Relation of left ventricular mass and concentric remodeling to extent of coronary artery disease by computed tomography in patients without left ventricular hypertrophy: ROMICAT study

Abstract

Objective: Cardiac computed tomography allows for simultaneous assessment of left ventricular mass (LVM) and coronary artery disease (CAD). We aimed to determine whether LVM, LVM index (LVMi), and the left ventricular geometric pattern of concentric remodeling are associated with the extent of CAD in patients without left ventricular hypertrophy.

Methods: In 348 patients from the Rule Out Myocardial Infarction Using Computer Assisted Tomography trial, 64-slice computed tomography was performed and LVM measured at end-diastole. We used three LVM indexation criteria to obtain three cohorts: LVM indexed to body surface area by echocardiography (n = 337) and computed tomography criteria (n = 325), and by height (n = 326). The cohorts were subdivided into concentric remodeling and normal geometry. Extent of coronary plaque was classified based on a 17-segment model, treated as a continuous variable, and stratified into three groups: zero segment, one to four segments, and more than four segments.

Results: Patients with more than four segments of coronary plaque had higher LVM (Delta12.8-15.1 g) and LVMi (Delta4.0-5.5 g/m and Delta2.2 g/m) than those without CAD (all P < or = 0.03). After multivariable adjustment, LVM and LVMi remained independent predictors of extent of coronary plaque, with 0.27-0.29 segments more plaque per 20 g increase of LVM (all P = 0.02), 0.32-0.34 segments more plaque per 10 g/m increase of LVMi (both P = 0.02), and 0.80 segments more plaque per 10 g/m increase of LVMi (P = 0.008). Concentric remodeling patients had 1.1-1.3 segments more plaque than those with normal geometry (all P < or = 0.05). Patients with more than four segments of plaque had two-fold increase in odds (all P < or = 0.05) of having concentric remodeling as compared with those without CAD.

Conclusion: Increased LVM, LVMi, and concentric remodeling are associated with a greater degree of coronary plaque burden in patients without left ventricular hypertrophy. These findings could provide an indication to intensify medical therapy in patients with subclinical CAD and hypertension.

Figure 1

Four-chamber (A) and short-axis (B) views of the left ventricle in a 53-year old man with normal geometry (normal LVM/BSA of 64 g/m², normal LVM/height^2.7 of 28 g/m^2.7, and normal RWT ratio 0.33) and no coronary artery disease. Four-chamber (C) and short-axis (D) views of the left ventricle in a 64-year old man with concentric remodeling (normal LVM/BSA of 97 g/m², normal LVM/height^2.7 of 44 g/m^2.7, but increase RWT ratio 0.45) and coronary artery disease (12 segments of plaque). LVM denotes left ventricular mass; BSA, body mass index; and RWT, relative wall thickness.

Figure 2

Proportion of patients with concentric remodeling as stratified by the number of segments with coronary artery plaque for each of the 3 LVMi cohorts. A gradient stepwise increase in the percentage of patients with concentric remodeling and extent of coronary plaque is noted. LVMi denotes left ventricular mass index.

Figure 3

Odds ratio and 95% confidence interval for concentric remodeling as stratified by the 3 categories of extent of coronary plaque, with no plaque as the reference standard.