BackgroundThe prevalence of echocardiographic left ventricular hypertrophy in essential hypertension ranges from 12 to 96% depending on the threshold values used to define it, and on the selection bias.ObjectiveTo estimate the prevalence of echocardiographic left ventricular hypertrophy by different criteria in essential hypertensives seen in primary care centres.MethodsCross-sectional study in a population-based sample of 946 essential hypertensives randomly selected in 39 primary care centres across Spain. Echo-cardiographic studies were performed in reference hospitals by trained observers (concordance Cohen κ index > 0.7) and analysed by a single observer.ResultsPrevalence of left ventricular hypertrophy ranged from 59.2% [95% confidence interval (CI) 56.1–62.3] by Framingham criteria to 72.7% (95% CI 69.9–75.6) using the criteria of De Simoneet al.(J Am Coll Cardiol1995; 25: 1056–1062). Prevalence was higher in males by the Cornell–Penn criteria, but higher in females when using Framingham or De Simoneet al.criteria. Eccentric hypertrophy was more frequent (51.3–54.1%) independently of the criteria used, particularly when adjusting wall-thickness-ratio for age (56.2–58.9%). Concentric remodelling was present in 6.5–11.4% and only 20.8–29.7% of patients had no evidence of left ventricular structural alterations. Factors independently associated with left ventricular hypertrophy in the logistic regression analysis were age, gender, systolic blood pressure, pulse pressure and body mass index.ConclusionPrevalence of echo left ventricular structural alterations among essential hypertensives seen in primary care centres in Spain ranged from 70.3 to 79.2% depending on the threshold values used. Left ventricular hypertrophy ranged from 59.2 to 72.7% and age-adjusted concentric remodelling ranged from 6.5 to 11.4% depending on the criteria used. Only one-quarter of hypertensive patients were free from morphological alterations.