A Strain Value Drops Before the Ejection Fraction Does: Her Fourth Chemo Cycle in Question
Her ejection fraction still looks normal. A more sensitive measurement, checked because her cancer regimen requires it, has already crossed the line that defines early cardiac injury — before anything a symptom or an EF number would have caught.
P.L., a 47-year-old woman, has worked as a hair stylist for over twenty years and has kept a reduced client schedule at her salon between chemotherapy appointments, handing most of her regulars off to a business partner rather than stopping entirely. She was diagnosed with stage 2, HER2-negative invasive ductal carcinoma three months ago and started on doxorubicin and cyclophosphamide with a taxane planned to follow, curative intent throughout. Her baseline echocardiogram before starting chemotherapy was normal — ejection fraction 60%, global longitudinal strain negative 19%, no cardiac risk factors of any kind.
She has now completed three of her planned four AC cycles, asymptomatic throughout, and her surveillance echocardiogram ahead of cycle four shows something her ejection fraction alone would have missed: global longitudinal strain has declined to negative 15.5%, a relative reduction of more than fifteen percent from her own baseline, while her ejection fraction remains preserved at 56%. That pattern — strain moving before ejection fraction does — is exactly what global longitudinal strain is designed to catch, and it meets the 2022 ESC cardio-oncology criteria for mild, asymptomatic cancer therapy-related cardiac dysfunction after only three of four planned cycles. The guideline's own pathway for this specific finding is not to hold chemotherapy but to continue it with closer monitoring while starting cardioprotective therapy — an ACE inhibitor and/or beta-blocker, which it grades Class 2a, "should be considered," rather than as a firm requirement; what remains genuinely unsettled is whether a strain change appearing this early, after only three cycles, should be trusted as safe to continue through on cardioprotection alone, or whether it deserves closer confirmation before the fourth and final dose goes in.
At the cardio-oncology pre-cycle-4 review
This meets the 2022 ESC criteria for mild, asymptomatic cancer therapy-related cardiac dysfunction — a greater than 15% relative GLS decline from baseline with preserved LVEF. The guideline's pathway for exactly this finding is to continue chemotherapy with monitoring every one to two cycles, and it says an ACE inhibitor and/or beta-blocker should be considered — Class 2a, on small and heterogeneous studies, not Class 1.
I agree holding chemotherapy outright would be premature — this is a subclinical finding, not a treatment-halting threshold, and interrupting curative-intent therapy for it isn't proportionate. What I'd ask is whether we extend the interval to cycle four slightly, just enough to repeat imaging first, since this is the first cycle where anything has changed at all.
That's a reasonable, bounded ask rather than a full hold, and I don't think it conflicts with starting cardioprotection now regardless of what the repeat imaging shows. Lisinopril and low-dose carvedilol start today; repeat GLS and troponin just before cycle four to confirm this is a real, continuing trend rather than measurement variability, with cycle four proceeding on schedule if the repeat is stable or only slightly changed.
Lisinopril and low-dose carvedilol started today. Repeat global longitudinal strain and troponin scheduled just before cycle 4, a short, bounded delay rather than an outright hold, with cycle 4 proceeding on schedule if the repeat is stable or only minimally changed.
Left explicitly open, and named as the case's real unresolved question rather than settled by starting cardioprotection:
The guideline's own pathway — continue chemotherapy on cardioprotection — is validated for her specific case, and cycle 4 proceeds as planned.
Cycle 4 would be reconsidered specifically, testing whether “mild asymptomatic” was doing more reassurance work than the finding actually supported this early in treatment.