Impact of Coronary Plaque on the Precision of Computational Fractional Flow Reserve Derived from CTA / 中山大学学报(医学科学版)

ObjectiveThe fractional flow reserve （FFR） computed from coronary computed tomographic （CT） angiograms makes it possible to noninvasively assess coronary artery disease， but the impact of plaque on FFR derived from computed tomography angiography （CTA） is still unknown. The study used invasive FFR as the reference standard to analyze the impact of plaque on coronary computed tomography angiography （CCTA）-based quantitative flow ratio （CT-QFR）. MethodsThe retrospective study included 108 patients with suspected coronary heart disease （CHD） who underwent both CCTA and FFR within 60 days. CCTA images were analyzed by the software. We obtained the CT-QFR of target vessels， perfomed the quantitative and qualitative analyses on target vascular plaques， including total plaque volume （TPV）， plaque burden， calcified plaque volume （CPV）， fibrous plaque volume （FPV）， lipid plaque volume （LPV）， and the presence or absence of high-risk plaque. ResultsAccording to the difference between CT-QFR and FFR at blood vessel level， 137 target vessels of 108 patients were divided into the overestimated group （difference＞0.03， n＝29）， reference group （-0.03≤difference≤0.03， n＝88） and underestimated group （difference＜-0.03， n＝20）. The underestimated group （14.81mm3） presented higher LPV than overestimated group （1.97mm3， P < 0.05）. There was a negative correlation between LPV and the difference （P＜0.05）. ConclusionsWhen CT-QFR is used to estimate hemodynamics of coronary artery stenosis， the presence of lipid plaque may underestimate the virtual FFR.

Late and Incidental Discovery of an Anomalous Coronary Artery Originating from the Opposite Sinus after Stemi

Coronary artery anomalies (CAAs) comprise a diverse group of congenital malformations with widely varying expressions and pathophysiological mechanisms. The most notable group of CAAs has been termed ‘Anomalous coronary artery originating from the opposite sinus of Valsalva’ (ACAOS), a rare congenital heart disease that is associated with sudden cardiac death and ischemia. We present the case of an 80-year-old man presenting with inferior STEMI having a single coronary ostium and a rare variant of the coronary artery origin belonging to type A4d with an interatrial LAD course according to Angelini's classification. This abnormal finding was managed conservatively and the patient underwent successful drug-eluding stent implantation in the culprit right coronary artery in its middle portion.

Image Quality of Coronary CT Angiography (CCTA) using 640-slice Scanner: Qualitative and Quantitative Assessments of Coronary Arteries Visibility (Kualiti Imej Tomografi Berkomputer Angiografi Koronari Menggunakan Mesin Pengimbas 640 Hirisan: Penilaian Kualitatif dan Kuantitatif ke atas Keterlihatan Arteri Koronari) / Jurnal Sains Kesihatan Malaysia

@#The purpose of this study was to evaluate the image quality and diagnostic accuracy of coronary computed tomography angiography (CCTA) using 640-slice scanner. Advancement of multidetector computed tomography (MDCT) technology with higher spatial, temporal resolution, and increasing detector array have improved the image quality and diagnostic accuracy of CCTA. A total of 25 patients (12 men and 13 women) underwent CCTA examination was chosen and data was acquired by 640-slice scanner. All 16 segments of coronary arteries were evaluated by two reviewers using a 4-likert scale for qualitative assessment. In quantitative assessment, the evaluation of 4 main coronary arteries were analysed in terms of signal intensity (SI), image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). All 25 patients with a mean age of 52.88 ± 14.75 years old and body mass index (BMI) of 24.24 ± 3.28 kg/m2 were analysed. In qualitative assessment, from the total of 400 segments, 379 segments (95%) had diagnostic value while 21 segments did not have diagnostic value, which means 5% artefact was detected. In quantitative assessment, there was no statistical differences in gender, race, and BMI (p>0.05). Overall evaluation showed that higher SI at the left main artery (LM) at 393.7 ± 47.19. Image noise was higher at right coronary artery (RCA) at 39.01 ± 13.97. SNR and CNR showed higher at left anterior descending (LAD) with 12.73 ± 5.17 and LM 9.14 ± 4.2, respectively. In conclusion, this study indicates that 640-slice MDCT has higher diagnostic value in CCTA examination with 95% vessel visibility with 5% artefact detection.

Pulmonary Arterial Enlargement is Associated with Acute Chest Pain in Patients without Coronary Artery Disease

Background: Pulmonary hypertension (PH) is an uncommon cause for chest pain in patients without significant coronary artery disease (CAD). Therefore, we studied the association between chest pain, right ventricular dimensions (RVDs), and PA size on coronary coronary tomographic angiography (CCTA). Materials and methods: It was a prospective study done from the February 1, 2015 to August 31, 2015. Total of 98 patients were identified, 67 in the chest pain and 31 in the non-chest pain group. Results: Patients with chest pain without CAD showed markedly dilated right atrial and ventricular chambers compared with standard parameters. PAD was measured as 24.81± 0.47 mm in the chest pain group and 21.91 ± 0.41 mm in the control group (P < 0.05). Odds ratio between chest pain and a significantly higher PAD was 10.11 (2.76-41.91, P < .05), 10.33 (2.15-61.41, P < .05) after adjusting for age, sex, BMI, history of HTN, HLP, CHF, COPD, OSA, and smoking. The chest pain group had an RAD1 of 47.19± 0.61 mm, RAD2 of 43.83 ± 1.79 mm, RVD1 of 37.91± 0.75 mm, RVD2 of 30.87± 0.73 mm, and RVD3 of 60.31± 1.1 mm. Based on the existing echocardiographic reference ranges, these measures fall within the upper limits of normal range. When comparing chest pain vs non-chest pain group, respectively, the mean RAD2 measured 39.98 ± 0.73 mm vs 33.78± 1.13 mm (P = .005), and the mean RVD2 measured 30.87± 0.73 mm vs 26.71± 1.73 (P = .03). Conclusion: In patients presenting with chest pain without CAD on CCTA, there is a strong association between the presence of chest pain and enlarged PAD.

ASpirin and Plavix Following Coronary Artery Bypass Grafting (ASAP-CABG): A Randomized, Double-Blind, Placebo-Controlled Pilot Trial.

Background: Vein graft thrombosis is the leading cause of acute graft failure within the first post-operative month. Several studies have shown the benefit of post-operative dual anti-platelet therapy (DAPT) in preventing acute graft thrombosis. The purpose of this study was to determine whether peri-operative initiation of DAPT will improve short and intermediate term graft patency. Methods: This was a randomized, double-blind, placebo controlled trial of 20 patients undergoing CABG to compare DAPT versus aspirin monotherapy. The primary outcome was post-operative graft patency at 2 and 52 weeks determined by <50% bypass graft stenosis by cardiac computed tomography angiography (CCTA). The secondary outcomes were (1) major adverse cardiovascular events (MACE), defined as myocardial infarction, thrombotic events, and angina, and (2) safety end-points defined as TIMI major and minor bleeding events. Results: The study population consisted predominately of men (19/20 patients). At 2 weeks, all LIMA grafts were patent although vein graft patency for the DAPT group was only 83.3% (20/24) compared to 89.5% (17/19) for placebo (p=0.597). At 52 weeks, the patency rate in the placebo group was 52.6% (10/19) as compared to a patency of 71.4% (15/24) in the dual anti-platelet therapy arm (p=0.244). Conclusion: The addition of clopidogrel to aspirin post-bypass surgery did not significantly improve venous graft patency at 2 weeks but trended toward higher graft patency at 52 weeks.

Utility of Per Vessel Coronary Artery Calcium (CAC) Score in Symptomatic Patients Undergoing Coronary Computed Tomography in Predicting Major Adverse Cardiovascular Events: Single Center Experience and Literature Review.

Background: Atherosclerotic vascular disease remains a significant etiology of morbidity and mortality in the United States. Coronary artery calcium (CAC) is associated with increased stroke incidence and coronary atherosclerotic burden. Uncertainty remains regarding how best to interpret non-zero CAC scores, particularly in symptomatic patients. Methods: A review of the first 1122 patients who underwent coronary CT angiography (CCTA) with CAC scoring from January 2005 until July 2012 was performed. Patients were dichotomized into 2 groups, zero CAC score and non-zero CAC score. Non-zero CAC patients were further subdivided based on the specific coronary artery containing calcium. Rates of major adverse cardiovascular events (MACE) defined as all-cause mortality, non-fatal myocardial infarction (MI), ischemic stroke, and late revascularization (>90 days following CCTA) were evaluated in each group. Results: 505 patients (63% male, mean age 60 ± 11) with non-zero CAC scores were analyzed over a six year period with resultant median follow up period of 22 months (IQR25,75 13-34 months). Major adverse cardiovascular events were observed in 11 patients. Receiver-operator curve (ROC) analysis on each coronary segment showed significance with the presence of left main (LM) CAC (AUC 0.752, p=0.004). Conclusions: The presence of CAC at any value in the LM in this case series appears to predispose patients to increased rates of MACE.

Temporal Trends in Radiation Exposure and Utilization of Coronary CT Angiography, SPECT, and Invasive Coronary Angiography.

Background: The use of noninvasive medical imaging has increased over the past decade at a cost of significant lifetime radiation exposure to study subjects. We report the implementation of radiation dose reduction methods and associated reduction in ionizing radiation exposure with Coronary Computed Tomography Angiography (CCTA) over time. Methods: Radiation doses and total number of studies performed were evaluated constantly from January 2010 to September 2012 for CCTA (N=2613), as well as Single photon emission computed tomography (SPECT, N=8060) part of an ongoing effort to minimize radiation exposure. Analysis of variance was used to evaluate the radiation exposure reduction among modalities. We compared CCTA radiation doses in the era of retrospective protocols coupled with dose modulation (40%-80%phase) using Siemens® 64-slice Dual Source technology, with prospective scanning on the same equipment, as well as radiation doses on the newer Siemens® Flash Equipment and the implementation of nursing/technologist aggressively driven protocol for heart rate control and image acquisition independent of imaging provider presence during acquisition. Results: The radiation dose reduction with implementation of multiple measures of radiation reduction to include physician independent-technician driven CCTA protocol resulted in a reduction from mean of 9.85±5.96 (median 8.8mSv) to mean of 3.00±2.53(median 2.1mSv) (p<0.0001). CCTA radiation dose has decreased by 69.2% since January of 2010 while SPECT radiation dose remained constant at 14mSv (p<0.0001). Conclusion: Continued advances in software and hardware technology, combined with “physician independent-technician driven” CCTA protocol have drastically reduced radiation dosing in CCTA to annual background radiation exposure, while maximizing the benefit of the study and without sacrificing patient safety.

La importancia del diagnóstico multi-imagen en cardiología / The importance of multi-imaging diagnosis in cardiology

La imagen cardiovascular es una de las disciplinas que más ha evolucionado en el campo de la cardiología. Ante esto, la enseñanza de la cardiología debe moverse a la par. En 2009, el Colegio Americano de Cardiología decidió publicar una declaración en la que señala que: todos los residentes de cardiología deben llevar un entrenamiento básico en cada una de las técnicas de imagen cardiovascular disponibles. La cardiopatía isquémica es la principal causa de muerte en casi todo el mundo, incluido México. Hasta 43% de los pacientes que habían sufrido un infarto del miocardio y 31% de los pacientes con muerte súbita de origen cardiaco, tenían un estudio de perfusión por medicina nuclear prácticamente normal en el año previo al desenlace, poniendo en evidencia la importancia del abordaje por medio de distintos métodos de imagen. Con el mejor entendimiento de los procesos fisiopatológicos de la enfermedad arterial coronaria, se han desarrollado técnicas diagnósticas que nos permiten identificar esta patología prácticamente desde su inicio, a través de la detección de disfunción endotelial por medio de la tomografía por emisión de positrones. Más adelante, cuando los pacientes desarrollan ateroesclerosis manifiesta, contamos con herramientas como el score de calcio y la detección de las placas ateroscleróticas por medio de la tomografía computarizada. Para detectar la presencia de isquemia miocárdica contamos con dos métodos ampliamente utilizados: la ecocardiografía en estrés con dobutamina o dipiridamol y la medicina nuclear. Otras opciones para la identificación de isquemia son la resonancia magnética y la tomografía computada, gracias a la tecnología Dual Source y Flash. Posterior a un evento coronario, la imagen cardiovascular tiene como funciones la estratificación de riesgo y la detección de tejido miocárdico viable, siendo hoy en día el método de elección la tomografía por emisión de positrones.

Cardiovascular imaging is one of the disciplines in cardiology with the most recent advances. This means that the teaching of Cardiology must evolve in the same way. In 2009, the American College of Cardiology published a statement, which points out that all of the cardiology residents must have basic training in every one of the cardiovascular imaging modalities available. Ischemic heart disease is the main cause of death in the world, including Mexico. Up to 43% of the patients that suffered a myocardial infarction and up to 31% of the patients with sudden cardiac death had an almost normal nuclear myocardial perfusion study in the year before the event, thus evidencing the importance of a multi-imaging approach. With the better understanding of the pathophysiological processes of coronary artery disease, new techniques have been developed that allows the detection of this disease almost from the beginning, through the detection of endothelial dysfunction by Positron Emission Tomography. Later on, when the patient develops diffuse atherosclerosis, we can rely on the use of de coronary calcium score and the detection of atherosclerotic plaques with coronary computed tomography angiography. To detect the presence of myocardial ischemia, two methods are widely used: echocardiography and nuclear medicine. Other options to identify myocardial ischemia are magnetic resonance imaging and computed tomography, due to the development of the "Dual Source" and "Flash" technologies. After an acute coronary event, cardiovascular imaging is useful for risk stratification and detection of myocardial viability, being the positron emission tomography the gold standard.