During the acute phase of COVID-19, many patients experience a complex coagulopathy characterized by a procoagulant pattern. The present study investigates the persistence of hemostatic changes in post-COVID patients at a long-term follow up, and the link with the persistence of physical and neuropsychological symptoms. We completed a prospective cohort study on 102 post-COVID patients. Standard coagulation and viscoelastic tests were performed, along with an assessment of persistent symptoms and recording of acute phase details. A procoagulant state was adjudicated in the presence of fibrinogen > 400 mg/dL, or D-dimer > 500 ng/mL, or platelet count > 450,000 cells/µL, or a maxim clot lysis at viscoelastic test < 2%. A procoagulant state was identified in 75% of the patients at 3 months follow up, 50% at 6 months, and 30% at 12–18 months. Factors associated with the persistence of a procoagulant state were age, severity of the acute phase, and persistence of symptoms. Patients with major physical symptoms carry a procoagulant state relative risk of 2.8 (95% confidence interval 1.17–6.7, p = 0.019). The association between persistent symptoms and a procoagulant state raises the hypothesis that an ongoing process of thrombi formation and/or persistent microthrombosis may be responsible for the main physical symptoms in long-COVID patients.

According to the World Health Organization’s definition, long COVID is the persistence or development of new symptoms 3 months after the initial infection. Various conditions have been explored in studies with up to one-year follow-up but very few looked further. This prospective cohort study addresses the presence of a wide spectrum of symptoms in 121 patients hospitalized during the acute phase of COVID-19 infection, and the association between factors related to the acute phase of the disease and the presence of residual symptoms after one year or longer from hospitalization. The main results are as follows: (i) post-COVID symptoms persist in up to 60% of the patient population at a mean follow-up of 17 months; (ii) the most frequent symptoms are fatigue and dyspnea, but neuropsychological disturbances persist in about 30% of the patients (iii) when corrected for the duration of follow-up with a freedom-from-event analysis; only complete (2 doses) vaccination at the time of hospital admission remained independently associated with persistence of the major physical symptoms, while vaccination and previous neuropsychological symptoms remained independently associated with persistence of major neuropsychological symptoms.

OBJECTIVES: The multifactorial dynamic perfusion index was recently introduced as a predictor of cardiac surgery-associated acute kidney injury. The multifactorial dynamic perfusion index was developed based on retrospective data retrieved from the patient files. The present study aims to prospectively validate this index in an external series of patients, through an on-line measure of its various components. METHODS: Inclusion criteria were adult patients undergoing cardiac surgery with cardiopulmonary bypass. Data collection included preoperative factors and cardiopulmonary bypass-related factors. These were collected on-line using a dedicated monitor. Factors composing the multifactorial dynamic perfusion index are the nadir haematocrit, the nadir oxygen delivery, the time of exposure to a low oxygen delivery, the nadir mean arterial pressure, cardiopulmonary bypass duration, the use of red blood cell transfusions and the peak arterial lactates. RESULTS: Two hundred adult patients were investigated. The multifactorial dynamic perfusion index had a good (c-statistics 0.81) discrimination for cardiac surgery-associated acute kidney injury (any stage) and an excellent (c-statistics 0.93) discrimination for severe patterns (stage 2–3). Calibration was modest for cardiac surgery-associated acute kidney injury (any stage) and good for stage 2–3. The use of vasoconstrictors was an additional factor associated with cardiac surgery-associated acute kidney injury. CONCLUSIONS: The multifactorial dynamic perfusion index is validated for discrimination of cardiac surgery-associated acute kidney injury risk. It incorporates modifiable risk factors, and may help in reducing the occurrence of cardiac surgery-associated acute kidney injury.

Background/Objectives: A low level of soluble coagulation factors after cardiac surgery may cause excessive bleeding and trigger clinical correction using prothrombin complex concentrate (PCC). According to the current guidelines, the trigger values for PCC administration are not defined. In the published algorithms, when driven by ROTEM^®, the triggers vary from 80 s to >100 s of coagulation time (CT) during an EXTEM test. Two randomized controlled trials on fibrinogen (FC) supplementation after cardiac surgery previously pointed out that the patients receiving FC supplementation had a significant decrease in their EXTEM CT. This study investigates the hypothesis that after increasing the availability of a substrate (fibrinogen), thrombin generation induces fibrin network formation faster, and that, before considering PCC administration, the normalization of fibrinogen levels should be sought. Methods: A retrospective study based on a post-hoc analysis of the data collected in two previous RCTs involving 85 patients, all of whom received FC supplementation. Results: The results of this post-hoc analysis demonstrate that there is a significant negative association between FIBTEM maximum clot firmness (MCF) and the EXTEM CTs before and after FC supplementation; FC supplementation decreases the EXTEM CTs both in patients with a low FIBTEM MCF and a normal FIBTEM MCF. After FC supplementation, 45 (53%) of the patients had an EXTEM CT of >80 s, 22 (26%) had an EXTEM CT of >90 s, and 8 (9%) had an EXTEM CT of >100 s. Conclusions: Our study confirms and quantifies the effects of reducing EXTEM CTs through FC supplementation. A stepwise strategy of factors correction with FC supplementation should be used before considering PCC administration as it might reduce the need for PCC.

Objectives: Maintaining a nadir oxygen delivery ≥ 280 mL/min/m2 during cardiopulmonary bypass is a pillar of the goal-directed perfusion strategy in cardiac surgery. However, there are patients who develop a cardiac surgery associated acute kidney injury despite an adequate oxygen delivery and others who do not develop an acute kidney injury despite a low oxygen delivery. The present study aims to determine the independent factors associated with these 2 conditions. Methods: Post-hoc analysis of 2 previously published series. Results: The population size was 1030 patients. Inability to maintain the target oxygen delivery was found in 35% of the patients, and the independent determinants were female gender, low creatinine clearance, low preoperative haematocrit, and non-elective surgery. Acute kidney injury was found in 18.3% of the total patient population. Within the patients with a nadir oxygen delivery < 280 mL/min/m2, 73% did not develop an acute kidney injury. These patients were younger, with a lower baseline serum creatinine, shorter cardiopulmonary bypass, and lower peak lactate. Within the patients with a nadir oxygen delivery ≥ 280 mL/min/m2, 13% developed an acute kidney injury: these patients were older, with a lower baseline haematocrit and longer cardiopulmonary bypass. Conclusions: Preoperative anaemia is the main determinant of a failing goal-directed perfusion. In younger patients at short cardiopulmonary bypass may be possible to reduce the target oxygen delivery. Acute kidney injury in patients with a nadir oxygen delivery ≥ 280 mL/min/m2 is a relatively rare condition whose mechanisms remain to be elucidated.

The currently available point-of-care hemostasis tests are burdened by criticisms concerning the use of different activators and inhibitors and the lack of dynamic flow. These operating conditions may constitute an impediment to the determination of the patient’s hemostatic condition. Hence, the diffusion of these tests in clinical practice is still limited to specific scenarios. In this work, we present a new method for analyzing the patient’s global hemostasis based on the visualization of the main components of the coagulation process and its computerized quantitative image analysis. The automated “Smart Clot” point-of-care system presents a micro-fluidic chamber in which whole blood flows, without the addition of any activator or inhibitor. In this micro-channel, platelet adhesion, activation and aggregation to the type I collagen-coated surface take place (primary hemostasis), leading to the production of endogenous thrombin on the surface of platelet aggregates and the consequent fibrin mesh and thrombus formation (secondary hemostasis). These observations are verified by inhibiting primary hemostasis with the antiplatelet drugs Indomethacin (−70% on platelet aggregation, −60% on fibrin(ogen) formation) and Tirofiban (complete inhibition of platelet aggregation and fibrin(ogen) formation) and secondary hemostasis with the antithrombin drugs Heparin (−70% on platelet aggregation, −80% on fibrin(ogen) formation) and Lepirudin (−80% on platelet aggregation, −90% on fibrin(ogen) formation). Smart Clot, through a single test, provides quantitative results concerning platelet aggregation and fibrin formation and is suitable for undergoing comparative studies with other coagulation point-of-care devices.