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1.
Crit Care Med ; 49(5): 804-815, 2021 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-33470780

RESUMEN

OBJECTIVES: Severe coronavirus disease 2019 is associated with an extensive pneumonitis and frequent coagulopathy. We sought the true prevalence of thrombotic complications in critically ill patients with severe coronavirus disease 2019 on the ICU, with or without extracorporeal membrane oxygenation. DESIGN: We undertook a single-center, retrospective analysis of 72 critically ill patients with coronavirus disease 2019-associated acute respiratory distress syndrome admitted to ICU. CT angiography of the thorax, abdomen, and pelvis were performed at admission as per routine institution protocols, with further imaging as clinically indicated. The prevalence of thrombotic complications and the relationship with coagulation parameters, other biomarkers, and survival were evaluated. SETTING: Coronavirus disease 2019 ICUs at a specialist cardiorespiratory center. PATIENTS: Seventy-two consecutive patients with coronavirus disease 2019 admitted to ICU during the study period (March 19, 2020, to June 23, 2020). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: All but one patient received thromboprophylaxis or therapeutic anticoagulation. Among 72 patients (male:female = 74%; mean age: 52 ± 10; 35 on extracorporeal membrane oxygenation), there were 54 thrombotic complications in 42 patients (58%), comprising 34 pulmonary arterial (47%), 15 peripheral venous (21%), and five (7%) systemic arterial thromboses/end-organ embolic complications. In those with pulmonary arterial thromboses, 93% were identified incidentally on first screening CT with only 7% suspected clinically. Biomarkers of coagulation (e.g., d-dimer, fibrinogen level, and activated partial thromboplastin time) or inflammation (WBC count, C-reactive protein) did not discriminate between patients with or without thrombotic complications. Fifty-one patients (76%) survived to discharge; 17 (24%) patients died. Mortality was significantly greater in patients with detectable thrombus (33% vs 10%; p = 0.022). CONCLUSIONS: There is a high prevalence of thrombotic complications, mainly pulmonary, among coronavirus disease 2019 patients admitted to ICU, despite anticoagulation. Detection of thrombus was usually incidental, not predicted by coagulation or inflammatory biomarkers, and associated with increased risk of death. Systematic CT imaging at admission should be considered in all coronavirus disease 2019 patients requiring ICU.


Asunto(s)
COVID-19/complicaciones , COVID-19/diagnóstico por imagen , Angiografía por Tomografía Computarizada , Enfermedad Crítica , Trombosis/diagnóstico por imagen , Trombosis/etiología , Adulto , Anciano , Femenino , Humanos , Unidades de Cuidados Intensivos , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Mortalidad , Alta del Paciente/estadística & datos numéricos , Prevalencia , Estudios Retrospectivos , SARS-CoV-2
2.
J Thromb Thrombolysis ; 51(3): 595-607, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33586113

RESUMEN

A prothrombotic state is reported with severe COVID-19 infection, which can manifest in venous and arterial thrombotic events. Coagulopathy is reflective of more severe disease and anticoagulant thromboprophylaxis is recommended in hospitalized patients. However, the prevalence of thrombosis on the intensive care unit (ICU) remains unclear, including whether this is sufficiently addressed by conventional anticoagulant thromboprophylaxis. We aimed to identify the rate of thrombotic complications in ICU-treated patients with COVID-19, to inform recommendations for diagnosis and management. A systematic review was conducted to assess the incidence of thrombotic complications in ICU-treated patients with COVID-19. Observational studies and registries reporting thrombotic complications in ICU-treated patients were included. Information extracted included patient demographics, use of thromboprophylaxis or anticoagulation, method of identifying thrombotic complications, and reported patient outcomes. In 28 studies including 2928 patients, thrombotic complications occurred in 34% of ICU-managed patients, with deep venous thrombosis reported in 16.1% and pulmonary embolism in 12.6% of patients, despite anticoagulant thromboprophylaxis, and were associated with high mortality. Studies adopting systematic screening for venous thrombosis with Duplex ultrasound reported a significantly higher incidence of venous thrombosis compared to those relying on clinical suspicion (56.3% vs. 11.0%, p < 0.001). Despite thromboprophylaxis, there is a very high incidence of thrombotic complications in patients with COVID-19 on the ICU. Systematic screening identifies many thrombotic complications that would be missed by relying on clinical suspicion and should be employed, with consideration given to increased dose anticoagulant thromboprophylaxis, whilst awaiting results of prospective trials of anticoagulation in this cohort.


Asunto(s)
COVID-19/complicaciones , Trombosis/mortalidad , Trombosis/virología , Anticoagulantes/uso terapéutico , Oxigenación por Membrana Extracorpórea , Mortalidad Hospitalaria , Humanos , Unidades de Cuidados Intensivos/estadística & datos numéricos , Trombosis/prevención & control
3.
J Card Surg ; 35(7): 1420-1424, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32340065

RESUMEN

BACKGROUND: The ease of implantation of the rapid deployment (RD) and sutureless valves has contributed to the adoption of anterior right thoracotomy (ART) approach for aortic valve replacement (AVR). AIM OF THE STUDY: This study evaluates the safety and haemodynamic performance of minimally invasive AVR through ART using the RD valves. METHODS: This is a retrospective, single-center review of a total of 50 consecutive patients who received RD-AVR through ART. RESULTS: The median age of patients was 75 years (interquartile range [IQR]: 69-80), and median Euroscore II was 5.1 (IQR: 2.4-7.5). ART RD-AVR was successfully performed in all cases with no conversion to sternotomy, paravalvular leaks or need for valve explantation. The mean size of the implanted valve was 23.2 ± 2.3 mm. In-hospital mortality was 2%. The mean and maximum pressure gradients across the aortic prosthesis were 10 mm Hg (IQR: 9-12) and 19 mm Hg (IQR: 16-23). CONCLUSIONS: Rapid deployment aortic valve replacement can be safely performed through anterior right thoracotomy wit excellent haemodynamic performance and low postoperative complications rate.


Asunto(s)
Estenosis de la Válvula Aórtica/cirugía , Válvula Aórtica/cirugía , Implantación de Prótesis de Válvulas Cardíacas/métodos , Prótesis Valvulares Cardíacas , Hemodinámica , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Procedimientos Quirúrgicos sin Sutura/métodos , Toracotomía/métodos , Anciano , Anciano de 80 o más Años , Estenosis de la Válvula Aórtica/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento
4.
Catheter Cardiovasc Interv ; 93(4): 685-691, 2019 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-30280466

RESUMEN

OBJECTIVES: The aim of the present study was to compare the incidence of periprocedural complications and short-term outcomes between the second-generation recapturable 34 mm Evolut-R and its first-generation 31 mm predecessor. BACKGROUND: Although already in extensive clinical use in real world patients, the periprocedural complications and clinical outcomes of the new 34 mm device have not been investigated yet. METHODS: Consecutive patients who had undergone transcatheter aortic valve implantation in two centers with either a 31 mm CoreValve or a 34 mm Evolut-R device were retrospectively studied. Periprocedural complications of malpositioning, valve-in-valve implantation, conversion to full sternotomy or percutaneous coronary intervention and vascular complications were compared between the two groups. Short-term outcomes at discharge were compared using Valve Academic Research Consortium (VARC-2) criteria. RESULTS: The study group included 106 patients (35 Evolut-R 34 mm; 71 CoreValve 31 mm). Significantly lower rates of valve-in-valve implantation were demonstrated for the 34 mm group compared to the first-generation device (0% vs. 11.9%, respectively, P = 0.036). All other periprocedural complications were similar between groups. At discharge, the rates of new pacemaker implantation (5.7% vs. 26.8%, P = 0.037) and bleeding complications (2.9% vs. 19.6%, P = 0.025) were statistically significantly lower among the 34 mm group. With regards to VARC-2 defined combined endpoints, rates of early safety were significantly improved among the 34 mm group compared to 31 mm group (0% vs. 27.9%, respectively, P = 0.004). CONCLUSIONS: The recently introduced 34 mm Evolut-R seems to demonstrate an improved safety profile, as evidenced by the reduced bleeding rates, lower rates of valve-in-valve implantation and lower PPM rates compared to its 31 mm predecessor.


Asunto(s)
Estenosis de la Válvula Aórtica/cirugía , Válvula Aórtica/cirugía , Prótesis Valvulares Cardíacas , Reemplazo de la Válvula Aórtica Transcatéter/instrumentación , Anciano , Anciano de 80 o más Años , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/fisiopatología , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/fisiopatología , Femenino , Hemodinámica , Humanos , Masculino , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/terapia , Diseño de Prótesis , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Resultado del Tratamiento
5.
Eur Radiol ; 28(6): 2639-2646, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29294153

RESUMEN

OBJECTIVES: Noncardiac findings are common on coronary computed tomography angiography (CCTA). We assessed the clinical impact of noncardiac findings, and potential changes to surveillance scans with the application of new lung nodule guidelines. METHODS: This substudy of the SCOT-HEART randomized controlled trial assessed noncardiac findings identified on CCTA. Clinically significant noncardiac findings were those causing symptoms or requiring further investigation, follow-up or treatment. Lung nodule follow-up was undertaken following the 2005 Fleischner guidelines. The potential impact of the 2015 British Thoracic Society (BTS) and the 2017 Fleischner guidelines was assessed. RESULTS: CCTA was performed in 1,778 patients and noncardiac findings were identified in 677 (38%). In 173 patients (10%) the abnormal findings were clinically significant and in 55 patients (3%) the findings were the cause of symptoms. Follow-up imaging was recommended in 136 patients (7.6%) and additional clinic consultations were organized in 46 patients (2.6%). Malignancy was diagnosed in 7 patients (0.4%). Application of the new lung nodule guidelines would have reduced the number of patients undergoing a follow-up CT scan: 68 fewer with the 2015 BTS guidelines and 78 fewer with the 2017 Fleischner guidelines; none of these patients subsequently developed malignancy. CONCLUSIONS: Clinically significant noncardiac findings are identified in 10% of patients undergoing CCTA. Application of new lung nodule guidelines will reduce the cost of surveillance, without the risk of missing malignancy. KEY POINTS: • Clinically significant noncardiac findings occur in 10% of patients undergoing CCTA. • Noncardiac findings may be an important treatable cause of chest pain • Further imaging investigations for noncardiac findings were recommended in 8% of patients after CCTA. • New lung nodule follow-up guidelines will result in cost savings.


Asunto(s)
Dolor en el Pecho/diagnóstico por imagen , Neoplasias Pulmonares/diagnóstico por imagen , Anciano , Angiografía por Tomografía Computarizada/métodos , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Femenino , Humanos , Hallazgos Incidentales , Masculino , Persona de Mediana Edad , Cintigrafía , Tomografía Computarizada por Rayos X/métodos
6.
Eur Radiol ; 27(3): 1114-1124, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27334015

RESUMEN

OBJECTIVES: Computed tomography (CT) can perform comprehensive cardiac imaging. We compared CT coronary angiography (CTCA) and CT myocardial perfusion (CTP) with 15O-water positron emission tomography (PET) and invasive coronary angiography (ICA) with fractional flow reserve (FFR). METHODS: 51 patients (63 (61-65) years, 80 % male) with known/suspected coronary artery disease (CAD) underwent 320-multidetector CTCA followed by "snapshot" adenosine stress CTP. Of these 22 underwent PET and 47 ICA/FFR. Obstructive CAD was defined as CTCA stenosis >50 % and CTP hypoperfusion, ICA stenosis >70 % or FFR <0.80. RESULTS: PET hyperaemic myocardial blood flow (MBF) was lower in obstructive than non-obstructive territories defined by ICA/FFR (1.76 (1.32-2.20) vs 3.11 (2.44-3.79) mL/(g/min), P < 0.001) and CTCA/CTP (1.76 (1.32-2.20) vs 3.12 (2.44-3.79) mL/(g/min), P < 0.001). Baseline and hyperaemic CT attenuation density was lower in obstructive than non-obstructive territories (73 (71-76) vs 86 (84-88) HU, P < 0.001 and 101 (96-106) vs 111 (107-114) HU, P 0.001). PET hyperaemic MBF corrected for rate pressure product correlated with CT attenuation density (r = 0.579, P < 0.001). There was excellent per-patient sensitivity (96 %), specificity (85 %), negative predictive value (90 %) and positive predictive value (94 %) for CTCA/CTP vs ICA/FFR. CONCLUSION: CT myocardial attenuation density correlates with 15O-water PET MBF. CTCA and CTP can accurately identify obstructive CAD. KEY POINTS: •CT myocardial perfusion can aid the assessment of suspected coronary artery disease. • CT attenuation density from "snapshot" imaging is a marker of myocardial perfusion. • CT myocardial attenuation density correlates with 15 O-water PET myocardial blood flow. • CT attenuation density is lower in obstructive territories defined by invasive angiography. • Diagnostic accuracy of CTCA+CTP is comparable to invasive angiography + fractional flow reserve.


Asunto(s)
Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Estenosis Coronaria/diagnóstico por imagen , Reserva del Flujo Fraccional Miocárdico , Imagen de Perfusión Miocárdica/métodos , Adenosina , Anciano , Angiografía por Tomografía Computarizada/métodos , Angiografía Coronaria/métodos , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radioisótopos de Oxígeno , Tomografía de Emisión de Positrones/métodos , Valor Predictivo de las Pruebas , Estudios Prospectivos , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos X/métodos , Vasodilatadores , Agua
7.
Eur Heart J ; 37(8): 713-23, 2016 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-26491110

RESUMEN

AIMS: Midwall myocardial fibrosis on cardiovascular magnetic resonance (CMR) is a marker of early ventricular decompensation and adverse outcomes in aortic stenosis (AS). We aimed to develop and validate a novel clinical score using variables associated with midwall fibrosis. METHODS AND RESULTS: One hundred forty-seven patients (peak aortic velocity (Vmax) 3.9 [3.2,4.4] m/s) underwent CMR to determine midwall fibrosis (CMR cohort). Routine clinical variables that demonstrated significant association with midwall fibrosis were included in a multivariate logistic score. We validated the prognostic value of the score in two separate outcome cohorts of asymptomatic patients (internal: n = 127, follow-up 10.3 [5.7,11.2] years; external: n = 289, follow-up 2.6 [1.6,4.5] years). Primary outcome was a composite of AS-related events (cardiovascular death, heart failure, and new angina, dyspnoea, or syncope). The final score consisted of age, sex, Vmax, high-sensitivity troponin I concentration, and electrocardiographic strain pattern [c-statistic 0.85 (95% confidence interval 0.78-0.91), P < 0.001; Hosmer-Lemeshow χ(2) = 7.33, P = 0.50]. Patients in the outcome cohorts were classified according to the sensitivity and specificity of this score (both at 98%): low risk (probability score <7%), intermediate risk (7-57%), and high risk (>57%). In the internal outcome cohort, AS-related event rates were >10-fold higher in high-risk patients compared with those at low risk (23.9 vs. 2.1 events/100 patient-years, respectively; log rank P < 0.001). Similar findings were observed in the external outcome cohort (31.6 vs. 4.6 events/100 patient-years, respectively; log rank P < 0.001). CONCLUSION: We propose a clinical score that predicts adverse outcomes in asymptomatic AS patients and potentially identifies high-risk patients who may benefit from early valve replacement.


Asunto(s)
Estenosis de la Válvula Aórtica/patología , Miocardio/patología , Anciano , Estenosis de la Válvula Aórtica/mortalidad , Femenino , Fibrosis , Humanos , Angiografía por Resonancia Magnética , Masculino , Pronóstico , Medición de Riesgo/métodos , Análisis de Supervivencia
9.
J Cardiovasc Magn Reson ; 18(1): 57, 2016 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-27624746

RESUMEN

BACKGROUND: Mathematical modeling of perfusion cardiovascular magnetic resonance (CMR) data allows absolute quantification of myocardial blood flow and can potentially improve the diagnosis and prognostication of obstructive coronary artery disease (CAD), against the current clinical standard of visual assessments. This study compares the diagnostic performance of distributed parameter modeling (DP) against the standard Fermi model, for the detection of obstructive CAD, in per vessel against per patient analysis. METHODS: A pilot cohort of 28 subjects (24 included in the final analysis) with known or suspected CAD underwent adenosine stress-rest perfusion CMR at 3T. Data were analysed using Fermi and DP modeling against invasive coronary angiography and fractional flow reserve, acquired in all subjects. Obstructive CAD was defined as luminal stenosis of ≥70 % alone, or luminal stenosis ≥50 % and fractional flow reserve ≤0.80. RESULTS: On ROC analysis, DP modeling outperformed the standard Fermi model, in per vessel and per patient analysis. In per patient analysis, DP modeling-derived myocardial blood flow at stress demonstrated the highest sensitivity and specificity (0.96, 0.92) in detecting obstructive CAD, against Fermi modeling (0.78, 0.88) and visual assessments (0.79, 0.88), respectively. CONCLUSIONS: DP modeling demonstrated consistently increased diagnostic performance against Fermi modeling and showed that it may have merit for stratifying patients with at least one vessel with obstructive CAD. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov NCT01368237 Registered 6 of June 2011. URL: https://clinicaltrials.gov/ct2/show/NCT01368237.


Asunto(s)
Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Circulación Coronaria , Estenosis Coronaria/diagnóstico por imagen , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Cinemagnética/métodos , Modelos Cardiovasculares , Imagen de Perfusión Miocárdica/métodos , Modelación Específica para el Paciente , Adenosina/administración & dosificación , Anciano , Área Bajo la Curva , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/fisiopatología , Estenosis Coronaria/fisiopatología , Estudios de Factibilidad , Femenino , Reserva del Flujo Fraccional Miocárdico , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Valor Predictivo de las Pruebas , Curva ROC , Reproducibilidad de los Resultados , Índice de Severidad de la Enfermedad , Vasodilatadores/administración & dosificación
10.
J Cardiovasc Magn Reson ; 18(1): 46, 2016 07 27.
Artículo en Inglés | MEDLINE | ID: mdl-27465647

RESUMEN

BACKGROUND: Ultrasmall superparamagnetic particles of iron oxide (USPIO)-enhanced magnetic resonance imaging (MRI) can detect tissue-resident macrophage activity and identify cellular inflammation. Clinical studies using this technique are now emerging. We aimed to report a range of normal R2* values at 1.5 and 3 T in the myocardium and other tissues following ferumoxytol administration, outline the methodology used and suggest solutions to commonly encountered analysis problems. METHODS: Twenty volunteers were recruited: 10 imaged each at 1.5 T and 3 T. T2* and late gadolinium enhanced (LGE) MRI was conducted at baseline with further T2* imaging conducted approximately 24 h after USPIO infusion (ferumoxytol, 4 mg/kg). Regions of interest were selected in the myocardium and compared to other tissues. RESULTS: Following administration, USPIO was detected by changes in R2* from baseline (1/T2*) at 24 h in myocardium, skeletal muscle, kidney, liver, spleen and blood at 1.5 T, and myocardium, kidney, liver, spleen, blood and bone at 3 T (p < 0.05 for all). Myocardial changes in R2* due to USPIO were 26.5 ± 7.3 s-1 at 1.5 T, and 37.2 ± 9.6 s-1 at 3 T (p < 0.0001 for both). Tissues showing greatest ferumoxytol enhancement were the reticuloendothelial system: the liver, spleen and bone marrow (216.3 ± 32.6 s-1, 336.3 ± 60.3 s-1, 69.9 ± 79.9 s-1; p < 0.0001, p < 0.0001, p = ns respectively at 1.5 T, and 275.6 ± 69.9 s-1, 463.9 ± 136.7 s-1, 417.9 ± 370.3 s-1; p < 0.0001, p < 0.0001, p < 0.01 respectively at 3 T). CONCLUSION: Ferumoxytol-enhanced MRI is feasible at both 1.5 T and 3 T. Careful data selection and dose administration, along with refinements to echo-time acquisition, post-processing and analysis techniques are essential to ensure reliable and robust quantification of tissue enhancement. TRIAL REGISTRATION: ClinicalTrials.gov Identifier - NCT02319278 . Registered 03.12.2014.


Asunto(s)
Medios de Contraste/administración & dosificación , Dextranos/administración & dosificación , Óxido Ferrosoférrico/administración & dosificación , Corazón/diagnóstico por imagen , Imagen por Resonancia Cinemagnética/métodos , Nanopartículas de Magnetita/administración & dosificación , Compuestos Organometálicos/administración & dosificación , Artefactos , Medios de Contraste/farmacocinética , Dextranos/farmacocinética , Estudios de Factibilidad , Femenino , Voluntarios Sanos , Humanos , Interpretación de Imagen Asistida por Computador , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Distribución Tisular
11.
J Cardiovasc Magn Reson ; 17: 83, 2015 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-26381872

RESUMEN

Cardiovascular Magnetic Resonance (CMR) has become a primary tool for non-invasive assessment of cardiovascular anatomy, pathology and function. Existing contrast agents have been utilised for the identification of infarction, fibrosis, perfusion deficits and for angiography. Novel ultrasmall superparamagnetic particles of iron oxide (USPIO) contrast agents that are taken up by inflammatory cells can detect cellular inflammation non-invasively using CMR, potentially aiding the diagnosis of inflammatory medical conditions, guiding their treatment and giving insight into their pathophysiology. In this review we describe the utilization of USPIO as a novel contrast agent in vascular disease.


Asunto(s)
Arterias/patología , Aterosclerosis/patología , Medios de Contraste/administración & dosificación , Dextranos/administración & dosificación , Inflamación/patología , Macrófagos/patología , Imagen por Resonancia Magnética/métodos , Nanopartículas de Magnetita/administración & dosificación , Placa Aterosclerótica , Animales , Arterias/metabolismo , Aterosclerosis/metabolismo , Medios de Contraste/metabolismo , Dextranos/metabolismo , Humanos , Inflamación/metabolismo , Macrófagos/metabolismo , Tamaño de la Partícula , Valor Predictivo de las Pruebas , Pronóstico
12.
J Cardiovasc Magn Reson ; 17: 17, 2015 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-25885056

RESUMEN

BACKGROUND: Mathematical modeling of cardiovascular magnetic resonance perfusion data allows absolute quantification of myocardial blood flow. Saturation of left ventricle signal during standard contrast administration can compromise the input function used when applying these models. This saturation effect is evident during application of standard Fermi models in single bolus perfusion data. Dual bolus injection protocols have been suggested to eliminate saturation but are much less practical in the clinical setting. The distributed parameter model can also be used for absolute quantification but has not been applied in patients with coronary artery disease. We assessed whether distributed parameter modeling might be less dependent on arterial input function saturation than Fermi modeling in healthy volunteers. We validated the accuracy of each model in detecting reduced myocardial blood flow in stenotic vessels versus gold-standard invasive methods. METHODS: Eight healthy subjects were scanned using a dual bolus cardiac perfusion protocol at 3T. We performed both single and dual bolus analysis of these data using the distributed parameter and Fermi models. For the dual bolus analysis, a scaled pre-bolus arterial input function was used. In single bolus analysis, the arterial input function was extracted from the main bolus. We also performed analysis using both models of single bolus data obtained from five patients with coronary artery disease and findings were compared against independent invasive coronary angiography and fractional flow reserve. Statistical significance was defined as two-sided P value < 0.05. RESULTS: Fermi models overestimated myocardial blood flow in healthy volunteers due to arterial input function saturation in single bolus analysis compared to dual bolus analysis (P < 0.05). No difference was observed in these volunteers when applying distributed parameter-myocardial blood flow between single and dual bolus analysis. In patients, distributed parameter modeling was able to detect reduced myocardial blood flow at stress (<2.5 mL/min/mL of tissue) in all 12 stenotic vessels compared to only 9 for Fermi modeling. CONCLUSIONS: Comparison of single bolus versus dual bolus values suggests that distributed parameter modeling is less dependent on arterial input function saturation than Fermi modeling. Distributed parameter modeling showed excellent accuracy in detecting reduced myocardial blood flow in all stenotic vessels.


Asunto(s)
Medios de Contraste/administración & dosificación , Enfermedad de la Arteria Coronaria/diagnóstico , Circulación Coronaria , Vasos Coronarios/fisiopatología , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Imagen de Perfusión Miocárdica/métodos , Compuestos Organometálicos/administración & dosificación , Adenosina/administración & dosificación , Velocidad del Flujo Sanguíneo , Estudios de Casos y Controles , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/fisiopatología , Vasos Coronarios/diagnóstico por imagen , Reserva del Flujo Fraccional Miocárdico , Humanos , Modelos Cardiovasculares , Valor Predictivo de las Pruebas , Flujo Sanguíneo Regional , Reproducibilidad de los Resultados , Vasodilatadores/administración & dosificación
13.
J Comput Assist Tomogr ; 38(3): 444-50, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24651741

RESUMEN

OBJECTIVE: We aimed to establish the feasibility of single-heartbeat 320-multidetector computed tomographic coronary angiography (CTCA) and assess variables affecting image quality. METHODS: Consecutive patients (n = 249, 38% male) underwent CTCA. Two observers assessed image quality using a 4-point scale (1, excellent; 4, poor). RESULTS: Mean heart rate was 60 beats per minute (95% confidence interval, 59-62); body mass index, 29 kg/m (28-30); and dose-length product, 283 mGy·cm (266-301). During scanning, 133 (51%) received sublingual glyceryl trinitrate (GTN), 9 (4%) had ectopics, and 12 (5%) had atrial fibrillation. Diagnostic image quality was obtained in 99% with mean image quality of 1.4 (1.3, 1.5). Age, sex, atrial fibrillation, ectopics, diabetes mellitus (12%), and obstructive disease were not related to image quality. A lower heart rate and GTN were associated with improved image quality (P ≤ 0.001). CONCLUSIONS: Optimal image quality in single-heartbeat 320-multidetector CTCA is achievable in 99% of unselected patients. Image quality is improved by lower heart rate and GTN.


Asunto(s)
Técnicas de Imagen Sincronizada Cardíacas/métodos , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/fisiopatología , Tomografía Computarizada Multidetector/métodos , Intensificación de Imagen Radiográfica/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Algoritmos , Estudios de Factibilidad , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
14.
Int J Numer Method Biomed Eng ; : e3865, 2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39209425

RESUMEN

The opening and closing dynamics of the aortic valve (AV) has a strong influence on haemodynamics in the aortic root, and both play a pivotal role in maintaining normal physiological functions of the valve. The aim of this study was to establish a subject-specific fluid-structure interaction (FSI) workflow capable of simulating the motion of a tricuspid healthy valve and the surrounding haemodynamics under physiologically realistic conditions. A subject-specific aortic root was reconstructed from magnetic resonance (MR) images acquired from a healthy volunteer, whilst the valve leaflets were built using a parametric model fitted to the subject-specific aortic root geometry. The material behaviour of the leaflets was described using the isotropic hyperelastic Ogden model, and subject-specific boundary conditions were derived from 4D-flow MR imaging (4D-MRI). Strongly coupled FSI simulations were performed using a finite volume-based boundary conforming method implemented in FlowVision. Our FSI model was able to simulate the opening and closing of the AV throughout the entire cardiac cycle. Comparisons of simulation results with 4D-MRI showed a good agreement in key haemodynamic parameters, with stroke volume differing by 7.5% and the maximum jet velocity differing by less than 1%. Detailed analysis of wall shear stress (WSS) on the leaflets revealed much higher WSS on the ventricular side than the aortic side and different spatial patterns amongst the three leaflets.

15.
Eur Heart J Imaging Methods Pract ; 2(1): qyae007, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-39045205

RESUMEN

Aims: Aortic root motion is suspected to contribute to proximal aortic dissection. While motion of the aorta in four dimensions can be traced with real-time imaging, displacement and rotation in quantitative terms remain unknown. The hypothesis was to show feasibility of quantification of three-dimensional aortic root motion from dynamic CT imaging. Methods and results: Dynamic CT images of 40 patients for coronary assessment were acquired using a dynamic protocol. Scans were ECG-triggered and segmented in 10 time-stepped phases (0-90%) per cardiac cycle. With identification of the sinotubular junction (STJ), a patient-specific co-ordinate system was created with the z-axis (out-of-plane) parallel to longitudinal direction. The left and right coronary ostia were traced at each time-step to quantify downward motion in reference to the STJ plane, motion within the STJ plane (in-plane), and the degree of rotation. Enrolled individuals had an age of 65 ± 12, and 14 were male (35%). The out-of-plane motion was recorded with the largest displacement of 10.26 ± 2.20 and 8.67 ± 1.69 mm referenced by left and right coronary ostia, respectively. The mean downward movement of aortic root was 9.13 ± 1.86 mm. The largest in-plane motion was recorded at 9.17 ± 2.33 mm and 6.51 ± 1.75 mm referenced by left and right coronary ostia, respectively. The largest STJ in-plane motion was 7.37 ± 1.96 mm, and rotation of the aortic root was 11.8 ± 4.60°. Conclusion: In vivo spatial and temporal displacement of the aortic root can be identified and quantified from multiphase ECG-gated contrast-enhanced CT images. Knowledge of normal 4D motion of the aortic root may help understand its biomechanical impact in patients with aortopathy and pre- and post-surgical or transcatheter aortic valve replacement.

16.
Clin Endocrinol (Oxf) ; 78(5): 639-45, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23173989

RESUMEN

UNLABELLED: Turner syndrome (TS), the result of a structurally abnormal or absent X chromosome, occurs in one in 2 000 live born females. The phenotype is highly variable, but short stature and gonadal dysgenesis are usually present. The main objective in adults with TS is health surveillance, but TS still causes a reduction in life expectancy of up to 13 years, with cardiovascular disease, congenital or acquired, as the major cause of an early death. While it has been established that all women with TS should undergo in-depth cardiovascular examination at diagnosis, advice on the cardiovascular management of women with TS is limited. Here, we provide a summary of our current practice within a multidisciplinary team, supported by our expertise in various aspects of cardiovascular risk management, and the evidence from research where it is available, with the aim of providing optimal support to our patients with TS. BACKGROUND: A dedicated Adult Turner Clinic was established in South East Scotland in 2002. This gynaecology-led clinic serves a population of roughly 1·2 million and, currently, reviews around 50 women with TS annually. Referrals for adult care come from paediatrics or general practice. Following a series of individual case discussions regarding the management of more complex cardiovascular problems, we have assembled a dedicated multidisciplinary group to determine a timely cardiovascular screening strategy, a basis for specialist referral, and appropriate hypertension management. This team now includes a paediatric endocrinologist, gynaecologist, cardiologist (with an interest in inherited disorders), vascular radiologist and hypertension specialist. Here, we review the literature on cardiovascular disease in women with TS and, make recommendations, based on relatively limited high-quality evidence, together with our experience, on the optimal timing of cardiovascular screening.


Asunto(s)
Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/etiología , Síndrome de Turner/complicaciones , Adulto , Femenino , Humanos , Factores de Riesgo
17.
JVS Vasc Sci ; 4: 100125, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37771369

RESUMEN

Objective: Takayasu arteritis (TA) is a difficult disease to deal with because there are neither reliable clinical signs, laboratory biomarkers, nor a single noninvasive imaging technique that can be used for early diagnosis and disease activity monitoring. Knowledge of aortic hemodynamics in TA is lacking. This study aimed to fill this gap by assessing hemodynamics in patients with TA using image-based computational fluid dynamics (CFD) simulations. Methods: Eleven patients with TA were included in the present study. Patient-specific geometries were reconstructed from either clinical aortic computed tomography angiography or magnetic resonance angiography studies and coupled with physiological boundary conditions for CFD simulations. Key anatomical and hemodynamic parameters were compared with a control group consisting of 18 age- and sex-matched adults without TA who had healthy aortas. Results: Compared with controls, patients with TA had significantly higher aortic velocities (0.9 m/s [0.7, 1.1 m/s] vs 0.6 m/s [0.5, 0.7 m/s]; P = .002), maximum time-averaged wall shear stress (14.2 Pa [9.8, 20.9 Pa] vs 8.0 Pa [6.2, 10.3 Pa]; P = .004), and maximum pressure drops between the ascending and descending aorta (36.9 mm Hg [29.0, 49.3 mm Hg] vs 28.5 mm Hg [25.8, 31.5 mm Hg]; P = .004). These significant hemodynamic alterations in patients with TA might result from abnormal anatomical features including smaller arch diameter (20.0 mm [13.8, 23.3 mm] vs 25.2 mm [23.3, 26.8 mm]; P = .003), supra-aortic branch diameters (21.9 mm [18.5, 24.6 mm] vs 25.7 mm [24.3, 28.3 mm]; P = .003) and descending aorta diameter (14.7 mm [12.2, 16.8 mm] vs 22.5 mm [19.8, 24.0 mm]; P < .001). Conclusions: CFD analysis reveals hemodynamic changes in the aorta of patients with TA. The applicability of CFD technique coupled with standard imaging assessments in predicting disease progression of such patients will be explored in future studies. Future large cohort study with outcome correlation is also warranted. Clinical Relevance: Based on patient-specific computational fluid dynamics simulations, the present retrospective study revealed significant difference in aortic hemodynamics between the patients with and without Takayasu arteritis (TA). To the best of our knowledge, this study is the first to evaluate hemodynamic conditions within TA, demonstrating the potential of computational flow modeling in capturing abnormal hemodynamic forces, such as high wall shear stress, resulted from irregular morphological changes. In the future, assessing the hemodynamic parameters within patients with TA during the prestenotic period, together with longitudinal computational fluid dynamics studies may allow better monitoring and management of TA.

18.
Front Cardiovasc Med ; 10: 1215720, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37388636

RESUMEN

Objective: This study aimed to comprehensively examine the roles of size, location, and number of tears in the progression of surgically repaired type A aortic dissection (TAAD) by assessing haemodynamic changes through patient-specific computational fluid dynamic (CFD) simulations. Methods: Two patient-specific TAAD geometries with replaced ascending aorta were reconstructed based upon computed 15 tomography (CT) scans, after which 10 hypothetical models (5 per patient) with different tear configurations were artificially created. CFD simulations were performed on all the models under physiologically realistic boundary conditions. Results: Our simulation results showed that increasing either the size or number of the re-entry tears reduced the luminal pressure difference (LPD) and maximum time-averaged wall shear stress (TAWSS), as well as areas exposed to abnormally high or low TAWSS values. Models with a large re-entry tear outperformed the others by reducing the maximum LPD by 1.88 mmHg and 7.39 mmHg, for patients 1 and 2, respectively. Moreover, proximally located re-entry tears in the descending aorta were more effective at reducing LPD than distal re-entry tears. Discussion: These computational results indicate that the presence of a relatively large re-entry tear in the proximal descending aorta might help stabilize post-surgery aortic growth. This finding has important implications for the management and risk stratification of surgically repaired TAAD patients. Nevertheless, further validation in a large patient cohort is needed.

19.
Open Heart ; 10(2)2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37666643

RESUMEN

INTRODUCTION: Severe aortic stenosis is a major cause of morbidity and mortality. The existing treatment pathway for transcatheter aortic valve implantation (TAVI) traditionally relies on tertiary Heart Valve Centre workup. However, this has been associated with delays to treatment, in breach of British Cardiovascular Intervention Society targets. A novel pathway with emphasis on comprehensive patient workup at a local centre, alongside close collaboration with a Heart Valve Centre, may help reduce the time to TAVI. METHODS: The centre performing local workup implemented a novel TAVI referral pathway. Data were collected retrospectively for all outpatients referred for consideration of TAVI to a Heart Valve Centre from November 2020 to November 2021. The main outcome of time to TAVI was calculated as the time from Heart Valve Centre referral to TAVI, or alternative intervention, expressed in days. For the centre performing local workup, referral was defined as the date of multidisciplinary team discussion. For this centre, a total pathway time from echocardiographic diagnosis to TAVI was also evaluated. A secondary outcome of the proportion of referrals proceeding to TAVI at the Heart Valve Centre was analysed. RESULTS: Mean±SD time from referral to TAVI was significantly lower at the centre performing local workup, when compared with centres with traditional referral pathways (32.4±64 to 126±257 days, p<0.00001). The total pathway time from echocardiographic diagnosis to TAVI for the centre performing local workup was 89.9±67.6 days, which was also significantly shorter than referral to TAVI time from all other centres (p<0.003). Centres without local workup had a significantly lower percentage of patients accepted for TAVI (49.5% vs 97.8%, p<0.00001). DISCUSSION: A novel TAVI pathway with emphasis on local workup within a non-surgical centre significantly reduced both the time to TAVI and rejection rates from a Heart Valve Centre. If adopted across the other centres, this approach may help improve access to TAVI.


Asunto(s)
Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Estudios Retrospectivos , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Ecocardiografía , Pacientes Ambulatorios , Derivación y Consulta
20.
JACC Cardiovasc Imaging ; 16(8): 1056-1065, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37052559

RESUMEN

BACKGROUND: Fractional flow reserve-computed tomography (FFR-CT) is endorsed by UK and U.S. chest pain guidelines, but its clinical effectiveness and cost benefit in real-world practice are unknown. OBJECTIVES: The purpose of this study was to audit the use of FFR-CT in clinical practice against England's National Institute for Health and Care Excellence guidance and assess its diagnostic accuracy and cost. METHODS: A multicenter audit was undertaken covering the 3 years when FFR-CT was centrally funded in England. For coronary computed tomographic angiograms (CCTAs) submitted for FFR-CT analysis, centers provided data on symptoms, CCTA and FFR-CT findings, and subsequent management. Audit standards included using FFR-CT only in patients with stable chest pain and equivocal stenosis (50%-69%). Diagnostic accuracy was evaluated against invasive FFR, when performed. Follow-up for nonfatal myocardial infarction and all-cause mortality was undertaken. The cost of an FFR-CT strategy was compared to alternative stress imaging pathways using cost analysis modeling. RESULTS: A total of 2,298 CCTAs from 12 centers underwent FFR-CT analysis. Stable chest pain was the main symptom in 77%, and 40% had equivocal stenosis. Positive and negative predictive values of FFR-CT were 49% and 76%, respectively. A total of 46 events (2%) occurred over a mean follow-up period of 17 months; FFR-CT (cutoff: 0.80) was not predictive. The FFR-CT strategy costs £2,102 per patient compared with an average of £1,411 for stress imaging. CONCLUSIONS: In clinical practice, the National Institute for Health and Care Excellence criteria for using FFR-CT were met in three-fourths of patients for symptoms and 40% for stenosis. FFR-CT had a low positive predictive value, making its use potentially more expensive than conventional stress imaging strategies.


Asunto(s)
Enfermedad de la Arteria Coronaria , Estenosis Coronaria , Reserva del Flujo Fraccional Miocárdico , Humanos , Estenosis Coronaria/diagnóstico por imagen , Estenosis Coronaria/terapia , Constricción Patológica , Valor Predictivo de las Pruebas , Tomografía Computarizada por Rayos X , Angiografía Coronaria/métodos , Dolor en el Pecho , Costos y Análisis de Costo , Angiografía por Tomografía Computarizada/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/terapia
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