The Silent Threat: How Unaddressed Inflammation Fuels Heart Attacks and Strokes

BAGSVÆRD, Denmark – May 26, 2026 – A major global study has uncovered a pervasive and largely unaddressed threat in cardiovascular medicine: persistent inflammation. The landmark POSEIDON study, sponsored by Novo Nordisk and presented today at the 94th European Atherosclerosis Society (EAS) Congress, revealed that two in five people with established cardiovascular disease have significant cardiovascular inflammation, placing them at a higher risk of heart attack and stroke, even while receiving current standard-of-care treatments.

The findings from the 18,904-patient study highlight a critical gap in modern cardiology. While doctors have become adept at managing traditional risk factors like high cholesterol and blood pressure, this underlying inflammatory risk continues to endanger millions of patients worldwide, signaling an urgent need for a new therapeutic approach.

A Hidden Risk in Modern Cardiology

The POSEIDON study, conducted across 18 countries between 2023 and 2025, is one of the largest contemporary assessments of this inflammatory burden. It found that 40% of patients with atherosclerotic cardiovascular disease (ASCVD), chronic kidney disease (CKD), or heart failure have elevated levels of high-sensitivity C-reactive protein (hsCRP), a key blood marker for inflammation. An hsCRP level of 2 mg/L or higher is recognized by medical guidelines as an independent risk factor for major adverse cardiovascular events.

This “residual inflammatory risk” persists despite patients receiving guideline-recommended therapies. It suggests that the smoldering fire of inflammation within the circulatory system continues to drive disease progression, regardless of how well a patient’s cholesterol or blood pressure is controlled.

"POSEIDON makes clear that inflammation is not a peripheral concern – it is a shared driver of risk affecting millions of patients worldwide with cardiovascular disease who remain vulnerable despite our best current therapies," said Professor Carolyn S.P. Lam, a senior consultant at the National Heart Centre Singapore and a study investigator. "What is striking is the consistency of inflammatory signals across such diverse patient populations. That consistency points to a practical way forward – identifying patients most likely to benefit from therapies that directly target inflammation."

Inflammation plays a central role in the development of atherosclerosis, the process where plaque builds up in arteries. It destabilizes these plaques, making them more likely to rupture and cause a heart attack or stroke. In patients with heart failure or chronic kidney disease, inflammation contributes to disease progression and worsens outcomes, creating a vicious cycle that amplifies cardiovascular risk.

Novo Nordisk's Strategic Pivot Beyond Diabetes

For Novo Nordisk, a company renowned for its dominance in diabetes and obesity care with blockbuster drugs like Ozempic and Wegovy, the POSEIDON study is more than a scientific disclosure—it's a strategic declaration. The findings meticulously lay the groundwork for the company's aggressive expansion into the cardiovascular disease market, a field intrinsically linked to the metabolic conditions it already treats.

The timing is critical. Novo Nordisk is advancing ziltivekimab, an investigational antibody that targets the inflammatory cytokine IL-6, through late-stage clinical trials. The Phase 3 ZEUS trial is specifically studying ziltivekimab's ability to reduce cardiovascular events in patients with ASCVD, chronic kidney disease, and inflammation—the exact population highlighted as high-risk by the POSEIDON study. The study's results effectively define the significant unmet need that ziltivekimab aims to address.

"The POSEIDON study provides critical evidence that cardiovascular inflammation represents a significant source of persistent risk... despite receiving standard of care treatment today," said Filip Knop, chief medical officer at Novo Nordisk. "Understanding the scope of cardiovascular inflammatory risk is essential, as we continue our innovation-driven research to develop a first-in-class therapy with the potential to address this critical unmet need."

This focus on inflammation is part of a broader, multi-billion-dollar push into cardiology. In October 2023, Novo Nordisk acquired ocedurenone, a late-stage drug for uncontrolled hypertension, for $1.3 billion. More recently, in March 2024, it acquired Cardior Pharmaceuticals to gain access to a novel therapy for heart failure. These moves, coupled with the internal development of ziltivekimab, signal a concerted effort to build a powerful and diversified cardiovascular franchise.

The Evolving Science of Heart Disease Prevention

The focus on inflammation represents a significant paradigm shift in cardiology, moving beyond a purely mechanical and lipid-centric view of heart disease. For decades, the primary battle was against cholesterol. Now, inflammation is recognized as a co-conspirator.

This concept was validated by the landmark CANTOS trial, which showed that the anti-inflammatory drug canakinumab could reduce recurrent cardiovascular events, independent of cholesterol lowering. While canakinumab's side effect profile limited its widespread adoption, it provided crucial proof-of-concept. More recently, the repurposed anti-inflammatory drug colchicine received FDA approval for secondary cardiovascular prevention, further cementing the role of anti-inflammatory therapy in routine care.

Leading medical bodies, including the American Heart Association (AHA) and the European Society of Cardiology (ESC), have already incorporated hsCRP into their guidelines as a “risk-enhancing” factor. This allows clinicians to identify patients who may need more intensive preventive strategies. The POSEIDON results reinforce the importance of this measurement and make a strong case for making hsCRP testing a routine part of cardiovascular risk assessment.

Economic and Patient Implications of a Costly Problem

The clinical burden of cardiovascular inflammation is matched by a staggering economic one. Recent research from Danish national health registers revealed that ASCVD and CKD patients with systemic inflammation generate 40% higher healthcare costs than those without. Over a three-year period, this translated to an excess expenditure of nearly €15,000 per patient, driven primarily by hospitalizations.

Addressing this inflammatory risk, therefore, is not only a clinical imperative but also an economic one. Effective anti-inflammatory therapies could potentially reduce hospital admissions, alleviate the strain on healthcare systems, and generate substantial long-term savings.

For patients, these developments offer new hope. The widespread prevalence of inflammatory risk identified by POSEIDON could spur more routine screening with the simple and widely available hsCRP blood test. This would allow for better risk stratification, identifying individuals who remain in the danger zone despite their cholesterol being in check. Ultimately, the successful development of safe and effective inflammation-targeting therapies could usher in a new era of preventative cardiology, offering another layer of protection to finally quiet the silent threat driving so many cardiovascular events.