Our results confirmed the strict connection between AN, weight loss and the reduction of LV mass. In particular, we showed a LV wall thickness and LV mass decrease of -1.8 and − 2.1 of Z-score, respectively. These data were not significant when considering the differences between patients with a BMI below or above the chosen cut-off of 14.5.
This is in line with the literature, where a lower BMI reflects a lower LV mass index, as well as a smaller LV mass: in fact, a decrease in LV mass ranging from 30–50% is described [27]. These data suggest that cardiac volume is initially reduced in severe AN, although this alteration is apparently reversible [28–30]
In addition, we found that the majority of patients with AN had pericardial effusion (65.3%), in agreement with previous studies that described this complication as between 20% and 70%. [21, 31]
[FIGURE 1 GOES HERE]
Our data showed this higher rate of pericardial involvement in patients with AN probably because, due to the COVID19 pandemic, patients with AN presented a more severe clinical status [25]. Conversely, none of our patients reported cardiac tamponade, which is considered a very rare complication in this group of patients in the literature [32]. This finding reinforces the importance of early echocardiographic evaluation of patients with AN in order to reduce and limit cardiologic complications.
Moreover, a statistically significant difference was found between the presence of pericardial effusion in our AN population and increased TSH (p < 0.001), similar to previous research that reported this connection with T3 hormone levels [31]; however, we did not measure T3 hormone levels as this is increasingly converted to reverse T3 under semi-starvation [33].
Another cardiac complication documented in patients with AN has been mitral valve disease. Although an incidence of mitral valve prolapse in AN ranging from 33 to 60% [34] has been recorded in the literature, arching of the superior leaflet, which is the echocardiographic counterpart of angiographically defined prolapse [35] was reported in 20% of our sample. According to this definition, no mitral valve prolapse was detected by Borgia et al. in their sample of 38 children and adolescents with anorexia nervosa [36]. Nonetheless, a similar rate of mitral regurgitation (50%) was observed compared to our sample (45%).
[FIGURE 2 GOES HERE]
AN and cardiac abnormalities have been linked to electrolyte alterations such as hypophosphatemia, hypokalemia, and hypocalcemia. [35, 36]. Our results showed a reduction in average sodium, potassium, phosphate and calcium values below or above the chosen BMI cut-off of 14.5, with no statistical differences. Early detection of these changes are fundamental to limit worsening of clinical status.
Although AN has been linked to cardiac complications and increased morbidity, these are reversible in most cases, with weight recovery [18]. Our study did not focus on the recovery aspects, and this may be called a limitation, yet our goal was to identify early cardiac involvement in AN in order to manage these patients early. Further long-term prospective studies on the effects of weight recovery in such patients should consider both echocardiographic and MRI parameters to investigate any long-term effect, such as myocardial fibrosis, as suggested in the literature [37]. Moreover, clinicians should be aware of refeeding syndrome and congestive heart failure, as described in previous findings [38].
Our study period goes from January 1, 2021 to June 30, 2021 and overlaps with the SARS-CoV-2 pandemic. Although recent reports have documented cardiac abnormalities during the pandemic, such as pericardial effusion and left ventricular dysfunction [39], we could not confirmed these findings in our sample, as all of our patients were tested for SARS-CoV-2 and found negative at the time of admission.