Impact of the most recent HF guideline implementation on optimal medical therapy, guideline adherence, ejection fraction recovery and primary prevention ICD indication – a two-center experience

Introduction

Patients with heart failure (HF) and severely reduced left ventricular ejection fraction (LVEF) <35% (HFrEF) are at elevated risk for arrhythmias and sudden cardiac death (SCD). Based on potential LVEF recovery under optimal guideline-directed medical therapy (GMDT) after initial HF diagnosis, patients can be provided with SCD protection by a wearable cardioverter-defibrillator (WCD) for the first 3 months. According to the ESC-HF guideline (HF-GL) introduced in 2021 GMDT consists of the well-known “fantastic four” combination.

Purpose

The objective of this analysis was to evaluate the change/adherence in GMDT therapy before/after heart failure (HF)-GL, rate of LVEF recovery to >35% and resulting indication for ICD-implantation in a well-defined WCD HF patient cohort.

Methods

We performed a retrospective bi-centric cohort study at 2 tertiary care centers, examining 232 patients fitted with a WCD from 03/2015 until 03/2024 for primary prevention due to first diagnosis of HFrEF. We included 114 before and 118 patients after implementation of the HF-GL in 09/2021. For every patient we calculated a Quad Medical Score (QMS) as surrogate of guideline adherence which is calculated on the presence of quadruple HF therapy and their dosages. LVEF was assessed at baseline and 3 months (FU) after GDMT initiation. In addition, we calculated a QMS cut-off to predict LVEF recovery and subsequent ICD indication. A logistic regression was performed to determine the correlation between QMS score and a later ICD indication.

Results

A total of 232 patients were analyzed: 19% female (n = 19%), ischemic heart disease (ICM) in 53% (n=124). Mean (m) LVEF overall at baseline was 25% and increased to 34% after a median follow up (FU) of 67 days (figure 1). In patients, treated before HF-GL update, m-LVEF was 24% at baseline with Δ-LVEF of +9% at FU, while patients treated after HF-GL update showed a recovery up to m-LVEF 36% resulting in a Δ-LVEF of 11% at FU (p<0.05; BL vs. FU), while the rate of ICD indication was not significantly (p=0.23) reduced (52% vs. 61% patients, BL vs. FU). In total, 7 patients (3%) showed ventricular tachycardia occurred during the FU. Mean QMS score in all patients before and after HF-GL update was 9 vs. 18, respectively (p<0.001; figure 2).  Median QMS score of the cohort was 12. Dividing the groups in n=97 with QMS < 12 and a group with QMS ≥ 12 (n=135) showed a significantly higher LVEF at FU in higher QMS values (36% vs. 32%, p<0.01; figure 2). In line with this, a higher QMS resulted in lower rate of ICD indications (48% vs. 67%, p=0.01). The logistic regression showed a negative correlation of an ICD indication depending on higher QMS scores (p<0.01).

Conclusion

The HF GL update had a significant impact on the medication prescribed for patients with HFrEF in our centers. Our data suggest that adequate implementation of the current guidelines resulted in lower rate of ICD indications and larger LVEF recovery. Moreover, we showed that a higher QMS score was correlated with a higher LVEF recovery. Since ventricular arrhythmias occurred during this GMDT initiation, the WCD seems to be an important tool for SCD prevention during this period.

Figure 1: