Left ventricular extracellular volume on computed tomography is significant predictor of patient prognosis after cardiac resynchronization therapy

BACKGROUND: Cardiac resynchronization therapy (CRT) is useful for patients with severe heart failure (HF); however, almost 30% of patients are non-responders. PURPOSE: This study aimed to evaluate the utility of left ventricular (LV) extracellular volume (ECV) on computed tomography (CT) for the prediction of prognosis in CRT candidates. METHODS: This study included 52 patients who underwent cardiac CT before CRT device implantation between 2008 and 2024. The primary outcomes were cardiac death, hospitalization for HF, and fatal arrhythmia after CRT device implantation. CRT responders were defined as patients who exhibited a 15% or greater reduction in LV end-systolic volume. RESULTS: Nineteen patients (37%) experienced one of the primary outcomes (7 cardiac deaths, 7 fatal arrhythmias, and 5 ​H ​F hospitalizations). LVECV was lower in CRT responders (n ​= ​26) than in the others (n ​= ​23) (36% ​± ​7.6% vs 40% ​± ​6.0%, p ​= ​0.03). LVECV was higher in patients with one of the primary outcomes (n ​= ​19) than the others (n ​= ​33) (42% ​± ​7.5% vs 35% ​± ​5.7%, p ​< ​0.001). Receiver operating characteristic analysis identified 44.03% as the optimal LVECV threshold for predicting primary outcomes. In the Cox proportional hazards model, LVECV was a significant predictor of a primary outcome (hazard ratio, 3.21; 95% confidence interval, 1.08-9.51; p ​= ​0.04). Kaplan-Meier analysis showed that patients with an LVECV ≥44.03% had significantly more primary events than those with lower LVECV (p ​< ​0.01). CONCLUSION: LVECV on cardiac CT may be useful for predicting CRT response and prognosis.