Evaluating importance of pulmonary disease-related chest CT features as cardiovascular disease and COPD predictors

Can chest CT abnormalities such as pleural effusion, airway thickening, pulmonary ground-glass opacity, and mediastinal lymphadenopathy — all characteristics associated with cardiovascular disease — improve risk assessment of a patient?

Using data from the PROgnostic Value of unrequested Information in Diagnostic Imaging (PROVIDI) study, researchers from University Medical Center Utrecht in the Netherlands investigated the incremental predictive value of pulmonary, mediastinal and pleural features over cardiovascular imaging findings. Based on their analysis of a patient sample of Caucasian Dutch descent, the researchers concluded that non-cardiovascular chest CT features have limited predictive value according to an article published in the June issue of European Radiology.

The patient cohort for the study included two groups:

• 1,148 patients who had a cardiovascular-disease diagnosed event within seven years (median 3.7 years) following a routine diagnostic chest CT performed for various clinical indications between 2002 and 2005at a hospital participating in the PROVIDI study; and
• 1,203 randomly selected patients who experienced no indications of cardiovascular disease during the same time frame. This group represented 10% of the 10,410 patients who participated in the study.

None of the participants in the PROVIDI study had lung cancer or a distant metastatic disease for which a chest CT had been ordered between 2002 and 2004. Nor did they have a chest CT originally ordered for a specific coronary suspicion.

The objective of the PROVIDI study was to determine the prognostic relevance of uncertain incidental findings. This ancillary study specifically evaluated the incidental predictive value of pulmonary, mediastinal, and pleural findings found on routine diagnostic chest CT scans compared to a cardiovascular CT features-based prediction model.

After analysis, lead author Puspa M. Jairam, M.D., of the department of radiology, and colleagues determined that ground glass, pleural effusion, and lymphadenopathy were associated with an increased risk of cardiovascular events. However, improvement of event prediction with these identified features was only marginal.

However, a different analysis of 6,406 participants in the PROVIDI study published in the August issue of Thorax determined that emphysema and airway thickening detected on CT scans obtained for other non-pulmonary indications are strong independent predictors of subsequent development of acute exacerbations of COPD resulting in hospitalization or death.

Dr. Jairam and colleagues at the University Medical Center Utrecht visually graded CT scans from patients diagnosed with COPD and from a random sample of 10% of the remaining cohort. Emphysema severity, airway thickening, and bronchiectasis were given numeric grades. The research team used weighted Cox proportional hazards analysis to assess the independent association between CT findings and subsequent hospitalization or death over an ensuing five year period.

REFERENCES

1. Jairam PM, de Jong PA, Mali WPTM, et al. Cardiovascular disease prediction: do pulmonary disease-related chest CT features have added value? 2015 Eur Radiol 25: 1646-1654.
2. Jairam PM, van der Graaf Y, Lammers JW et al. Incidental findings on chest CT imaging are associated with increased COPD exacerbations and mortality. 2015 Thorax 70;8: 725-731.