Distinct Aspects of Left Ventricular Mechanical Function Are Differentially Associated With Cardiovascular Outcomes and All-Cause Mortality in the Community.

BACKGROUND

There are few data relating novel measures of left ventricular (LV) mechanical function to cardiovascular disease (CVD) outcomes in the community. Whether distinct components of LV mechanical function provide information regarding risk for different CVD outcomes is unclear.

METHODS AND RESULTS

We used speckle tracking echocardiography to quantify distinct components of LV mechanical function (measured as LV strain in multiple planes) in 2831 Framingham Offspring Study participants (mean age, 66 years; 57% women, 97% with LV fractional shortening >0.29). Participants were followed for 6.0±1.2 years for onset of 69 coronary heart disease (CHD), 71 heart failure (HF), and 199 mortality events. Adjusting for CVD risk factors, longitudinal LV strain appeared associated with incident CHD (hazards ratio [HR] per SD increment, 1.29; 95% confidence interval [CI], 1.00-1.67; P=0.05), whereas circumferential and radial strain were not (P>0.37 for both); however, the association of longitudinal strain with CHD was nonsignificant after Bonferroni correction. By contrast, circumferential strain was a significant predictor of incident HF (HR per SD increment, 1.79; 95% CI, 1.35-2.37; P<0.0001). Decrements in circumferential, radial, and longitudinal strain measures were related to all-cause mortality (P<0.008 for all). Results remained similar in multivariable models adjusting additionally for the conventional echocardiographic measures of LV mass and fractional shortening.

CONCLUSIONS

In our large, community-based sample, distinct components of LV mechanical function were associated with specific CVD outcomes. Additional studies are needed to replicate these findings and investigate the prognostic and therapeutic utility of these novel measures of LV mechanical function.