Ankle –branchial index (ABI)
When detecting CAVI and ba-PWV, the value of ABI will be detected
respectively. In this study, we will analyze the differences between the
two kinds of ABI.
Carotid ultrasound
detection
Carotid intima-media thickness
(CIMT) and plaque are assessed with ultrasound (VIVID E80, GE, USA) with
a connected electrocardiogram. The whole extracranial carotid artery was
scanned by longitudinal and cross-sectional two-dimensional (2D) B-mode
image, including common carotid artery, bifurcation of common carotid
artery (CCA), extracranial segment of internal carotid artery (ICA) and
extracranial segment of extracranial carotid artery (ECA) according to
the Mannheim Carotid Intima-Media Thickness and Plaque
Consensus13 .
CIMT is a double-line pattern visualized by echography on both walls of
the CCA in a longitudinal image. Two parallel lines, which consist of
the leading edges of two anatomical boundaries, form it: the
lumen-intima and media-adventitia interfaces13. Edge
detection system is used for semi-automatic measurements performed on a
10-mm segment of CCA instantaneously. Using the semi-automatic
measurement software, the sampling frame was sampled at 1cm in
two-dimensional mode and measured the posterior wall at the bifurcation
of the common carotid artery and 1cm from the bifurcation of the common
carotid artery. Measurement of CIMT should occur within a region free of
plaque with a clearly identified double-line pattern in diastole on the
selected frame. The measurement parameters include the average value of
CIMT, the maximum value of CIMT, the minimum value of CIMT, the standard
deviation of CIMT and the number of successful CIMT measurements. CIMT ≥
1.0 mm is defined as thickening.
Plaques are focal structures encroaching into the arterial lumen of at
least 0.5 mm or 50% of the surrounding CIMT value, or demonstrates a
thickness >1.5 mm as measured from the intima-lumen
interface to the media-adventitia interface from 2 different angles of
insonation, in longitudinal and cross-sectional
views13.
The evaluation of carotid stenosis will be combined with the results of
vascular diameter and area measurement and hemodynamic parameters. A
peak systolic velocity (PSV) of less than 125 cm/s corresponds to lower
than 50% stenosis; of 125-230 cm/s corresponds to 50%-69% stenosis;
and one of more than 230 cm/s corresponds to greater than 70%
stenosis14, 15. The intravascular diameter method was
used to evaluate the carotid stenosis using the European Carotid Surgery
Trial (ECST), that is, the ratio of the residual diameter of the
stenosis to the original diameter of the stenosis. The area method
evaluates the stenosis rate as the area stenosis rate = [1-(minimum
lumen cross-sectional area / original lumen cross-sectional area)]
x100%.
End points and assessment
The primary outcome will be the
incidence of MACEs.
MACEs include all cause death, cardiovascular death, non-cardiovascular
death, undetermined cause of death, myocardial infarction (MI),
hospitalization for unstable angina (UA), transient ischemic attack
(TIA) and stroke, heart failure (HF) event, percutaneous coronary
intervention (PCI), coronary artery bypass grafting (CABG), peripheral
vascular intervention (PVI), stent thrombosis16.
Cardiovascular death includes acute MI, sudden cardiac death, heart
failure, stroke, cardiovascular procedure and cardiovascular hemorrhage
etc.
Definition of MI is clinical syndrome where there is evidence of
myocardial necrosis in a clinical setting consistent with acute
myocardial ischemia, including presence of acute symptoms of myocardial
ischemia, such as chest, upper extremity, mandibular, or epigastric
discomfort, or an ischemic equivalent such as dyspnea or fatigue;
presence of new or presumed new significant ST-segment–T wave (ST-T)
changes or new left bundle-branch block (LBBB) consistent with acute
myocardial ischemia; presence of new or presumed new pathological Q
waves consistent with MI; presence of thrombus in a major epicardial
vessel consistent with an acute MI; demonstration of a new change in
myocardial viability or function consistent with MI; occurrence of an
adverse angiographic finding during PCI consistent with acute myocardial
ischemia; angiographic documentation of a new CABG or new native
coronary artery occlusion within 48 h of CABG surgery; cardiac biomarker
level16.
Definition of hospitalization for UA include unscheduled hospitalization
for the management of UA, occurring within 24 h of the most recent
symptoms. Hospitalization is defined as an admission to an inpatient
unit or a visit to an emergency department (ED) that results in at least
a 24-h stay (or a change in calendar date if the hospital admission or
discharge times are not available) 16.
Stroke is defined as an acute episode of focal or global neurological
dysfunction caused by brain, spinal cord, or retinal vascular injury as
a result of hemorrhage or infarction. Categorical description of stroke
type classified into 1 of 3 mutually exclusive categories (ischemic,
hemorrhagic, undetermined) 16.
TIA is defined as transient episode of focal caused by brain, spinal
cord, or retinal ischemia without acute infarction16.
HF event is defined as presentation of the patient for an urgent,
unscheduled clinic/office/ED visit or hospital admission, with a primary
diagnosis of HF, where the patient exhibits new or worsening symptoms of
HF on presentation, has objective evidence of new or worsening HF, and
receives initiation or intensification of treatment specifically for
HF16.
PCI is the placement of an angioplasty guidewire, balloon, or other
device (eg. stent, atherectomy, brachytherapy, or thrombectomy catheter)
into a native coronary artery or CABG
for the purpose of mechanical coronary
revascularization16.
CABG surgery is a procedure performed to bypass partially or completely
occluded coronary arteries with veins and/or arteries harvested from
elsewhere in the body, thereby improving the blood supply to the
coronary circulation supplying the myocardium (heart muscle)16.
A PVI is a catheter-based or open surgical procedure designed to improve
arterial or venous blood flow or otherwise modify or revise vascular
conduits. Procedures may include, but are not limited to, percutaneous
transluminal balloon angioplasty, stent placement, thrombectomy,
embolectomy, atherectomy, dissection repair, aneurysm exclusion,
treatment of dialysis conduits, placement of various devices,
intravascular thrombolysis or other pharmacotherapies, and open surgical
bypass or revision16.