The prognostic value of the ratio of early transmitral filling velocity to early diastolic strain rate in a large general population cohort

Abstract

Abstract Background The ratio of early transmitral filling velocity (E) to early diastolic strain rate (e'sr) (E/e'sr) has recently been proposed as a novel non-invasive measure of early LV filling pressure. Using two-dimensional speckle tracking derived e'sr instead of Doppler-derived e' circumvents several of the limitations known to the Doppler-based method including angle-dependency and the high susceptibility to sampling location. The prognostic value of E/e'sr in relation to cardiovascular morbidity and mortality has previously been demonstrated in a range of specific patient populations including patients with type 2 diabetes, heart failure, atrial fibrillation, and a smaller general population study. Purpose To investigate the prognostic value of E/e'sr in relation to major adverse cardiovascular events (MACE) in a large low-risk general population. Methods A total of 3,782 participants were included in the present study. All participants had a comprehensive echocardiographic examination performed and analyzed. Two-dimensional speckle tracking analysis was performed to determine e'sr. Additionally, participants answered a questionnaire and underwent a general health examination. The outcome was MACE defined as a composite of incident heart failure, acute myocardial infarction, and cardiovascular death. Cox proportional hazards regression models were used to assess the relationship between E/e'sr and MACE. Results The mean age of the study population was 56±17 years and 57.2% were female. Mean E/e'sr was 63.4±19.6cm, mean E/e' was 7.6±2.8, and mean left ventricular ejection fraction was 56.8±5.9%. During follow-up (median: 3.5 years, IQR: 2.6, 4.3) a total of 133 (3.5%) met the composite outcome. Increasing E/e'sr was significantly associated with MACE in a univariable model (Figure 1) with a Harrel's C-statistic of 0.73. Increasing E/e'sr remained significantly associated with MACE in a multivariable model adjusted for age, sex, smoking status, hypercholesterolemia, hemoglobin, diabetes, history of ischemic heart disease, hypertension, heart rate, LVEF <50%, systolic blood pressure, and left atrial volume index (HR=1.09 [95% CI: 1.03; 1.16], p=0.002, per 10cm increase). A total of 824 participants had an E/e' in the indeterminate zone (E/e' between 9 and 14). In this subgroup, E/e'sr remained significantly associated with MACE (HR=1.14 [95% CI: 1.01; 1.29], p=0.038, per 10cm increase). This was also the case in all participants with a E/e <14 (n=3,649) (HR=1.12 [95% CI: 1.02; 1.23], p=0.018, per 10cm increase). Conclusion In this large general population sample, E/e'sr provides independent prognostic information in relation to MACE. This was even the case in participants with normal E/e'. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): Gentofte University Hospital