With regard to the characteristics of spasm segment, had been clearly described by other invasive imaging methods including intravascular ultrasound and optical coherence tomography. However, there is potential risk during these invasive procedures, such as severe myocardial ischemia or fatal arrhythmia. Presently available imaging test for coronary artery disease in multi detector-row computed tomography angiography (MDCTA) evaluation has high diagnostic accuracy to evaluate coronary artery stenosis. However, previous report assessing imaging findings or diagnostic accuracy of MDCTA in patients with vasospastic angina (VSA) is lacking.
Previously investigators analyzed the characteristics of coronary spasm segment in an observational individual dataset, suspected VSA patients (n=20) underwent dual-acquisition of MDCTA (initial and intravenous nitrate injected CT imaging), the diagnostic accuracy showed sensitivity: 73%, specificity: 100%, positive predictive value: 100%, and negative predictive value: 56%. Further study is necessary because previous analysis presented limited sample size and deficiency of healthy control. Therefore, investigators hypothesis that dual-acquisition of MDCTA in noninvasive tool for coronary assessment provide more information of coronary characteristics, and the diagnostic efficacy would be non-inferior as compared with the invasive coronary imaging modality in coronary spasm-induced angina attacks.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
90
Investigators define the positive criteria for VSA on MDCTA as follows: 1. Significant stenosis (≥ 50%) with negative remodeling but no definite evidence of plaques, which completely dilated on IV nitrate CT, or 2. Diffuse small diameter (\< 2mm) of a major coronary artery with beaded appearance which completely dilated on IV nitrate CT.
Suspected vasospastic angina subjects with negative MDCTA-derived VSA are considered as reference modality.
Dong-A University Hospital
Busan, South Korea
RECRUITINGSafety and Tolerability
MDCTA procedure: all subjects will undergo MDCTA without a vasodilator ("initial CT") in the early morning before the ergonovine provocation spasm test. Subsequent "IV nitrate CT" will be allowed at a 3-day washout period after the first contrast usage. The scan protocol for the IV nitrate CT is as follows: during continuous injection of the intravenous vasodilating agent (isosorbidedinitrate 2 mg/hr), blood pressure will be checked every 2 minutes. When both the systolic and diastolic blood pressure decrease by 10 mmHg in comparison to the initial value, the CT scan initiate and images will be acquired during the nitrate infusion. Investigators define the positive criteria for VSA on MDCTA as follows: 1. Significant stenosis (≥ 50%) with negative remodeling but no definite evidence of plaques, which completely dilated on IV nitrate CT, or 2. Diffuse small diameter (\< 2mm) of a major coronary artery with beaded appearance which completely dilated on IV nitrate CT.
Time frame: 3 days
Coronary vessel distensibility
To evaluate the extent of coronary vessel distensibility by dual-acquisition of cardiac MDCTA in patients with VSA
Time frame: 3 days
Cutoff value of coronary vessel distensibility index
To consider the cutoff value of coronary vessel distensibility index (CVDI) to predict the coronary spasm induced angina-like attacks. Investigators define the CVDI as following formulas: 1. CVDI-CSA (cross-section area)= \[(CSA\_IV nitrate - CSA\_initial) / CSA\_IV nitrate\]ⅹ100% or 2. CVDI-D (diameter)= \[(D\_IV nitrate - D\_initial) / D\_IV nitrate\]ⅹ100%.
Time frame: 3 days
Incidence of multi-vessel spasm
To examine the incidence of multi-vessel coronary spasm by MDCTA.
Time frame: 3 days
Diagnostic accuracy of MDCTA
To determine the diagnostic accuracy of MDCTA modalities for detection of VSA.
Time frame: 3 days
Characteristics of spasm-related coronary artery segment
To describe the characteristics of spasm-related coronary artery segment including vessel remodeling, plaque composition and stenosis degree.
Time frame: 3 days
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