Comprehensive biomechanical and anatomical atherosclerotic plaque metrics predict major adverse cardiovascular events: A new tool for clinical decision making

BACKGROUND AND AIMS

Anatomical imaging alone of coronary atherosclerotic plaques is insufficient to identify risk of future adverse events and guide management of non-culprit lesions. Low endothelial shear stress (ESS) and high plaque structural stress (PSS) are associated with events, but individually their predictive value is insufficient for risk prediction. We determined whether combining multiple complementary, biomechanical and anatomical plaque characteristics improves outcome prediction sufficiently to inform clinical decision-making.

METHODS

We examined baseline ESS, ESS gradient (ESSG), PSS, and PSS heterogeneity index (HI), and plaque burden in 22 lesions that developed subsequent events and 64 control lesions that remained quiescent from the PROSPECT study.

RESULTS

86 fibroatheromas were analysed from 67 patients. Lesions with events showed higher PSS HI (0.32 vs. 0.24, p<0.001), lower local ESS (0.56Pa vs. 0.91Pa, p = 0.007), and higher ESSG (3.82 Pa/mm vs. 1.96 Pa/mm, p = 0.007), while high PSS HI (hazard ratio [HR] 3.9, p = 0.006), high ESSG (HR 3.4, p = 0.007) and plaque burden>70 % (HR 2.6, p = 0.02) were independent outcome predictors in multivariate analysis. Combining low ESS, high ESSG, and high PSS HI gave both high positive predictive value (80 %), which increased further combined with plaque burden>70 %, and negative predictive value (81.6 %). Low ESS, high ESSG, and high PSS HI co-localised spatially within 1 mm in lesions with events, and importantly, this cluster was distant from the minimum lumen area site.

CONCLUSIONS

Combining complementary biomechanical and anatomical metrics significantly improves risk-stratification of individual coronary lesions. If confirmed from larger prospective studies, our results may inform targeted revascularisation vs. conservative management strategies.

Anthracyclines and the risk of arrhythmias: A systematic review and meta-analysis

BACKGROUND

There have been controversial findings from recent studies regarding anthracyclines use and the subsequent risk of arrhythmias. This study aimed to evaluate the existing evidence of the risk of arrhythmias in patients treated with anthracyclines.

METHODS

PubMed, Scopus, and Web of Science databases were searched up to April 2022 using keywords such as "anthracycline" and "arrhythmia." Dichotomous data were presented as relative risk (RR) and confidence interval (CI), while continuous data were presented as mean difference (MD) and CI. Revman software version 5.4 was used for the analysis.

RESULTS

Thirteen studies were included with a total of 26891 subjects. Pooled analysis showed that anthracyclines therapy was significantly associated with a higher risk of arrhythmia (RR: 1.58; 95% CI: 1.41-1.76; P < .00001), ST segment and T wave abnormalities (RR: 1.73, 95% CI: 1.18-2.55, P = .005), conduction abnormalities and AV block (RR = 1.86, 95% CI = 1.06-3.25, P = .03), and tachycardia (RR: 1.736, 95% CI: 1.11-2.69, P = .02). Further analyses of the associations between anthracyclines and atrial flutter (RR = 1.30, 95% CI = 0.29-5.89, P = .74), atrial ectopic beats (RR: 1.27, 95% CI: 0.78-2.05, P = .34), and ventricular ectopic beats (RR: 0.93, 95% CI: 0.53-1.65, P = .81) showed no statistically significant results. Higher doses of anthracycline were associated with a higher risk of arrhythmias (RR: 1.49; 95% CI: 1.08-2.05; P = .02) compared to the lower doses (RR: 1.36; 95% CI: 1.00-1.85; P = .05). Newer generations of Anthracycline maintained the arrhythmogenic properties of previous generations, such as Doxorubicin.

CONCLUSION

Anthracyclines therapy was significantly associated with an increased risk of arrhythmias. Accordingly, Patients treated with anthracyclines should be screened for ECG abnormalities and these drugs should be avoided in patients susceptible to arrhythmia. The potential benefit of the administration of prophylactic anti-fibrotic and anti-arrhythmic drugs should also be explored.

The plaque hypothesis: understanding mechanisms of plaque progression and destabilization, and implications for clinical management

PURPOSE OF REVIEW

Major adverse cardiac events (MACE) typically arise from nonflow-limiting coronary artery disease and not from flow-limiting obstructions that cause ischemia. This review elaborates the current understanding of the mechanism(s) for plaque development, progression, and destabilization and how identification of these high-risk features can optimally inform clinical management.

RECENT FINDINGS

Advanced invasive and noninvasive coronary imaging and computational postprocessing enhance an understanding of pathobiologic/pathophysiologic features of coronary artery plaques prone to destabilization and MACE. Early investigations of high-risk plaques focused on anatomic and biochemical characteristics (large plaque burden, severe luminal obstruction, thin cap fibroatheroma morphology, and large lipid pool), but more recent studies underscore that additional factors, particularly biomechanical factors [low endothelial shear stress (ESS), high ESS gradient, plaque structural stress, and axial plaque stress], provide the critical incremental stimulus acting on the anatomic substrate to provoke plaque destabilization. These destabilizing features are often located in areas distant from the flow-limiting obstruction or may exist in plaques without any flow limitation. Identification of these high-risk, synergistic plaque features enable identification of plaques prone to destabilize regardless of the presence or absence of a severe obstruction (Plaque Hypothesis).

SUMMARY

Local plaque topography, hemodynamic patterns, and internal plaque constituents constitute high-risk features that may be located along the entire course of the coronary plaque, including both flow-limiting and nonflow-limiting regions. For coronary interventions to have optimal clinical impact, it will be critical to direct their application to the plaque area(s) at highest risk.

The role of endothelial shear stress, shear stress gradient, and plaque topography in plaque erosion

BACKGROUND AND AIMS

Plaque erosion is a common underlying cause of acute coronary syndromes. The role of endothelial shear stress (ESS) and endothelial shear stress gradient (ESSG) in plaque erosion remains unknown. We aimed to determine the role of ESS metrics and maximum plaque slope steepness in plaques with erosion versus stable plaques.

METHODS

This analysis included 46 patients/plaques from TOTAL and COMPLETE trials and Brigham and Women's Hospital's database who underwent angiography and OCT. Plaques were divided into those with erosion (n = 24) and matched stable coronary plaques (n = 22). Angiographic views were used to generate a 3-D arterial reconstruction, with centerlines merged from angiography and OCT pullback. Local ESS metrics were assessed by computational fluid dynamics. Among plaque erosions, the up- and down-slope (Δ lumen area/frame) was calculated for each culprit plaque.

RESULTS

Compared with stable plaque controls, plaques with an erosion were associated with higher max ESS (8.3 ± 4.8 vs. 5.0 ± 1.9 Pa, p = 0.02) and max ESSG any direction (9.2 ± 7.5 vs. 4.3 ± 3.11 Pa/mm, p = 0.005). Proximal erosion was associated with a steeper plaque upslope while distal erosion with a steeper plaque downslope. Max ESS and Max ESSG any direction were independent factors in the development of plaque erosion (OR 1.32, 95%CI 1.06-1.65, p = 0.014; OR 1.22, 95% CI 1.03-1.45, p = 0.009, respectively).

CONCLUSIONS

In plaques with similar luminal stenosis, plaque erosion was strongly associated with higher ESS, ESS gradients, and plaque slope as compared with stable plaques. These data support that ESS and slope metrics play a key role in the development of plaque erosion and may help prognosticate individual plaques at risk for future erosion.

Endothelial shear stress computed from coronary computed tomography angiography: A direct comparison to intravascular ultrasound

INTRODUCTION

Intravascular ultrasound (IVUS) studies have shown that biomechanical variables, particularly endothelial shear stress (ESS), add synergistic prognostic insight when combined with anatomic high-risk plaque features. Non-invasive risk assessment of coronary plaques with coronary computed tomography angiography (CCTA) would be helpful to enable broad population risk-screening.

AIM

To compare the accuracy of ESS computation of local ESS metrics by CCTA vs IVUS imaging.

METHODS

We analyzed 59 patients from a registry of patients who underwent both IVUS and CCTA for suspected CAD. CCTA images were acquired using either a 64- or 256-slice scanner. Lumen, vessel, and plaque areas were segmented from both IVUS and CCTA (59 arteries, 686 3-mm segments). Images were co-registered and used to generate a 3-D arterial reconstruction, and local ESS distribution was assessed by computational fluid dynamics (CFD) and reported in consecutive 3-mm segments.

RESULTS

Anatomical plaque characteristics (vessel, lumen, plaque area and minimal luminal area [MLA] per artery) were correlated when measured with IVUS and CCTA: 12.7 ​± ​4.3 vs 10.7 ​± ​4.5 ​mm2, r ​= ​0.63; 6.8 ​± ​2.7 vs 5.6 ​± ​2.7 ​mm2, r ​= ​0.43; 5.9 ​± ​2.9 vs 5.1 ​± ​3.2 ​mm2, r ​= ​0.52; 4.5 ​± ​1.3 vs 4.1 ​± ​1.5 ​mm2, r ​= ​0.67 respectively. ESS metrics of local minimal, maximal, and average ESS were also moderately correlated when measured with IVUS and CCTA (2.0 ​± ​1.4 vs 2.5 ​± ​2.6 ​Pa, r ​= ​0.28; 3.3 ​± ​1.6 vs 4.2 ​± ​3.6 ​Pa, r ​= ​0.42; 2.6 ​± ​1.5 vs 3.3 ​± ​3.0 ​Pa, r ​= ​0.35, respectively). CCTA-based computation accurately identified the spatial localization of local ESS heterogeneity compared to IVUS, with Bland-Altman analyses indicating that the absolute ESS differences between the two CCTA methods were pathobiologically minor.

CONCLUSION

Local ESS evaluation by CCTA is possible and similar to IVUS; and is useful for identifying local flow patterns that are relevant to plaque development, progression, and destabilization.

Association between insomnia and the incidence of myocardial infarction: A systematic review and meta-analysis

BACKGROUND

Insomnia has been closely associated with cardiovascular disease (CVD) including myocardial infarction (MI). Our study aims to assess the eligibility of insomnia as a potential risk factor for MI.

METHODS

PubMed, Scopus, and Web of Science were searched using terms; such as "Insomnia" and "MI." Only observational controlled studies with data on the incidence of MI among insomniacs were included. Revman software version 5.4 was used for the analysis.

RESULTS

Our pooled analysis showed a significant association between insomnia and the incidence of MI compared with noninsomniacs (relative risk [RR] = 1.69, 95% confidence interval [CI] = 1.41-2.02, p < .00001). Per sleep duration, we detected the highest association between ≤5 h of sleep, and MI incidence compared to 7-8 h of sleep (RR = 1.56, 95% CI = 1.41-1.73). Disorders of initiating and maintaining sleep were associated with increased MI incidence (RR = 1.13, 95% CI = 1.04-1.23, p = .003). However, subgroup analysis of nonrestorative sleep and daytime dysfunction showed an insignificant association with MI among both groups (RR = 1.06, 95% CI = 0.91-1.23, p = .46). Analysis of age, follow-up duration, sex, and comorbidities showed a significant association in insomniacs.

CONCLUSION

Insomnia and ≤5 h of sleep are highly associated with increased incidence of MI; an association comparable to that of other MI risk factors and as such, it should be considered as a risk factor for MI and to be incorporated into MI prevention guidelines.

Multimodality imaging results of TAP versus novel modified TAP stenting in coronary bifurcation: From bench testing to first-in-man investigation

OBJECTIVES

We investigated the results of T and small protrusion (TAP) versus a novel modification of TAP (mTAP) stenting by multimodality imaging in bench testing and in patients with coronary bifurcation lesions (CBL).

BACKGROUND

TAP stenting is a suboptimal technique for bailout side branch (SB) stenting.

METHODS

In a bench model, optical coherence tomography (OCT), microscopic examinations (ME), and computational fluid dynamics (CFD) were performed after TAP and mTAP stenting. In 20 patients with CBL, 80 intravascular ultrasound (IVUS) examinations were performed during mTAP stenting in which the SB stent was pulled-back to indent the inflated main vessel (MV) balloon and deployed while deflating it. For TAP stenting, the tip of the SB stent was positioned in the MV and deployed.

RESULTS

In bench testing, OCT showed neocarina length (NL) was shorter and minimum stent area (MSA) was larger after mTAP versus TAP stenting (2.84 ± 0.70 vs. 4.80 ± 020 mm; 6.75 ± 1.50 vs. 4.5 ± 2.2 mm² ; respectively; p < 0.05). By ME, NL was shorter and shear rate trended lower after mTAP versus TAP stenting. In patients, IVUS showed MSA was larger after versus before mTAP stenting (6.32 ± 0.58 vs. 5.21 ± 0.56 mm² ; p < 0.01); NL was 1.43 ± 0.22 mm with SB ostium coverage. The Seattle Angina questionnaire (SAQ) score was higher at 6 months versus baseline (85 ± 4.0 vs. 48 ± 6.0, respectively; p < 0.001).

CONCLUSIONS

This multimodality imaging study showed, for the first time, mTAP stenting resulted in larger stent area and shorter neocarina than TAP stenting in bench testing. In patients with CBL, mTAP stenting led to larger stent area, short neocarina with complete SB ostium coverage, and improved the SAQ score at follow-up.

The role of far-field intravascular ultrasound in transcatheter aortic valve replacement

Precise and accurate characterization of the aortic valve complex is a vital step in the procedure planning for transcatheter aortic valve replacement (TAVR). Far-field intravascular ultrasound (IVUS) is a novel technology that can be utilized to assess aortic valve annulus and predict paravalvular leak, with comparable results to multi-detector computed tomography-the current gold standard in the preprocedural planning in TAVR. Far-field IVUS carries the advantage of minimal contrast use and lower radiation exposure. In this commentary, we describe two cases of far-field IVUS use during TAVR procedures and review its role as a complementary tool to current the imaging modalities used in TAVR.

Reviewing imaging modalities for the assessment of plaque erosion

Plaque rupture followed by intracoronary thrombus formation is recognized as the most common pathophysiological mechanism in acute coronary syndromes (ACS). The second most common underlying substrate for ACS is plaque erosion whose hallmark is thrombus formation without cap disruption. Invasive and non-invasive methods have emerged as a promising tool for evaluation of plaque features that either predict or detect plaque erosion. Optical coherence tomography (OCT), high-definition intravascular ultrasound (IVUS), near-infrared spectroscopy (NIRS), and near-infrared autofluorescence (NIRF) have been used to study plaque erosion. The detection of plaque erosion in the clinical setting, mainly facilitated by OCT, has shed light upon the complex pathophysiology underlying ACS not related to plaque rupture. Coronary computed tomography angiography (CCTA), which is to date the most commonly used non-invasive technique for coronary plaque evaluation, may also have a role in the evaluation of patients predisposed to erosion. Also, computational models enabling quantification of endothelial shear stress may pave the way to new research in coronary plaque pathophysiology. This review focuses on the recent imaging techniques for the evaluation of plaque erosion including invasive and non-invasive assessment.

Large-field intravascular ultrasound for annular sizing and predicting paravalvular regurgitation during TAVR: comparisons with multidetector computed tomography and transoesophageal echocardiography

Aims

The use of contrast media with multidetector computed tomography (MDCT) may induce acute kidney injury in patients with renal failure undergoing transcatheter aortic valve replacement (TAVR). We investigated the role of large-field intravascular ultrasound (IVUS) vs. MDCT and two-dimensional transoesophageal echocardiography (2D-TEE) for annular sizing and predicting paravalvular regurgitation (PVR) during TAVR.

Methods and Results

The aortic annulus was measured by large-field IVUS and 2D-TEE, and compared with MDCT in 50 patients undergoing TAVR. The IVUS and MDCT annular areas and diameters were not significantly different (446 ± 87 mm2 and 23.8 ± 84 mm vs. 466 ± 84 mm2 and 24 ± 2.1 mm, respectively; P > 0.05). IVUS and MDCT mean annular diameters were significantly greater than TEE diameter (23.8 ± 2.4 and 24 ± 2.1 vs. 22 ± 0.65 mm, respectively; P < 0.01). PVR ≥ Mild occurred in 13 patients (26%); 5 patients required post-dilation and 2 patients a second valve. Receiver operating characteristic analyses showed that transcatheter heart valve (THV) area - IVUS or MDCT areas equally predicted of ≥ mild PVR (areas under the curve [AUC] 0.79 and 0.81, respectively; P < 0.001), and were greater than THV diameter-TEE diameter (AUC 0.79 and 0.81 vs. 0.56, respectively; P < 0.05).

Conclusions

The aortic annular measurements and predicting PVR by large field IVUS were not significantly different from those of MDCT, but were greater than those of TEE. Large filed IVUS can be reliably used in lieu of MDCT for annular sizing in patients with aortic stenosis and renal failure or suboptimal MDCT images.

Role of Proximal Optimization Technique Guided by Intravascular Ultrasound on Stent Expansion, Stent Symmetry Index, and Side-Branch Hemodynamics in Patients With Coronary Bifurcation Lesions

BACKGROUND

Bench models of coronary bifurcation lesions demonstrated that the proximal optimization technique (POT) expanded the stent and opened the side branch (SB). We investigated the role of POT guided by intravascular ultrasound on the main vessel (MV) stent expansion and SB fractional flow reserve (FFR) in patients with coronary bifurcation lesion.

METHODS AND RESULTS

In 40 patients with coronary bifurcation lesion, 120 intravascular ultrasound examinations of the MV were performed at baseline, after MV stenting, and POT followed by 95 FFR measurements of the SB. In the proximal stent segment, stent volume index and minimum stent area were larger after POT versus MV stenting (9.2±3.4 versus 7.40±2.0 mm³/mm and 7.65±1.8 versus 6.38±1.7 mm², respectively; P<0.01). In the bifurcation segment, minimum stent area was larger after POT versus MV stenting (6.45±2.1 versus 5.9±2.0 mm², respectively; P<0.05). POT expanded the stent symmetrically. After POT, SB FFR was <0.75 in 12 patients (30%), which improved to >0.75 after SB dilation or SB stenting+final POT. SB FFR was significantly higher after POT+SB dilation or SB stenting+final POT versus after MV stenting and POT.

CONCLUSIONS

This is the first study of POT guided by intravascular ultrasound in patients with coronary bifurcation lesion, demonstrating that POT symmetrically expanded the proximal and bifurcation segments of the stent. After POT, SB FFR was <0.75 in a third of patients, which improved to >0.75 after SB dilation or SB stenting+final POT.

Relationship between biomarkers and subsequent clinical and angiographic restenosis after paclitaxel-eluting stents for treatment of STEMI: a HORIZONS-AMI substudy

Drug-eluting stents (DES) reduce the incidence of in-stent restenosis (ISR) after primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI). Whether the use of biomarkers might be of utility to identify patients who remain at risk for DES ISR after primary PCI has never been examined. A total of 26 biomarkers were measured at enrollment and 30 days and analyzed at a central core laboratory in 501 STEMI patients from the HORIZONS-AMI trial. All patients underwent primary PCI with the TAXUS paclitaxel-eluting stent (PES), were scheduled for routine angiographic follow-up at 13 months, and were followed for 3 years. Mean in-stent late-loss was 0.28 ± 0.57 mm, and target lesion revascularization (TLR) at 3 years occurred in 9.1 % of patients. Low levels of interleukin-6 (IL-6) and placental growth factor (PLGF) at admission were associated with both higher in-stent late loss and ischemia-driven TLR. Additionally, low admission levels of cardiotrophin-1 (CT-1) were associated with higher rates of ischemia-driven TLR. At 30-day follow-up lower values of IL-1ra (IL-1ra), matrix metalloproteinase 9 (MMP9), and myeloperoxidase (MPO), and a decline relative to admission in IL-1ra, monocyte chemotactic protein-1 (MCP-1), and MMP9 were associated with higher in-stent late loss. Low values of IL-6 at 30 days were also associated with ischemia-driven TLR. After multivariate adjustment, only MPO at 30 days and a decline of MCP-1 between admission and 30 days were associated with in-stent late loss, and only CT-1 was associated with TLR. MPO at 30 days and a decline of MCP-1 between admission and 30 days were independently associated with in-stent late loss, and CT-1 was associated with TLR. Additional studies to confirm and validate the utility of these biomarkers are warranted.

High platelet reactivity on clopidogrel therapy correlates with increased coronary atherosclerosis and calcification: a volumetric intravascular ultrasound study

OBJECTIVES

This study sought to evaluate the relationship between platelet reactivity and atherosclerotic burden in patients undergoing percutaneous coronary intervention (PCI) with pre-intervention volumetric intravascular ultrasound (IVUS) imaging.

BACKGROUND

Atherosclerosis progresses by the pathologic sequence of subclinical plaque rupture, thrombosis, and healing. In this setting, increased platelet reactivity may lead to more extensive arterial thrombosis at the time of plaque rupture, leading to a more rapid progression of the disease. Alternatively, abnormal vessel wall biology with advanced atherosclerosis is known to enhance platelet reactivity. Therefore, it is possible that by either mechanism, increased platelet reactivity may be associated with greater atherosclerotic burden.

METHODS

This study included patients who underwent PCI with pre-intervention IVUS imaging and platelet reactivity functional assay (P2Y(12) reaction units) performed >16 h after PCI, after the stabilization of clopidogrel therapy (administered before PCI). Platelet reactivity >230 P2Y(12) reaction units defined high on-treatment platelet reactivity (HPR).

RESULTS

Among 335 patients (mean age 65.0 years, 71% men), there were 109 patients with HPR (32.5%) and 226 without HPR (67.5%), with HPR being associated with diabetes and chronic renal insufficiency. By IVUS analysis, patients with HPR had significantly greater target lesion calcium lengths, calcium arcs, and calcium indexes. Furthermore, patients with HPR tended to have longer lesions and greater volumetric dimensions, indicating higher plaque volume, larger total vessel volume, and also greater luminal volume, despite similar plaque burden. By multivariate analysis controlling for baseline clinical variables, HPR was the single consistent predictor of all IVUS parameters examined, including plaque volume, calcium length, and calcium arc.

CONCLUSIONS

Increased platelet reactivity on clopidogrel treatment, defined as >230 P2Y(12) reaction units, is associated with greater coronary artery atherosclerotic disease burden and plaque calcification.

Enhanced stent imaging improves the diagnosis of stent underexpansion and optimizes stent deployment

OBJECTIVES

To investigate the clinical value and diagnostic accuracy of enhanced stent imaging (ESI) as compared with quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS).

BACKGROUND

ESI is an image acquisition and processing angiography-based software that improves visualization and provides measurements of deployed stents.

METHODS

A total of 40 consecutive patients (42 stents) were studied. Stent deployment was evaluated sequentially and independently by angiography, ESI, and IVUS. Following each imaging modality, the operator determined the necessity of postdilation unrelated to the other modalities. Stent diameters were measured off-line by QCA, ESI, and IVUS at several sites along the deployed stent and compared.

RESULTS

Following stent deployment and based solely on angiography, the operator decided to postdilate seven of the 42 stents (16.7%). This decision was not changed after reviewing the ESI images of these seven stents. Of the 35 stents not requiring postdilation based on angiography alone, ESI influenced the operator to change the decision and postdilate 10 of 35 stents (28.6%). The ESI-based measurements had better correlation with IVUS (r = 0.721, P < 0.0001) than did QCA with IVUS (r = 0.563, P < 0.0001). Bland-Altman analysis showed a trend towards better agreement between ESI and IVUS than between QCA and IVUS (mean differences = 0.038 vs. 0.121; P = 0.19, respectively).

CONCLUSIONS

ESI is an easy to use modality that enhances stent visualization, helps in the decision making process whether to postdilate the stent, and provides estimation of stent expansion with better correlations than QCA when compared to IVUS. © 2012 Wiley Periodicals, Inc.