Coronary CT angiography (CCTA) often reveals incidental extracardiac abnormalities, including many pulmonary nodules. But more studies need to be conducted to determine the cost effectiveness of downstream tests for these incidental findings, according to a study published in the June issue of the American Journal of Roentgenology.
Christoph I. Lee, MD, from Stanford University Medical Center in Stanford, Calif., and colleagues examined studies of 151 patients who underwent a coronary CT with a multidetector CT (MDCT) at the facility over a seven-year period between 2001 and 2007.
“There was a statistically significant correlation between advanced patient age and the incidence of both extracardiac incidental findings and pulmonary incidental findings,” the authors wrote.
The researchers found that hyperlipidemia, a first or second-degree stroke, hypertension or myocardial infarcation and smoking history were the most common primary study indications.
Lee and colleagues found a significant correlation between smoking and detection of pulmonary incidental findings and procurement of imaging follow-up—28 percent of patients were either current or former smokers.
However, the authors wrote, “There were no statistically significant relationships between the remainder of primary study indications and the detection of extracardiac incidental findings, pulmonary incidental findings, imaging follow-up or clinical follow-up.”
Results showed that 102 incidental extracardiac findings took place in 43 percent of patients—76 of the 102 were pulmonary incidental findings.
According to the researchers, over half of the incidental findings were clinically significant and affected 31 percent of patients overall.
Of those deemed clinically insignificant, 13 percent were deemed stable on prior imaging reports. Of patients who had indeterminate pulmonary nodules, 50 percent had recommendations for further follow-up. Compared to previous studies where only 12 percent of cases were recommended for follow-up, 35 percent of patients were provided with specific timelines and follow-up techniques.
Only 6 percent of patients during the study received clinical follow-up or interventions for incidental findings.
The researchers used Medicare reimbursement rates from 2009 to decipher the medical costs potentially involved with incidental findings. Results showed that the average cost of additional diagnostic workup per patient was $17.42 and the direct cost for additional diagnostic workup per patient with follow-up imaging was $438.39.
“As the use of coronary MDCT becomes more widespread in both the outpatient and inpatient U.S. patient populations, determining the downstream consequences of reporting extracardiac incidental findings from both a clinical and a cost-effectiveness standpoint will be essential,” the authors wrote.
They said that indeterminate pulmonary nodules should be better managed.
“Until more studies clarify the benefits and risks of identifying early lung neoplasms, we cannot say for certain whether it is prudent to report incidental extracardiac findings on MDCT,” the authors concluded. “Reporting physicians, whether radiologists or cardiologists, can prevent unnecessary follow up and associated costs by careful comparison of incidental findings with prior studies and by providing unequivocal follow-up recommendations."