In Vitro Apixaban Removal By CytoSorb Whole Blood Adsorber: An Experimental Study

OBJECTIVES

The use of unopposed oral anticoagulants while undergoing cardiothoracic surgery is associated with severe bleeding and increased morbidity. The aim of this experimental study was to examine if the apixaban concentration in reconstituted blood could be reduced in an in vitro setup by the use of CytoSorb whole blood adsorber, and to study how this affected global coagulation assays.

DESIGN AND SETTING

An experimental study performed in a laboratory.

PARTICIPANTS

An in vitro setup with reconstituted whole blood.

INTERVENTIONS

Reconstituted whole blood spiked with apixaban circulated in an in vitro circuit with the CytoSorb 300 mL device connected.

MEASUREMENTS AND MAIN RESULTS

Blood samples were drawn at 0, 5, 15, 30, 60, and 120 minutes of adsorption. The apixaban concentration was measured at each time point. In addition, the global coagulation assays, thromboelastometry clotting time and thrombin generation, were performed, and the results were compared with baseline values obtained before spiking blood with apixaban. After 30 minutes of adsorption, the mean apixaban concentration was reduced from 414.3 (±69.1) ng/mL to 33 (±11.4) ng/mL. Thrombin generation showed maximum effect after 60 minutes, and the thromboelastometry clotting time was close to baseline values after 120 minutes.

CONCLUSIONS

In this in vitro study, apixaban concentrations were effectively reduced, and the clotting time and thrombin generation assays were normalized by the use of CytoSorb whole blood adsorber.

Operative survival in patients with acute aortic disease in the era of newer oral anticoagulants

Aims

The aim of this study was the analysis of the risk associated with direct oral anticoagulants (DOACs) in patients undergoing non-elective operations on the proximal aorta due to aortic disease.

Methods and results

Data from the department’s register of cardiac surgery was analysed retrospectively with emphasis on operative mortality. 135 non-elective operations for proximal aortic disease (October 2016 to 2018) were identified, of which 19 died during the first 90 days. DOAC use was the top-ranked risk factor in the univariate analysis with a HR of 9.6 (3.1 to 29), p=0.00007. Using a Cox proportional hazards model including the most relevant risk factors, the risk associated with DOAC use remained significant with a HR of 6.1 (1.4 to 26.3), p=0.015. We did not find increased risk associated with warfarin use.

Conclusion

In patients undergoing non-elective operations on the proximal aorta due to aortic disease, the use of DOAC is associated with increased operative mortality.

Short- and long-term survival after isolated coronary artery bypass grafting, the impact of gender and age

Objectives. Assess the short- and long-term survival for patients who underwent isolated coronary artery bypass grafting (CABG) and evaluate the impact of gender and age. Furthermore to assess the long-term survival in the CABG group compared to the general population. Design. This study included 4044 consecutive patients who underwent isolated CABG at Oslo University Hospital, Ullevål, in Oslo, Norway in the time period from 01 January 2003 to 31 December 2015. Patient data was collected retrospectively from the quality register at the department. Information on survival status was obtained from the Norwegian National Registry. Life expectancy data for the general population was gained from Statistics Norway. Results. Female patients were significantly older than male patients at the time of surgery (mean age 67.0 and 63.9 years, respectively, p < .001), and had significantly lower 30-day survival (mortality was 1.4% and 0.6%, respectively, p = .017). Male gender was independently associated with lower long-term survival (p = .0037) in a multivariate analysis. Male patients aged less than 60 years also showed significantly lower long-term survival (SMR = 1.84, 95% CI = 1.49-2.25) compared to the age-matched general population. Among patients older than 60 years, survival was similar to survival in the age-matched general population. Conclusions. Survival was excellent for patients undergoing surgery. Despite increased age and operative mortality, female patients had better adjusted long-time survival than male patients. There was lower long-term survival among male patients aged less than 60 compared to the general population. Our findings may help clinicians in selecting appropriate patients for surgery.

Reduced visfatin levels in aortic stenosis increase after aortic valve replacement and may contribute to reverse left ventricular remodelling

AIM

Visfatin may play a part in reverse left ventricular remodelling. Using a mouse model of reversible left ventricle pressure overload, we examined if visfatin was altered in the myocardium. Furthermore, we addressed this issue in patients with aortic stenosis (AS) and examined whether visfatin levels are related to reverse remodelling following aortic valve replacement (AVR).

METHODS

Myocardial visfatin was analysed after aortic banding (AB) and debanding (DB) in mice and compared to sham operated animals. Myocardial visfatin was measured in biopsies from patients undergoing AVR and compared to controls. Serum visfatin was measured before and after AVR in patients with AS and correlated with echocardiographic measurments of cardiac morphology and function.

RESULTS

Four weeks after AB, myocardial visfatin protein was reduced by 50% compared to sham. Three days after DB, myocardial protein levels increased significantly. Myocardial visfatin and serum visfatin levels were reduced by 23% and 64%, respectively, in patients with AS compared to controls. Twelve months after AVR, serum visfatin levels increased compared to preoperative values and correlated negatively with degree of left ventricular hypertrophy.

CONCLUSION

Myocardial visfatin and serum visfatin levels are reduced by cardiac pressure overload. Visfatin levels increase after correction of pressure overload and may play a part in postoperative reverse remodelling.

[A man in his fifties with syncope and hypotension]

A man in his fifties was admitted to our hospital because of syncope and hypotension. In the emergency room he reported abdominal pain, but focused assessment with sonography for trauma (FAST) was negative. His systolic blood pressure varied between 60 and 90 mmHg and an arterial blood gas revealed lactic acidosis with normal haemoglobin, which still might indicate acute bleeding. An ECG did not indicate myocardial infarction. In the absence of an obvious bleeding focus, the patient was urgently transported to a CT lab nearby, to identify possible bleeding and rule out other causes of circulatory shock, such as cardiac tamponade. Before radiologic scanning was initiated, the patient lost consciousness and displayed pulseless electrical activity. Resuscitation was initiated and pericardiocentesis was resultless. On vital indication and clinical suspicion of cardiac tamponade, an emergency median sternotomy was performed and a haematoma was evacuated from the pericardial space. The patient was stabilised and immediately taken to the operation theatre where a ruptured ascending aortic aneurysm was identified. The operation was successful, but following serious hypoperfusion, the patient suffered acute kidney failure requiring dialysis for several months, gram-negative septicaemia caused by a central venous catheter, cerebral infarction leading to hemiparesis and impaired vision, ventilator-associated pneumonia/acute lung injury and acalculous cholecystitis. This case report describes the findings on admission, the diagnostic process including surgical resuscitation and a complicated course of multi-organ failure. After almost 5 months, the patient was discharged from our hospital to another institution for further rehabilitation. He now has minimal sequelae and lives at home. Our take-home message is that seriously ill patients require fast, resolute and broad examination; they may need immediate surgical treatment including emergency intervention; and a good clinical outcome may be achieved in spite of serious complications.

A mouse model of reverse cardiac remodelling following banding-debanding of the ascending aorta

AIM

Myocardial remodelling during pressure overload might contribute to development of heart failure. Reverse remodelling normally occurs following aortic valve replacement for aortic stenosis; however, the details and regulatory mechanisms of reverse remodelling remain unknown. Thus, an experimental model of reverse remodelling would allow for studies of this process. Although models of aortic banding are widely used, only few reports of debanding models exist. The aim of this study was to establish a banding-debanding model in the mouse with repetitive careful haemodynamic evaluation by high-resolution echocardiography.

METHODS

C57Bl/6 mice were subjected to ascending aortic banding and subsequent debanding. Cardiac geometry and function were evaluated by echocardiography, and left ventricular myocardium was analysed by histology and quantitative real-time polymerase chain reaction.

RESULTS

The degree of aortic banding was controlled by non-invasive estimation of the gradient, and we found a close correlation between left ventricular mass estimated by echocardiography and weight at the time of killing. Aortic banding led to left ventricular hypertrophy, fibrosis and expression of foetal genes, indicating myocardial remodelling. Echocardiography revealed concentric left ventricular remodelling and myocardial dysfunction. Following debanding, performed via a different incision, there was rapid regression of left ventricular weight and normalization of both cardiac geometry and function by 14 days.

CONCLUSIONS

We have established a reproducible and carefully characterized mouse model of reverse remodelling by banding and debanding of the ascending aorta. Such a model might contribute to increased understanding of the reversibility of cardiac pathology, which in turn might give rise to new strategies in heart failure treatment.