Abstract
BACKGROUND: Left ventricular hypertrophy (LVH) categories are based on left ventricular mass index (LVMi). This study aimed to generate and externally validate sex-stratified LVMi cutoffs according to incremental mortality risk.
METHODS: LVH information was determined on 155 668 men (aged 61.3±17.3 years) and 147 880 women (61.8±18.3 years) from the National Echocardiography Database of Australia. Sex-specific mild to severe thresholds of the increasing 5-year mortality rate based on LVMi increments were generated. These new thresholds were then validated in a US Medicare-linked echocardiographic database.
RESULTS: In the National Echocardiography Database, 36198 men (23.3%) and 38 898 women (26.3%) had LVH, with an actual 5-year mortality rate of 38.3% and 31.2%, respectively. The statistical threshold at which LVMi was associated with an increased mortality rate was lower than traditional criteria in both men (≥88 g/m2 versus ≥115 g/m2) and women (≥82 g/m2 versus ≥95 g/m2). In men, compared with the lowest-risk LVMi stratum, the fully adjusted risk of 5-year death was 14% (95% CI, 3%-25%) and 68% higher (95% CI, 49%-90%) when LVMi levels were mildly (88 to <116 g/m2) to severely (≥140 g/m2) increased, respectively. In women, the equivalent LVMi thresholds of 82 to <112 g/m2 and ≥140 g/m2 were associated with a 13% (95% CI, 3%-24%), and 81% higher (95% CI, 58%-208%) risk. The association of these LVMi thresholds and mortality risk was confirmed in the US validation cohort selected for the absence of 27 separate comorbidities (n=12 355; mean age, 65.9±13.1 years; 49.7% female).
CONCLUSIONS: A high proportion of men and women have LVMi levels associated with an elevated mortality risk, despite absence of LVH. Such individuals may benefit from more proactive recognition and clinical management.