Practical utilization of cardiac computed tomography for the success in complex coronary intervention

The estimation of coronary artery calcium thickness by computed tomography angiography based on optical coherence tomography measurements

Optical coherence tomography (OCT) is recommended to be the most appropriate modality in assessing calcium thickness, however, it has limitations associated with infrared attenuation. Although coronary computed tomography angiography (CCTA) detects calcification, it has low resolution and hence not recommended to measure the calcium size. The aim of this study was to devise a simple algorithm to estimate calcium thickness based on the CCTA image. A total of 68 patients who had CCTA for suspected coronary artery disease and subsequently went on to have OCT were included in the study. 238 lesions of them divided into derivation and validation dataset at 2:1 ratio (47 patients with 159 lesions and 21 with 79, respectively) were analyzed. A new method was developed to estimate calcium thickness from the maximum CT density within the calcification and compared with calcium thickness measured by OCT. Maximum Calcium density and measured calcium-border CT density had a good correlation with a linear equation of y = 0.58x + 201 (r = 0.892, 95% CI 0.855-0.919, p < 0.001). The estimated calcium thickness derived from this equation showed strong agreement with measured calcium thickness in validation and derivation dataset (r2 = 0.481 and 0.527, 95% CI 0.609-0.842 and 0.497-0.782, p < 0.001 in both, respectively), more accurate than the estimation by full width at half maximum and inflection point method. In conclusion, this novel method provided the estimation of calcium thickness more accurately than conventional methods.

Comparison of Outcomes of Elective Percutaneous Coronary Intervention between Complex and High-Risk Intervention in Indicated Patients (CHIP) versus Non-CHIP

AIMS

Complex and high-risk intervention in indicated patients (CHIP) is an emerging concept in the contemporary percutaneous coronary intervention (PCI). CHIP is known to consist three factors, namely, (1) patient factors, (2) complicated heart disease, and (3) complex PCI. However, it remains unclear whether additional CHIP factors further increase the incidence of complications in complex PCI. Thus, in this study, we aim to compare the incidence of complications among definite CHIP, possible CHIP, and non-CHIP in terms of complex PCI and to further investigate the association between CHIP and complications.

METHODS

The primary aim of this study was to determine the major complications in PCI. We included 989 PCI lesions and divided those into definite CHIP (n=140), possible CHIP (n=397), and the non-CHIP groups (n=452).

RESULTS

The incidence of major complications was noted to be the highest in the definite CHIP, followed by the possible CHIP, and lowest in the non-CHIP (p=0.001). The multivariate logistic regression analysis using a generalized estimating equation revealed definite CHIP (versus non-CHIP: odds ratio (OR) 2.099, 95% confidence interval (CI) 1.062-4.150, p=0.033) was significantly associated with major complications after controlling for confounding factors. Another multivariate logistic regression analysis revealed immunosuppressive drugs (OR 3.040, 95% CI 1.251-7.386, p=0.014), unstable hemodynamics (OR 5.753, 95% CI 1.217-27.201, p=0.027), and frailty (OR 2.039, 95% CI 1.108-3.751, p=0.022) were significantly associated with major complications among CHIP factors.

CONCLUSIONS

The incidence of major complications in complex PCI was determined to be the highest in the definite CHIP, followed by the possible CHIP and lowest in the non-CHIP. Thus, more attention should be given to the three components of CHIP to prevent major complications in complex PCI.

Magnetically assisted soft milli-tools for occluded lumen morphology detection

Methodologies based on intravascular imaging have revolutionized the diagnosis and treatment of endovascular diseases. However, current methods are limited in detecting, i.e., visualizing and crossing, complicated occluded vessels. Therefore, we propose a miniature soft tool comprising a magnet-assisted active deformation segment (ADS) and a fluid drag-driven segment (FDS) to visualize and cross the occlusions with various morphologies. First, via soft-bodied deformation and interaction, the ADS could visualize the structure details of partial occlusions with features as small as 0.5 millimeters. Then, by leveraging the fluidic drag from the pulsatile flow, the FDS could automatically detect an entry point selectively from severe occlusions with complicated microchannels whose diameters are down to 0.2 millimeters. The functions have been validated in both biologically relevant phantoms and organs ex vivo. This soft tool could help enhance the efficacy of minimally invasive medicine for the diagnosis and treatment of occlusions in various circulatory systems.

Comparison of Long-Term Clinical Outcomes of Elective Percutaneous Coronary Intervention Between Complex and High-risk Intervention in Indicated Patients (CHIP) versus Non-CHIP

Recently, there has been a growing interest in complex and high-risk intervention in indicated patients (CHIP) in the contemporary percutaneous coronary intervention (PCI). CHIP is composed of the following 3 factors: (1) patient factors, (2) complicated heart disease, and (3) complex PCI. However, there are few studies that investigated the long-term outcomes of CHIP-PCI. The purpose of this study was to compare the incidence of long-term major adverse cardiovascular events (MACEs) among the definite CHIP, possible CHIP, and non-CHIP groups in complex PCI. We included 961 patients and divided them into the definite CHIP (n = 129), the possible CHIP (n = 369), and the non-CHIP groups (n = 463). During the median follow-up duration of 573 days (quartile 1:226 days to quartile 3:1,165 days), a total of 189 MACE were observed. The incidence of MACE was highest in the definite CHIP group, followed by the possible CHIP group, and lowest in the non-CHIP group (p = 0.001). Definite CHIP (vs non-CHIP: odds ratio 3.558, 95% confidence interval 2.249 to 5.629, p <0.001) and possible CHIP (vs non-CHIP: odds ratio 2.260, 95% confidence interval 1.563 to 3.266, p <0.001) were significantly associated with MACE after controlling for confounding factors. Among CHIP factors, active malignancy, pulmonary disease, hemodialysis, unstable hemodynamics, left ventricular ejection fraction, and valvular disease were significantly associated with MACE. In conclusion, the incidence of MACE in complex PCI was highest in the definite CHIP group, followed by the possible CHIP group, and lowest in the non-CHIP group. The concept of CHIP should be recognized to predict the long-term MACE in patients who undergo complex PCI.

Mean density of computed tomography for predicting rotational atherectomy during percutaneous coronary intervention

BACKGROUND

Multi-slice computed tomography (CT) allows noninvasive evaluation of the severity of coronary calcification. However, there has yet to be a definitive parameter based on the cross-sectional CT image for predicting the need for rotational atherectomy (RA). Therefore, we aimed to investigate the mean density of cross-sectional CT images to predict the need for RA during percutaneous coronary intervention (PCI).

METHODS

A total of 154 lesions with moderate to severe calcification detected in coronary angiography were identified in 126 patients who underwent coronary CT prior to PCI for stable angina. PCI with RA was performed for 48 lesions, and the remaining 106 were treated without RA. Multi-slice CT was retrospectively evaluated for its ability to predict the use of RA. We chose the most severely calcified cross-sectional image for each lesion. The mean density within the outer vessel contour, calcium arc quadrant of the cross-sectional CT image, calcium length, calcification remodeling index, and per-lesion coronary artery calcium score was studied.

RESULTS

Receiver-operator characteristic curve analysis revealed 637 Hounsfield units (HU) (area under the curve ​= ​0.98, 95% confidence interval: 0.97-1.00, p ​< ​0.001) as the best mean density cutoff value for predicting RA. Multivariate logistic regression analysis showed that a mean calcium level >637 HU was a strong independent predictor (odds ratio: 32.8, 95% confidence interval: 7.0-153, p ​< ​0.001) for using RA.

CONCLUSIONS

The mean density of the cross-sectional CT image, a simple quantitative parameter, was the strongest predictor of the need for RA during PCI.