Coronary distensibility index measured by computed tomography is associated with the severity of coronary artery disease

Synergistic prognostic value of coronary distensibility index and fractional flow reserve based cCTA for major adverse cardiac events in patients with Coronary artery disease

BACKGROUND

Coronary distensibility index (CDI), as an early predictor of cardiovascular diseases, has the potential to complement coronary computed tomography angiography (cCTA)-derived fractional flow reserve (CT-FFR) for predicting major adverse cardiac events (MACEs). Thus, the prognostic value of CT-FFR combined with CDI for MACEs is worth exploring.

METHODS

Patients with a moderate or severe single left anterior descending coronary artery stenosis were included and underwent FFR and CDI analysis based on cCTA, followed up at least 1 year, and recorded MACEs. Multivariate logistic regression analysis was performed to determine independent predictors of MACEs. The area under of receiver operating characteristic (ROC) curve was used to evaluated evaluate the diagnostic performance of CT-FFR, CDI, and a combination of the two.

RESULTS

All the vessel-specific data were from LAD. 150 patients were analysed. 55 (37%) patients experienced MACEs during follow-up. Patients with CT-FFR ≤ 0.8 had higher percentage of MACEs compared with CT-FFR > 0.8 (56.3% vs.7.3%, p < 0.05). Patients' CDI was significantly decreased in MACEs group compared with non-MACEs group (p < 0.05). Multivariate analysis revealed that diabetes (p = 0.025), triglyceride (p = 0.015), CT-FFR ≤ 0.80 (p = 0.038), and CDI (p < 0.001) are independent predictors of MACEs. According to ROC curve analysis, CT-FFR combined CDI showed incremental diagnostic performance over CT-FFR alone for prediction of MACEs (AUC = 0.831 vs. 0.656, p = 0.0002).

CONCLUSION

Our study provides initial evidence that combining CDI with CT-FFR shows incremental discriminatory power for MACEs over CT-FFR alone, independent of clinical risk factors. Diabetes and triglyceride are also associated with MACEs.

Automatic Assessment of 3D Coronary Artery Distensibility from Time-Resolved Coronary CT Angiography

Measuring coronary artery distensibility can determine the arterial remodeling type, arterial wall inflammation, and atherosclerotic plaques in early stage even before any observed narrowing in the lumen. This is crucial to promote an appropriate, preventive, and effective treatment. This study introduces a framework for calculating the 3D distensibility of the left coronary artery (LCA) from time-resolved coronary computerized tomography angiography (CCTA) images. Vesselness, region growing, and level sets are utilized for segmenting the LCA lumen in the systole and diastole CCTA time frames. The segmented arteries are then analyzed and registered using computational geometry to calculate the changes in the lumen cross-section areas between both time frames. In-vivo validation of the framework performance was accomplished against that of two radiologists and their consensus. Results demonstrate that the framework was accurate and reliable tool for measuring the coronary arteries distensibility.

The Long-Term Clinical Outcome of Posttraumatic Stress Disorder With Impaired Coronary Distensibility

OBJECTIVE

Coronary Distensibility Index (CDI) impairments reflect endothelial-dependent process associated with vulnerable-plaque composition. This study investigated the relation of impaired CDI with posttraumatic stress disorder (PTSD) and their predictive value for major adverse cardiovascular events (MACE).

METHODS

This study involved 246 patients (age = 63 [10] years, 12% women) with (n = 50) and without (n = 196) PTSD, who underwent computed tomography angiography to determine coronary artery disease and CDI. Extent of coronary artery disease was defined as normal, nonobstructive (<50% luminal stenosis), and obstructive (>50%). Incidence of MACE, defined as myocardial infarction or cardiovascular death, was documented during a mean follow-up of 50 months. Survival regression was employed to assess the longitudinal association of impaired CDI and PTSD with MACE.

RESULTS

A significant inverse correlation between CDI and Clinical Global Impression Severity scale of PTSD symptoms was noted (r = .81, p = .001). CDI was significantly lower in patients with PTSD (3.3 [0.2]) compared with those without PTSD (4.5 [0.3]), a finding that was more robust in women (p < .05). Covariate-adjusted analyses revealed that the relative risk of MACE was higher in patients with PTSD (hazard ratio [HR] = 1.56, 95% CI = 1.34-3.14) and those with impaired CDI (HR = 1.95, 95% CI = 1.27-3.01, per standard deviation lower CDI value). There was also a significant interaction between PTSD and impaired CDI (HR = 3.24, 95% CI = 2.02-5.53).

CONCLUSIONS

Impaired CDI is strongly associated with the severity of PTSD symptoms. Both impaired CDI and PTSD were independently associated with an increased risk of MACE during follow-up, and evidence indicated an interaction between these two factors. These findings highlight the important role of CDI in identifying individuals with PTSD at risk for MACE.

Assessing Vessel Tone during Coronary Artery Spasm by Dual-Acquisition Multidetector Computed Tomography Angiography

BACKGROUND

Diminished vascular tone is an established biomarker of heart damage. Little is known about the extent of coronary vessel tone (CVT) with spasm as assessed by dual-acquisition multidetector computed tomography angiography (MCTA) in patients with vasospastic angina (VSA).

OBJECTIVE

We evaluated the CVT modulated by intravenous nitrate injection (INI) using MCTA imaging in VSA patients.

METHODS

Twenty-one VSA patients (60 ± 9 years; 76% males) who underwent initial MCTA (without morning vasodilation), followed by an intracoronary ergonovine provocation test were included. Within 3 days after the initial MCTA patients received INI followed by 28-vessel segment spasm analyzed by MCTA 3D software, applying the following formula as the definition of CVT index (CVTI): (CSAIV nitrate - CSAinitial/CSAIV nitrate) ×100 %, where CSA is the cross-sectional area.

RESULTS

Compared to the initial MCTA measures, the INI provocation resulted in the significant increase of average diameter and CSA at the spasm site (2.60 mm [2.11-3.16] vs. 1.42 mm [1.13-2.13]; 5.37 mm2 [3.67-7.54] vs. 1.62 mm2 [1.02-3.02]; p < 0.001). The CVTI at the spastic segments was higher than at the proximal reference segments (41.0% [21.8-52.3] vs. 18.8% [5.9-26.6] for CVTI diameter; 65.1% [38.6-77.0] vs. 33.9% [5.2-48.1] for CVTI CSA, respectively). To predict VSA, the cut-off value for CVTI diameter was 38.6% (AUC 0.777; 95% CI 0.653-0.901) and 62.5% (AUC 0.779; 95% CI 0.657-0.902) for CVTI CSA in a receiver-operating characteristic curve analysis, with 57.1% sensitivity and 92.9% specificity.

CONCLUSIONS

This novel imaging technique for assessing CVT by dual-acquisition MCTA after applying INI provocation is suitable for the detection of coronary artery spasm in patients with VSA.

Influence of aortic valve leaflet calcification on dynamic aortic valve motion assessed by cardiac computed tomography

BACKGROUND

Computed tomography is the best noninvasive imaging modality for evaluating valve leaflet calcification.

OBJECTIVE

To evaluate the association of aortic valve leaflet calcification with instantaneous valve opening and closing using dynamic multidetector computed tomography (MDCT).

METHODS

We retrospectively evaluated 58 consecutive patients who underwent dynamic MDCT imaging. Aortic valve calcification (AVC) was quantified using the Agatston method. The aortic valve area (AVA) tracking curves were derived by planimetry during the cardiac cycle using all 20 phases (5% reconstruction). da/dt in cm²/s was calculated as the rate of change of AVA during opening (positive) or closing (negative). Patients were divided into 3 three groups according to Agatston score quartile: no AVC (Q2, Score 0, n = 18), mild AVC (Q3, Score 1-2254, n = 24), and severe AVC (Q4 Score >2254, n = 14).

RESULTS

In multivariable linear regression, compared to the non AVC group, the mild and severe AVC groups had lower maximum AVA (by -1.71 cm² and -2.25 cm², respectively), lower peak positive da/dt (by -21.88 cm²/s and -26.65 cm²/s, respectively), and higher peak negative da/dt (by 13.78 cm²/s and 18.11 cm²/s, respectively) (p < 0.05 for all comparisons).

CONCLUSIONS

AVA and its opening and closing were influenced by leaflet calcification. The present study demonstrates the ability of dynamic MDCT imaging to assess quantitative aortic valve motion in a clinical setting.

Impaired coronary artery distensibility is an endothelium-dependent process and is associated with vulnerable plaque composition

Coronary endothelial-dependent microvascular dysfunction, an early reversible stage of coronary artery disease (CAD), is associated with poor clinical outcome. The current study investigated whether coronary artery distensibility index (CDI) is associated with: (i) coronary endothelial-dependent microvascular dysfunction and (ii) vulnerable plaque composition among subjects with non-obstructive CAD. Seventy-four subjects with non-obstructive CAD (luminal stenosis <30%) were studied. In 20 subjects with and without coronary endothelial-dependent microvascular dysfunction, coronary flow reserve (CFR) of target segment during intracoronary (IC) infusion of acetylcholine (Ach) and bolus injection of adenosine as well as CDI at rest of corresponding target segment were measured. In 54 subjects, plaque compositions and CDI at rest of 154 non-obstructive coronary segments as well as proximal segment without disease were measured by intravascular ultrasound (IVUS). CDI was defined as: [(Early-diastolic cross-sectional-area (CSA) - End-diastolic CSA of target segment)/(end-diastolic CSA of target segment × coronary-pulse-pressure) × 10(3) ]. There is a direct association between endothelial dysfunction and impaired CDI of a coronary segment both in the given coronary segment and corresponding microvessels in which a strong agreement between CDI and CFR Ach (r(2)  = 0·85, P = 0·0001) was observed. Multivariable regression-analysis showed that CDI was an independent predictor of the vulnerable plaque characteristics. The risk of impaired CDI was 125% higher in segments with necrotic core and 60% higher in segments with fibrofatty components as compared to normal segments (P = 0·001). In conclusions, the current study reveals that impaired CDI is an endothelial-dependent process of both given coronary segment and corresponding microvessels and is associated with vulnerable plaque composition.

Noninvasive evaluation of coronary distensibility in older adults: a feasibility study with MR angiography

PURPOSE

To assess the feasibility of using magnetic resonance (MR) angiography to noninvasively measure the coronary distensibility index (CDI) in older adults.

MATERIALS AND METHODS

This study was approved by the institutional review board and was compliant with HIPAA. Informed consent was obtained from all participants. Three-dimensional MR angiography was performed in 23 patients with type 2 diabetes mellitus (DM) (mean age, 72.9 years ± 5.8 [standard deviation]; age range, 65-84 years; 12 men, 11 women) and 50 healthy aging control subjects (mean age, 73.1 years ± 5.6; age range, 64-84 years; 28 men, 22 women). Imaging data were acquired in the rest periods of cardiac motion identified during end systole and middiastole. For imaging data with different acquisition windows, cross-sectional coronary planes were reconstructed and matched for the same anatomy according to coronary landmarks. The CDI, defined as [(lumen area at systole--lumen area at diastole)/(lumen area at diastole × pulse pressure)] × 1000, was compared between patients with DM and control subjects by using the Student t test. With the same protocol, CDIs were calculated in 10 randomly selected subjects by two independent readers. In addition, MR angiography (in systole and diastole) was repeated in those 10 subjects after repositioning.

RESULTS

CDIs were measured in 43 coronary segments of patients with DM and in 124 coronary segments of control subjects. The mean CDI in patients with DM was significantly lower than that in control subjects (2.79 mm Hg(-1) ± 2.12 vs 9.14 mm Hg(-1) ± 5.87, respectively; P < .001). CDI measurements showed good intraobserver (r = 0.914), interobserver (r = 0.820), and imaging-repeat imaging agreements (r = 0.811).

CONCLUSION

Coronary MR angiography is a reproducible and repeatable noninvasive method for detecting significant differences in coronary distensibility between patients with DM and healthy aging control subjects.

Coronary artery distensibility assessed by 3.0 Tesla coronary magnetic resonance imaging in subjects with and without coronary artery disease

Coronary vessel distensibility is reduced with atherosclerosis and normal aging, but direct measurements have historically required invasive measurements at cardiac catheterization. Therefore, we sought to assess coronary artery distensibility noninvasively using 3.0 Telsa coronary magnetic resonance imaging (MRI) and to test the hypothesis that this noninvasive technique can detect differences in coronary distensibility between healthy subjects and those with coronary artery disease (CAD). A total of 38 healthy, adult subjects (23 men, mean age 31 ± 10 years) and 21 patients with CAD, diagnosed using x-ray angiography (11 men, mean age 57 ± 6 years) were studied using a commercial whole-body MRI system. In each subject, the proximal segment of a coronary artery was imaged for the cross-sectional area measurements using cine spiral MRI. The distensibility (mm Hg(-1) × 10(3)) was determined as (end-systolic lumen area - end-diastolic lumen area)/(pulse pressure × end-diastolic lumen area). The pulse pressure was calculated as the difference between the systolic and diastolic brachial blood pressure. A total of 34 healthy subjects and 19 patients had adequate image quality for coronary area measurements. Coronary artery distensibility was significantly greater in the healthy subjects than in those with CAD (mean ± SD 2.4 ± 1.7 mm Hg(-1) × 10(3) vs 1.1 ± 1.1 mm Hg(-1) × 10(3), respectively, p = 0.007; median 2.2 vs 0.9 mm Hg(-1) × 10(3)). In a subgroup of 10 patients with CAD, we found a significant correlation between the coronary artery distensibility measurements assessed using MRI and x-ray coronary angiography (R = 0.65, p = 0.003). In a group of 10 healthy subjects, the repeated distensibility measurements demonstrated a significant correlation (R = 0.80, p = 0.006). In conclusion, 3.0-Tesla MRI, a reproducible noninvasive method to assess human coronary artery vessel wall distensibility, is able to detect significant differences in distensibility between healthy subjects and those with CAD.