ESC Congress 2026 Abstract · Oct 26, 2026

The effect of left bundle branch block on pharmacotherapy and changes of left ventricular ejection fraction after the rapid-up titration of guideline-directed medical therapy in heart failure

By Czurko K, Banfi-Bacsardi F, Forrai Z et al.

Introduction: The 2023 ESC Heart Failure (HF) Guidelines (GLs) recommend the rapid up-titration of GL-directed medical therapy (GDMT) for all patients (pts) after a HF hospitalisation to improve prognosis. The literature suggests that left bundle branch block (LBBB) may have a negative impact on the implementation of GDMT and prognosis in HF. Aims: To assess the effect of the presence of LBBB on the achieved target doses (TDs) of GDMT and the changes in left ventricular ejection fraction (LVEF) after the 6-week rapid-up titration programme (RTP) of GDMT, in a real-world, consecutive cohort of HF pts. Patients and methods: In accordance with the 2023 ESC HF GLs, a 6-week RTP with weekly visits was implemented in the routine clinical practice of our HF Outpatient Clinic at our cardiology centre. In the current retrospective single-centre analysis, the data of the first 89 consecutive HF pts, completing the RTP after a HF hospitalisation were included (male: 79%, age: 58 [51-66] years, de novo HF: 67%, LVEF: 25 [20-32]%, NT-proBNP at discharge: 1491 [735-3077] pg/mL, GDMT at discharge: RASi/TD RASi: 100%/13%, βB/TD βB: 98%/3%, MRA/TD MRA: 99%/96%, SGLT2i: 96%, triple therapy [TT: RASi + βB + MRA]/TD TT: 97%/0%, quadruple therapy [QT: TT + SGLT2i]/TD QT: 93%/0%). Before RTP, no differences were observed in the LVEF between LBBB and non-LBBB pts (median LVEF: 23 [19-30] % vs 25 [20-33] %, p=0.147). The effect of LBBB (detected on the native ECG) on the achieved TDs of GDMT at 6-week RTP and the predictors of the achievement of TD QT at 6 weeks were analysed. Changes in LVEF at 3 months of follow-up (FUP) were also evaluated in the context of LBBB. Results: After the 6-week RTP, a remarkable proportion of pts received TDs of GDMT (TD RASi: 78%, TD βB: 53%, TD MRA: 90%, TD TT: 45%, ≥ 50% of TDs of QT: 76%, TD QT: 42%). 14% of the total cohort had LBBB on the native ECG. At 6 weeks of RTP, an unfavourable tendency was observed in the TD application of βB (25% vs 57%, p=0.060; LBBB vs non-LBBB, respectively) and TT (17% vs 49%, p=0.058). According to the univariate binary logistic regression analysis, age, de novo diagnosis of HF, NT-proBNP at discharge, elevated serum potassium level (> 5 mmol/L) during the 6-week RTP and LBBB influenced the achievement of TD QT at the end of the RTP. At 3 months after the RTP, the non-LBBB subgroup had a significantly greater improvement of LVEF (median LVEF: 30 [20-34] % vs 45 [34-54] %, p<0.001). In the LBBB subgroup, 30% of pts achieved ≥10% improvement in LVEF, whereas 68% of non-LBBB pts experienced the same improvement (p=0.032). Conclusions: According to our single-centre retrospective analysis, within a consecutive HF pt population who achieved TDs of QT at a remarkable rate after the RTP (TQ QT: 42%), LBBB was accompanied by less favourable improvement in LVEF at 3 months of FUP. Additionally, a higher proportion of non-LBBB pts experienced at least 10% improvement in LVEF.The effect of LBBB on the changes of LVEFThe effect of LBBB on the pharmacotherapy

doi.org/10.1093/eurheartj/ehag785.1324 Open access Interventions