CMR-derived LACI ≥21% independently predicted higher 3-year risk of all-cause mortality (HR 1.011), HF, and arrhythmic events, adding value over LVEF and LGE.
Does CMR-derived LACI predict all-cause mortality, heart failure, and major adverse arrhythmic cardiac events in patients with ischemic and non-ischemic cardiomyopathy and LVEF <50%?
CMR-derived LACI is an independent predictor of all-cause mortality, heart failure, and major adverse arrhythmic cardiac events in patients with reduced ejection fraction, providing additive prognostic value over LVEF and LGE.
Abstract Background The left atrioventricular coupling index (LACI), defined as the ratio between left atrial end-diastolic volume (LAEDV) and left ventricle end-diastolic volume (LVEDV), has emerged as a possible prognostic marker in different clinical settings. Purpose To assess the prognostic value of CMR-derived LACI in patients with ischemic cardiomyopathy (ICM) and non-ischemic cardiomyopathy (NICM) and left ventricular (LV) ejection fraction (EF) 50%. Methods LACI was calculated using CMRs of patients included in the DERIVATE registry, enrolling subjects with LVEF50%. Univariable and multivariable Cox regression models were used to estimate the hazard ratio (HR) with 95% confidence intervals (95% CI) for LACI to predict all-cause mortality (ACM), ACM or heart failure (HF), and major adverse arrhythmic cardiac events (MAACE). Time-dependent receiver operating characteristic analysis was performed to identify the best cutoff for predicting 3-year outcomes. Likelihood ratio test was used to assess the additive value of LACI over LVEF 35% and other clinical and instrumental prognosti stratification tools. Results 2170 patients were included. The median follow-up time was 1016 days (25th-75th percentiles: 580.3 – 1609.5 days). ACM affected 191 (8.8%) patients during follow-up. 565 patients (26.0%) experimented ACM or HF, while 199 (9.2%) had a MAACE. Median LACI was 19.4% (13.3 – 28.8%). After adjustment for clinical (including age, sex, cardiovascular risk factors, NYHA class, AF, ischaemic aetiology of HF) and CMR parameters (as LV dimensions, LVEF, and late gadolinium enhancement (LGE)) and with bootstrap resampling, the HR with 95% CI for LACI in predicting ACM, ACM or HF, and MAACE were 1.011 (1.002-1.021), 1.017 (1.011-1.024), and 1.015 (1.007-1.024) respectively. The best cutoff in the prediction of 3-year ACM was LACI ≥21%. This cutoff allowed the identification of patients at higher risk of ACM, ACM or HF and MAACE (log-rank test p-value 0.001 for all) both in NICM and ICM groups. Moreover, LACI ≥21% conferred a higher risk of ACM or HF in patients with LVEF 40% (HR 3.403, 95% CI 2.169-5.340) than in those with LVEF ≤40% (HR 1.967, 95% CI 1.635-2.366). The likelihood ratio test showed a significant additive value of LACI ≥21% in predicting outcomes over LVEF 35% by echocardiography, LVEDV, and LGE by CMR (p0.001). Conclusions CMR-derived LACI is an independent predictor of ACM, ACM or HF, and MAACE, with an additional value over classical risk stratification tools including LVEF and LGE. A cutoff of ≥21% identifies high-risk patients that may require further clinical evaluation.Kaplan-Meier for LACI stratification Likelihood ratio test
Ciarlantini et al. (2025) studied this question. CMR-derived LACI ≥21% independently predicted higher 3-year risk of all-cause mortality (HR 1.011), HF, and arrhythmic events, adding value over LVEF and LGE.