Abstract 3163: Gender-Specific Reference Values for Left Ventricular Anatomy and Systolic Function Using Modern Cardiovascular Magnetic Resonance Methods in a Longitudinally Followed Normotensive Population: The Framingham Heart Study
INTRODUCTION Cardiovascular magnetic resonance imaging (CMR) is widely considered the gold standard for in vivo determination of left ventricular (LV) parameters, but gender specific CMR reference values for healthy adults using state-of-art steady-state free precession (SSFP) sequences have not been reported for a large longitudinally followed population known to be free of hypertension.
METHODS A total of 1367 adult participants in the Framingham Heart Study (FHS) were scanned on a 1.5-T Philips CMR system. Of these, data from 606 (239 men, 367 women) without hypertension (no SBP> 140 or DBP> 90 mmHg at any cycle examination, and never on any antihypertensive medication) were analyzed. SSFP CMR was used to encompass the LV with 30 – 40ms temporal resolution, 1.92mm x1.56mm in-plane resolution and contiguous 10-mm thick slices. LV epi and endocardial contours were manually segmented and end-diastolic and end-systolic volumes (EDV, ESV) and mass (LVM) were computed using the method of disks. Values were also indexed by height (HT, m), HT2.7 and BSA (m2) and are summarized as mean±SD.
RESULTS There was no difference in age between men and women (60.9±7.9y versus 61.3±8.5, respectively, p=0.53), but as expected men were taller, heavier, and had greater BSA than women (p< 0.001 for all comparisons). Men had greater raw EDV, ESV and LVM than women and this difference persisted after indexation to HT, HT2.7 and BSA (Table⇓). LV ejection fraction (EF) was slightly but significantly greater in women than men (0.67±0.05 vs. 0.65±0.05, p < 0.001.)
CONCLUSIONS Using modern CMR methods in this longitudinally followed cohort free of hypertension, we define gender specific normative ranges for LV volumes, mass and EF based on over 600 healthy adult subjects. The participants in this FHS CMR study are unique in that they are known to have been free of hypertension throughout their adult lives, allowing determination of normative LV reference values based on a strictly normotensive population.