Abstract 2990: Left Ventricular Hypertrophy in the Stroke Belt, Contrasted with the rest of the USA: The Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study
BACKGROUND AND PURPOSE: Stroke mortality is higher in the Southeastern U.S. (the “Stroke Belt”) compared to rest of the US. We hypothesized that left ventricular hypertrophy (LVH), a stroke risk factor, would have a higher prevalence in the Stroke Belt
METHODS: REGARDS is a longitudinal observational study recruiting a national sample of 30,000 black and white participants aged ≥ 45 years to examine causes of geographic and racial disparities in stroke mortality. Centralized telephone interviews obtain medical history and an in-home visit collects anthropomorphic, and physiological measurements, blood samples, and a resting ECG. All ECGs are coded centrally. For the first 8325 participants the ECG recorded only a 7-lead ECG, then the study contined with 12-lead recordings. Only the latter are reported. Excluded were ECGs with QRS ≥ 120ms, or of poor quality (< 1.3%). As of February 1, 2006, data were available for 11,923 participants. Three indices of LVH were estimated: Minnesota code (MC) (with “strain pattern”), Cornell voltage (CV), and CV/QRS product (CP). The MCLVH criteria included codes 3.1 + (4.1 or 4.2 or 4.3 or 5.1 or 5.2 or 5.3).The sex-specific cutpoints for CVLVH were women: 2200 μV,and men: 2800μV. The CPLVH cutpoint was 2440 mm ms.
RESULTS: LVH prevalence for the US was lowest for MC (0.39%), next for CP (4.1%), and highest for CV (4.3%). The Table⇓ contains the odds of LVH by factors of interest, adjusted for the other variables in the table⇓. None of the 3 LVH indices showed a significant excess of LVH in the Stroke Belt, whereas all 3 of the indices show an excess of LVH in blacks vs. whites. Women had significantly more LVH by CV and CP criteria and age was marginally associated with LVH.
CONCLUSIONS: There is excess LVH, an independent risk factor for stroke, among blacks compared to whites.However, given no significant association of LVH with the Stroke Belt, it is unlikely that LVH is a substantial contributing factor to the excess stroke mortality in that region