Segment Length in Cine Strain Analysis Predicts Cardiac Resynchronization Therapy Outcome Beyond Current Guidelines

Area of Science:

• Cardiology
• Medical Imaging
• Biomedical Engineering

Background:

• Cardiac resynchronization therapy (CRT) benefits are well-established for Class I patients, but outcomes for Class II patients are variable, necessitating improved patient selection.
• The segment length in cine strain analysis of the septum (SLICE-ESSsep) is a novel measurement from cardiac magnetic resonance (CMR) cine imaging that predicts left ventricular functional recovery post-CRT.
• The prognostic value of SLICE-ESSsep for long-term clinical outcomes after CRT remains uninvestigated.

Purpose of the Study:

• To evaluate the prognostic significance of SLICE-ESSsep in predicting clinical outcomes following CRT implantation.
• To determine if SLICE-ESSsep can refine patient selection for CRT, particularly in the heterogeneous Class II patient group.

Main Methods:

• Two hundred eighteen patients with left bundle branch block or intraventricular conduction delay and Class I or II CRT indications were retrospectively analyzed.
• Preimplantation CMR cine imaging was used for manual measurement of SLICE-ESSsep.
• The primary endpoint was a composite of all-cause mortality, left ventricular assist device implantation, or heart transplantation, with secondary endpoints including appropriate implantable cardioverter defibrillator therapy and heart failure hospitalization.

Main Results:

• 65% of patients exhibited a positive SLICE-ESSsep (≥0.9%), indicating systolic septal stretching.
• During a median follow-up of 3.8 years, patients with a positive SLICE-ESSsep showed a significantly lower risk of the primary composite endpoint (HR 0.36, P<0.001) and heart failure hospitalization (HR 0.41, P=0.019).
• In Class II patients, a positive SLICE-ESSsep was associated with clinical outcomes comparable to those of Class I patients, suggesting its utility in this subgroup.

Conclusions:

• SLICE-ESSsep derived from CMR cine imaging is a valuable prognostic marker for clinical outcomes after CRT.
• Identifying patients with a positive SLICE-ESSsep, especially within the Class II indication group, can predict improved CRT response and outcomes.
• Patients with a negative SLICE-ESSsep demonstrate a poorer prognosis, highlighting the need for careful consideration before CRT implantation.