O. Raffel

In vivo diagnosis of plaque erosion and calcified nodule in patients with acute coronary syndrome by intravascular optical coherence tomography.

OBJECTIVES The aim of this study was to characterize the morphological features of plaque erosion and calcified nodule in patients with acute coronary syndrome (ACS) by optical coherence tomography (OCT). BACKGROUND Plaque erosion and calcified nodule have not been systematically investigated in vivo. METHODS A total of 126 patients with ACS who had undergone pre-intervention OCT imaging were included. The culprit lesions were classified as plaque rupture (PR), erosion (OCT-erosion), calcified nodule (OCT-CN), or with a new set of diagnostic criteria for OCT. RESULTS The incidences of PR, OCT-erosion, and OCT-CN were 43.7%, 31.0%, and 7.9%, respectively. Patients with OCT-erosion were the youngest, compared with those with PR and OCT-CN (53.8 ± 13.1 years vs. 60.6 ± 11.5 years, 65.1 ± 5.0 years, p = 0.005). Compared with patients with PR, presentation with non-ST-segment elevation ACS was more common in patients with OCT-erosion (61.5% vs. 29.1%, p = 0.008) and OCT-CN (100% vs. 29.1%, p < 0.001). The OCT-erosion had a lower frequency of lipid plaque (43.6% vs. 100%, p < 0.001), thicker fibrous cap (169.3 ± 99.1 μm vs. 60.4 ± 16.6 μm, p < 0.001), and smaller lipid arc (202.8 ± 73.6° vs. 275.8 ± 60.4°, p < 0.001) than PR. The diameter stenosis was least severe in OCT-erosion, followed by OCT-CN and PR (55.4 ± 14.7% vs. 66.1 ± 13.5% vs. 68.8 ± 12.9%, p < 0.001). CONCLUSIONS Optical coherence tomography is a promising modality for identifying OCT-erosion and OCT-CN in vivo. The OCT-erosion is a frequent finding in patients with ACS, especially in those with non-ST-segment elevation ACS and younger patients. The OCT-CN is the least common etiology for ACS and is more common in older patients. (The Massachusetts General Hospital Optical Coherence Tomography Registry; NCT01110538).

In vivo association between positive coronary artery remodelling and coronary plaque characteristics assessed by intravascular optical coherence tomography

AIMS Positive coronary arterial remodelling has been shown to be associated with unstable coronary syndromes and ex vivo histological characteristics of plaque vulnerability such as a large lipid core and high macrophage content. The aim of this study is to evaluate the in vivo association between coronary artery remodelling and underlying plaque characteristics identified by optical coherence tomography (OCT). OCT is a unique imaging modality capable of characterizing these important morphological features of vulnerable plaque. METHODS AND RESULTS OCT and intravascular ultrasound imaging was performed at corresponding sites in patients undergoing catheterization. OCT plaque characteristics for lipid content, fibrous cap thickness, and macrophage density were derived using previously validated criteria. Thin-cap fibroatheroma (TCFA) was defined as lipid-rich plaque (two or more quadrants) with fibrous cap thickness <65 microm. Remodelling index (RI) was calculated as the ratio of the lesion to the reference external elastic membrane area. A total of 54 lesions from 48 patients were imaged. Positive remodelling compared with absent or negative remodelling was more commonly associated with lipid-rich plaque (100 vs. 60 vs. 47.4%, P = 0.01), a thin fibrous cap (median 40.2 vs. 51.6 vs. 87 microm, P = 0.003) and the presence of TCFA (80 vs. 38.5 vs. 5.6%, P < 0.001). Fibrous cap macrophage density was also higher in plaques with positive remodelling showing a positive linear correlation with the RI (r = 0.60, P < 0.001). CONCLUSION Coronary plaques with positive remodelling exhibit characteristic features of vulnerable plaque. This may explain the link between positive remodelling and unstable clinical presentations.

Cardiac optical coherence tomography

Acute coronary syndromes (ACS) are a major cause of morbidity and mortality in the developed world. The risk of future acute coronary events appears to be largely dependent on the presence of morphologically distinct, atherosclerotic plaques,1 rather than the presence of severely stenotic lesions as assessed by angiography.2 Angiography, however, cannot provide details of the vascular wall and identify these so-called “vulnerable plaques”. To identify, study and potentially treat these lesions many invasive and non-invasive imaging modalities are undergoing evaluation. While techniques such as intravascular ultrasound (IVUS), especially combined with radiofrequency analysis, have been significant developments providing valuable information in this quest, all have the fundamental drawback of inadequate spatial resolution to image important lesion characteristics. With the development of optical coherence tomography (OCT) and the demonstration of its feasibility for intravascular imaging, a technique with micron-scale resolution became a reality, potentially enabling the ability to capture in vivo what was previously seen only through a pathologist’s microscope. Further, with the widespread adaptation of percutaneous coronary intervention (PCI) for the treatment of coronary disease, OCT is also emerging as a promising technology both to image the acute results of PCI and to monitor the response of the vessel wall to stent deployment. With ongoing development of this modality, OCT has the potential to be an important clinical imaging modality, complementary to angiography and IVUS. OCT is the optical analogue of pulse-echo IVUS, where electromagnetic waves using a light source as opposed to acoustic (sound) waves are used to create the image.3 A light source is emitted towards the sample. Information from the echo time delay (time for the light to be reflected back) and the intensity of backscatter of light from internal microstructures with varying optical properties within the sample is used to create the image. The …

Association of statin therapy with reduced coronary plaque rupture: an optical coherence tomography study

ObjectiveStatin therapy induces plaque regression and may stabilize atheromatous plaques. Optical coherence tomography (OCT) is a high-resolution in-vivo imaging modality that allows characterization of atherosclerotic plaques. We aimed to demonstrate the potential utility of OCT in evaluating coronary plaques in patients with or without statin therapy. MethodsPatients undergoing cardiac catheterization were enrolled. We identified culprit lesions and performed intracoronary OCT imaging. Plaque lipid pool, fibrous cap thickness, and frequency of thin-cap fibroatheroma were evaluated using previously validated criteria. Macrophage density was determined from optical signals within fibrous caps. Presence of calcification, thrombosis, and rupture was assessed. ResultsForty-eight patients were included (26 on statins, 22 without statins). Baseline characteristics were similar apart from lipid profile. Patients on statin therapy had lower total and low-density lipoprotein cholesterol concentrations (4.45±1.35 vs. 5.26±0.83 mmol/l, P=0.02; 2.23±0.78 vs. 3.26±0.62 mmol/l, P<0.001, respectively). Frequencies of lipid-rich plaque (69 vs. 82%), thin-cap fibroatheroma (31 vs. 50%), plaque calcification (15 vs. 5%) and thrombosis (15 vs. 32%), and fibrous cap macrophage density were comparable between statin and nonstatin groups (5.9 vs. 6.3%; all P=NS). Ruptured plaques were, however, significantly less frequent in patients on established statin therapy (8 vs. 36%; P=0.03) with a trend toward increased minimum fibrous cap thickness (78 vs. 49 μm; P=0.07). ConclusionWe demonstrated the use of OCT in plaque characterization and found that patients on prior statin therapy have reduced incidence of ruptured plaques and a trend toward thicker fibrous caps. This suggests that statins may stabilize coronary plaques.

Spontaneous Coronary Artery Dissection Utility of Intravascular Ultrasound and Optical Coherence Tomography During Percutaneous Coronary Intervention

Spontaneous coronary artery dissection (SCAD) is an infrequent cause of acute coronary syndromes but is represented disproportionately in young female patients. No specific guidelines exist concerning the appropriate treatment (medical therapy, intracoronary stents, coronary bypass surgery) or the optimal type of stents in otherwise atheroma-free vessels. The role of intracoronary imaging with intravascular ultrasound (IVUS) and optical coherence tomography (OCT) has yet to be fully established. A 39-year-old woman with no traditional risk factors for coronary artery disease presented with an anterior ST-segment elevation myocardial infarct after undergoing rigorous aerobic exercises. The patient was gravida 3 para 3, not known to be pregnant, and not postmenopausal. Her last pregnancy was 5 years earlier, and subsequent β human chorionic gonadotropin was negative. Coronary angiography suggested a long spiral dissection in the left anterior descending artery. Her other coronary arteries were smooth walled with no evidence of atherosclerosis. With ongoing symptoms and persisting ST elevation of the surface …

Impact of optimising fluoroscopic implant angles on paravalvular regurgitation in transcatheter aortic valve replacements - utility of three-dimensional rotational angiography.

AIMS The clinical value of optimising implant angles during transcatheter aortic valve replacements (TAVR) remains undefined. The Aortic Valve Guide (AVG) is a proprietary software that provides structured analysis of three-dimensional images from rotational angiography (DynaCT). This study compares AVG with preprocedural multislice computed tomography (MSCT) and DynaCT in optimal implant angle prediction for TAVR, and evaluates if an optimised implant angle is associated with reduced paravalvular regurgitation (PVR). METHODS AND RESULTS One hundred and six consecutive patients were included, comprising three groups. Group 1 (n=19) underwent no preprocedural MSCT or DynaCT (or AVG); Group 2 (n=44) underwent periprocedural DynaCT, without AVG; Group 3 (n=43) had DynaCT with AVG. Implant angles yielded were graded as excellent, satisfactory or poor. Group 3 were more likely than Groups 2 and 1 to have excellent implant angles (83.7% vs. 52.3% vs. 42.1%, respectively, p=0.001). In 100 patients who had 30-day transthoracic echocardiogram follow-up, an excellent implant angle was significantly more likely to be associated with no PVR than a non-excellent angle (41.3% vs. 21.6%, respectively, p=0.045), independent of operator experience and THV used. CONCLUSIONS Optimising implant angles may be important in reducing PVR. This is significantly more likely to be achieved with AVG rotational angiography.

Takotsubo cardiomyopathy: an Australian single centre experience with medium term follow up.

Background:  Takotsubo cardiomyopathy (TC) is increasingly recognised in patients presenting with features of acute coronary syndrome. We present a single centre experience of TC with medium term follow up.

Spontaneous recanalization of a coronary artery after thrombotic occlusion: in vivo demonstration with optical coherence tomography.

![Figure][1] A 50-year-old man with a recent embolic stroke was referred by a neurologist for abnormal electrocardiography results consistent with large anterior myocardial infarction. Echocardiogram results showed akinesis of the anteroapical left ventricular wall without obvious mural

Hyperglycemia on admission predicts larger infarct size in patients undergoing percutaneous coronary intervention for acute ST-segment elevation myocardial infarction

AIMS To determine if hyperglycemia on admission correlates to infarct size measured by single-photon emission computed tomography (SPECT) in patients with acute ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI). METHODS We evaluated 347 STEMI patients who underwent primary PCI. Infarct size was determined by SPECT on Day 5. The population was divided into: hyperglycemia (glycemia on admission >11mmol/L) or non-hyperglycemia (<or=11mmol/L) regardless of diabetic status. RESULTS 61 (17.6%) patients presented with hyperglycemia on admission. There were no significant differences in baseline characteristics or in PCI characteristics between the two groups. Final TIMI 3 flow was achieved in 81.7% of patients with hyperglycemia vs 85.7% of patients with non-hyperglycemia (p=0.43). The infarct size was larger in the hyperglycemia group (6 [2-14]% vs 8.5 [3-18.25]%; p=0.016). A multivariate linear regression analysis showed that hyperglycemia on admission was an independent predictor of infarct size at Day 5 post-MI (p=0.004). CONCLUSION In patients with STEMI treated with primary PCI, hyperglycemia on admission is associated with larger infarct size determined by SPECT.

Pre-Hospital Ambulance Notification and Initiation of Treatment of ST Elevation Myocardial Infarction is Associated with Significant Reduction in Door-to-Balloon Time for Primary PCI

BACKGROUND Mortality in ST elevation myocardial infarction (STEMI) is strongly predicted by the time from first medical contact to reperfusion. The aim of this study was to examine the impact of pre-hospital diagnosis by paramedics in the field on the door-to-balloon (DTB) times of patients with ST elevation myocardial infarction undergoing primary percutaneous intervention. METHODS Paramedics in the field identified patients with ST elevation myocardial infarction on a 12-lead electrocardiograph, activated the cardiac catheter laboratory team from the field and initiated therapy with anticoagulants and antiplatelet agents in the pre-hospital setting. This cohort of patients was compared to a similar group of patients without pre-hospital diagnosis and notification. The primary outcome measure was DTB times. A secondary end point was mortality at 30 days and mortality at six months. RESULTS A total of 281 patients, mean age of 61.1±12.9 years underwent primary percutaneous intervention with pre-hospital notification occurring in 63 cases. DTB times were lower in those with pre notification than in those without pre-hospital notification (40.4 vs. 75.6 minutes, p<0.001). This represented a 47.6% shorter DTB time. A non-statistically significant mortality reduction at one month and six months was observed in the pre-hospital notification group (1.6 versus 4.3%, p= 0.307 and 1.6 versus 6.4%, p= 0.203, respectively). CONCLUSION Pre-hospital intervention at our centre had a powerful effect in reducing the time to reperfusion in patients with STEMI undergoing primary percutaneous intervention.