Comprehensive MRI analysis of early cardiac and vascular remodeling in middle-aged patients with abdominal obesity
Résumé
Objectives: To determine, using a comprehensive MRI investigation, prevalence and vascular correlates of early left-ventricular concentric remodeling in middle-aged patients with abdominal obesity. Left-ventricular and vascular remodeling are commonly associated with hypertension, but little is known for abdominal obesity patients, a population with definite increase in cardiovascular risk and high rates of further developments of hypertension and of the metabolic syndrome.
Methods: Seventy middle-aged abdominal obesity patients (56 ± 5 years, 49% women, 69% with body mass index > 30 kg/m), who had no additional cardiovascular risk factor except for untreated stage 1 hypertension (16%), and 40 controls underwent MRI for detecting concentric remodeling (increase in left-ventricular mass/end-diastolic volume ratio) and identifying potential determinants, including arterial compliance indexes [aortic pulse wave velocity and total arterial compliance (TAC)] and total peripheral vascular resistances (TPVRs).
Results: Twenty abdominal obesity patients (29%) had concentric remodeling (concentric remodeling+), whereas 50 did not (concentric remodeling-). Concentric remodeling+ patients were mostly men (85%), they frequently had stage 1 hypertension (45%) and few had left-ventricular hypertrophy (20%). When adjusted for sex, there was a step-by-step decline in TAC between controls (mean ± SEM: 2.10 ± 0.06 ml/mmHg), concentric remodeling- (1.82 ± 0.06 ml/mmHg) and concentric remodeling+ (1.42 ± 0.09 ml/mmHg, P < 0.005 for inter-group comparisons) and TPVRs were lower than controls for concentric remodeling- (14.7 ± 0.5 vs. 16.8 ± 0.5 ml/mmHg, P = 0.005) but not for concentric remodeling+ (17.5 ± 0.7 mmHg/min per l).
Conclusions: Concentric remodeling is frequently documented by MRI in the middle-aged men with abdominal obesity and in association with a decrease in TAC no longer counter-balanced by a decrease in TPVR, suggesting a remodeling from proximal to peripheral vasculature.