Impact of left ventricular concentricity on long-term mortality in a hospital-based population in Japan

Background The prognostic impact of relative wall thickness (RWT), ventricular concentricity, is controversial. Methods We retrospectively analyzed data obtained from 4444 consecutive patients who had undergone both transthoracic echocardiography and electrocardiography at our hospital in 2013. Those who presented with a history of previous episodes of myocardial infarctions and severe or moderate valvular disease were excluded from the analysis. We calculated RWT as follows: (2 x diastolic posterior wall thickness) / (the diastolic LV dimension). We defined high RWT as a ratio > 0.42. A total of 3654 patients were categorized into two groups: 492 with high RWT, and 3162 with normal RWT. Results The mean ages of those in the normal and high RWT groups were 64.6 (+/- standard deviation 16.3) and 71.6 (+/- 12.7) years, respectively (p<0.001). Prevalence of male sex, history of diabetes, hypertension, and chronic kidney disease, and the left atrium volume index was higher for the high RWT group than for the normal RWT group. The median follow-up period was 1274 days (interquartile range, 410-1470). The Kaplan-Meier curves showed a constant increase in all-cause death, with cumulative 3-year incidences of 18.3% and 10.8% for the high RWT and normal RWT groups, respectively (log-rank p<0.001). After adjusting for confounders, the increased mortality risk for those with high RWT relative to normal RWT was significant (hazard ratio, 1.64; 95% confidence interval, 1.27-2.10). This trend was consistent for the composite of deaths and major adverse cardiac events. Conclusion High RWT has a deleterious impact on long-term mortality.