Geographic variation in left ventricular mass and mass index: a systematic review

Abstract

Left ventricular (LV) hypertrophy, defined as an abnormal increase in LV mass (LVM), is an important prognostic indicator and therapeutic target. LVM is often divided by body surface area to derive indexed mass; however, this does not correctly identify pathological LV hypertrophy in all people, especially when body composition is altered, or in different ethnic groups. We evaluated published ranges of echocardiographic LVM in healthy adult populations from different countries, excluding control groups, and compared them with the American Society of Echocardiography reference ranges. A total of 33 studies met the inclusion criteria. In men and women, there was wide variation in the ranges of LVM with a tendency for the upper limit to increase geographically westward; this variation remained for indexed mass. Several ranges fell outside the upper reference limits: in men, 13 of the mass ranges and 16 of indexed mass; and in women, 8 mass and 16 indexed mass. This review has shown that current guidelines may need revision as some published series suggest that greater LV mass should be considered normal. This may be explained by ethnic differences and supports the need for widely applicable and ethnically diverse reference ranges to be established.

Normal values of left-ventricular mass

“…The results show that the upper normality limits for left-ventricular mass as adjusted for BSA or height are lower than those reported in several previous studies either in the whole population or in female sex [9,10,14]. In our population the upper limits of left-ventricular mass were substantially lower than those adopted by the ESH/ESC guidelines on hypertension [11] the difference being similar both in men (114 vs. 125 g/m 2 ) and in women (99 vs. 110 g/m 2 ).…”

“…An up-dated review by Poppe et al [14] of 33 studies providing normal ranges of echocardiographic left-ventricular mass in healthy adult populations from different countries has documented that 15 studies included individuals with type 2 diabetes mellitus, and 13 studies overweight or obese individuals. Finally, and most importantly, in all studies on identification of normal left-ventricular mass values and thus left-ventricular hypertrophy (LVH) the BP status has been assessed only by office BP measurement [15].…”

Prognostic value of left ventricular mass normalized to different body size indexes

“…It is worth noting that the reference values for LVM index in apparently healthy individuals are not expected to be superimposable across studies aimed to define normal thresholds that differ for factors such as age and body size distribution, sex prevalence, and ethnicity, all of which impact on left ventricular structure [27]. It is important to underline, however, that some sources of errors such as inclusion of patients with overweight/obesity, diabetes, or cardiovascular disease, should be avoided.…”

Recommendations on the Use of Echocardiography in Adult Hypertension: A Report from the European Association of Cardiovascular Imaging (EACVI) and the American Society of Echocardiography (ASE)†

“…Only a part of these differences is accountable to ethnic variation in body size, and can be corrected by scaling. 22 It is still unclear to what extent ethnic differences prevail when scaling for fatfree mass. It remains to be clarified to what extent these ethnic and population differences include a different prognosis and how to integrate ethnicities and populations in the definition of hypertrophy.…”