1.4 BLOOD PRESSURE LEVELS ARE THE SOLE DETERMINANT OF DIFFUSE MYOCARDIAL FIBROSIS IN HYPERTENSIVE PATIENTS

Abstract

Objectives. Myocardial fibrosis occurs early in hypertension and plays a major role in CV disease. Our goal was to assess the mutual influence of blood pressure (BP) and cardiovascular (CV) risk factors on diffuse myocardial fibrosis, as assessed non-invasively from Cardiovascular Magnetic Resonance (CMR) T1 mapping images in a population of non-diabetic hypertensive patients in primary prevention. Methods. CMR MOLLI T1 mapping sequence was acquired on a median LV slice pre-contrast and then at 5, 10 and 15 minutes after a bolus injection of Gadolinium (0.2 mml/kg). After T1 estimation in myocardium and LV cavity, myocardial ECV was calculated as =(1 − hematocrit) × (1/T1post − 1/T1pre) myo / (1/T1post − 1/T1pre) blood. Patients also underwent routine clinical and biological assessments and BP levels were determined using 3 days home measurements (hBP). Results. 37 patients (median age 57, range 31 to 71, 54% males) were included. Population characteristics are summarized in table 1. Mean ECV remained unchanged at 5, 10 and 15 minutes (0.21 ± 0.04). In univariate analysis, ECV was significantly associated with systolic hBP (r = 0.48, p = 0.017) but not with other risk factors (LDL-C, Hba1c, smoking status). This association remained significant after adjustment for age and hBP remained the only significant determinant of changes in ECV. Conclusion. In hypertensive patients, home BP levels were found to be the sole significant and independent determinant of myocardial fibrosis.