Case Report:
A 48-year-old woman was diagnosed with right sided Grade 2 invasive breast carcinoma (no special type (NST), oestrogen receptor/ progesterone receptor (ER/PR) negative and human epidermal growth factor receptor 2 (HER2) positive), in April 2021. She had received adjuvant chemotherapy with four cycles of anthracycline, twelve cycles of Paclitaxel, and two cycles of Trastuzamab chemotherapies, to be followed by bilateral mastectomy and adjuvant radiation and on-going Trastuzumab. Prior to the initiation of chemotherapy, a transthoracic echocardiogram (TTE) demonstrated normal left ventricular (LV) systolic function, with LV ejection fraction (LVEF) of 64% with a global longitudinal strain (GLS) of -21% (Figure 1, A). She had routine cardiac surveillance as is clinical practice at our centre with a repeat TTE (August 2021) after anthracycline therapy and prior to commencement of Trastuzamab (Figure 1, B). This demonstrated LVEF of 59% with GLS of -19% (9% relative reduction in GLS compared to baseline). As is standard of care, a TTE is performed at 3 monthly intervals after commencement of Trastuzumab. Her next routine 3 monthly TTE (November 2021) demonstrated a further reduction in LVEF to 56% and GLS of -18% (14% relative reduction compared to baseline (TTE measurements were repeated by an experienced and independent sonographer and verified by the consulting cardiologist), triggering review by a cardiologist (Figure 1, C). There was no significant change in blood pressure, heart rate, LV volumes, LA volume or E/e’ over this period.
At cardiologist review, the patient reported no cardiovascular symptoms, in particular no dyspnoea, fatigue, or pedal oedema. She mentioned that she had COVID-19 infection (although having been vaccinated prior (x 2 doses) in late September 2021 and had mild – moderate symptoms of dyspnoea and fatigue for approximately three weeks, though she denied any chest pain or palpitations., she did not have any blood tests (for cardiac biomarkers), require hospitalisation, and did not receive specific antiviral therapy. On examination, she had a heart rate of 60 bpm, was normotensive with a blood pressure of 124/78 mmHg, with normal heart sounds, no murmurs or rubs. Electrocardiogram showed sinus rhythm with normal axis, and non-specific T wave inversion in leads III and aVF.
The patient had an asymptomatic drop in LVEF of 9% and 14% relative reduction in LV GLS compared with her baseline study whilst on Trastuzumab, and therefore met criteria for commencement of cardioprotective therapy (angiotensin-converting enzyme inhibitor +/- Beta blocker therapy). However, given the history of COVID infection in the interim with resolution of symptoms subsequently, a decision was made to continue with Trastuzumab therapy with TTE surveillance after further two cycles of Trastuzamab, without initiation of cardioprotective therapy.
At follow up, the patient reported no further symptoms and did not have dyspnoea or fatigue. Her TTE in January 2022 demonstrated improved LVEF of 59% and GLS of -19% (Figure 1, D). She has subsequently continued Trastuzumab with standard clinical surveillance, without commencement of cardioprotective agents.