Coronary CT Angiography Indicates Complexity of PCI
Background. Coronary computed tomography angiography (CCTA) provides information regarding lesion morphology and three-dimensional coronary anatomy incremental to coronary angiography. We addressed the question whether preprocedural CCTA bears potential for guiding percutaneous coronary interventions (PCI). Methods and Results. Sixty-six coronary lesions attempted with PCI within 6 months of preprocedural CCTA were retrospectively assessed. Lesion parameters from unenhanced computed tomography (CT) for calcium scoring and CCTA were analyzed and compared with PCI complexity. Complex PCI was defined as use of buddy wire, kissing balloon, necessity of high pressure balloons, or rotablator. Complex PCIs were observed in 32 interventions (48%). Median Agatston score and Hounsfield Units were higher in lesions with complex as compared to those with non-complex interventions with 130 (interquartile range, 23–276) vs 29 (0–158; P=.01), and 493 (245–631) vs 341 (68–520 Hounsfield Units; P=.04), respectively. Median local plaque volume and plaque mass were higher in complex PCI with 17 (2–39) vs 5 (0–19.5 mm3; P=.007), and 48 (15–99) vs. 16 (1.5–63 mg hydroxyapatite/mm; P=.03), respectively. Lesions leading to complex PCI were longer [1.8 (1.2–2.8) vs 1.3 (0.8–1.7) cm; P=.03], and had a higher rate of calcified plaques (23% vs 3%; P=.03). There was a significant correlation between CCTA- and angiography-derived local SYNTAX Scores (P<.001); the CCTA-derived score seems to be predictive for failed and complex PCI (area under the curve = 0.75 ± 0.13 and 0.66 ± 0.08, respectively). Conclusions. Preprocedural lesion assessment by CCTA indicates complexity of PCI. In patients with suspected complex coronary anatomy, prior CCTA adds important information for planning PCI.
Percutaneous coronary intervention (PCI) nowadays has become standard of care in symptomatic coronary artery disease (CAD) with suitable anatomy, and it is increasingly used in the treatment of complex CAD. However, overall lesion complexity impacts in many respects on the procedure itself, as well as on short- and long-term outcome. Lesion localization, severe calcifications, and vessel tortuosity may challenge the skills of the operator and increase the risk of procedural complications such as coronary artery dissection, perforation, and plaque shift. Hence, comprehensive preprocedural patient evaluation and lesion characterization are fundamental. In recent years, coronary computed tomography angiography (CCTA) has become a promising non-invasive imaging technique, mostly applied prior to coronary angiography. Although preferentially used in patients with low to intermediate probability of CAD to avoid invasive diagnostics for exclusion of the condition in these patients, CCTA provides nevertheless important incremental information to coronary angiography with regard to lesion characterization and three-dimensional coronary anatomy.
The angiographic SYNTAX score, developed to determine the complexity of CAD, is a comprehensive lesion-based scoring system, comprising the number of lesions, location, and complexity such as tortuosity, length, and calcification. An individual score is calculated for each significant lesion, and the total SYNTAX score is derived by adding all separate scorings together. The SYNTAX score has become an easily applicable angiographic scoring tool to assist in patient selection for interventional or surgical revascularization and risk stratification with respect to major adverse events following PCI.
So far, the potential incremental information of CCTA for guiding PCI has been studied only for chronic total occlusions (CTO), although suggestions for a broader use have been made. Indeed, lesion length >15 mm, target vessel tortuosity, and severe calcification assessed by CCTA and unenhanced computed tomography (CT) have been identified as independent predictors of procedural failure for CTO.
Thus, we hypothesized that preprocedural lesion characterization by CCTA and unenhanced CT might contribute to predict PCI complexity in extensive and complex CAD. To support this hypothesis and to provide the rationale for future research, we analyzed retrospectively the correlation between specific CCTA parameters and indicators of complex PCI, an operational study definition for the purpose of this study, comprising use of buddy wire, kissing balloon, necessity of high-pressure balloon, or use of rotablator due to heavy calcifications. Furthermore, we compared the lesion-related SYNTAX scores obtained by CCTA with those obtained by coronary angiography. Preprocedural lesion characterization by CCTA might provide important additional information on lesion complexity prior to invasive diagnostics, and thus may allow for early stratification of the most appropriate PCI strategy.
Abstract and Introduction
Abstract
Background. Coronary computed tomography angiography (CCTA) provides information regarding lesion morphology and three-dimensional coronary anatomy incremental to coronary angiography. We addressed the question whether preprocedural CCTA bears potential for guiding percutaneous coronary interventions (PCI). Methods and Results. Sixty-six coronary lesions attempted with PCI within 6 months of preprocedural CCTA were retrospectively assessed. Lesion parameters from unenhanced computed tomography (CT) for calcium scoring and CCTA were analyzed and compared with PCI complexity. Complex PCI was defined as use of buddy wire, kissing balloon, necessity of high pressure balloons, or rotablator. Complex PCIs were observed in 32 interventions (48%). Median Agatston score and Hounsfield Units were higher in lesions with complex as compared to those with non-complex interventions with 130 (interquartile range, 23–276) vs 29 (0–158; P=.01), and 493 (245–631) vs 341 (68–520 Hounsfield Units; P=.04), respectively. Median local plaque volume and plaque mass were higher in complex PCI with 17 (2–39) vs 5 (0–19.5 mm3; P=.007), and 48 (15–99) vs. 16 (1.5–63 mg hydroxyapatite/mm; P=.03), respectively. Lesions leading to complex PCI were longer [1.8 (1.2–2.8) vs 1.3 (0.8–1.7) cm; P=.03], and had a higher rate of calcified plaques (23% vs 3%; P=.03). There was a significant correlation between CCTA- and angiography-derived local SYNTAX Scores (P<.001); the CCTA-derived score seems to be predictive for failed and complex PCI (area under the curve = 0.75 ± 0.13 and 0.66 ± 0.08, respectively). Conclusions. Preprocedural lesion assessment by CCTA indicates complexity of PCI. In patients with suspected complex coronary anatomy, prior CCTA adds important information for planning PCI.
Introduction
Percutaneous coronary intervention (PCI) nowadays has become standard of care in symptomatic coronary artery disease (CAD) with suitable anatomy, and it is increasingly used in the treatment of complex CAD. However, overall lesion complexity impacts in many respects on the procedure itself, as well as on short- and long-term outcome. Lesion localization, severe calcifications, and vessel tortuosity may challenge the skills of the operator and increase the risk of procedural complications such as coronary artery dissection, perforation, and plaque shift. Hence, comprehensive preprocedural patient evaluation and lesion characterization are fundamental. In recent years, coronary computed tomography angiography (CCTA) has become a promising non-invasive imaging technique, mostly applied prior to coronary angiography. Although preferentially used in patients with low to intermediate probability of CAD to avoid invasive diagnostics for exclusion of the condition in these patients, CCTA provides nevertheless important incremental information to coronary angiography with regard to lesion characterization and three-dimensional coronary anatomy.
The angiographic SYNTAX score, developed to determine the complexity of CAD, is a comprehensive lesion-based scoring system, comprising the number of lesions, location, and complexity such as tortuosity, length, and calcification. An individual score is calculated for each significant lesion, and the total SYNTAX score is derived by adding all separate scorings together. The SYNTAX score has become an easily applicable angiographic scoring tool to assist in patient selection for interventional or surgical revascularization and risk stratification with respect to major adverse events following PCI.
So far, the potential incremental information of CCTA for guiding PCI has been studied only for chronic total occlusions (CTO), although suggestions for a broader use have been made. Indeed, lesion length >15 mm, target vessel tortuosity, and severe calcification assessed by CCTA and unenhanced computed tomography (CT) have been identified as independent predictors of procedural failure for CTO.
Thus, we hypothesized that preprocedural lesion characterization by CCTA and unenhanced CT might contribute to predict PCI complexity in extensive and complex CAD. To support this hypothesis and to provide the rationale for future research, we analyzed retrospectively the correlation between specific CCTA parameters and indicators of complex PCI, an operational study definition for the purpose of this study, comprising use of buddy wire, kissing balloon, necessity of high-pressure balloon, or use of rotablator due to heavy calcifications. Furthermore, we compared the lesion-related SYNTAX scores obtained by CCTA with those obtained by coronary angiography. Preprocedural lesion characterization by CCTA might provide important additional information on lesion complexity prior to invasive diagnostics, and thus may allow for early stratification of the most appropriate PCI strategy.