#SUCCOUR trial results are out. My congratulations to the authors for this great effort. It studied prospectively a cohort of 331 patients undergoing anthracycline tx with at least 1 risk for HF randomized 1:1 to either LVEF guided monitoring or GLS guided monitoring. 1/10

When cardiotoxicity was identified, intervention was starting ACEI, ARB when not tolerated and followed if possible by adding BB. Key definitions for cardiotoxicity for EF arm: symptomatic drop of >5% or asymptomatic drop of >10% in LVEF compared to baseline to <55%. 2/

For GLS arm, cardiotoxicity was defined as a ≥12% relative reduction [(baseline − current GLS) / baseline GLS] at any follow-up timepoint. All GLS analyses were performed with EchoPAC (GE). Core lab reviewed data from 28 centers. 3/10

Results: 1-year follow-up visit, LVEF was less in the EF-guided arm compared to the GLS-guided arm (55 +/-7% vs. 57 +/-6%, respectively; p=0.05). Authors report a trend of worse GLS in the LVEF guided arm
–19.0 +/-2.6% vs. –19.6 +\\-2.5,(p=0.08). 4/10

Final follow-up, 21 patients (13.7%) in the EF-guided arm and 9 patients (5.8%) in the GLS-guided arm met criteria for CTRCD (p=0.022).
GLS arm had higher proportion of patients receiving BB, ACEI/ARB & combined tx. But no differences in max doses achieved among groups. 5/10

My take is that this study adds to data in regards to making the case for GLS surveillance, however, it cannot be ignored the significant differences among HF meds received in two arms, GLS arm being the group that received the most GDMT for HF which accounts for differences 6/10

Lack of differences in LVEF, no tying to hard outcomes and higher proportion of intervention in GLS still makes challenging to differentiate an effect caused by drugs vs. meaningful intervention to prevent HF. At present GLS seems to be favorable. 7/10

Because it seems to trigger GDMT preserving mechanics, however I wonder if this study could continue strengthening the case of role of preventive anti remodeling tx for pts at risk for HF and if that effect is more related to drugs rather than decision making
8/10

There has been some data of prophylactic anti remodeling tx by multiple studies showing similar effect sizes of minimal LVEF changes or trends toward higher LVEF when using antiremodeling tx as prophylaxis in pts receiving anthracyclines & trastuzumab 9/10

Is it the drug or the monitoring? That likely can be answered in a study with longer follow up and including hard endpoints such as HF incidence and so forth. 10/10

Link to the article in @JACCJournals https://www.jacc.org/doi/pdf/10.1016/j.jacc.2020.11.020