Graded MESA-LVH as a marker of left ventricular electrical remodeling: spectrum-based diagnosis, prognosis analysis.

Background

Emerging evidence suggests that electrocardiographic (ECG) voltage reflects left ventricular electrical remodeling (LVER) beyond left ventricular hypertrophy (LVH), with independent clinical and prognostic significance.

Objective

To determine whether graded increases in QRS amplitude provide diagnostic and prognostic information for cardiac magnetic resonance (CMR)-defined LVH.

Methods

We analyzed 4644 participants of the Multi-Ethnic Study of Atherosclerosis (MESA) with paired ECG and CMR. CMR-LVH was defined as left ventricular (LV) mass index >91 g/m2 in men and >77 g/m2 in women. ECG indices included Sokolow-Lyon, Cornell voltage, Peguero-Lo Presti, RaVL, and MESA-LVH(SV1 + SV2 + RV5). Likelihood ratios (LR) were calculated at matched specificities. Hazard ratios (HR) for all-cause mortality, major adverse cardiovascular events (MACE), and their composite were estimated adjusting for clinical covariates and CMR-LVH.

Results

CMR-LVH prevalence was 28.6%; 763 deaths and 639 MACE occurred. MESA-LVH combined a coherent monotonic gradient with the widest dynamic range of the indices tested, with LR- ≈ 0.6 at <30 mm and LR+ ≈ 3, 5, 10 at ≥40, ≥50, ≥60 mm, respectively. After CMR-LVH adjustment, MESA-LVH ≥50 mm predicted MACE (HR 1.41), and ≥60 mm predicted MACE (HR 2.08) and, less robustly, death-or-MACE (HR 1.61). The MACE signal was confined to heart-failure hospitalization (HR 4.21 at ≥60 mm), which remained associated after adjustment for continuous LV mass index (HR 2.73, 95% CI 1.34-5.56).

Conclusions

Graded MESA-LVH provides the broadest diagnostic-prognostic spectrum for QRS amplitude interpretation; at its upper range it predicted MACE after adjustment for binary CMR-LVH, and heart-failure hospitalization even after adjustment for continuous LV mass index, reinforcing the LVER paradigm.