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Longitudinal Arrhythmic Risk Assessment Based on Ejection Fraction in Patients with Recent-Onset Nonischemic Dilated
Giulia De Angelis1, Marco Merlo1, Giulia Barbati2
1Cardiovascular Department, Azienda Sanitaria Universitaria Giuliano Isontina and University of Trieste, Trieste, Italy.
Insights
For patients with dilated cardiomyopathy (DCM), a left ventricular ejection fraction (LVEF) ≤ 35% indicates higher arrhythmic risk after 24 months of guideline-directed medical therapy (GDMT), not after 6 months. Waiting 24 months optimizes risk assessment for ICD implantation.
Area of Science:
- Cardiology
- Electrophysiology
- Heart Failure
Background:
- Current guidelines recommend implantable cardioverter-defibrillators (ICDs) for left ventricular ejection fraction (LVEF) ≤ 35% after 3-6 months of guideline-directed medical therapy (GDMT).
- The optimal timing for ICD implantation in patients with dilated cardiomyopathy (DCM) is uncertain due to potential for reverse ventricular remodeling up to 24 months with GDMT.
Purpose of the Study:
- To evaluate the relationship between LVEF ≤ 35% and arrhythmic risk over time in patients with recent-onset nonischemic DCM receiving GDMT.
- To determine the appropriate timeframe for risk stratification using LVEF in DCM patients for primary prevention ICD implantation.
Main Methods:
- Retrospective analysis of patients with recent-onset DCM and GDMT initiation.
- Assessment of major ventricular arrhythmic events or sudden cardiac death risk relative to LVEF ≤ 35% at baseline, 6 months, and 24 months post-GDMT initiation.
Main Results:
- LVEF ≤ 35% was associated with increased arrhythmic risk starting at 24 months (HR 2.126, P=.03), but not at 6 months.
- Sixty-seven percent of patients with LVEF ≤ 35% at 6 months showed improvement to >35% by 24 months.
- Late LVEF improvement by 24 months correlated with reduced arrhythmic risk (P=.012) and was preceded by LV dimension reduction within 6 months.
Conclusions:
- Risk stratification for ventricular arrhythmias in DCM patients using LVEF ≤ 35% is effective at 24 months of GDMT, but not at 6 months.
- A 24-month waiting period before primary prevention ICD implantation may be appropriate for selected DCM patients to allow for potential LVEF recovery.
Background:
Practice guidelines suggest the use of implantable cardioverter-defibrillators in patients with left ventricular ejection fractions (LVEF) ≤ 35% despite 3 to 6 months of guideline-directed medical therapy (GDMT). It remains unclear whether this strategy is appropriate for patients with dilated cardiomyopathy (DCM), who can experience reverse ventricular remodeling for up to 24 months after the initiation of GDMT. The aim of this study was to assess the longitudinal dynamic relationship between LVEF ≤ 35% and arrhythmic risk in patients with recent-onset nonischemic DCM on GDMT.
Methods:
A retrospective analysis was conducted among patients with recent-onset DCM (≤6 months) and recent initiation of GDMT (≤3 months) consecutively enrolled in a longitudinal registry. Risk for major ventricular arrhythmic events or sudden cardiac death was assessed in relationship to LVEF ≤ 35% at enrollment and 6 and 24 months after initiation of GDMT.
Results:
Five hundred forty-four patients met the inclusion criteria. LVEF ≤ 35% identified patients with increased risk for major ventricular arrhythmic events or sudden cardiac death starting from 24 months after initiation of GDMT (hazard ratio, 2.126; 95% CI, 1.065-4.245; P = .03). However, LVEF ≤ 35% at presentation or 6 months after enrollment did not have prognostic significance. Sixty-seven percent of 131 patients with LVEF ≤ 35% at 6 months after initiation of GDMT had improved LVEFs (to >35%) by 24 months. This late LVEF improvement correlated with lower arrhythmic risk (P = .012) and was preceded by a reduction of LV dimensions in the first 6 months of GDMT.
Conclusions:
In patients with DCM, the present findings suggest that risk stratification for major ventricular arrhythmic events or sudden cardiac death on the basis of LVEF ≤ 35% is effective after 2 years of GDMT, but not after 6 months. In selected patients with DCM, it would be appropriate to wait 24 months before primary prevention ICD implantation.
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