Response to guideline-directed medical therapy in patients with dilated cardiomyopathy and left bundle branch block: a single-center observational study
D D Anutoni, A M Bondoc, A M Bumbar, A A Faur-Grigori, L Cirin, S A Luca, S Crisan, C T Luca, D Gaita, D Cozma, C VacarescuAbstract
Background
Guideline-directed medical therapy (GDMT), including angiotensin receptor–neprilysin inhibitors (ARNI) and sodium–glucose cotransporter 2 (SGLT2) inhibitors, represents the cornerstone of treatment in heart failure with reduced ejection fraction. In patients with dilated cardiomyopathy (DCM) and left bundle branch block (LBBB), optimization of medical therapy is recommended prior to consideration of cardiac resynchronization therapy (CRT); however, real-world data regarding functional response remain limited.
Purpose
To evaluate echocardiographic response to optimized GDMT in patients with DCM and LBBB managed at a single tertiary center.
Methods
Consecutive patients with DCM, LBBB, and NYHA class II–III heart failure were screened. Patients receiving ARNI and SGLT2 inhibitor therapy and not undergoing CRT during mid-term follow-up were included in the analysis. Prospective echocardiographic assessment was performed at baseline and during follow-up. Changes in left ventricular ejection fraction (LVEF) were analyzed. Patients achieving LVEF ≥40% at follow-up were classified as having a marked functional response.
Results
Out of 500 screened patients, 64 (50 males, mean age 65.2 ± 11.5 years) fulfilled inclusion criteria and were followed for a mean of 15.2 ± 13.8 months. Ischemic etiology was present in 39.1% of cases, while 60.9% had non-ischemic DCM. A significant improvement in LVEF was observed following GDMT optimization (30.3 ± 7.6% at baseline vs 34.3 ± 8.6% at follow-up, p = 0.0001). Twenty-three patients (35.9%) achieved LVEF ≥40%, the majority of whom had non-ischemic DCM (21 vs 2 patients).
Conclusions
In this single-center observational cohort of patients with DCM and LBBB, optimization of GDMT including ARNI and SGLT2 inhibitors was associated with a modest but still significant improvement in left ventricular systolic function. A more pronounced response was observed predominantly in patients with non-ischemic DCM. These findings support current guideline recommendations emphasizing medical therapy optimization prior to CRT consideration, while highlighting the need for larger, controlled studies to better define predictors of functional recovery in this population.