We found significant differences in the technical difficulty of image acquisition as rated by echo technicians when comparing left/bilateral TE to a right-sided/no TE group. Interestingly, this did not translate to physician-assessed image qualities of the same studies. As such, we found no significant difference in image quality as assessed by cardiologists when comparing left/bilateral TE to a right-sided/no TE group.
Our study is unique in that we evaluated both the technical difficulty of the acquired studies as assessed by the echo technicians, as well as image quality reviewed by our experienced cardiologist echo readers. To our knowledge, this is the first study to have examined both in patients post breast reconstruction; and possibly has implications for clinical decision-making. In addition, our study focused on breast tissue expanders particularly (rather than all reconstructive techniques).
Our results are different from the findings from a previous study by Pignati et al. [15] in which patients with left-sided/bilateral tissue expanders had significantly poorer image quality. In that retrospective study, from 2000 to 2012, 44 women post breast reconstruction after mastectomy for breast cancer, were divided in 2 groups: left/bilateral vs right breast implant (control group). In the study group, it was judged as adequate in only 50% of cases (15 patients) vs. 100% of the controls (p < 0.001). There could be a number of explanations for the differences in both study findings. Ours was a larger study including more patients. Furthermore, our study was more rigorous and parsimonious as the echocardiographic image qualities in our study were assessed by only 2 independent cardiologists.
As mentioned, many women are choosing breast reconstruction after mastectomy as evidenced by an increase in breast reconstruction procedures [5]. This trend raised an important clinical question in the surveillance of this patient population since the effects of breast implants on the quality of acquired echo images have been described in case reports [12, 13]. We decided to study this effect by assessing not only the impact of TE on the acquisition of good-quality echocardiographic images, but also the effects on physician interpretation.
The heart is located in the left pectoral area; as such, most of echocardiographic imaging involves the left chest. It therefore follows that procedures that involve the left-side of the chest (including left breast, whether purely left-sided or bilateral) are more likely to impact cardiac imaging, while no chest procedures or those that purely involve the right breast or right side of the chest are not.
Our study suggests that while the technicians found the presence of breast TE to increase the technical difficulty for performance of the studies, they were able to adequately complete the studies such that the cardiologist echo readers were able to visualize the cardiac structures and rate them as better image quality. This may suggest that well-trained sonographers can overcome the intricacies of echocardiographic imaging associated with breast TE, and thereby prevent possible inadequate and incompetent clinical decision-making as a consequence of poor quality images. This has particular relevance in the population of patients with breast cancer whom might receive cardiotoxic chemotherapy such as anthracyclines and/or trastuzumab as well as radiation therapy, in whom (sometimes frequent) cardiac monitoring with echocardiography is paramount.
In our study, the case group had larger tumors and younger ages and accordingly received more anthracyclines, radiotherapy and trastuzumab. Larger and aggressive tumors are more likely to undergo systemic therapy, and less likely to undergo surgery. Multivariate analysis showed a relationship dependent on implant side (left/bilateral vs right/none) even when adjusted for age, tumor size, COPD status and treatment received (anthracyclines, radiotherapy and trastuzumab). A separate analysis was run with the ungrouped categories of technical assessment and image quality (Table 3); no significant difference was found between technical assessment or image quality and study group.
The limitations of our study include the number of patients excluded due to lack of information during the initial screening, lack of randomization, and the retrospective nature of the study. Another limitation is the fact that the scales utilized for technical difficulty and image quality assessment are based on subjective assessments. The categories were grouped to simplify reporting and increase the amount of subjects per group.