Long COVID: Persistent Cardiac and Pulmonary Inflammation Risks

Long COVID presents significant challenges by uncovering complications that extend well beyond the acute phase of SARS-CoV-2 infection. A growing body of research reveals that some patients continue to experience persistent inflammation in heart and lung tissues for up to a year, posing a hidden risk for future complications—even when standard diagnostic tests return normal results.

A study from the Icahn School of Medicine at Mount Sinai demonstrated that cardiac and pulmonary inflammation can linger for months post-infection. Crucially, this inflammation often eludes routine diagnostics, uncovering a form of organ damage that is both discreet and potentially dangerous.

These findings carry major implications. Persistent inflammation in critical organs should be considered a central component of long COVID management, even when baseline evaluations appear unremarkable.

Recognizing that standard tests may not capture ongoing inflammation is key to effective clinical care. The Mount Sinai team, using advanced modalities such as 18F-FDG PET/MRI and dual-energy CT, identified subtle myocardial injury, pericarditis, and lung inflammation that would have gone unnoticed by conventional means.

An independent report from EMJ Radiology echoed these concerns, describing widespread tissue abnormalities in long COVID patients nearly a year after infection resolution. These imaging results suggest that more sensitive diagnostics are urgently needed to inform early intervention strategies.

Beyond biochemical markers, long COVID can lead to structural remodeling of heart and lung tissues. Persistent inflammation is known to contribute to fibrosis, impaired cardiac function, and compromised pulmonary compliance. These changes, often occurring below the detection threshold of routine imaging, may predispose patients to chronic conditions like heart failure and interstitial lung disease.

As advanced imaging continues to reveal these subclinical changes, it becomes increasingly clear that current diagnostic protocols may underestimate the true burden of long COVID–related organ damage.

The risk is compounded by the misleading reassurance of normal test results. Patients with lingering symptoms may be 2.3–2.5 times more likely to develop cardiac complications, even when basic evaluations fail to show abnormalities. These findings highlight the need for a paradigm shift in post-COVID care—one that accounts for invisible yet impactful inflammation.

Guidelines from major institutions like the American College of Cardiology continue to emphasize the value of high-resolution imaging and longitudinal monitoring for these patients, though widespread clinical adoption remains limited.

The persistence of inflammation in long COVID patients underscores the urgent need for refined diagnostic and monitoring strategies. Even when traditional tests appear normal, subtle damage may continue to unfold at the tissue level—especially in the heart and lungs. By proactively integrating advanced imaging, vigilant surveillance, and multidisciplinary care, clinicians can better safeguard long-term outcomes and reduce the future burden of cardiac and pulmonary disease linked to long COVID.