follow-up echocardiography 3 months after the initial diagnosis demonstrated no evidence of septal haematoma.

Discussion

This report suggests that even large intramyocardial haematoma may recede without operative intervention. Echocardiography, CT, and MRI are all helpful in quantifying the size of the haematoma. The appropriate management should be patient-oriented, depending on clinical stability and progression of the haematoma. Conservative treatment in clinically stable patients suffering from septal haematoma following MI and coronary intervention can be a feasible option.

A decade of surgical therapy in an all-comer cohort with type A aortic dissection

BACKGROUND

We reported on a decade of aortic surgery for type A aortic dissection to assess surgical techniques employed and outcomes over time in an all-comer analysis of a mid-size university cardiosurgical center.

METHODS

From 2009 to 2018, 283 patients (189 males and 94 females, mean age 62 years, range 30-85 years), who underwent surgical therapy for type A aortic dissection in our institution were included in a retrospective statistical analysis.

RESULTS

Among all the patients, 55.5% of them were hemodynamically stable, 10.3% came in intubated. A neurological deficit was present in 18.9% of cases, extremity malperfusion was noted in 17.4%, and abdominal malperfusion detected in 8.2%. The extent of the aortic dissection corresponded to DeBakey type I in 88% of cases, a thoracoabdominal involvement was seen in 64%. In 51.9% of patients, only the ascending aorta replaced, another 40.6% of patients had proximal arch replacement too. A separate stent placement into the descending aorta was achieved in 13.4% of patients, during surgery (5.7%) or thereafter (7.7%). Overall survival to discharge was 79.5%. Most frequent complications were stroke and paralysis (15.2%), but only visceral malperfusion (OR 9.0) and heart failure mandating ECMO therapy (OR 29.5) were associated with significantly increased mortality.

CONCLUSIONS

Surgery for type A aortic dissection is still challenging. Along with the refinement of surgical techniques, the indication for the various procedures has moved from a simplified general strategy to a more individualized concept.

The 'Weekend Effect' in adult patients who receive extracorporeal cardiopulmonary resuscitation after in- and out-of-hospital cardiac arrest

Aim

This study investigates the potentially adverse association between extracorporeal cardiopulmonary resuscitation (ECPR) after cardiac arrest on weekends versus weekdays.

Methods

Single-centre, retrospective, stratified (weekday versus weekend) analysis of 318 patients who underwent in-hospital ECPR after out-of-hospital and in-hospital cardiac arrest (OHCA/IHCA) between 01/2008 and 12/2018. Weekend was defined as the period between Friday 17:00 and Monday 06:59.

Results

Seventy-three patients (23%) received ECPR during the weekend and 245 arrests (77%) occurred during the weekday. Whereas survival to discharge did not differ between both groups, long-term survival was significantly lower in the weekend group (p = 0.002). In the multivariate analysis, independent risk factors associated with hospital mortality were no flow time (OR 1.014; 95% CI 1.004–1.023) and serum lactate prior ECPR (OR 1.011; 95% CI 1.006–1.012), whereas each unit serum haemoglobin above average had a protective effect on in-hospital mortality (OR 0.87; 95% CI 0.79–0.96). New onset kidney failure requiring renal replacement therapy occurred more often in the weekend group (30.1% versus 18.4%; p = 0.04). One third of patients experienced complications regardless ECPR was initiated at weekdays or weekends.

Conclusion

Extracorporeal cardiopulmonary resuscitation at weekends adversely seems to impact long-term survival regardless timing (dayshift/nightshift). Duration of CPR and serum lactate prior ECPR were demonstrated as independent risk factors for in-hospital mortality. As ECPR at weekends could not be shown to be an independent outcome predictor a thorough analysis of clinical events subsequent to this intervention is warranted to understand long-term consequences of ECPR initiation after cardiac arrest.

Candida Endocarditis in Patients with Candidemia: A Single-Center Experience of 14 Cases

A retrospective, single-center analysis of 14 cases of Candida endocarditis (from 355 candidemia cases during the years 2012–2019) revealed a high in-hospital mortality (57.1%), a high proportion of healthcare-associated infections (13/14) and a high treatment preference for echinocandins. Transthoracic echocardiography and ¹⁸F-FDG PET/CT had a sensitivity of 54.5% and 57.1%, respectively. Patients were older than previously described and most patients with Candida endocarditis had persistent candidemia for ≥ 3 days despite antifungal therapy.

Extracorporeal Life Support in Postcardiotomy Cardiogenic Shock: A View on Scenario, Outcome, and Risk Factors in 261 Patients

BACKGROUND

Weaning failure from cardiopulmonary bypass, postoperative low cardiac output (LCO), and cardiopulmonary resuscitation (CPR) are common scenarios preceding extracorporeal life support (ECLS) implantation after cardiac surgery. The impact of these scenarios on short- and long-term outcome are not well described.

METHODS

Between March 2006 and December 2018, 261 patients received ECLS support after cardiac surgery. Data of patients with weaning failure (NW), postoperative LCO, and CPR leading to ECLS implantation were retrospectively analyzed regarding outcome. Risk factors for outcome after postcardiotomy ECLS were assessed by uni- or multivariate regression analysis.

RESULTS

Median duration of extracorporeal support was 5.5 ± 8.5 days. Overall mortality on ECLS was 39.1%. Scenario analysis revealed weaning failure from cardiopulmonary bypass in 40.6%, postoperative LCO in 24.5%, and postoperative CPR in 34.9% leading to initiation of ECLS. Most common cause of death was refractory LCO (25.3%). Overall follow-up survival was 23.7%. Survival after weaning and during follow-up in all subgroups was 9.2% (CPR), 5.0% (LCO), and 9.6% (NW), respectively. Uni- or multivariate regression analysis revealed age, aortic surgery, and vasopressor medication level on day 1 as risk for death on support, as well as postoperative renal failure, and body mass index (BMI) as risk factors for death during follow-up.

CONCLUSION

Mortality after postcardiotomy ECLS is high. Overall, outcome after CPR, NW, weaning failure and LCO is comparable. Postoperative resuscitation does not negatively affect outcome after postcardiotomy ECLS. Neurological status of ECLS survivors is good.

Central Sleep Apnea Predicts Pulmonary Complications After Cardiac Surgery

BACKGROUND

Postoperative major pulmonary complications (MPCs) continue to be leading causes of increased morbidity and death after cardiac surgery. Although various risk factors have been identified, reports on the association between sleep-disordered breathing (SDB) and postoperative MPCs remain inconclusive.

RESEARCH QUESTION

What is the incidence of the composite end point postoperative MPCs? What are predictors for postoperative MPCs in patients without SDB, with OSA, and with central sleep apnea (CSA) who undergo cardiac surgery?

STUDY DESIGN AND METHODS

In this subanalysis of the ongoing prospective observational study "Impact of Sleep-disordered breathing on Atrial Fibrillation and Perioperative complications in Patients undergoing Coronary Artery Bypass grafting Surgery (CONSIDER AF)," preoperative risk factors for postoperative MPCs were examined in 250 patients who underwent cardiac surgery. Postoperative MPCs (including respiratory failure, acute respiratory distress syndrome, pneumonia, or pulmonary embolism) were registered prospectively within the first seven postoperative days. Presence and type of SDB were assessed the night prior to surgery with the use of portable SDB-monitoring.

RESULTS

Patients with SDB experienced significantly more often postoperative MPCs than patients without SDB (24% vs 7%; P < .001). Multivariable logistic regression analysis showed that CSA (OR, 4.68 [95% CI, 1.78-12.26]; P = .002), heart failure (OR, 2.65 [95% CI, 1.11-6.31]; P = .028), and a history of transient ischemic attack or stroke (OR, 2.73 [95% CI, 1.07-6.94]; P = .035) were associated significantly with postoperative MPCs. Compared with patients without MPCs, those with postoperative MPCs had a significantly longer hospital stay (median days, 9 [25th/75th percentile, 7/13] vs 19 [25th/75th percentile, 11/38]; P < .001).

INTERPRETATION

Among established risk factors for postoperative MPCs, CSA, heart failure, and history of transient ischemic attack or stroke were associated significantly with postoperative MPCs. Our findings contribute to the identification of patients who are at high-risk for postoperative MPCs.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02877745.

Increasing use of the Impella®-pump in severe cardiogenic shock: a word of caution

Impella® pumps are increasingly utilized in patients in cardiogenic shock. We report on a case series where Impella support was insufficient, and a switch to venoarterial extracorporeal membrane oxygenation (VA ECMO) became necessary. ECMO patients with previous Impella devices were identified utilizing our institutional ECMO database. Since 2014, 10 patients with a mean age of 62 ± 3 years were identified. Despite correct placement of all Impella pumps, cardiogenic shock persisted with progressive multi-organ failure (Impella type 2.5/CP n = 6/4 patients). Femoro-femoral VA ECMO was implanted percutaneously on the contralateral side with the Impella initially left on standby but retracted into the descending aorta for transport reasons after a mean support time of 20 ± 8 h. All patients were able to unload their heart by left ventricular ejection with a blood pressure amplitude of 15 ± 3 mmHg on VA ECMO support. After VA ECMO implantation haemodynamic parameters improved significantly within 24 h of support (mean serum lactate levels decreased from 92 ± 17 to 44 ± 10 mg/dl, P = 0.031). Survival to hospital discharge was 70%. These data indicate that the Impella 2.5® and CP® might not be sufficient in profound cardiogenic shock. Comparative studies are necessary to specify which patient population benefits from which type of circulatory support.

Enhanced CaMKII-Dependent Late I Na Induces Atrial Proarrhythmic Activity in Patients With Sleep-Disordered Breathing

Rationale:

Sleep-disordered breathing (SDB) is frequently associated with atrial arrhythmias. Increased CaMKII (Ca/calmodulin-dependent protein kinase II) activity has been previously implicated in atrial arrhythmogenesis.

Objective:

We hypothesized that CaMKII-dependent dysregulation of Na current (I Na ) may contribute to atrial proarrhythmic activity in patients with SDB.

Methods and Results:

We prospectively enrolled 113 patients undergoing elective coronary artery bypass grafting for cross-sectional study and collected right atrial appendage biopsies. The presence of SDB (defined as apnea-hypopnea index ≥15/h) was assessed with a portable SDB monitor the night before surgery. Compared with 56 patients without SDB, patients with SDB (57) showed a significantly increased level of activated CaMKII. Patch clamp was used to measure I Na . There was a significantly enhanced late I Na , but reduced peak I Na due to enhanced steady-state inactivation in atrial myocytes of patients with SDB consistent with significantly increased CaMKII-dependent cardiac Na channel phosphorylation (Na V 1.5, at serine 571, Western blotting). These gating changes could be fully reversed by acute CaMKII inhibition (AIP [autocamtide-2 related inhibitory peptide]). As a consequence, we observed significantly more cellular afterdepolarizations and more severe premature atrial contractions in atrial trabeculae of patients with SDB, which could be blocked by either AIP or KN93 (N-[2-[[[(E)-3-(4-chlorophenyl)prop-2-enyl]-methylamino]methyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulfonamide). In multivariable linear regression models incorporating age, sex, body mass index, existing atrial fibrillation, existing heart failure, diabetes mellitus, and creatinine levels, apnea-hypopnea index was independently associated with increased CaMKII activity, enhanced late I Na and correlated with premature atrial contraction severity.

Conclusions:

In atrial myocardium of patients with SDB, increased CaMKII-dependent phosphorylation of Na V 1.5 results in dysregulation of I Na with proarrhythmic activity that was independent from preexisting comorbidities. Inhibition of CaMKII may be useful for prevention or treatment of arrhythmias in SDB.

Clinical Trial Registration:

URL: http://www.clinicaltrials.gov . Unique identifier: NCT02877745.

Visual Overview:

An online visual overview is available for this article.

P3508A novel mouse model of sleep-disordered breathing is associated with contractile dysfunction and CaMKII overexpression

Background

Patients with sleep-disordered breathing (SDB) develop arrhythmias and contractile dysfunction, but the mechanisms are poorly understood, possibly due to the lack of mouse models that mimic airway obstruction in spontaneously sleeping mice. Interestingly, New Zealand obese mice have been shown to develop airway obstruction with inspiratory flow limitation resulting in apneas, but these mice also develop diabetes.

Purpose

We developed a novel mouse model of increased airway obstruction in spontaneously sleeping lean mice and investigated the impact on sleep-related apneas and contractile function.

Methods and results

Male C57BL6 mice at 8–12 weeks of age were subjected to polytetrafluoroethylene (PTFE) injection (100 μl) into the tongue. This resulted in an increased tongue volume and reduced pharyngeal luminal diameter. Conscious mice behave normal and there was no difference in body weight between PTFE injected mice and untreated littermates (control). Whole body plethysmography was used to monitor spontaneous breathing for 8h in a quiet environment. Interestingly, compared to control, mice with PTFE injection showed a significantly increased frequency of apneas (lasting >1s, fig. A, * indicated P<0.05, t-test). Echocardiographic analysis revealed that ejection fraction was significantly reduced in PTFE-treated mice 8 weeks after surgery (vs. control, fig. B). In accordance, the developed force of isolated papillary muscles from hearts of PTFE mice was significantly reduced compared to control (fig. C). Ca/calmodulin-dependent protein kinase II (CaMKII) has been implicated in the development of heart failure. Intriguingly, compared to control, CaMKII expression was significantly increased in ventricular heart homogenates of PTFE-treated mice (fig. D). Moreover, the magnitude of CaMKII overexpression correlated significantly with the frequency of apneas (fig. E). Papillary muscle post-pause contractions can be used as measure of diastolic sarcoplasmic reticulum (SR) Ca leak, which is known to be enhanced by CaMKII. Compared to control, post-pause contraction amplitude was significantly smaller in PTFE-treated mice, indicating an increased SR Ca leak (fig. F).

Figure 1

Conclusion

PTFE injection in mice results in an increased frequency of spontaneous apneas. PTFE-treated mice develop mild contractile dysfunction, which is accompanied by CaMKII overexpression. This novel mouse model offers great opportunities for investigation of sleep-related breathing disorders.

Acknowledgement/Funding

This study was supported by the Medical Faculty of the University of Regensburg (ReForM programme).

Predictors of delirium after cardiac surgery in patients with sleep disordered breathing

Introduction

Delirium ranks among the most common complications after cardiac surgery. Although various risk factors have been identified, the association between sleep disordered breathing (SDB) and delirium has barely been examined so far. Here, our objectives were to determine the incidence of post-operative delirium and to identify the risk factors for delirium in patients with and without SDB.

Methods

This subanalysis of the ongoing prospective observational study CONSIDER-AF (ClinicalTrials.govidentifierNCT02877745) examined risk factors for delirium in 141 patients undergoing cardiac surgery. The presence and type of SDB were assessed with a portable SDB monitor the night before surgery. Delirium was prospectively assessed with the validated Confusion Assessment Method for the Intensive Care Unit on the day of extubation and for a maximum of 3 days.

Results

Delirium was diagnosed in 23% of patients: in 16% of patients without SDB, in 13% with obstructive sleep apnoea and in 49% with central sleep apnoea. Multivariable logistic regression analysis showed that delirium was independently associated with age ≥70 years (OR 5.63, 95% CI 1.79–17.68; p=0.003), central sleep apnoea (OR 4.99, 95% CI 1.41–17.69; p=0.013) and heart failure (OR 3.3, 95% CI 1.06–10.35; p=0.039). Length of hospital stay and time spent in the intensive care unit/intermediate care setting were significantly longer for patients with delirium.

Conclusions

Among the established risk factors for delirium, central sleep apnoea was independently associated with delirium. Our findings contribute to identifying patients at high risk of developing post-operative delirium who may benefit from intensified delirium prevention strategies.

Anaesthesia-related complications and side-effects in TAVI: a retrospective study in Germany

OBJECTIVES

This study was performed to analyse anaesthesia-related complications and side effects in patients undergoing transcatheter aortic valve implantation (TAVI) under general anaesthesia.

DESIGN

Retrospective study.

SETTING

The study was performed as a single-centre study in a hospital of tertiary care in Germany.

PARTICIPANTS

All 853 patients, who underwent TAVI at the Universitätsklinikum Regensburg between January 2009 and July 2015, were included. 52.5% were female patients.

PRIMARY AND SECONDARY OUTCOME MEASURES

We gathered information, such as recent illness, vital parameters and medication administered during the intervention and postoperatively for 12 hours. We analysed all anaesthesia-related complications and anaesthesia-related side effects that occurred during the intervention and entire hospital stay.

RESULTS

We analysed all 853 TAVI procedures. The mean patient age was 79 ± 6 years. In 99.5% of cases, we used volatile-based anaesthesia. 2.8% (n=24; transfemoral (TF): n=19 [3.8%]; transapical (TA): n=5 [1.4%]) of all cases suffered from anaesthesia-related complications. 819 (TF: n=447; TA: n=372) anaesthesia-related side effects occurred in 586 (68.7%, TF: n=325 [64.2%], TA: n=261 [75.2%]) patients. Neither the complications nor the side effects had any serious consequences. Intraoperative hypothermia in 44% of cases (TF: n=202 [39.9%]; TA: n=173 [49.9%]) and postoperative nausea and vomiting in 27% (n=232; TF: n=131 [25.9%], TA: n=101 [29.1%]) of cases were the most common anaesthesia-related side effects.

CONCLUSION

In this study, serious anaesthesia-related complications were rarely seen, and non-critical anaesthesia-related side effects could have been avoided through consistent prophylaxis and management. Therefore, despite their high anaesthetic risk, general anaesthesia is justifiable in patients who underwent TAVI.

Double, triple and quadruple cannulation for veno-arterial extracorporeal membrane oxygenation support: is there a limit?

Each cannulation strategy for venoarterial extracorporeal membrane oxygenation (VA ECMO) has distinct benefits and drawbacks. In this article, various cannulation strategies including their indications are discussed. The gold standard for cannulation involves peripheral, percutaneous double cannulation utilizing the patient's femoral vein and artery. In emergency situations under mechanical resuscitation, a simple and fast cannulation technique is crucial to reestablish circulation. This is usually performed percutaneously utilizing the femoral approach. However, in cases of anticipated long-term support, such as while awaiting cardiac transplantation, more sophisticated cannulation techniques (e.g., internal jugular vein to left axillary artery, left axillary artery for neuroprotection) are necessary to facilitate mobilization and physical conditioning on VA ECMO. More complicated are cases involving combined respiratory and cardiac failure requiring dual organ support or triple cannulation with an additional venous return cannula resulting in a veno-arterio-venous (VAV) configuration. Cases with left ventricular stasis with need for unloading are also highly demanding. Unloading the left ventricle (LV) can be performed in numerous ways, described elsewhere in this issue. However, one particular mode of unloading the LV is described as a stepwise and cost saving bridge to a durable paracorporeal left ventricular assist device in patients with an uncertain prognosis, which involves implantation of Berlin Heart^® EXCOR cannulas with temporary right heart support as an example of quadruple cannulation.

Conventional or minimized cardiopulmonary bypass support during coronary artery bypass grafting? - An analysis by means of perfusion and body mass index

The use of minimized cardiopulmonary bypass support to reduce the side effects of extracorporeal circulation is still contradictorily discussed. This study compares perfusion operated by conventional (CCPB) and minimized (MCPB) cardiopulmonary bypass support during coronary artery bypass grafting (CABG). This study includes the data of 5164 patients treated at our department between 2004 and 2014. Tissue perfusion during cardiopulmonary bypass support and cardiac arrest was assessed by means of body mass index, hemodilution, blood pressure with corresponding pump flow and venous oxygen saturation, serum lactate, and serum pH. Hemodilution was more pronounced after CCPB: hemoglobin had dropped to 4.47 ± 0.142 g/dL after CCPB and to 2.77 ± 0.148 g/dL after MCPB (P = 0.0022). Despite the higher pump flow in conventional circuits (4.86-4.95 L/min vs. 4.1-4.18 L/min), mean blood pressure was higher during minimized bypass support (53 ± 10 vs. 56 ± 13 mm Hg [aortic clamping], 57 ± 9 vs. 61 ± 12 mm Hg [34°C], 55 ± 9 vs.59 ± 11 mm Hg [aortic clamp removal], P < 0.0001) at all time points. Venous oxygen saturation remained on comparable levels of >70% during both conventional and minimized cardiopulmonary bypass support. The increase in serum lactate was more pronounced after CCPB (8.98 ± 1.28 vs. 3.66 ± 1.25 mg/dL, P = 0.0079), corresponding to a decrease in serum pH to acidotic levels (7.33 ± 0.06 vs. 7.35 ± 0.06, P < 0.0001). These effects were evident in all BMI ranges. Minimized cardiopulmonary bypass support provides efficient perfusion in all BMI ranges and is thus equivalent to conventional circuits.

Postoperative complications after elective coronary artery bypass grafting surgery in patients with sleep-disordered breathing

BACKGROUND

Sleep-disordered breathing (SDB) may increase the risk of postoperative complications in patients after cardiac surgery. This study evaluated the length of hospital stay as well as postoperative cardiac, respiratory, and renal complications after elective coronary artery bypass grafting (CABG) in patients without SDB, with central sleep apnea (CSA), or with obstructive sleep apnea (OSA).

METHODS

The presence and type of SDB had been assessed with polygraphic recordings in 100 patients the night before elective CABG surgery. SDB was defined as an apnea-hypopnea index (AHI) of ≥ 15/h. Prolonged length of hospital stay (LOS) and postoperative hemodynamic instability due to any cause were retrospectively evaluated as primary endpoints and cardiac, respiratory, and renal complications as secondary endpoints.

RESULTS

37% of patients had SDB, 14% CSA, and 23% OSA. LOS differed significantly between patients without SDB and those with CSA and OSA [median (25;75. percentile): 8.0 days (7.5;11.0) vs. 9.5 days (7.0;12.5) vs. 12.0 days (9.0;17.0), Kruskal-Wallis test between three groups: p = 0.023; OSA vs. no SDB: p = 0.005]. AHI was significantly associated with prolonged LOS [> 9 days; odds ratio (OR) (95% confidence interval): 1.047 (1.001;1.095), p = 0.044]. Prolonged need of vasopressors (≥ 48 h) was observed in 36% of patients without SDB, in 64% with CSA, and in 62% with OSA (p = 0.037). AHI was significantly associated with prolonged (≥ 48 h) need of vasopressors [OR (95% CI): 1.052 (1.002;1.104), p = 0.040], independent of any confounders.

CONCLUSIONS

SDB, particularly OSA, is associated with prolonged LOS after CABG, independent of known confounders. Prolonged LOS in patients with SDB may be due to increased postoperative hemodynamic instability due to any cause.

Long-term survival and quality of life after extracorporeal life support: a 10-year report

OBJECTIVES

Information is lacking about long-term survival and quality of life (QOL) after treating patients on extracorporeal life support.

METHODS

Outcome data were assessed by phone interviews, a QOL analysis using the EuroQol 5-dimensions questionnaire and a retrospective inquiry of the Regensburg ECMO Registry database for the decade 2006-2015. A statistical analysis was obtained by comparing patients with a cardiosurgical intervention (CS = 189 patients) with those without (w/oCS = 307 patients).

RESULTS

Survival to discharge in the w/oCS group was higher than that in the CS group (w/oCS: 41.7% vs CS: 29.5%; P  = 0.004). A Kaplan-Meier analysis showed a significant difference between both groups in favour of patients w/oCS (log rank P  = 0.02). This difference was no longer statistically significant after propensity score matching ( P  = 0.07). The 1- and 2-year survival rates of discharged patients were 67% and 50% in the w/oCS group vs 60% and 45% in the CS group (log rank P  = 0.29). Eighty-two patients answered the QOL questionnaire after a mean follow-up time of 4.2 ± 2.9 years. A total of 75% could handle their daily life; 57% were not limited in their usual activities. Mobility impairment was noted in 50%; 25% returned to work or school. There were no differences in the EuroQol 5-dimension indices between the patient groups. However, compared to a normative age-matched population, significantly lower indices were calculated.

CONCLUSIONS

Long-term survival rates in patients requiring extracorporeal life support are acceptable with a probable advantage for patients without an operation and a narrowed QOL. The results are promising and encouraging, but there is also a need for improvement.

Further options and survival results after failure following extracorporeal life support implantation

BACKGROUND

A retrospective study was designed to analyze the outcome of patients with extracorporeal life support (ECLS) who needed a consecutive cardiac or pulmonary support system.

METHODS

From 2006 to 2016, 93 out of 587 patients with their age ranging from 2.4 to 77.3 years required an exchange of an ECLS by another mechanical support system. Sixty-one patients were inhospital cases, 39 patients were referred with ECLS from other institutions by ambulance car (N.=15) or helicopter (N.=24). Sixty-five patients came from internal medicine wards, of which 38 patients had CPR, whereas 24 patients suffered postcardiotomy failure with CPR in 11 cases. Ten patients were referred from other hospitals for failure to wean from ECLS.

RESULTS

Leading symptoms were continuing cardiac failure in 43 patients (46%) and ongoing respiratory failure after cardiac recovery in 50 patients (54%). Patients with cardiac failure underwent implantation of a ventricular assist device (N.=36) or remained on long-term ECLS (N.=7) until a donor organ for heart transplantation was available (mean waiting time 43 days). Respiratory failure was treated by veno-venous ECMO (N.=34) or vav-ECMO (N.=16). Overall inhouse survival was 50.5% (N.=47). Only 22.6% of patients (N.=21) died during ongoing support. In contrast, 26.9% of patients (N.=25) deceased 35+/-51 days after weaning from vv- or vav-ECMO. Major reasons of death were multi-organ failure in 16 patients, cerebral hypoxia in 12 patients, sepsis in 10 patients, and intractable ow output in 5 patients.

CONCLUSIONS

Despite a switch from ECLS to another mechanical support system, survival remains limited as irreversible multi-organ failure and sepsis still jeopardize the patients' life.

Perforation of myocardial wall and great vessels after cardiovascular interventions-a 5-year analysis

Background

Less invasive procedures have replaced open surgical treatment in many cardiovascular disorders. During these interventions, iatrogenic cardiac perforation may ensue, which is a severe complication and requires immediate diagnostic assessment and treatment.

Methods

From March 2011 to April 2016, all patients referred to the Dept. of Cardio-thoracic Surgery with the diagnosis of iatrogenic perforation of myocardial wall or great vessels were included into the retrospective study. Complications during transapical transcutaneous aortic valve replacements (TAVR) procedures and percutaneous coronary intervention (PCI) were excluded from analysis. Symptoms, therapeutic strategy, intraoperative findings, and outcome were evaluated.

Results

Forty-four patients suffered from myocardial wall or vessel perforation. Most common site of perforation were right (n=26; 59.1%) and left (n=8; 18.2%) ventricle. Other structures were involved in ten cases (22.7%). Open surgical treatment was required in 27 cases (61.4%). Mortality after left and right ventricular laceration was 75.0% and 11.5%, respectively. Most common cause of death was cardiocirculatory failure (n=5).

Conclusions

Iatrogenic perforation of myocardial wall or central vessels during percutaneous interventional procedures is a rare but life-threatening complication. Despite immediate treatment efforts, mortality is high, particularly after left ventricular laceration.

NSE serum levels in extracorporeal life support patients-Relevance for neurological outcome?

BACKGROUND

Good neurological outcome is a major determinant after cardiac resuscitation. Extracorporeal life support may rapidly stabilize the patient, but cerebral ischemia remains a frequent complication relevant for further therapy. The aim of this study was to prove the value of NSE to indicate cerebral injury in patients with extracorporeal support after CPR.

METHODS

159 patients with CPR were included. NSE 48h peak levels and trends were tested for usability as predictive marker of brain injury, in-hospital mortality and long-term outcome.

RESULTS

Overall mortality in this cohort was 53.5%. Incidence of relevant brain injury was 34.6% with severe diffuse hypoxia in 23.2%. NSE peaks were comparable in patients with and without focal ischemia, but were increased in patients with severe diffuse hypoxic injury (p<0.0001). ROC analysis (area under the curve) of peak values indicating brain injury and in-hospital mortality was 0.73 (95% confidence interval [CI] 0.65-0.82) and 0.74 (95% CI 0.66-0.81), respectively. NSE increased in 56.6% of patients with a sensitivity of 0.82 (95% CI 0.69-0.92) and a specificity of 0.43 (CI 0.0.31-0.55) indicating cerebral injury. Sensitivity and specificity of NSE peak levels >100μg/L was 0.6 (CI 0.49-0.72) and 0.74 (CI 0.63-0.84). In-hospital mortality of patients with NSE >100μg/L was 71.7%. 46.2% of discharged patients are in good neurological status (cerebral performance category scale [CPC] 1-2). Patients with NSE <100μg/L showed an in-hospital mortality of 36.4%, and good neurological status in 67.9%.

CONCLUSION

NSE monitoring reliably indicates relevant cerebral injury in patients on extracorporeal support after cardiopulmonary resuscitation.

Reduction of INCOR® driveline infection rate with silicone at the driveline exit site

Objectives

A silicone interface at skin level of left ventricular assist device (LVAD) may reduce the risk of driveline (DL) exit site infections when compared with other materials (e.g. velour). The purpose of this study was to evaluate the rate of DL exit site infection according to the presence of silicone or velour at the exit site with the redesigned INCOR, facilitating the positioning of silicone at the exit site.

Methods

The rate of DL exit site infection and overall survival were compared between the two groups (silicone group, n = 16/velour group, n = 24) with 1-year follow-up postimplantation.

Results

Risk factors for infection were more prevalent in the silicone group (obesity P = 0.33, prevalence of renal dysfunction P = 0.007, higher CRP levels P = 0.001). During the observation period, 6 patients developed a DL infection (25%) in the velour group, whereas 1 patient developed a DL infection in (6%) in the silicone group (P = 0.19). The event-per-patient year (EPPY) rates were 0.34 and 0.10 for velour group and silicone group, respectively (P = 0.30). All DL infections could be treated successfully by the antibiotic treatment, surgical debridement and ultimately high urgency heart transplantation, resulting in no direct DL infection-related mortality in this cohort. One-year survival was similar in both the groups (silicone 69 vs 75% in the velour group; P = 0.67).

Conclusions

Fewer infections were observed at the exit site in case of a silicone-covered DL, without reaching statistical significance. More patients and longer observation periods are needed to demonstrate a statistical difference.

Pericardiectomy for Constrictive Pericarditis: An Institution's 21 Years Experience

Background The aim of this retrospective study was to evaluate our experience with the surgical pericardiectomy procedure for patients suffering from isolated severe constrictive pericarditis.

Methods From 1995 to 2016, 39 patients underwent isolated pericardiectomy for constrictive pericarditis. Fifteen patients were excluded because of concomitant surgery. There were 31 male (79.5%) patients and 8 female (20.5%) patients, 28 to 76 years old (mean, 56.6 ± 13.6 years). The underlying etiologies were idiopathic pericarditis (74.5%), infection (10%), rheumatic disorders (8%), status post cardiac surgery (2.5%), tuberculosis (2.5%), and status post mediastinal irradiation (2.5%).

Results Pericardiectomy was performed through midline sternotomy in all cases. Sixteen patients (41%) underwent pericardiectomy electively employing cardiopulmonary bypass with the heart beating, and 23 patients (59%) had surgery without extracorporeal circulation (ECC). The overall 30-day mortality rate was 50% if cardiopulmonary bypass was used (13.8% since 2007). If surgery was performed without a heart–lung machine, mortality was 0%. On-pump patients had a significantly longer intensive care unit (ICU) stay (12 ± 9 vs. 4 ± 4 days, p = 0.013). Likewise, the duration of mechanical ventilation was much longer (171 ± 246 vs. 21 ± 40 hours, p = 0.04). The hospital stay was comparable with 28 ± 10 and 24 ± 18 days (p = 0.21).

Conclusion The present study demonstrates that pericardiectomy, without the use of cardiopulmonary bypass as treatment for constrictive pericarditis, is a safe procedure with an excellent outcome in critically ill patients.

Frontiers of robotic endoscopic capsules: a review

Digestive diseases are a major burden for society and healthcare systems, and with an aging population, the importance of their effective management will become critical. Healthcare systems worldwide already struggle to insure quality and affordability of healthcare delivery and this will be a significant challenge in the midterm future. Wireless capsule endoscopy (WCE), introduced in 2000 by Given Imaging Ltd., is an example of disruptive technology and represents an attractive alternative to traditional diagnostic techniques. WCE overcomes conventional endoscopy enabling inspection of the digestive system without discomfort or the need for sedation. Thus, it has the advantage of encouraging patients to undergo gastrointestinal (GI) tract examinations and of facilitating mass screening programmes. With the integration of further capabilities based on microrobotics, e.g. active locomotion and embedded therapeutic modules, WCE could become the key-technology for GI diagnosis and treatment. This review presents a research update on WCE and describes the state-of-the-art of current endoscopic devices with a focus on research-oriented robotic capsule endoscopes enabled by microsystem technologies. The article also presents a visionary perspective on WCE potential for screening, diagnostic and therapeutic endoscopic procedures.