Abstract 698: Effects of Aging on Ventricular Structure and Function in Normal Subjects: A Prospective Study
Background: Cross-sectional studies of effects of age on ventricular structure and function show lower ventricular volumes with increasing age, including Framingham, MESA, the Dallas Heart Study and our own single center study. We sought to assess aging effects on ventricular size and function prospectively in a subset of our cross-sectional study.
Methods: Of 257 normotensive, non-diabetic, non-obese (BMI<28) volunteers, screened with clinical history, physical examination and 2D echocardiography in whom cardiac magnetic resonance imaging (CMR, 1.5T Siemens Sonata or Avanto) was performed, we recruited 78 (mean age = 62±14 yrs, 43 females) for a 5 year follow-up study using echocardiography and CMR. SSFP cine imaging of contiguous 8mm short axis slices of left (LV) and right (RV) ventricles was obtained. Volumes at end-diastole and end-systole and mass were determined (Medis, MASS)
Results: Our cross-sectional study demonstrated increasing systolic blood pressure and decreasing biventricular volumes with age. In contrast, in the prospective study, LV and RV end diastolic volumes increased significantly (126 ± 36 to 138 ± 39, 118 ± 36 to 134 ± 38, p <.0001 for both), as did the end systolic volumes (54±21 to 60± 24, 54 ± 20 to 60± 23, p = 0.0005 and p = 0.0008). LV ejection fraction (EF) remained unchanged while RVEF increased slightly (55 ± 7 to 57 ± 7, p = 0.007). LV mass (88 ± 24 to 92 ± 25, p = 0.003) increased, while RV mass was unchanged. Systolic blood pressure increased (120 ± 12 to 131 ± 21, p <.0001). In 23 subjects new moderate valvular dysfunction developed. When these were excluded, significant increases in chamber volumes persisted. Males and females and subjects with intake age <50 years and ≥50 years behaved similarly.
Conclusions: LV and RV volumes increased with age on serial determinations in the same normal individuals, in contrast to cross-sectional studies showing decreases in LV and RV volumes associated with older age. This may reflect generational differences that confound cross-sectional studies, but do not affect longitudinal studies. Larger serial studies are needed to confirm these unexpected findings.