Author + information
- Stefano Bartoletti, MS,
- Francesco Perna, MD,
- Pasquale Santangeli, MD and
- Michela Casella, MD, PhD* ()
- ↵*Institute of Cardiology, Department of Cardiovascular Medicine, Catholic University of the Sacred Heart, Largo Gemelli 8, 00168 Rome, Italy
MacHaalany et al. (1) recently reported that incidental findings (IFs) on computed tomography performed to diagnose coronary artery disease (CAD) are common but do not predict noncardiac death, and investigating them further “is not without cost or risk.”
Although we appreciate the detailed analysis of IFs and costs, we believe a significant flaw affects the study design. Drawing conclusions on whether mortality differs between patients with and without IFs becomes statistically unsound if some patients receive potentially lifesaving (or at least life-prolonging) interventions, such as lobectomy for lung carcinoma or chemotherapy for mediastinal lymphoma. In other words, although Kaplan-Meier survival curves show no difference in survival between patients with IFs and those without, any intervention that may prolong survival beyond the reported follow-up time significantly impairs the validity of the analysis.
Moreover, the investigators recognize that an 18-month follow-up time may be inadequate to correctly evaluate indeterminate IFs, as some of them may become significant with a longer follow-up time. We concur, but we also add that an 18-month follow-up time is probably inadequate even for the prognostic evaluation of the smaller number of IFs that were already significant, as they include disorders with a natural course that may be longer than 18 months (2).
Further studies are certainly necessary to clarify whether any benefit lies in further investigating indeterminate findings, but from the point of view of evidence-based medicine, that question cannot be answered by comparing a group of patients with IFs and another group without. A more appropriate study design would exclude patients who already have a clear management pathway set before them (i.e., those without any IFs and those with an immediately significant IF) and randomize the remaining patients with indeterminate IFs to either further investigations or simple follow-up.
As the number of procedures increases, invasive cardiologists increasingly will be called to acquire sufficient preparation to consider the global significance of imaging findings, and we appreciate the relevance of the work of MacHaalany et al. (1) in that direction.
- American College of Cardiology Foundation