Brazilian Position Statement on the Use Of Multimodality Imaging in Cardio-Oncology - 2021

Anthracycline cardiotoxicity: current methods of diagnosis and possible role of 18F-FDG PET/CT as a new biomarker

Despite advances in chemotherapy, the drugs used in cancer treatment remain rather harmful to the cardiovascular system, causing structural and functional cardiotoxic changes. Positron-emission tomography associated with computed tomography (PET/CT) has emerged like a promising technique in the early diagnosis of these adverse drug effects as the myocardial tissue uptake of fluorodeoxyglucose labeled with fluorine-18 (¹⁸F-FDG), a glucose analog, is increased after their use. Among these drugs, anthracyclines are the most frequently associated with cardiotoxicity because they promote heart damage through DNA breaks, and induction of an oxidative, proinflammatory, and toxic environment. This review aimed to present the scientific evidence available so far regarding the use of ¹⁸F-FDG PET/CT as an early biomarker of anthracycline-related cardiotoxicity. Thus, it discusses the physiological basis for its uptake, hypotheses to justify its increase in the myocardium affected by anthracyclines, importance of ¹⁸F-FDG PET/CT findings for cardio-oncology, and primary challenges of incorporating this technique in standard clinical oncology practice.

Echocardiographic strategy for early detection of cardiotoxicity of doxorubicin: a prospective observational study

Background

Cancer chemotherapy using anthracyclines is associated with cardiotoxicity (CTX), and left ventricular ejection fraction (LVEF) analysis is not sensitive to early cardiotoxic changes. Left ventricular global longitudinal strain (LV GLS) monitoring helps screen subclinical CTX; however, the intervals at which it should be performed remain unclear. We aimed to evaluate the incidence of CTX in women with breast cancer and the associated factors and compare two echocardiographic monitoring strategies using two cutoff points for LV GLS variation.

Methods

Patients with breast cancer prescribed doxorubicin underwent serial LVEF and LV GLS assessments using two-dimensional echocardiography every 3 weeks for 6 months.

Results

We included 43 women; none developed a clinical CTX. Considering a relative reduction of LV GLS > 15%, subclinical CTX was present in 12 (27.9%) and six (14%) patients at 3-week and 3-month intervals, respectively (P = 0.28). Additionally, considering a reduction of > 12%, subclinical CTX was present in 17 (39.5%) and 10 (23.3%) patients (P = 0.16), respectively. There were no significant differences in either reference value at 3-week (P = 0.19) and 3-month intervals (P = 0.41). Age ≥ 60 years (P = 0.018) and hypertension (HTN) (P = 0.022) were associated with subclinical CTX in the univariate analysis.

Conclusions

There was no difference in the incidence of subclinical CTX between the two cutoff points and no benefit in performing echocardiography every 3 weeks compared with quarterly monitoring. Advanced age and HTN were associated with the development of subclinical CTX.

Right ventricular function during trastuzumab therapy for breast cancer

Cardiotoxicity (CDT) is the main adverse effect related to trastuzumab (TTZ). The role of the right ventricle (RV) in this context is not clear. We aimed to evaluate the longitudinal changes in RV function during TTZ therapy and to determine RV function changes associated with subclinical CDT. Breast cancer patients underwent echocardiograms at the beginning of TTZ treatment (Exam 1) and every 3 months during the first year (Exams 2, 3, and 4). Subclinical CDT was defined as ≥ 12% relative reduction of left ventricle global longitudinal strain (LV GLS). Twenty-five women (52.1 ± 13.1 y-o) were included. We found a decrease in LV ejection fraction between the first and fourth exams (Ex1: 64.1% ± 4.9 vs Ex4: 60.9% ± 4.9, p = 0.003) and the LV GLS gradually decreased during follow-up (Ex1: - 20.6% ± 2.0; Ex2: - 19.4% ± 2.1; Ex3: - 19.2% ± 1.8; Ex4: - 19.0% ± 2.1, all p < 0.05). RV GLS changed from baseline to 3 month and to 6 month (Ex1: - 23.9% ± 1.6; Ex2: - 22.5% ± 2.1; Ex3: - 22.5% ± 2.3, all p < 0.05), and the RV Fractional Area Change was lower in the third exam (Ex1: 44.3% ± 6.6 vs Ex3: 39.9% ± 6.0, p = 0.004). We found subclinical CDT in 13 patients (52%); worsening in RV parameters did not differ between those with and without subclinical CDT. In this sample, the RV function decreased during TTZ therapy and the decrease was not associated to the observed LV cardiotoxicity.