The optimal measure of microvascular function with velocity time integral for cardiovascular risk prediction

Abstract

Methods Study population and study designThis study included 399 male subjects, a subset of the Firefighters and Their Endothelium (FATE) study cohort. The FATE study protocol has been described previously. 12 Briefly, all subjects were assessed for cardiovascular risk factors through physical examination and blood work. TheThe optimal measure of microvascular function with velocity time integral for cardiovascular risk prediction Vincent Lee, Billie-Jean Martin, Marinda Fung and Todd J Anderson Abstract Recent evidence suggests that microvascular function may be important in cardiovascular risk prediction. One measure of microvascular function is hyperaemic velocity time integral (VTI). We assessed whether the VTI of more than one beat of reactive hyperaemia would provide a stronger correlate to traditional cardiovascular risk factors using a subset of subjects from the Firefighters and Their Endothelium (FATE) study. Vascular function was assessed by measurement of hyperaemic blood velocity with high-resolution ultrasound of the brachial artery. We evaluated three measures in the current analysis: the VTI of the first beat, average VTI of 10 beats, and maximum VTI of 10 beats post-cuff release. A total of 399 male subjects (45.5 ± 10 years) were included in this analysis. Univariate correlations between the three end points and cardiovascular risk factors were calculated, and multivariable regression models constructed. Intra-observer variability was approximately equal for all VTI end points (coefficient of variation: first = 1.6%, average = 1.4%, maximum = 1.4%). Univariate correlations between VTI and cardiovascular risk factors were similar across all three end points. In multivariable analyses, there were no differences in the relationships between cardiovascular risk factors and the various VTI end points (R 2 from 0.090 to 0.102). Age, systolic blood pressure, and BMI were predictors of the three VTI end points (p < 0.05). In conclusion, the first beat of reactive hyperaemia remains the suitable measure of microvascular function.

The Association Between Testosterone and Vascular Function in Reproductive-Aged Females With Chronic Kidney Disease

“…Median measurements for PWV, AIx, FMD, and VTI were 7.5 m/s (Q1: 6.5m/s, Q3: 8.3 m/s), 22.5% (Q1: 15%, Q3: 31%), 8.2% (Q1: 5.4%, Q3: 11.4%), and 115.0 cm (Q1: 90.0 cm, Q3: 154.0 cm), respectively. Median outcome measurements in the study population did not appear to be markedly different from previously reported measurements in the general population, 17 , 18 , 19 , 20 , 21 , 22 although it is critical to recognize that standardized clinical reference ranges do not exist for any of these outcomes.

Figure 1 Testosterone levels in study sample, stratified by CKD treated with or without dialysis.

…”

Reactive hyperemia: a review of methods, mechanisms, and considerations

“…2). Investigators have reported peak velocity (52,84,92,114), peak blood flow (2,49,92,105), velocity-time integral (3,65,66), average hyperemic velocity (79,92,113), and average hyperemic flow (92,113). For RH to be more widely accepted and adapted for clinical evaluation, this variability will need to be addressed.…”

Microvascular dysfunction in schizophrenia: a case–control study

“…VTI has gained acceptance as a surrogate marker of cardiovascular risk in persons without overt CVD 16 , 17 and appears to be the optimal measure of microvascular function. 18 Microvascular function can also be measured using pulse arterial tonometry (PAT), 19 which may be used in risk stratification of cardiovascular risk. 20 On the other hand, flow-mediated dilation (FMD) of the brachial artery is the gold standard for the conduit vessel function.…”