To the editor

We read with interest the article by Piwoński et al,1 published in the current issue of Polish Archives of Internal Medicine (Pol Arch Intern Med), regarding their study including 20 514 Polish patients from 3 cross-sectional surveys who completed a Beck Depression Inventory questionnaire. The aim of the authors was to assess the prevalence of depression in association with cardiovascular diseases and various demographic features. In the original cross-sectional surveys, patients were reported as having coronary artery disease (CAD) if they had been previously hospitalized for acute coronary syndrome, had undergone a percutaneous coronary intervention, or even if they had been treated for CAD in outpatient settings. In this large group of patients, the frequency of CAD, hypertension, and diabetes was higher in men compared with women, regardless of age. The conclusion of this study was that depressive symptoms were common in the general Polish population, albeit they were more severe in a subset of Polish individuals with cardiovascular disease, irrespective of other concomitant diseases, age, education, and marital status.

In our recent study, based on a completely different concept and design, we obtained similar results to the ones achieved by Piwoński et al;1 namely, that the incidence of depression was higher among patients with myocardial disease. We evaluated the role of depression and anxiety in 80 patients who underwent a single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) to assess their myocardial status. Our patient cohort completed the Zung Self-Rating Depression Scale (ZDS) and the Hamilton Anxiety Rating Scale (HAMA). Overall, 65% of patients had abnormal MPI findings due to myocardial impairment. Over half of patients with myocardial disease (53.8%) had depression, anxiety, or both. Among the remaining patients with normal SPECT MPI evaluation, only 35.7% demonstrated abnormal psychological status.2 In addition, we found that women had higher anxiety levels compared with men; this finding was similar to the one from the study by Piwoński et al,1 in which there were more women than men with depressive symptoms.

However, there were some minor differences between the findings of the two studies, which were probably due to different study populations and designs. In our analysis, we observed an additional association between myocardial dysfunction and obesity and inherited cardiac conditions, whereas Piwoński et al1 found a correlation between CAD and diabetes mellitus and hypertension, as was to be expected as a general rule.

Although in most cases the etiology of abnormal SPECT MPI findings is linked to CAD, recent evidence suggests that patients with depression and anxiety may exhibit coronary artery spasm without coronary artery stenosis.3 In fact, coronary vasospasm may represent an alternative mechanism in patients who show myocardial ischemia without coronary artery stenosis.4 Thus, depression may represent an additional risk factor for myocardial ischemia, even in the absence of CAD.

In summary, patients with depression have high rates of myocardial ischemia or CAD and are at increased risk for future cardiovascular events.1,2 Such patients should be closely monitored and screened for early diagnosis and proper management of their myocardial condition or CAD. It should also be emphasized that SPECT MPI, an imaging modality available in any nuclear medicine laboratory, is a reliable tool that provides information about the myocardial status in both symptomatic and asymptomatic patients, including those without CAD.4,5