Resting heart rate is an independent predictor of left ventricular diastolic dysfunction in obese patients with or without arterial hypertension

Abstract

Background: Left Ventricular Diastolic Dysfunction (LVDD) represents one of the cardiac consequences in overweight and obese patients. Resting heart rate (RHR) is an easy measure but important indicator of cardiovascular health. In this study, we sought to assess if RHR is a reliable determinants of LVDD in obese patients with or without arterial hypertension. Methods and results: A perspective echo-Doppler study was performed in 154 consecutive asymptomatic patients with grade 1-to-3 obesity (body mass index [BMI]: 43±8) who averaged 47 years in age (women 80%). All patients had a LV ejection fraction (EF) ≥50% and no history of heart failure or coronary artery disease. LVDD was identified by an E/A ratio >1.5 and an E/A ratio <0.8. Long-axis function was assessed by global longitudinal strain. For means of comparison, 56 age-matched subjects with or without hypertension were also studied. Prevalence of hypertension was 42% in obese patients, while it was 29% in the control group. LVDD was present in 46 obese patients (30%) and in 12 controls (21%). Patients with grade 3 obesity (BMI ≥40) exhibited higher LV volumes and mass (p<0.0001), cardiac output (p<0.0001), left atrial size (p<0.0001), stroke volume (p<0.0001) and RHR (p<0.0001), and a worse LV long-axis function (p<0.001) as compared to patients with grade 1-2 obesity (BMI between 30 and 40) and the control group. In patients with grade 2-to-3 obesity, BMI directly correlated with stroke volume (r=0.24; p=0.003) and cardiac output (r=0.37; p<0.0001), RHR inversely correlated with LV end-diastolic volume index (r=-0.48; p<0.0001), LV end-systolic volume index (r=-0.42; p<0.0001) and LV mass index (r=-0.40; p<0.0001). RHR (hazard ratio [HR]:1.06, p=0.003) and age (HR: 1.05, p=0.025) were independently associated with LVDD in patients with grade 2-to-3 obesity. Conclusion: In obese patients with or without hypertension, RHR was a major predictor of LVDD and negatively correlated with LV mass and volumes. Obese patients with a disproportionate increase in RHR are likely to carry inadequate allometric scaling of LV mass and volumes relative to their BMI values.