Pre-hypertension and subclinical cardiac damage: A meta-analysis of echocardiographic studies.

AIM: The association between pre-hypertension (pre-HTN) and subclinical cardiac damage remains undefined. We performed a systematic meta-analysis of echocardiographic studies in order to provide a comprehensive information on structural and functional cardiac changes in untreated pre-HTN subjects.

DESIGN: Studies were identified by crossing the following search terms: "pre-hypertension", "high normal blood pressure" "heart" "left ventricular hypertrophy", "left ventricular function", "diastolic function", "left atrial size", "aortic root size", "echocardiography."

RESULTS: A total 73,556 subjects (44,170 normotensive, 17,314 pre-HTN, and 12,072 HTN individuals) of both genders were included in 20 studies. Left ventricular (LV) mass index and relative wall thickness (RWT) were greater in pre-HTN than in normotensives (standard means difference: 0.32 ± 0.07 and 0.30 ± 0.07, respectively, p < 0.001 for both). The E/e' ratio (0.26 ± 0.02, p < 0.001) and left atrium (LA) diameter were higher (0.55 ± 0.02, p < 0.001) in pre-HTN than in normotensive subjects. HTN subjects showed a greater LV mass index (0.27 ± 0.03, p < 0.001), RWT (0.23 ± 0.02, p < 0.001), increased E/e' ratio (0.38 ± 0.09, p < 0.001) as well as LA diameter (0.31 ± 0.12, p < 0.001) than pre-HTN subjects.

CONCLUSIONS: Our meta-analysis suggests that alterations in cardiac structure and function in pre-HTN subjects are intermediate between normotensive and HTN individuals. These findings suggest that pre-HTN may not be a benign entity. If so, early preventive strategies may prevent preclinical cardiac damage.