Abstract 11917: Midlife Cardiovascular Risk Factors and Late-Life Unrecognized and Recognized Myocardial Infarction Detected by Cardiac Magnetic Resonance (ICELAND-MI, the AGES-Reykjavik Study)

Abstract

Introduction: The association of midlife atherosclerosis risk factors (RF) with later unrecognized myocardial infarction (UMI) is unclear. We investigated associations of midlife RF with UMI and recognized MI (RMI) detected 31 years later by cardiac magnetic resonance (CMR). Methods: The Reykjavik Study (1967-91) collected serial measures of RF in subjects born 1907-35, mean (SD) age 48 ± 7 years. In ICELAND-MI (2004-07), 936 randomly selected survivors (76 ± 5 years) were evaluated by CMR. Analysis included logistic regression and random effects modeling adjusted for age, sex, and covariates. All comparisons are relative to the no MI group. Results: At baseline midlife evaluation, atherosclerotic risk assessed by a modified Framingham risk score was significantly higher in RMI and UMI than in no MI (7.4 ± 6.3%; 7.1 ± 6.2% vs 5.4 ± 5.8% respectively, p<0.001). RMI and UMI were more common in men (65%, 64% vs 43%; p<0.0001). Compared with no MI, baseline systolic BP was significantly higher in UMI (138 ± 17 mm Hg vs 133 ± 17 mm Hg; p=0.006), and trended higher in RMI (p=0.06). Likewise, baseline diastolic BP was significantly elevated in both RMI and UMI (88 ± 10 mm Hg and 87 ± 10 mm Hg vs 84 ± 10 mm Hg; p<0.02). Serum cholesterol was significantly higher in RMI (6.7 ± 1.1 mmol/L vs 6.2 ± 1.1 mmol/L; p=0.005), as were serum triglycerides (1.4 ± 0.7 mmol/L vs 1.3 ± 0.7 mmol/L; p<0.03). Serum cholesterol trended higher in UMI (p=0.08). Compared to no MI, serial midlife systolic and diastolic BP were significantly higher in RMI [beta=4.03 ± 1.64 (SE) mm Hg, p=0.014 and 2.05 ± 0.94 mm Hg, p=0.025, respectively] as were cholesterol and triglycerides [0.43 ± 0.11 mmol/L, p=0.001 and 0.31 ± 0.07 mmol/L, p<0.0001, respectively]. Systolic BP was significantly higher in UMI [beta=2.76 ±1.31 mm Hg, p=0.036, figure]. Conclusions: Midlife vascular risk factors are associated with UMI and RMI detected by CMR 31 years later. Systolic BP was the most important individual risk factor associated with later UMI.