P5684Left ventricular wall thickness measured with computed tomography stratifies the response to cardiac resynchronization therapy in patients with non-ischemic cardiomyopathy

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Abstract Background Cardiac resynchronization therapy (CRT) has provided benefit in selected heart failure (HF) patients. Unfortunately, up to 30% of device recipients do not benefit clinically from CRT. Left ventricular (LV) wall geometry analyzed using computed tomography (CT) has not been evaluated in the response to CRT. The objective of this study was to examine the association of LV wall thickness (WT) and the ability for reverse LV remodeling after CRT in non ischemic cardiomyopathy (NICM) patients. Methods In this prospective study, a total 54 patients (33 NICM) scheduled for CRT, underwent pre procedural CT. Reduced LV WT was defined as WT≤6mm and was quantified as a percentage of total LV area. End points were 6-month clinical and echocardiographic response to CRT (NYHA functional class, LV ejection fraction (LVEF), LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVEDV)) and 2-year major adverse cardiac events (MACE). Of note, positive reduction was defined as in reduction LVESV and LVEDV by ≥15% and ≥10% respectively and ≥5% absolute increase in LVEF. Results The 33 NICM enrolled patients were divided in 3 groups according to the percentage of LV WT<6mm area: ≤20% (low LV WT area); 20–50% (moderate LV WT area) and ≥50% (high LV WT area). At 6 months, 78%, 67% and 25% of the patients experienced NYHA class improvement by ≥1 in the ≤20%, 20–50% and ≥50% group respectively. Furthermore, majority of patients in the ≤20% and 20–50% groups (92% and 75% respectively) had a significant improvement of their global assessment compared to only 38% in the ≥50% group. Additionally, low LV WT area group presented a significant LVEF, LVEDV and LVESV positive response rate (92%, 69% and 85% respectively). Patients included in the moderate and high groups exhibited gradually lower LVEF, LVEDV and LVESV positive response rate (42% and 50%; 67% and 50%; 75% and 50%, respectively). Notably, patients with the least LV WT (i.e ≥50% group) experienced significantly lower 2-years MACE survival free probability than other groups. Left ventriculat segmentation Conclusion LV WT evaluated using CT could help to stratify the response to CRT in NICM patients.