Abstract 217: Association of Left Ventricular Concentric Hypertrophy and Thoracic Aortic Calcification With Cardiac Morbidity and Mortality in Elderly Subjects in the ICELAND-MI Substudy of AGES-Reykjavik
Background: Left ventricular (LV) mass increases with aging and cardiovascular risk factors. In this prospective, population based study we sought to evaluate the relations between LV hypertrophy and thoracic aorta atherosclerosis by way of directly measuring calcification and aortic distensibility and to determine their impact on cardiovascular morbidity and mortality.
Methods: The study participants (n = 698) were the cohort in the ICELAND-MI, the sub-study of the Age, Gene/Environment Susceptibility Study, an epidemiology study of Icelandic men and women 68 –93 years. All participants underwent cardiac MRI and CT of the thorax. Aortic distensibility was measured by MRI in 132 subjects. The clinical events consisted of congestive heart failure, myocardial infarction (MI), and all-cause mortality. Cox proportional hazard regression was used to assess the outcome risk.
Results: Of the 698 participants, the mean age was 76 years (ranging 68 to 93 years), 54% were women, 71% had hypertension, 11% had diabetes mellitus (DM), and 16% had a history of coronary disease. The average LV mass was 76±22 grams and LV ejection fraction (EF) 61±9%. Thoracic aortic calcification was present in all but 4 participants with a mean calcium score 3583±4448. Each quartile increase in aorta calcium was associated with a graded increase in pulse pressure (p<0.001), decrease in aortic distensibility (p=0.045), increase in LV mass (p=0.012), and increase in mass/volume ratio (p=0.014). Aorta calcification was not associated with LV volumes and LVEF. During 3.8 years of follow up there were 111 cardiac events and 58 deaths. In quartile analysis, the event rate was 8%, 21%, 25% and 31% in relation to the increase in aorta calcification and 15%, 18%, 23% and 29% in relation to LV mass increase. Aorta calcification and LV mass increase were independent risks for clinical events in multivariable models adjusting for clinical and MRI variables.
Conclusions: LV concentric hypertrophy in the elderly was closely associated with thoracic aortic atherosclerosis. The cardiac morbidity and mortality risk associated with LV hypertrophy and aortic atherosclerosis underscores the pivotal role of ventricular-arterial coupling in healthy aging.