Optical coherence tomography in coronary atherosclerosis assessment and intervention

Since optical coherence tomography (OCT) was first performed in humans two decades ago, this imaging modality has been widely adopted in research on coronary atherosclerosis and adopted clinically for the optimization of percutaneous coronary intervention. In the past 10 years, substantial advances have been made in the understanding of in vivo vascular biology using OCT. Identification by OCT of culprit plaque pathology could potentially lead to a major shift in the management of patients with acute coronary syndromes. Detection by OCT of healed coronary plaque has been important in our understanding of the mechanisms involved in plaque destabilization and healing with the rapid progression of atherosclerosis. Accurate detection by OCT of sequelae from percutaneous coronary interventions that might be missed by angiography could improve clinical outcomes. In addition, OCT has become an essential diagnostic modality for myocardial infarction with non-obstructive coronary arteries. Insight into neoatherosclerosis from OCT could improve our understanding of the mechanisms of very late stent thrombosis. The appropriate use of OCT depends on accurate interpretation and understanding of the clinical significance of OCT findings. In this Review, we summarize the state of the art in cardiac OCT and facilitate the uniform use of this modality in coronary atherosclerosis. Contributions have been made by clinicians and investigators worldwide with extensive experience in OCT, with the aim that this document will serve as a standard reference for future research and clinical application.

Electrocardiographic abnormalities in patients with acute pulmonary embolism complicated by cardiogenic shock

BACKGROUND

Cardiogenic shock (CS) is a predictor of poor prognosis in patients with acute pulmonary embolism (APE).

OBJECTIVES

The aim of this study was to compare electrocardiography (ECG) parameters in patients with APE presenting with or without CS.

METHODS

A 12-lead ECG was recorded on admission at a paper speed of 25 mm/s and 10 mm/mV amplification. All ECGs were examined by a single cardiologist who was blinded to all other clinical data. All ECG measurements were made manually.

RESULTS

Electrocardiographic data from 500 patients with APE were analyzed, including 92 patients with CS. The following ECG parameters were associated with CS: S1Q3T3 sign, (odds ratio [OR]: 2.85, P<.001), qR or QR morphology of QRS in lead V1, (OR: 3.63, P<.001), right bundle branch block (RBBB) (OR: 2.46, P=.004), QRS fragmentation in lead V1 (OR: 2.94, P=.002), low QRS voltage (OR: 3.21, P<.001), negative T waves in leads V2 to V4 (OR: 1.81, P=.011), ST-segment depression in leads V4 to V6 (OR: 3.28, P<.001), ST-segment elevation in lead III (OR: 4.2, P<.001), ST-segment elevation in lead V1 (OR: 6.78, P<.01), and ST-segment elevation in lead aVR (OR: 4.35, P<.01). The multivariate analysis showed that low QRS voltage, RBBB, and ST-segment elevation in lead V1 remained statistically significant predictors of CS.

CONCLUSIONS

In patients with APE, low QRS voltage, RBBB, and ST-segment elevation in lead V1 were associated with CS.

No long-term clinical benefit from manual aspiration thrombectomy in ST-elevation myocardial infarction patients. Data from NRDES registry

BACKGROUND

Current STEMI guidelines recommend thrombectomy should be considered during primary PCI. Multiple data from randomized clinical trials, registries, and metanalysis have confirmed the efficacy of thrombectomy in terms of surrogate endpoints like better myocardial perfusion, less pronounced distal embolization, and conflicting results on lower all-cause mortality. Our aim was to analyze long-term outcome of STEMI patients treated with manual thrombectomy during primary PCI in a contemporary national registry.

METHODS

There were 13 catheterization laboratories in Poland that enrolled patients in NRDES Registry. Patients were divided into two groups: those that were treated with manual thrombectomy for their primary PCI vs. those who were not.

RESULTS

There were altogether 2,686 patients enrolled in the NRDES Registry of whom 1,763 were diagnosed with STEMI (66%). Aspiration thrombectomy was used in 673 of these cases (38%) and 1,090 (62%) patients were treated without thrombectomy during the index primary PCI. Overall mortality at 1 year was 11.03% in thrombectomy and 7.46% in no thrombectomy group respectively (P = 0.0292 which became insignificant after propensity score matching adjustment P = 0.613). Specific subgroup analyses revealed that there was no benefit from aspiration thrombectomy in neither subgroup.

CONCLUSIONS

Manual aspiration thrombectomy in patients undergoing primary PCI for STEMI was not associated with improved long-term 1-year clinical outcome. Subgroup analysis did not reveal any specific setting in which thrombectomy would be clinically superior. © 2014 Wiley Periodicals, Inc.

Is right coronary artery chronic total vessel occlusion impacting the surgical revascularization results of patients with multivessel disease? A retrospective study

Introduction

Chronic total occlusion (CTO) is common in the presence of other significantly narrowed coronary arteries. The impact of total occlusion and its association with completeness of revascularization on patients with multivessel disease undergoing coronary artery bypass graft (CABG) remains largely unknown.

Aim

The aim of our study was to compare CABG operation characteristics, as well as 30-day mortality, incidence of post-operative major adverse cardiac and cerebrovascular events (MACCE) between patients with and without CTO in right coronary artery (RCA).

Materials and Methods

A total of 156 consecutive patients were included in the analysis. CTO of RCA or right posterior descending artery (RPD) was diagnosed in 57 patients (CTO-RCA group). Coronary stenosis without CTO in RCA was diagnosed in 99 patients (nonCTO-RCA group). Baseline characteristics were comparable in both groups.

Results

The majority of patients had class II (49.1% vs. 46%, p = 0.86) or class III (42.1% vs. 43%, p = 1.0) Canadian Cardiovascular Society grading system symptoms. Patients in the CTO-RCA group had in average 2.2 grafts implanted, as opposed to 2.4 grafts in patients in the nonCTO-RCA group (p = 0.003). Graft to the RCA was performed in 40.3% patients in the CTO-RCA group and in 81% patients in the nonCTO-RCA group (p = 0.001). The 30-day mortality from any cause or cardiac cause did not differ between groups (7% vs. 2%, p = 0.14 and 3.5% vs. 2%, p = 0.57 respectively). In a multivariate analysis CTO in RCA or RPD and peripheral artery disease were independent predictors of post-operative MACCE (7.9 (1.434-43.045) p = 0.02; 18.8 (3.451-101.833) p < 0.01, respectively).

Conclusions

Chronic total occlusion of RCA was found to be associated with smaller number of grafts performed during the CABG procedure. Although mortality between patients in the CTO-RCA and nonCTO-RCA groups did not differ, patients in the CTO-RCA group had higher incidence of post-operative MACCE.

What do Polish interventional cardiologists know about indications and qualification for recanalisation of chronic total coronary artery occlusions?

BACKGROUND

Chronic total occlusions (CTO) are diagnosed in about 20% of patients with significant coronary artery disease. A disproportion between the high prevalence of CTOs and low rate of invasive treatment still exists. Technical difficulties, clinical uncertainties whether patients benefit from recanalisation, and a lack of knowledge of CTO may be responsible for this fact.

AIM

To assess the knowledge of coronary arteries CTO among Polish interventional cardiologists.

METHODS

A self-designed questionnaire was used during two major Polish invasive cardiology workshops held in 2014.

RESULTS

The study included 113 physicians, mostly cardiologists certified as independent operators. Average self-declared efficacy of CTO recanalisation was 63.5%. Most of the respondents agreed that the operator involved in the CTO recanalisation program should perform at least 30-50 procedures per year. Only 67% stated that before CTO revascularisation the evaluation of myocardial viability should be performed with dobutamine stress echocardiography as a preferred test. One third of the physicians agreed that CTO percutaneous coronary intervention (PCI) should not be performed directly after diagnostic angiography, and 51.5% believed that in patients with multi-vessel coronary artery disease PCI of CTO should be performed first. Multi-slice spiral computed tomography during the qualification and planning of the CTO revascularisation, in the opinion of 91% of the responders, should not be used before each procedure but could be useful in selected cases.

CONCLUSIONS

Polish interventional cardiologists remains in compliance with current opinions about recanalisation of chronic coronary artery occlusions and the consensus of the EuroCTO Club, but there is still an unceasing need for further education and promotion of knowledge about CTOs.

Treatment of coronary chronic total occlusion by transradial approach: Current trends and expert recommendations

The aim of this review is to highlight the technical details and the scientific data on percutaneous coronary interventions (PCIs) in chronic total occlusion (CTO) performed by transradial approach (TRA). Transfemoral approach (TFA) is commonly regarded as the standard for CTO PCI, but there is a growing number of CTO recanalization procedures performed by TRA. We discuss the relevant technical details to approach a CTO by transradial access, especially the compatibility of various CTO recanalization techniques with specific guiding catheter sizes. Randomized prospective trials in this field are lacking and only data from observational studies are available. We can conclude that transradial access for CTO PCI is feasible and could be very useful in selected patients. In our opinion, transradial access in CTO PCIs should be limited to operators and centers highly experienced in CTO recanaliza¬tion and in TRA.

SYNTAX Score and Pre- and Poststent Optical Coherence Tomography Findings in the Left Anterior Descending Coronary Artery in Patients With Stable Angina Pectoris

SYNTAX score (SS) has been reported to be an independent predictor of future cardiac events including target lesion revascularization. The aim of this study was to assess the relation between SS and plaque characteristics and poststent vascular response using optical coherence tomography in coronary artery tree and left anterior descending artery (LAD) in patients with stable angina. A total of 179 lesions among 165 patients, including 100 lesions in LAD, were analyzed. Patients were stratified into tertiles. In pre-percutaneous coronary intervention analysis of whole coronary tree and LAD, lesions of the third tertile had the highest prevalence of lipid-rich plaque. Compared with the first tertile, the third tertile had greater lipid index, thinner fibrous cap, and higher prevalence of thin-cap fibroatheroma. In poststent optical coherence tomography, the incidence of stent edge dissection and irregular protrusion was higher in the third tertile compared with the first tertile in coronary tree analysis. In LAD analysis, the prevalence of irregular protrusion was the highest in the third tertile. In conclusion, high SS may reflect higher plaque vulnerability. Stent edge dissection and irregular protrusion were more frequent in patients with higher SS, indicating poor vascular response to stenting. Our results may explain higher cardiac event rate and target lesion revascularization in patients with higher SS.

Role of Lipid-Lowering and Anti-Inflammatory Therapies on Plaque Stabilization

Atherosclerosis is the predominant underlying etiopathology of coronary artery disease. Changes in plaque phenotype from stable to high risk may spur future major adverse cardiac events (MACE). Different pharmacological therapies have been implemented to mitigate this risk. Over the last two decades, intravascular imaging modalities have emerged in clinical studies to clarify how these therapies may affect the composition and burden of coronary plaques. Lipid-lowering agents, such as statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 inhibitors, were shown not only to reduce low-density lipoprotein levels and MACE but also to directly affect features of coronary plaque vulnerability. Studies have demonstrated that lipid-lowering therapy reduces the percentage of atheroma volume and number of macrophages and increases fibrous cap thickness. Future studies should answer the question of whether pharmacological plaque stabilization may be sufficient to mitigate the risk of MACE for selected groups of patients with atherosclerotic coronary disease.

Three-Dimensional Fibrous Cap Structure of Coronary Lipid Plaque - ST-Elevation Myocardial Infarction vs. Stable Angina

BACKGROUND

Fibrous cap thickness (FCT) is one of the key features of coronary vulnerable plaque. FCT is measured at an arbitrary point, determined on visual assessment of 2-D cross-sectional imaging. This method has poor reproducibility. The aim of this study was to compare the 3-D structure of FC in non-culprit lipid plaques between patients with ST-elevation myocardial infarction (STEMI) and with stable angina (SA) on optical coherence tomography.

METHODS AND RESULTS

A total of 54 non-culprit plaques from 23 STEMI and 23 SA patients were evaluated. Thin cap fibroatheroma (TCFA), defined as lipid plaque with FCT <80 µm, was identified using a novel algorithm. The number of TCFA, surface area of each TCFA, and the sum total area of TCFA in the target vessel were measured. Patients with STEMI had a greater median number of TCFA (9, IQR 1-17 vs. 2, IQR 0-5; P=0.002), the largest median single TCFA area (0.40, IQR 0.14-0.69 vs. 0.08, IQR 0.04-0.16 mm2; P<0.001) and median sum total area of TCFA (1.04, IQR 0.41-1.95 vs. 0.24, IQR 0.08-0.48 mm2, P<0.004).

CONCLUSIONS

Patients with STEMI, as compared with those with SA, have greater vulnerability to non-culprit plaque.

Intracoronary Imaging of Vulnerable Plaque-From Clinical Research to Everyday Practice

The introduction into clinical practice of intravascular imaging, including intravascular ultrasound (IVUS), optical coherence tomography (OCT) and their derivatives, allowed for the in vivo assessment of coronary atherosclerosis in humans, including insights into plaque evolution and progression process. Intravascular ultrasound, the most commonly used intravascular modality in many countries, due to its low resolution cannot assess many features of vulnerable plaque such as lipid plaque or thin-cap fibroatheroma. Thus, novel methods were introduced to facilitate this problem including virtual histology intravascular ultrasound and later on near-infrared spectroscopy and OCT. Howbeit, none of the currently used modalities can assess all known characteristics of plaque vulnerability; hence, the idea of combining different intravascular imaging methods has emerged including NIRS-IVUS or OCT-IVUS imaging. All of those described methods may allow us to identify the most vulnerable plaques, which are prone to cause acute coronary syndrome, and thus they may allow us to introduce proper treatment before plaque destabilization.

Sex-specific associations between the environmental exposures and low-grade inflammation and increased blood pressure in young, healthy subjects

Long-term exposures to environmental factors including airborne as well as noise pollutants, are associated with cardiovascular risk. However, the influence of environmental pollution on the young population is controversial. Accordingly, we aimed to investigate the relationships between long-term exposures to different environmental factors and major cardiovascular and inflammatory parameters and biomarkers in young, healthy subjects. Representative sample of permanent residents of two cities differing in air and noise pollution levels, aged 15-21 years, were recruited. Krakow and Lublin, both located in southern Poland, were chosen in relation to their similarities in demographic and geopolitical characteristics, but differences in air pollution (higher in Krakow) and noise parameters (higher in Lublin). A total of 576 subjects were studied: 292 in Krakow and 284 in Lublin. All subjects underwent health questionnaire, blood pressure measurements and biomarker determinations. Inflammatory biomarkers, such as CRP, hs-CRP, fibrinogen as well as homocysteine were all significantly higher in subjects living in Krakow as opposed to subjects living in Lublin (for hsCRP: 0.52 (0.32-0.98) mg/l vs. 0.35 (0.22-0.67) mg/l; p < 0.001). Increased inflammatory biomarker levels were observed in Krakow in both male and female young adults. Interestingly, significant differences were observed in blood pressure between male and female subjects. Males from Krakow had significantly higher mean systolic blood pressure (127.7 ± 10.4 mm/Hg vs. 122.4 ± 13.0 mm/Hg; p = 0.001), pulse pressure (58.7 ± 8.9 mm/Hg vs. 51.4 ± 12.3 mm/Hg; p < 0.001) and lower heart rate (p < 0.001) as compared to males living in Lublin. This was not observed in young adult females. Long-term exposure to environmental factors related to the place of residence can significantly influence inflammatory and cardiovascular parameters, even in young individuals. Interestingly, among otherwise healthy young adults, blood pressure differences exhibited significant variations based on biological sex.