We would like to thank Dr. Tully for bringing attention to a number of pertinent publications from the psychiatry literature, which, we believe reinforce our findings. Regardless of the instrument used to measure anxiety, the totality of the evidence points in a consistent direction—demonstrating that anxiety is a key predictor of outcomes for patients undergoing cardiac surgery. Whereas many of the publications cited by Dr. Tully concentrated on anxiety as a driver of long-term mortality and hospital readmissions, our study focused on anxiety as a predictor of short-term postoperative complications (an effect that persisted after adjusting for the Society of Thoracic Surgeons predicted risk).

We selected the HADS instrument because of its desirable balance of practicality and validity. The instruments used by Dr. Tully and the cited investigators were lengthy, including ≥40 anxiety-related questions (instead of 7 in the HADS-Anxiety module) and/or specialized neuropsychiatric interviews, which are not feasible for the average cardiovascular practitioner. The HADS has a long track record in clinical practice and has been repeatedly shown to be valid in differentiating anxiety from depression in various settings and in multiple languages.

Finally, despite the limited sample size in all these studies, the aggregated data have been concordant, highlighting the negative effects of anxiety before cardiac surgery. We look forward to ongoing prognostic data and, ultimately, to therapeutic studies aimed at reducing the morbidity caused by anxiety in our vulnerable cardiac surgery patients.