Fibrotic Lung Abnormalities Linked to Increased Coronary Artery Calcification

Incidental Interstitial Findings and Systemic Vascular Risk

Low-dose computed tomography for lung cancer screening frequently identifies incidental findings beyond pulmonary nodules, most notably interstitial lung abnormalities. These parenchymal changes, which may represent early-stage interstitial lung disease, are present in approximately 7% of screening cohorts and are associated with a three-fold increase in mortality risk (odds ratio 3.56; 95% CI, 2.19 to 5.81) [1, 2]. Beyond primary respiratory decline, patients with these abnormalities experience significantly higher rates of hospitalizations for cardiovascular (hazard ratio 1.8; 95% CI, 1.3 to 2.6) and malignant diseases [3]. While the prognostic significance of interstitial lung abnormalities regarding overall survival is well-documented, the specific relationship between these lung changes and subclinical coronary artery disease remains a critical area of investigation [2, 4]. A retrospective cohort study of 2,031 participants now examines how the presence and fibrotic nature of these abnormalities correlate with coronary artery calcification (a marker of subclinical atherosclerosis measured by calcium deposits in the vessel walls) and clinical cardiovascular outcomes [5].

Screening Cohort Characteristics and Radiologic Assessment

The researchers conducted a retrospective analysis of 2,031 participants enrolled at a single institution through the Korean National Lung Cancer Screening Program between September 2019 and January 2024. The cohort had a mean age of 61.4 years and was predominantly male, with only 54 women included in the final analysis. This demographic distribution reflects the specific high-risk smoking population targeted by the national screening initiative, providing a focused look at patients who often present with multiple comorbidities related to tobacco use.

To evaluate the presence of interstitial lung abnormalities, three radiologists utilized a modified sequential reading process. This standardized approach involved scoring findings on a scale where 0 represented no abnormality, 1 indicated equivocal findings, and 2 confirmed the presence of an interstitial lung abnormality. Beyond this initial identification, the radiologists further classified the abnormalities into specific types, such as non-fibrotic or fibrotic variants. This detailed categorization allowed the investigators to distinguish between simple inflammatory changes and more advanced architectural distortion within the lung parenchyma.

The study also quantified subclinical cardiovascular disease by assessing coronary artery calcification. The researchers graded and dichotomized calcification severity into two clinical groups: none or mild versus moderate or severe. To determine the clinical relevance of these radiologic markers, the authors tracked major adverse cardiovascular events, such as myocardial infarction or stroke, by reviewing patient data within electronic medical records. This methodology enabled a direct comparison between incidental computed tomography findings and subsequent hard clinical outcomes.

Correlation Between Fibrotic Lung Changes and Calcium Burden

Within the screening cohort of 2,031 participants, the researchers found that interstitial lung abnormalities were present in 4.1% of participants, while coronary artery calcification was identified in 49.2% of the total population. These baseline figures established a substantial presence of both pulmonary and vascular pathology within the screened group, allowing for a robust comparison of how these two conditions overlap in high-risk patients.

The analysis revealed a clear link between parenchymal lung changes and vascular health. Specifically, coronary artery calcification was more prevalent among participants with interstitial lung abnormalities than those without them (74.7% versus 48.1%; p < 0.001). This statistically significant difference suggests a strong association between incidental lung abnormalities and subclinical coronary atherosclerosis. For the clinician, these findings indicate that the discovery of even asymptomatic lung changes on a screening computed tomography scan may serve as a red flag for underlying coronary artery disease that has not yet reached the threshold of clinical symptoms.

The severity of the vascular burden also correlated with the specific subtype of lung pathology identified. The proportion of participants with moderate to severe coronary artery calcification increased progressively from the group without lung abnormalities to those with non-fibrotic and fibrotic changes (p < 0.001). The researchers noted that interstitial lung abnormalities, especially fibrotic variants, were associated with a higher prevalence and severity of coronary artery calcification. This suggests that the presence of architectural distortion or scarring in the lungs may be particularly indicative of a more advanced atherosclerotic process in the coronary vessels, further emphasizing the need for cardiovascular risk stratification in this patient subset.

Cardiovascular Outcomes and Clinical Stratification

To ensure a rigorous comparison between groups with disparate baseline characteristics, the researchers employed propensity score matching, a statistical method used to create comparable groups by balancing known patient variables. After this matching process, coronary artery calcification severity was compared across different interstitial lung abnormality types. The researchers further investigated the longitudinal impact of these findings by evaluating the association between coronary artery calcification severity and major adverse cardiovascular events, a composite clinical endpoint including myocardial infarction, stroke, or cardiovascular death. This assessment utilized Kaplan-Meier survival analysis, a statistical tool used to estimate the probability of an event occurring over a specific period, alongside the log-rank test to determine statistical significance between the survival curves.

Despite the clear correlation between lung pathology and calcium burden, the clinical progression to acute events followed a different pattern. The study found that major adverse cardiovascular event incidence did not differ significantly between patients with and without interstitial lung abnormalities when stratified according to coronary artery calcification severity. Furthermore, the researchers concluded that interstitial lung abnormalities were not associated with increased major adverse cardiovascular events in this cohort. While the presence of fibrotic lung changes serves as a marker for a higher burden of subclinical coronary atherosclerosis, it did not translate into a higher rate of immediate clinical events during the study period. For the practicing clinician, these findings suggest that while incidental interstitial lung abnormalities on low-dose computed tomography identify patients with higher vascular risk, the primary value of these findings lies in the opportunity for early cardiovascular risk stratification and primary prevention, rather than as an indicator of imminent cardiovascular crisis.

References

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2. Yang R, Wang H, Liu D, Li W. Prevalence and prognostic significance of interstitial lung abnormalities in lung cancer: A meta-analysis.. Lung cancer (Amsterdam, Netherlands). 2025. doi:10.1016/j.lungcan.2025.108458

3. Hoyer N, Thomsen L, Wille M, et al. Increase in hospital admissions in smokers with Interstitial Lung Abnormalities in the Danish Lung Cancer Screening Trial (DLCST). Epidemiology. 2018. doi:10.1183/13993003.CONGRESS-2018.OA1939

4. Upperton S, Beirne P, Bhartia B, et al. Diagnoses and treatments for participants with interstitial lung abnormalities detected in the Yorkshire Lung Screening Trial.. BMJ open respiratory research. 2023. doi:10.1136/bmjresp-2022-001490

5. Kim YN, You S, Kim Y, Park B, Sun JS, Park KJ. Clinical implications of coronary artery calcification in lung cancer screening populations with interstitial lung abnormalities: a retrospective cohort study.. European radiology. 2026. doi:10.1007/s00330-026-12589-2