Strain rate during isovolumic relaxation as a prognostic biomarker for long-term cardiovascular morbidity and mortality: an exploratory study on a general population.

Abstract

Left ventricular (LV) strain rate (SR) during early relaxation correlates with LV filling pressures and has been assessed as a prognostic biomarker in several cardiac diseases. Conversely, even though LV SR during isovolumic relaxation (SRIVR)is more strongly related to invasive measurements of LV diastolic function, to date, studies on the role of SRIVR in the long-term prognosis assessment are lacking. Thus, the goal of this study was to assess the potential additive prognostic value of SRIVR on top of conventional cardiovascular risk factors in a general population. 657 subjects (mean age 51.6y; 47.6% males) were included in this study and, besides clinical and standard echocardiographic assessment, tissue Doppler imaging (TDI)-based SR was measured during IVR (SRIVR), early diastole (SRe), and atrial contraction (SRa) in the mid-segment of the inferior, inferolateral, lateral, and septal wall of the LV. During the follow-up period (median 12.1years), the total number of major adverse cardiac events was 85 (13.4%). Overall, after adjustment for known cardiovascular risk factors and important echocardiographic indices in a multivariable-adjusted Cox regression model, SRIVR of the inferolateral wall (SRIVRinflat) remained an independent predictor of fatal and nonfatal cardiac events (HR: 1.49, p = 0.016), along with GLS (HR: 1.35, p = 0.027), age (HR: 1.09, p < 0.001), and male sex (HR: 2.06, p = 0.037). None of SRIVR measured in the other myocardial walls were associated with cardiac outcome. SRIVRinflat predicted adverse outcome in the general population, on top of conventional cardiovascular factors. However, its incremental value as a prognosticator remained limited.