COVID-19-Associated Coagulopathy Is Changing the Way Cardiac Surgeons Think About Haemostasis
Cardiac surgery has always carried a difficult hemostatic balance. Cardiopulmonary bypass can trigger both bleeding and thrombosis through systemic inflammation, endothelial activation, and contact activation of the coagulation cascade, leaving perfusion teams and surgeons to navigate a narrow therapeutic window. A narrative review by Wilkinson, Arjomandi Rad, Oliver, and Kourliouros argues that the pandemic added another layer to that challenge: COVID-19-associated coagulopathy, a hypercoagulable state that has outlasted the acute phase of the pandemic and now belongs in the risk calculus for contemporary cardiac surgery.
The central message is straightforward. COVID-19 did not merely complicate perioperative care during a temporary public health crisis; it altered how clinicians should interpret coagulation risk in the post-pandemic surgical population.
A Hypercoagulable State That Resembles DIC but Does Not Behave Like a Simple Clone
CAC is presented as a prothrombotic syndrome with laboratory and physiologic features that resemble disseminated intravascular coagulation, particularly elevated fibrinogen and D-dimer values. Yet the resemblance is incomplete, and that distinction matters at the bedside. In DIC, clinicians often think in terms of consumptive coagulopathy and rapidly failing hemostatic reserve. CAC, by contrast, reflects a distinct inflammatory-thrombotic state shaped by viral injury, immune activation, and vascular dysfunction.
The review traces several proposed mechanisms. Exaggerated inflammation during infection is one pathway. Antibody proliferation after vaccination is another proposed contributor in the broader discussion of COVID-related hemostatic changes. Direct epithelial injury mediated by angiotensin-converting enzyme 2, together with the concept of “hypoxithrombosis,” further explains why thrombosis can emerge in parallel with microvascular compromise and oxygen debt. None of these mechanisms fully resolves the syndrome, but together they help explain why a patient can appear both inflamed and coagulation-primed at the same time.
This is not an academic distinction. In the operating room, a patient whose coagulation system has already been pushed toward thrombin generation may respond differently to bypass, heparinization, protamine reversal, and post-bypass surveillance than a patient without that background state.
Why Cardiopulmonary Bypass Feels Different in the Post-Pandemic Era
Extracorporeal circulation has always been a biologic stress test. The circuit itself activates complement, induces inflammatory signaling, and exposes blood to nonphysiologic surfaces. During CPB, those effects can combine with pre-existing endothelial dysfunction and systemic inflammation to produce a volatile hemostatic profile. The review argues that CAC provides a useful framework for understanding why some patients may enter surgery with a coagulation system already tilted away from stability.
In practical terms, that means the perioperative team has to think beyond a single coagulation snapshot. Fibrinogen, D-dimer, anticoagulant response, platelet behavior, and viscoelastic profiles may all carry more interpretive weight when a patient has recent or prior COVID-19 exposure, or when the post-pandemic inflammatory background is part of the clinical context. The review does not claim that every patient with prior infection behaves the same way. It does argue that the population-level shift in thromboinflammatory biology is too important to ignore.
A bypass circuit does not care whether the prothrombotic signal came from viral injury, immune activation, or endothelial dysfunction. It amplifies the problem either way.
ECMO Experience Is Informing Cardiac Surgery in Real Time
One of the most useful aspects of the review is its focus on extracorporeal membrane oxygenation, where clinicians had to confront CAC in highly unstable patients and often in real time. ECMO exposed the limits of conventional monitoring and showed why standard laboratory testing alone can be too slow or too narrow for complex extracorporeal support. Experience from that setting now informs the post-pandemic approach to cardiac surgery, especially when patients present with layered risk: recent infection, persistent inflammatory burden, and exposure to circuit-based coagulation activation.
The authors place particular emphasis on monitoring strategies that have gained traction in modern perfusion practice. Anti-Xa assays and viscoelastic testing are discussed as tools that may better capture the dynamic hemostatic state than isolated conventional assays. For surgeons and anesthesiologists, the value is obvious: these tests can reveal whether heparin effect is adequate, whether clot formation is evolving abnormally, and whether transfusion or anticoagulation adjustments should be made before the patient destabilizes.
The review stops short of claiming that these tools solve the problem. It makes a narrower point: they are better aligned with the physiology of extracorporeal circulation than a static, one-size-fits-all laboratory approach.
Alternative Anticoagulation Strategies Are Moving From Theory Toward Relevance
The discussion extends beyond monitoring to pharmacology. Alternative anticoagulants, including factor XI inhibitors, are presented as promising options for future management of coagulation disorders more commonly seen during CPB in the post-pandemic climate. The appeal is mechanistic. If thrombin generation can be moderated more selectively, there may be less collateral bleeding risk while still blunting the pathologic clotting that can emerge on pump.
The review also mentions modulation of heparinase activity as another potential avenue. In a surgical environment where heparin remains foundational but not always perfectly predictable, any strategy that improves control over anticoagulant behavior deserves attention. The goal is not to abandon established practice overnight. It is to refine it in light of a changed biologic environment.
Cardiac surgery teams already know that bleeding and thrombosis can coexist during bypass. CAC sharpens that paradox by adding a systemic hypercoagulable overlay that may persist even after the acute infectious phase has ended.
What This Means for Surgical Selection and Postoperative Vigilance
The most clinically important implication is not a single drug or assay. It is a shift in how risk is framed before, during, and after surgery. Patient selection may need to account more carefully for the hemostatic sequelae of COVID-19, while intraoperative management may require closer attention to anticoagulant effect and clot dynamics. Postoperative care, too, may need a lower threshold for surveillance when coagulation remains unstable or difficult to interpret.
This review is a synthesis, not a trial, and it does not provide a new randomized strategy for changing practice on its own. Even so, it gives cardiac surgery a biologic map for a problem clinicians are already encountering: a post-pandemic cohort in which prior COVID-19 exposure can still shape the coagulation environment around CPB.
The practical challenge now is to translate that map into routine protocols without overreacting to every laboratory abnormality. The review makes the case that the pandemic’s hemostatic lessons are no longer confined to intensive care or ECMO. They now belong in the cardiac operating room as well.