Prognostic value of left ventricular diastolic dysfunction in a general population

Abstract

Background: New techniques of Tissue Doppler Imaging (TDI) enable the measurement of myocardial velocities and provide information about left ventricular (LV) diastolic function. Recent studies explored the prognostic role of TDI-derived indexes. However, these studies considered only total mortality and did not provide information on cardiovascular mortality and morbidity. Therefore, we investigated in continuous and categorical analyses whether Doppler diastolic indexes contained any prognostic information over and beyond traditional cardiovascular risk factors in a general population.

Methods and results: We measured early and late diastolic peak velocities of mitral inflow (E and A) by conventional Doppler, and the mitral annular velocities (e' and a') by TDI in 793 participants (mean age 50.9 years). We calculated multivariable-adjusted hazard ratios for conventional and TDI Doppler indexes, while accounting for family cluster and cardiovascular risk factors. Median follow-up was 4.8 years (5th to 95th percentile, 3.0 to 5.4). With adjustments applied for covariables, e' velocity was a significant predictor of fatal and nonfatal cardiovascular (n=59; P=0.004) and cardiac events (n=40; P=0.001). TDI e' yielded a net reclassification improvement of 54.2% for cardiovascular and 64.0% for cardiac events. Hazard ratios of all cardiovascular (2.21; P=0.042) and cardiac (4.50; P=0.002) events were significantly elevated in participants with increased LV filling pressure compared with subjects with normal diastolic function.

Conclusions: TDI e' velocity is a significant predictor of fatal and nonfatal cardiovascular events in a general population. Furthermore, we observed an increase in all cardiovascular events in the diastolic dysfunction group characterized by elevated LV filling pressure.

Keywords: diastole; echocardiography; epidemiology; survival; tissue Doppler imaging.

Figure 1.

Flowchart for participants in the study. FLEMENGHO indicates Flemish Study on Environment, Genes and Health Outcomes; FU, follow‐up; LV, left ventricular.

Figure 2.

Incidence rates of fatal and nonfatal cardiovascular and cardiac events by quartiles of the distributions of the tissue Doppler imaging (TDI) e' velocity (A) and E/e' ratio (B) in 793 participants. Incidence rates were calculated as number of events per 1000 subject/year and were standardized for sex and age (age groups: <40 years; 40 to 60 years; >60 years) by the direct method. The number of endpoints contributing to the rates is shown. P values are for trend.

Figure 3.

Cumulative incidence estimates (1‐Kaplan‐Meier survival estimates) for all cardiovascular and cardiac events. Normal left ventricular (LV) diastolic function is normal E/A and E/e'; impaired relaxation is low age‐specific E/A and normal E/e'; elevated LV filling pressure is high E/e'. P values are for the differences between groups by the log‐rank test. LVDD indicates left ventricular diastolic dysfunction.