Differentiation of athlete's heart and hypertrophic cardiomyopathy by the fractal dimension of left ventricular trabeculae.

BACKGROUND: Differentiation between exercise induced adaptive myocardial hypertrophy (athlete's heart) and hypertrophic cardiomyopathy (HCM) is currently based on echocardiographic and cardiac magnetic resonance (CMR) criteria, but these may be insufficient in patients with subtle phenotype expression. This study aimed to assess whether left ventricular (LV) fractal pattern could permit to differentiate athlete's heart from HCM. METHODS: We recruited retrospectively 61 elite marathon runners, 67 patients with HCM, and 33 healthy subjects. A CMR study was performed in all subjects and the LV trabeculae fractal dimension (FD) was measured in end-diastolic frames of each short-axis cine sequence. For group comparison, the ratio of maximal myocardial wall thickness (mMWT)/indexed LV end-diastolic volume (LVED) was determined. RESULTS: As compared with athletes, patients with HCM had significantly (p < 0.001) greater FD in the LV basal (1.30 ± 0.07 vs. 1.23 ± 0.05) and apical (1.38 ± 0.06 vs. 1.30 ± 0.07) regions and in the whole heart (1.34 ± 0.05 vs. 1.27 ± 0.05). FD increased with age, left atrial area and indexed left ventricular mass (p < 0.05 for all) and correlated negatively with LV and RV end-diastolic volumes (p < 0.05 each). The addition of whole heart FD to the ratio of maximal myocardial wall thickness/indexed LVEDV lead to an improvement in the ability to discriminate HCM with a net reclassification index (NRI) of 71%. CONCLUSIONS: The FD regional distribution of the LV trabeculae differentiates patients with athlete's heart from patients with HCM. The addition of whole heart FD to the mMWT/indexed LVEDV ratio improves the predictive capacity of the model to differentiate both entities.

Case 270: Spontaneous Coronary Artery Dissection Associated with Fibromuscular Dysplasia.

HistoryA 54-year-old woman presented with typical chest pain during physical training at the gym. She had a history of hypertension controlled with hydrochlorothiazide, without any other cardiovascular risk factor and with neither personal nor family history of ischemic heart disease. She was postmenopausal and had a long-standing history of migraine headaches without hormonal or drug therapy. The patient had no history of clinically important thoracic trauma or invasive chest interventions. Initial electrocardiography (ECG) showed signs of ongoing anterior ST segment elevation myocardial infarction, and emergent coronary angiography with angioplasty and intravascular US were performed. Maximal level of high-sensitive T troponins was 820 ng/L (normal, <13 ng/L), while echocardiography showed a normal left ventricular ejection fraction, with no apparent regional wall motion abnormalities. General physical examination findings were unremarkable, excluding ligamentous hyperlaxity and joint instability. C-reactive protein, rheumatoid factor, antinuclear antibody, cytoplasmic antineutrophil cytoplasmic antibody, and angiotensin-converting enzyme blood test results were negative. For further evaluation, arterial phase ECG-synchronized CT angiography from the skull base to the pubis symphysis was performed.

Case 270.

History A 54-year-old woman presented with typical chest pain during physical training at the gym. She had a history of hypertension controlled with hydrochlorothiazide, without any other cardiovascular risk factor and with neither personal nor family history of ischemic heart disease. She was postmenopausal and had a long-standing history of migraine headaches without hormonal or drug therapy. The patient had no history of clinically important thoracic trauma or invasive chest interventions. Initial electrocardiography (ECG) showed signs of ongoing anterior ST segment elevation myocardial infarction, and emergent coronary angiography with angioplasty and intravascular US were performed ( Fig 1 ). Maximal level of high-sensitive T troponins was 820 ng/L (normal, <13 ng/L), while echocardiography showed a normal left ventricular ejection fraction, with no apparent regional wall motion abnormalities. General physical examination findings were unremarkable, excluding ligamentous hyperlaxity and joint instability. C-reactive protein, rheumatoid factor, antinuclear antibody, cytoplasmic antineutrophil cytoplasmic antibody, and angiotensin-converting enzyme blood test results were negative. For further evaluation, arterial phase ECG-synchronized CT angiography from the skull base to the pubis symphysis was performed ( Fig 2 ). Figure 1a: Coronary angiography of the left anterior descending (LAD) and left circumflex (LCX) arteries (30° right anterior oblique and 20° caudally angulated projection) and intravascular US of the LCX artery were performed. (a) Initial coronary angiography projection. (b) Coronary angiography projection after LAD stent placement. (c, d) Intravenous US images of the distal (c) and proximal (d) LCX artery obtained after b. Figure 1b: Coronary angiography of the left anterior descending (LAD) and left circumflex (LCX) arteries (30° right anterior oblique and 20° caudally angulated projection) and intravascular US of the LCX artery were performed. (a) Initial coronary angiography projection. (b) Coronary angiography projection after LAD stent placement. (c, d) Intravenous US images of the distal (c) and proximal (d) LCX artery obtained after b. Figure 1c: Coronary angiography of the left anterior descending (LAD) and left circumflex (LCX) arteries (30° right anterior oblique and 20° caudally angulated projection) and intravascular US of the LCX artery were performed. (a) Initial coronary angiography projection. (b) Coronary angiography projection after LAD stent placement. (c, d) Intravenous US images of the distal (c) and proximal (d) LCX artery obtained after b. Figure 1d: Coronary angiography of the left anterior descending (LAD) and left circumflex (LCX) arteries (30° right anterior oblique and 20° caudally angulated projection) and intravascular US of the LCX artery were performed. (a) Initial coronary angiography projection. (b) Coronary angiography projection after LAD stent placement. (c, d) Intravenous US images of the distal (c) and proximal (d) LCX artery obtained after b. Figure 2a: Arterial phase electrocardiography-synchronized CT angiography from the skull base to the pubis symphysis was performed after coronary angiography, subsequent interventional procedures, and intravenous US. (a, b) Axial oblique slab maximum intensity projection image at the level of the left (a) and right (b) renal arteries. (c) Coronal volume-rendering image shows an anterior view of the renal arteries. Figure 2b: Arterial phase electrocardiography-synchronized CT angiography from the skull base to the pubis symphysis was performed after coronary angiography, subsequent interventional procedures, and intravenous US. (a, b) Axial oblique slab maximum intensity projection image at the level of the left (a) and right (b) renal arteries. (c) Coronal volume-rendering image shows an anterior view of the renal arteries. Figure 2c: Arterial phase electrocardiography-synchronized CT angiography from the skull base to the pubis symphysis was performed after coronary angiography, subsequent interventional procedures, and intravenous US. (a, b) Axial oblique slab maximum intensity projection image at the level of the left (a) and right (b) renal arteries. (c) Coronal volume-rendering image shows an anterior view of the renal arteries.

Prognostic value of a new semiquantitative score system for adenosine stress myocardial perfusion by CMR.

OBJECTIVES: Cardiovascular magnetic resonance (CMR) provides information on myocardial ischemia through stress perfusion studies. In clinical practice, the grading of induced perfusion defects is performed by visual estimation of their extension. The aim of our study is to devise a score of the degree of ischemia and to test its prognostic value. METHODS: Between 2009 and 2011, patients with diagnosed or suspected coronary artery disease underwent stress perfusion CMR. A score of ischemic burden was calculated on the basis of (1) stress-induced perfusion defect, (2) persistence, (3) transmurality, and (4) stress-induced contractile defect. Follow-up was censored after 4 years and primary end-point was defined by a composite of death, heart failure episode, acute coronary syndrome, and ventricular arrhythmias. Univariate and multivariate logistic regressions were used to assess the strength of the association between the CMR ischemic variables, and the composite outcome. RESULTS: Forty-four of the 128 patients (34%) presented with adverse events, while 84 (66%) did not. Sixty-one patients (48%) had negative perfusion studies while 67 (52%) showed perfusion defect. Patients with positive perfusion studies and adverse events (n = 39) had higher number of segments with persistent defect (3.3 vs 1.3, p = 0.001) and highest score (19.6 vs 13.3 p = 0.012) than patients with positive perfusion studies and absence of events (n = 28). The number of segments with persistent defect showed the strongest predictive value of adverse events (OR 1.54; CI 1.19-2.00; p < 0.001). CONCLUSIONS: The score of ischemic burden proposed herein has prognostic value. Persistence of a perfusion defect has the strongest impact on prognosis. KEY POINTS: • Cardiovascular magnetic resonance provides information on myocardial ischemia by visual estimation of the presence of perfusion defects induced by stress. • There is not a standardized method for grading perfusion defects which, in practice, is performed by visual estimation of their extension. • As proven in this study, the integration of several parameters of perfusion defects (in addition to extension) into a semiquantitative score has prognostic value.

Myocardial remodelling and tissue characterisation by cardiovascular magnetic resonance (CMR) in endurance athletes.

There is still some controversy about the benignity of structural changes observed in athlete's heart, especially regarding the observation of increased biomarkers and the presence of myocardial fibrosis (MF). AIM: Our purpose was to evaluate by cardiovascular magnetic resonance (CMR) the presence of diffuse as well as focal MF in a series of high-performance veteran endurance athletes. METHODS: Thirty-four veteran healthy male endurance athletes, still being in regular training, with more than 10 years of training underwent a CMR. A cardiopulmonary exercise test was also performed to assess their maximal physical performance. The control group consisted in 12 non-trained normal individuals. RESULTS: We found an increase in both, right and left ventricular (LV) volumes in the athlete's group when compared with controls. There was no increase in indexed LV myocardial mass despite of a significantly increased maximal myocardial wall thickness in comparison to controls. Native T1 values and extracellular volume (ECV) were normal in all cases. We did not find differences in native T1 values and ECV between both groups. In three athletes (9%), non-ischaemic late gadolinium enhancement (LGE) was observed. We did not find a correlation between total training volume and presence of LGE or with the ECV value. CONCLUSIONS: Our results show that the majority of veteran endurance athletes present with myocardial remodelling without MF as a physiological adaptive phenomenon. In the only three athletes with focal MF, the LGE pattern observed suggests an intercurrent event not related with the remodelling phenomenon.

P2Y12 antagonists and cardiac repair post-myocardial infarction: global and regional heart function analysis and molecular assessments in pigs.

Aims: P2Y12 antagonists are the standard in antiplatelet therapy but their potential effects on functional myocardial recovery and cardioprotection post-myocardial infarction (MI) are unknown. We investigated in a preclinical model of MI whether ticagrelor and clopidogrel differently affect cardiac repair post-MI. Methods and results: Pigs either received: (i) clopidogrel (600 mg; 75 mg/qd); (ii) ticagrelor (180 mg; 90 mg/bid); and (iii) placebo control. MI was induced by mid-left anterior descending coronary artery balloon occlusion (60 min) and animals received the maintenance doses for the following 42 days. Serial cardiac magnetic resonance was performed at Day 3 and Day 42 for the assessment of global and regional cardiac parameters. We determined cardiac AMP-activated protein kinase (AMPK), Akt/PKB, aquaporin-4, vascular density, and fibrosis. In comparison to controls, both P2Y12 antagonists limited infarct expansion at Day 3, although ticagrelor induced a further 5% reduction (P < 0.05 vs. clopidogrel) whereas oedema was only reduced by ticagrelor (≈23% P < 0.05). Scar size decreased at Day 42 in ticagrelor-treated pigs vs. controls but not in clopidogrel-treated pigs. Left ventricular ejection fraction was higher 3 days post-MI in ticagrelor-treated pigs and persisted up to Day 42 (P < 0.05 vs. post-MI). Regional analysis revealed that control and clopidogrel-treated pigs had severe and extensive wall motion abnormalities in the jeopardized myocardium and a reduced myocardial viability that was not as evident in ticagrelor-treated pigs (χ2P < 0.05 vs. ticagrelor). Only ticagrelor enhanced myocardial AMPK and Akt/PKB activation and reduced aquaporin-4 levels (P < 0.05 vs. control and clopidogrel). No differences were observed in vessel density and fibrosis markers among groups. Conclusions: Ticagrelor is more efficient than clopidogrel in attenuating myocardial structural and functional alterations post-MI and in improving cardiac healing. These benefits are associated with persistent AMPK and Akt/PKB activation.

Allogenic adipose-derived stem cell therapy overcomes ischemia-induced microvessel rarefaction in the myocardium: systems biology study.

BACKGROUND: Myocardial microvascular loss after myocardial infarction (MI) remains a therapeutic challenge. Autologous stem cell therapy was considered as an alternative; however, it has shown modest benefits due to the impairing effects of cardiovascular risk factors on stem cells. Allogenic adipose-derived stem cells (ASCs) may overcome such limitations, and because of their low immunogenicity and paracrine potential may be good candidates for cell therapy. In the present study we investigated the effects of allogenic ASCs and their released products on cardiac rarefaction post MI. METHODS: Pig subcutaneous adipose tissue ASCs were isolated, expanded and GFP-labeled. ASC angiogenic function was assessed by the in-vivo chick chorioallantoic membrane (CAM) model. Pigs underwent MI induction and 7 days after were randomized to receive: allogenic ASCs (intracoronary infusion); conditioned media (CM; intravenous infusion); ASCs + CM; or PBS/placebo (control). Cardiac damage and function were monitored by 3-T cardiac magnetic resonance imaging upon infusion (baseline CMR) and 1 and 3 weeks thereafter. We assessed in the myocardium: microvessel density; angiogenic markers (CD105, CD31, TF, VEGFR2, VEGFR1, vWF, eNOS, CD62); collagen deposition; and reparative fibrosis (TGFß/TßRII/collagen). Differential proteomics of ASCs and CM was performed to characterize the ASC protein signature. RESULTS: CAM indicated a significant ASC proangiogenic capacity. In pigs after MI, only PBS/placebo animals displayed an impaired cardiac function 3 weeks after infusion (p < 0.05 vs baseline). Administration of ASCs + CM significantly enhanced neovessel formation and favored cardiac repair post MI (p < 0.05 vs the other groups). Molecular markers of angiogenesis were significantly upregulated both at transcriptional and protein levels (p < 0.05). The in-silico bioinformatics analysis of the ASC and CM proteome (interactome) indicated activation of a coordinated protein network involved in the formation of microvessels and the resolution of rarefaction. CONCLUSION: Coadministration of allogenic ASCs and their CM synergistically contribute to the neovascularization of the infarcted myocardium through a coordinated upregulation of the proangiogenic protein interactome.

Protective Effects of Ticagrelor on Myocardial Injury After Infarction.

BACKGROUND: The P2Y12 receptor antagonist ticagrelor has been shown to be clinically superior to clopidogrel. Although the underlying mechanisms remain elusive, ticagrelor may exert off-target effects through adenosine-related mechanisms. We aimed to investigate whether ticagrelor reduces myocardial injury to a greater extent than clopidogrel after myocardial infarction (MI) at a similar level of platelet inhibition and to determine the underlying mechanisms. METHODS: Pigs received the following before MI induction: (1) placebo-control; (2) a loading dose of clopidogrel (600 mg); (3) a loading dose of ticagrelor (180 mg); or (4) a loading dose of ticagrelor followed by an adenosine A1/A2-receptor antagonist [8-(p-sulfophenyl)theophylline, 4 mg/kg intravenous] to determine the potential contribution of adenosine in ticagrelor-related cardioprotection. Animals received the corresponding maintenance doses of the antiplatelet agents during the following 24 hours and underwent 3T-cardiac MRI analysis. Platelet inhibition was monitored by ADP-induced platelet aggregation. In the myocardium, we assessed the expression and activation of proteins known to modulate edema formation, including aquaporin-4 and AMP-activated protein kinase and its downstream effectors CD36 and endothelial nitric oxide synthase and cyclooxygenase-2 activity. RESULTS: Clopidogrel and ticagrelor exerted a high and consistent antiplatelet effect (68.2% and 62.2% of platelet inhibition, respectively, on challenge with 20 µmol/L ADP) that persisted up to 24 hours post-MI (P<0.05). All groups showed comparable myocardial area-at-risk and cardiac worsening after MI induction. 3T-Cardiac MRI analysis revealed that clopidogrel- and ticagrelor-treated animals had a significantly smaller extent of MI than placebo-control animals (15.7 g left ventricle and 12.0 g left ventricle versus 22.8 g left ventricle, respectively). Yet, ticagrelor reduced infarct size to a significantly greater extent than clopidogrel (further 23.5% reduction; P=0.0026), an effect supported by troponin-I assessment and histopathologic analysis (P=0.0021). Furthermore, in comparison with clopidogrel, ticagrelor significantly diminished myocardial edema by 24.5% (P=0.004), which correlated with infarct mass (r=0.73; P<0.001). 8-(p-Sulfophenyl)theophylline administration abolished the cardioprotective effects of ticagrelor over clopidogrel. At a molecular level, aquaporin-4 expression decreased and the expression and activation of AMP-activated protein kinase signaling and cyclooxygenase-2 increased in the ischemic myocardium of ticagrelor- versus clopidogrel-treated animals (P<0.05). These protein changes were not observed in those animals administered the adenosine receptor blocker 8-(p-sulfophenyl)theophylline. CONCLUSIONS: Ticagrelor, beyond its antiplatelet efficacy, exerts cardioprotective effects by reducing necrotic injury and edema formation via adenosine-dependent mechanisms.

Troponina T de alta sensibilidad y angiotomografía computarizada coronaria para el diagnóstico rápido del dolor torácico en el servicio de urgencias / High-sensitivity troponin T testing and coronary computed tomography angiography for rapid diagnosis of chest pain in the emergency department

Objetivo: Determinar la probabilidad de encontrar lesiones coronarias significativas, el tiempo diagnóstico y la seguridad de una nueva estrategia basada en la utilización de troponina T de alta sensibilidad (TnT-as) seguida de angiotomografía computarizada coronaria (ATCC) en pacientes con dolor torácico de posible origen coronario, en comparación con la atención clínica habitual en un servicio de urgencias (SU). Método: Ensayo clínico diagnóstico aleatorizado y abierto realizado en un SU de un hospital terciario universitario entre febrero 2011 y abril 2013. Se incluyó a pacientes atendidos por dolor torácico con electrocardiograma no diagnóstico en urgencias. Se asignó de forma aleatorizada a la estrategia nueva (EN) (seriación de TnT-as seguida de ATCC cuando fue negativa) o la estrategia convencional (EC) (seriación de TnT de cuarta generación seguida de ergometría cuando fue negativa). Se indicó coronariografía invasiva si las troponinas, la ATCC o la ergometría fueron positivas. Se registró el resultado de la coronariografía invasiva, el tiempo diagnóstico y la aparición de un evento adverso (muerte por cualquier causa, nuevo infarto de miocardio, nueva angina inestable o necesidad de revascularización) durante los 3 meses de seguimiento. Resultados: De los 102 pacientes aleatorizados se excluyeron 7. Se incluyeron 95 pacientes, 45 asignados a la EC y 50 a la EN. La coronariografía mostró lesiones significativas en un 92,9% de los casos de la EN y en un 66,7% de la EC. La proporción de pacientes diagnosticados en las primeras 6 horas fue mayor en la EN en comparación con la EC (20,0% vs 4,4%; p = 0,023). Durante el periodo de 3 meses de seguimiento, se registró una muerte en la EN y ningún evento en la EC. Conclusiones: La EN podría aportar un diagnóstico más rápido, así como una mayor probabilidad de encontrar lesiones coronarias significativas, sin diferencias en la aparición de eventos adversos en los 3 primeros meses. Estos hallazgos necesitan ser confirmados en futuros estudios con mayor número de pacientes (AU)

Objective: To determine the probability of finding significant coronary lesions, the time to diagnosis, and the safety of a new diagnostic approach based on high-sensitivity cardiac troponin T (hsTnT) testing followed by coronary computed tomography angiography (CCTA) in patients with chest pain of possible coronary origin. The method was compared with our hospital emergency department’s standard practice. Methods: Unblinded randomized controlled trial in a tertiary level university hospital between February 2011 and April 2013. We included emergency patients with chest pain and nondiagnostic electrocardiographic findings. Patients were assigned randomly to the new approach (hsTnT assay, followed by CCTA if the assay findings were negative) or the conventional approach (fourth generation TnT assay and, if negative, followed by an exercise stress test). Invasive coronary angiography was ordered in all patients if the results of either troponin assay, the CCTA, or the stress test were positive. We recorded the results of angiography, time until diagnosis, and all-cause mortality, new myocardial infarction, new unstable angina, or need for revascularization within the next 3 months. Results: Of 102 patients randomized, 7 were excluded; 50 of the remaining 95 patients were assigned to the new strategy, and 45 to the conventional approach. Coronary angiography demonstrated significant lesions in 92.9% of the patients treated with the new strategy and 66.7% of those diagnosed conventionally. A higher percentage of patients were diagnosed within 6 hours with the new approach (20.0% vs 4.4% of conventional-approach patients, P = .023). During the 3 months following diagnosis, 1 death occurred in the intervention group and none in the conventional-approach group. Conclusions: The new strategy could accelerate diagnosis and increase the probability of finding significant coronary lesions, but we found no significant differences in adverse events in the 3 months following diagnosis. These findings should be confirmed in studies with larger numbers of patients (AU)

[High-sensitivity troponin T testing and coronary computed tomography angiography for rapid diagnosis of chest pain in the emergency department]. / Troponina T de alta sensibilidad y angiotomografía computarizada coronaria para el diagnóstico rápido del dolor torácico en el servicio de urgencias.

OBJECTIVES: To determine the probability of finding significant coronary lesions, the time to diagnosis, and the safety of a new diagnostic approach based on high-sensitivity cardiac troponin T (hsTnT) testing followed by coronary computed tomography angiography (CCTA) in patients with chest pain of possible coronary origin. The method was compared with our hospital emergency department's standard practice. MATERIAL AND METHODS: Unblinded randomized controlled trial in a tertiary level university hospital between February 2011 and April 2013. We included emergency patients with chest pain and nondiagnostic electrocardiographic findings. Patients were assigned randomly to the new approach (hsTnT assay, followed by CCTA if the assay findings were negative) or the conventional approach (fourth generation TnT assay and, if negative, followed by an exercise stress test). Invasive coronary angiography was ordered in all patients if the results of either troponin assay, the CCTA, or the stress test were positive. We recorded the results of angiography, time until diagnosis, and all-cause mortality, new myocardial infarction, new unstable angina, or need for revascularization within the next 3 months. RESULTS: Of 102 patients randomized, 7 were excluded; 50 of the remaining 95 patients were assigned to the new strategy, and 45 to the conventional approach. Coronary angiography demonstrated significant lesions in 92.9% of the patients treated with the new strategy and 66.7% of those diagnosed conventionally. A higher percentage of patients were diagnosed within 6 hours with the new approach (20.0% vs 4.4% of conventional-approach patients, P = .023). During the 3 months following diagnosis, 1 death occurred in the intervention group and none in the conventional-approach group. CONCLUSION: The new strategy could accelerate diagnosis and increase the probability of finding significant coronary lesions, but we found no significant differences in adverse events in the 3 months following diagnosis. These findings should be confirmed in studies with larger numbers of patients.

OBJETIVO: Determinar la probabilidad de encontrar lesiones coronarias significativas, el tiempo diagnóstico y la seguridad de una nueva estrategia basada en la utilización de troponina T de alta sensibilidad (TnT-as) seguida de angiotomografía computarizada coronaria (ATCC) en pacientes con dolor torácico de posible origen coronario, en comparación con la atención clínica habitual en un servicio de urgencias (SU). METODO: Ensayo clínico diagnóstico aleatorizado y abierto realizado en un SU de un hospital terciario universitario entre febrero 2011 y abril 2013. Se incluyó a pacientes atendidos por dolor torácico con electrocardiograma no diagnóstico en urgencias. Se asignó de forma aleatorizada a la estrategia nueva (EN) (seriación de TnT-as seguida de ATCC cuando fue negativa) o la estrategia convencional (EC) (seriación de TnT de cuarta generación seguida de ergometría cuando fue negativa). Se indicó coronariografía invasiva si las troponinas, la ATCC o la ergometría fueron positivas. Se registró el resultado de la coronariografía invasiva, el tiempo diagnóstico y la aparición de un evento adverso (muerte por cualquier causa, nuevo infarto de miocardio, nueva angina inestable o necesidad de revascularización) durante los 3 meses de seguimiento. RESULTADOS: De los 102 pacientes aleatorizados se excluyeron 7. Se incluyeron 95 pacientes, 45 asignados a la EC y 50 a la EN. La coronariografía mostró lesiones significativas en un 92,9% de los casos de la EN y en un 66,7% de la EC. La proporción de pacientes diagnosticados en las primeras 6 horas fue mayor en la EN en comparación con la EC (20,0% vs 4,4%; p = 0,023). Durante el periodo de 3 meses de seguimiento, se registró una muerte en la EN y ningún evento en la EC. CONCLUSIONES: La EN podría aportar un diagnóstico más rápido, así como una mayor probabilidad de encontrar lesiones coronarias significativas, sin diferencias en la aparición de eventos adversos en los 3 primeros meses. Estos hallazgos necesitan ser confirmados en futuros estudios con mayor número de pacientes.

Reliability of a new method for coronary artery calcium or metal subtraction by 320-row cardiac CT.

PURPOSE: To investigate the feasibility and diagnostic accuracy of subtraction CTA on patients with highly calcified coronary artery disease (CAD) or previous implanted stents, in comparison with invasive coronary angiography (ICA). MATERIALS AND METHODS: Twenty-three patients were recruited. All conventional and subtraction CTA exams were performed using a 320-row CT. Subjective image quality score was assessed for each segment using a 4-point scale: 1-uninterpretable to 4-good image quality. RESULTS: A total of 129 calcified or stented coronary segments were studied. Mean coronary image quality with conventional CTA was 2.73 ± 0.97 and in subtracted CTA 3.3 ± 0.92 (p < 0.01). After metal subtraction, image quality in stented coronary segments with >3 mm of diameter improved from 2.69 ± 0.97 to 3.34 ± 0.89 (p = 0.01) and in those with <3 mm of diameter from 2.11 ± 0.78 to 2.67 ± 0.87 (p = 0.17). There was an improvement in diagnostic accuracy to detect ICA stenosis >50 % by subtraction CTA compared with conventional CTA (AUC 0.93 to 0.87; p = 0.02). CONCLUSION: Subtraction CTA is promising in overcoming limitations of conventional CTA due to calcium or metal artefacts, especially if no motion artefact is present or when stents > 3 mm are studied. KEY POINTS: • Calcium and metal artefacts are still a limitation for conventional coronary CTA • Diagnostic accuracy is improved by subtraction as compared with conventional CTA • Subtraction CTA is a promising tool to overcome limitations of conventional CTA.

Permeabilidad de los injertos de arteria radial mediante tomografía computarizada cardiaca de 256 cortes y su impacto pronóstico a medio plazo / Assessment of radial artery graft patency through 256-slice cardiac computed tomography, and the mid-term prognostic impact of graft occlusion

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Lateral MI Explains the Presence of Prominent R Wave (R ≥ S) in V1.

AIMS: It is necessary to clarify if the presence of a prominent R wave in V1, in post-myocardial infarction (MI) patients, is due to the involvement of the posterior wall (currently inferobasal segment) or the lateral wall (as has been demonstrated recently by electrocardiographic contrast-enhanced cardiac magnetic resonance [ECG-CE-CMR] correlations studies). METHODS: In 155 patients with inferolateral zone MI, as detected by CE-CMR, the following ECG parameters were evaluated and correlated with MI location according to CE-CMR: R/S ratio in V1 ≥ 1 (classic criteria for posterior MI), R/S ratio in V1 ≥ 0.5, and R in V1 ≥ 3 mm. RESULTS: R/S ≥ 1 criterion: Present in 20 cases: 3 of lateral MI, 17 of inferolateral MI, 0 of inferior MI. Absent in 135 cases, 81 of lateral/inferolateral MI (28/53), 54 of inferior MI (SE 19.8%, SP 100%). R/S ≥ 0.5 criterion: Present in 47 cases: 6 of lateral MI, 39 of inferolateral MI, 2 of inferior MI. Absent in 108 cases, 56 of lateral/inferolateral MI (25/31), 52 of inferior MI (SE 44.6%, SP 96.4%). R ≥ 3 mm criterion: Present in 30 cases: 5 of IM lateral, 23 of inferolateral MI, 2 of inferior MI. Absent in 125 cases, 73 lateral/inferolateral MI (26/47), 52 inferior MI (SE 27.7%, SP 96.4%). CONCLUSIONS: The presence of prominent the R wave in V1 is due to the lateral MI and not to the involvement of inferobasal segment of inferior wall (old posterior wall).

Síndrome coronario agudo por oclusión de arteria conal / Acute coronary syndrome due to occlusion of the conus artery

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