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

Aims: 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 (SR_IVR) is more strongly related to invasive measurements of LV diastolic function, to date, studies on the role of SR_IVR in the long-term prognosis assessment are lacking. Thus, the goal of this study was to assess the potential additive prognostic value of SR_IVR on top of conventional cardiovascular risk factors in a general population.

Methods: 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 (SR_IVR), early diastole (SR_e), and atrial contraction (SR_a) in the mid-segment of the inferior, inferolateral, lateral, and septal wall of the LV.

Results: During the follow-up period (median 12.1 years), 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, SR_IVR of the inferolateral wall (SR_IVRinflat) 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 SR_IVR measured in the other myocardial walls were associated with cardiac outcome.

Conclusion: SR_IVRinflat predicted adverse outcome in the general population, on top of conventional cardiovascular factors. However, its incremental value as a prognosticator remained limited.