Prevalence of left ventricular hypertrophy in patients with mild hypertension in primary care: impact of echocardiography on cardiovascular risk stratification.

Background: Left ventricular hypertrophy (LVH) is an important predictor of cardiovascular risk, and its detection contributes to risk stratification. The aims of the present study were to estimate the prevalence of echocardiographic LVH and to evaluate the influence of echocardiography (ECHO) on cardiovascular risk stratification in hypertensive patients presenting in primary care.

Methods: In this cross-sectional study, 250 patients recently diagnosed with mild hypertension underwent clinical evaluation including electrocardiography (ECG), microalbuminuria measurement, 24-h blood pressure monitoring and ECHO. Level of cardiovascular risk was stratified, initially using routine procedures including ECG to assess target organ damage and then again after detection of LVH by ECHO.

Results: The frequency of echocardiographic LVH was 32%, substantially higher than that detected by ECG (9%). Initial cardiovascular risk stratification yielded the following results: 30% low risk, 49% medium risk, 16% high risk, and 5% very high risk subjects. The detection of LVH by ECHO provoked a significant change in the risk strata distribution, particularly in those patients initially classified as being at medium risk. In this group, 40% of subjects were reclassified as high risk subjects according to ECHO information. The new classification was as follows: 23% low risk, 30% medium risk, 42% high risk, and 5% very high risk subjects.

Conclusions: A substantial proportion of mildly hypertensive patients presenting in primary care have LVH determined by ECHO. Our results suggest that this procedure could significantly improve cardiovascular risk stratification in those patients with multiple risk factors, but no evidence of target organ damage by routine investigations.