The comparison of endothelial function between conduit artery and microvasculature in patients with coronary artery
Emi Tajima1, Masashi Sakuma2, Seiko Tokoi1
1Department of Cardiovascular Medicine, Dokkyo Medical University School of Medicine, Mibu, Japan.
Insights
Assessing vascular endothelial function using flow-mediated dilation (FMD) and reactive hyperemia-peripheral arterial tonometry (RH-PAT) reveals distinct clinical significance. Combined low FMD and reactive hyperemia index (RHI) independently predict multivessel coronary artery disease (CAD).
Area of Science:
- Cardiovascular Research
- Vascular Biology
- Diagnostic Medicine
Background:
- Flow-mediated dilation (FMD) and reactive hyperemia-peripheral arterial tonometry (RH-PAT) assess endothelial function in conduit and resistance arteries, respectively.
- Clinical significance may differ due to the distinct vascular beds evaluated by FMD and RH-PAT.
Purpose of the Study:
- To investigate the distinct clinical significance of FMD and RH-PAT.
- To determine if combined assessment provides incremental value in predicting coronary artery disease (CAD).
Main Methods:
- Simultaneous FMD and RH-PAT measurements were performed in 131 patients undergoing coronary angiography for suspected CAD.
- Patients were categorized based on FMD (<6% or ≥6%) and reactive hyperemia index (RHI) (<1.67 or ≥1.67) thresholds.
Main Results:
- No overall correlation was found between FMD and RHI.
- The group with both FMD <6% and RHI <1.67 showed the highest incidence of multivessel CAD (52%).
- Low FMD and low RHI together independently predicted multivessel CAD (OR: 4.160, p=0.006).
Conclusions:
- Noninvasive assessment of endothelial function provides pathophysiological insights into both conduit and resistance vessels in CAD patients.
- Combined FMD and RHI evaluation offers valuable prognostic information beyond individual measures.
Background:
Flow-mediated dilation (FMD) and reactive hyperemia-peripheral arterial tonometry (RH-PAT) are both established modalities to assess vascular endothelial function. However, clinical significance of FMD and RH-PAT may be different because these methods measure vascular function in different vessels (conduit arteries and resistance vessels).
Methods:
To elucidate differences in the clinical significance of FMD and RH-PAT, a simultaneous determination of FMD was performed and reactive hyperemia index (RHI) measured by RH-PAT in 131 consecutive patients who underwent coronary angiography for suspicion of coronary artery disease (CAD).
Results:
There was no significant correlation between FMD and RHI in patients overall. When patients were divided into four groups: FMD ≥ 6%/RHI ≥ 1.67 group, FMD ≥ 6%/RHI < 1.67 group, FMD < 6%/RHI ≥ 1.67 group and FMD < 6%/RHI < 1.67 group, the highest incidence of multivessel CAD was seen in the FMD < 6%/RHI < 1.67 group (52%). Multiple logistic regression analysis showed that a prevalence of both FMD < 6% and RHI < 1.67 was an independent predictor of multivessel CAD (odds ratio: 4.160, 95% confidence interval: 1.505-11.500, p = 0.006). RHI was negatively correlated with the baseline vessel diameter (R = -0.268, p = 0.0065) and maximum vessel diameter (R = -0.266, p = 0.0069) in patients with FMD < 6%, whereas these correlations were absent in patients with FMD ≥ 6%.
Conclusions:
Present results suggest that noninvasive assessment of vascular endothelial functions provide pathophysiological information on both conduit arteries and resistance vessels in patients with CAD.
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