RESUMEN
BACKGROUND: Adverse left ventricular (LV) remodelling following acute ST-segment elevation myocardial infarction (STEMI) has prognostic importance. We aimed to predict 90-day left ventricular (LV) function following acute STEMI using variables from clinical presentation, biomarkers, and cardiovascular magnetic resonance imaging (CMR). METHODS: Consecutive patients undergoing primary percutaneous coronary intervention for anterior STEMI as part of the Selective Inhibition of Delta-protein Kinase C for the Reduction of Infarct Size in Acute Myocardial Infarction (PROTECTION-AMI) trial were enrolled into the CMR sub-study at selected sites. CMR was performed at baseline (days 3 to 5) and 90 days and used to evaluate infarct size, myocardial salvage index, infarct heterogeneity, microvascular obstruction and global LV function. Biochemical markers including creatinine kinase area under the curve (CK AUC), peak CK, peak CK-myocardial band (CK-MB) and AUC, and troponin I were collected at specific time-points. RESULTS: Ninety-six patients were enrolled in the CMR sub study and 85 completed the 90-day follow-up, across 24 centres worldwide. LV ejection fraction (EF) was 56% (46-63%) at baseline and 60% (49-67%) at 90 days (p<0.001). Infarct size had moderate inverse correlation with 90-day EF (Spearman's rho=-0.7, p < 0.001) and had the strongest correlation when compared to myocardial salvage index (Spearman's rho=0.5, p=0.001), infarct heterogeneity (Spearman's rho=-0.4, p=0.02 or microvascular obstruction (Spearman's rho=-0.4, p<0.001). All biochemical markers had similar moderate relationship to LVEF at 90 days (Spearman's rho -0.6 to -0.8, p=0.001). In a multivariable model, only baseline LVEF, CMR infarct size and infarct heterogeneity independently predicted 90-day LVEF. CONCLUSION: This study reports findings of a combined CMR protocol (including myocardial oedema imaging) in a multi-centre, multi-vendor setting. We found infarct size, infarct heterogeneity and myocardial salvage index correlated favourably with 90-day LVEF, however only the former two were independently predictive.
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Infarto del Miocardio , Miocardio/metabolismo , Volumen Sistólico , Función Ventricular Izquierda , Remodelación Ventricular , Anciano , Biomarcadores/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/sangre , Infarto del Miocardio/fisiopatología , Infarto del Miocardio/terapia , Factores de TiempoRESUMEN
OBJECTIVES: There remains a paucity of mechanistic data on the effect of transcatheter aortic valve implantation (TAVI) on early left and right ventricular function and quantitative aortic valve regurgitation. We sought to assess and compare the early effects on myocardial function and aortic valve hemodynamics of TAVI and aortic valve replacement (AVR) using serial cardiovascular magnetic resonance (CMR) imaging and echocardiography. METHODS: A prospective comparison study of 47 patients with severe aortic stenosis undergoing either TAVI (n = 26) or high-risk AVR (n = 21). CMR (for left ventricle/right ventricle function, left ventricular mass, left atrial volume, and aortic regurgitation) was carried out before the procedure and early postprocedure (<14 days). RESULTS: Groups were similar with respect to Society of Thoracic Surgeons score (TAVI, 7.7 vs AVR, 5.9; P = .11). Preoperative left ventricular (TAVI, 69% ± 13% vs AVR, 73% ± 10%; P = .10) and right ventricular (TAVI, 61% ± 11% vs AVR, 59% ± 8%; P = .5) ejection fractions were similar. Postoperative left ventricular ejection fraction was preserved in both groups. In contrast, decline in right ventricular ejection fraction was more significant in the TAVI group (61%-54% vs 59%-58%; P = .01). Postprocedure aortic regurgitant fraction was significantly greater in the TAVI group (16% vs 4%; P = .001), as was left atrial size (110 vs 84 mL; P = .02). Further analysis revealed a significant relationship between the increased aortic regurgitant fraction and greater left atrial size (P = .006), and a trend toward association between the decline in right ventricle dysfunction and increased postprocedure aortic regurgitation (P = .08). CONCLUSIONS: There was no significant difference in early left ventricular systolic function between techniques. Whereas right ventricle systolic function was preserved in the AVR group, it was significantly impaired early after TAVI, possibly reflecting a clinically important pathophysiologic consequence of paravalvular aortic regurgitation.
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Estenosis de la Válvula Aórtica/fisiopatología , Estenosis de la Válvula Aórtica/cirugía , Válvula Aórtica/fisiopatología , Válvula Aórtica/cirugía , Implantación de Prótesis de Válvulas Cardíacas/métodos , Disfunción Ventricular/fisiopatología , Anciano , Anciano de 80 o más Años , Cateterismo Cardíaco , Medios de Contraste , Angiografía Coronaria , Ecocardiografía , Femenino , Pruebas de Función Cardíaca , Hemodinámica/fisiología , Humanos , Interpretación de Imagen Asistida por Computador , Imagen por Resonancia Cinemagnética , Masculino , Compuestos Organometálicos , Estudios Prospectivos , Resultado del Tratamiento , Disfunción Ventricular/diagnósticoRESUMEN
BACKGROUND: Nonvalvular atrial fibrillation (AF) confers a five-fold increased risk of stroke. Whether catheter ablation (CA) subsequently decreases prothrombotic risk is unknown. OBJECTIVE: The purpose of this study was to assess the long-term effects of CA for AF on prothrombotic risk. METHODS: Fifty-seven patients undergoing CA for AF were prospectively studied. Platelet activation (CD62P [platelet P-selectin] and PAC-1 [glycoprotein IIb/IIIa] expression) and endothelial function (asymmetric dimethylarginine [ADMA] levels) were measured at baseline and 6-months postablation. RESULTS: Thirty-seven (65%) patients remained in sinus rhythm (SR group) and 20 (35%) sustained AF recurrence (AF recurrence group) at 6-months. Patients with AF-recurrence were older, had a higher proportion of hypertension and long-standing persistent AF. There were no significant differences in CD62P (P = .3), PAC-1 (P = .1) and ADMA (P = .7) levels at baseline between the two groups. In the SR group, markers of platelet activation decreased significantly at 6-month follow-up compared to baseline; log CD62P % 0.79 ± 0.28 vs 1.03 ± 0.27 (P <.05) and log PAC-1 % 0.22 ± 0.58 vs 0.89 ± 0.31 (P <.01). This was not significant in the AF-recurrence group (P = .8, log CD62P; P = .1, log PAC-1). For endothelial function, ADMA levels decreased significantly at 6-months compared to baseline in the SR group (log ADMA µM/L 0.15 ± 0.02 vs 0.17 ± 0.04; P <.05), but did not alter significantly in the AF-recurrence group (P = .4, log ADMA). CONCLUSION: Catheter ablation and successful maintenance of SR leads to a decrease in platelet activation and improvement in endothelial function in patients with AF. These findings suggest that AF is an important determinant of the prothrombotic state and that this may be reduced by successful catheter ablation.
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Fibrilación Atrial/cirugía , Ablación por Catéter/métodos , Activación Plaquetaria , Anciano , Arginina/análogos & derivados , Arginina/sangre , Biomarcadores/sangre , Electrocardiografía , Endotelio Vascular/fisiología , Femenino , Estudios de Seguimiento , Humanos , Integrina beta3/sangre , Masculino , Persona de Mediana Edad , Selectina-P/sangre , Estudios Prospectivos , Recurrencia , Accidente Cerebrovascular/etiologíaRESUMEN
INTRODUCTION AND AIM: Tibial plateau fractures (TPFs) are an independent, non-modifiable risk factor for surgical site infections (SSIs). Current antero-lateral approaches to the knee dissect through the anterior tibial angiosome (ATA), which may contribute to a higher rate of SSIs. The aim of this study was to develop an angiosome-sparing antero-lateral approach to allow reduction and fixation of lateral TPFs and to investigate its feasibility in a consecutive cohort. METHODS: Twenty cadaveric knees were dissected to define the position of the vessels supplying the ATA from the lateral tibial condyle to the skin perforators. Based on these results, an angiosome-sparing surgical approach to treat lateral TPFs was developed. Fifteen consecutive patients were subsequently treated through this approach. Clinical outcomes included assessment of SSI and Lysholm score. Fracture healing and stability were assessed using the Rasmussen score and radiostereometric analysis (RSA). RESULTS: At the latest follow-up between 1 and 4 years, there was no report of SSI. Nine patients (60%) had good or excellent Lysholm scores. The mean Rasmussen score at final follow-up was 17 (median 18, range 14-18) with 10 patients (66%) graded as excellent. Fracture fragment migration measured using RSA was below 2mm in all cases. DISCUSSION: This study has demonstrated that an angiosome-sparing antero-lateral approach to the lateral tibial plateau is feasible. Adequate stability of these fracture types was achieved by positioning a buttress plate away from the bone and superficial to the regional fascial layer as an 'internal-external fixator'. CONCLUSION: The angiosome-sparing approach developed was able to be used in a prospective cohort and the clinical results to date are encouraging. Future clinical studies need to investigate the potential benefits of this surgical approach when compared with the previously described antero-lateral approaches.
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Placas Óseas , Fijación Interna de Fracturas , Articulación de la Rodilla/irrigación sanguínea , Articulación de la Rodilla/cirugía , Infección de la Herida Quirúrgica/prevención & control , Fracturas de la Tibia/cirugía , Adulto , Cadáver , Estudios de Factibilidad , Femenino , Curación de Fractura , Humanos , Articulación de la Rodilla/fisiopatología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Rango del Movimiento Articular , Recuperación de la Función , Flujo Sanguíneo Regional , Fracturas de la Tibia/fisiopatología , Factores de Tiempo , Resultado del Tratamiento , Soporte de PesoAsunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Doxorrubicina/uso terapéutico , Epirrubicina/uso terapéutico , Función Ventricular Izquierda/efectos de los fármacos , Función Ventricular Derecha/efectos de los fármacos , Anciano , Antibióticos Antineoplásicos/uso terapéutico , Antineoplásicos/uso terapéutico , Biomarcadores/metabolismo , Técnicas de Imagen Cardíaca , Femenino , Humanos , Persona de Mediana Edad , Estudios Prospectivos , TrastuzumabRESUMEN
Impaction bone grafting shows encouraging early results as a method of immediately restoring leg length, while allowing weight-bearing as tolerated, in the treatment of large segmental femoral defects after femoral shaft and metaphyseal non-unions. The operative technique followed is described in three consecutive cases and the effectiveness of impaction bone grafting for femoral non-unions with associated large segmental bone defects has been demonstrated. Between 80 and 120 cm3 of coarsely milled irradiated bone allograft was used to reconstruct the defects, which were contained in malleable metal mesh. All three patients were fully weight-bearing by three months postoperatively. At two years follow-up, plain radiographs demonstrated maintenance of reduction and healing in all three cases.
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Trasplante Óseo/métodos , Fracturas del Fémur/cirugía , Fijación Interna de Fracturas , Fracturas no Consolidadas/cirugía , Adulto , Desbridamiento , Femenino , Fracturas del Fémur/complicaciones , Fracturas del Fémur/diagnóstico por imagen , Fracturas no Consolidadas/complicaciones , Fracturas no Consolidadas/diagnóstico por imagen , Humanos , Diferencia de Longitud de las Piernas/etiología , Diferencia de Longitud de las Piernas/cirugía , Masculino , Tomografía Computarizada por Rayos X , Insuficiencia del Tratamiento , Soporte de PesoRESUMEN
BACKGROUND: Magnetic resonance imaging (MRI)-guided interventional electrophysiology (EP) has rapidly emerged as a promising alternative to x-ray-guided ablation. We aimed to evaluate an externally irrigated MRI-compatible ablation catheter and integrated EP pacing and recording system, testing the feasibility of pulmonary vein and cavo-tricuspid isthmus ablation. METHODS AND RESULTS: Externally irrigated MRI-compatible ablation and diagnostic EP catheters and an integrated EP recording system (Imricor Medical Systems, Burnsville, MN) were tested in n=11 sheep in a 1.5-T MRI scanner. Power-controlled (40 W, 120-second duration) lesions were formed at the pulmonary vein and cavo-tricuspid isthmus. Real-time intracardiac electrograms were recorded during MRI. Steady-state free precession non-breath-hold images were repeatedly acquired to guide catheter navigation. Lesion visualization was performed using noncontrast (T2-weighted turbo spin echo pulse sequence) and gadolinium-diethylene triamine pentaacetic acid-enhanced T1-weighted imaging (inversion-recovery gradient echo pulse sequence). Catheters were able to be visualized and navigated under cardiovascular magnetic resonance guidance. In total, 8±2.5 lesions (radiofrequency time, 16±4.2 minutes) were formed at the pulmonary vein ostia, and 6.5±1.3 lesions (radiofrequency time, 13±2.2 minutes) were formed at the cavo-tricuspid isthmus, with the end point of bidirectional block. The mean procedure time was 150±55 minutes. Lesion visualization with both T2W imaging and contrast-enhanced imaging correlated with sites of injury at autopsy. CONCLUSIONS: These data demonstrate the feasibility of using multiple catheters, an integrated EP pacing and recording system, and externally irrigated ablation with cardiovascular magnetic resonance guidance to undertake clinically relevant biatrial mapping and ablation.
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Ablación por Catéter/métodos , Técnicas Electrofisiológicas Cardíacas/métodos , Imagen por Resonancia Magnética/métodos , Venas Pulmonares/patología , Venas Pulmonares/cirugía , Válvula Tricúspide/patología , Válvula Tricúspide/cirugía , Animales , Estimulación Cardíaca Artificial , Ablación por Catéter/instrumentación , Electrocardiografía , Diseño de Equipo , Estudios de Factibilidad , Gadolinio , Masculino , Modelos Animales , OvinosRESUMEN
PURPOSE: Right ventricular (RV) systolic function as measured by right ventricular ejection fraction (RVEF) has long been recognized as an important predictor of outcome in heart failure patients. The echocardiographic measurement of RV volumes and RVEF is challenging, however, owing to the unique geometry of the right ventricle. Several nonvolumetric echocardiographic indices of RV function have demonstrated prognostic value in heart failure. Comparison studies of these techniques with each other using RVEF as a benchmark are limited, however. Furthermore, the contribution of these various elements of RV function to patient functional status is uncertain. We therefore aimed to: (1) Determine which nonvolumetric echocardiographic index correlates best with RVEF as determined by cardiac magnetic resonance (CMR) imaging (the accepted gold standard measure of RV systolic function) and (2) Ascertain which echocardiographic index best predicts functional capacity. METHODS: Eighty-three subjects (66 with systolic heart failure and 17 healthy controls) underwent CMR, 2D echocardiography, and cardiopulmonary exercise testing for comparison of echocardiographic indices of RV function with CMR RVEF, 6-minute walk distance and VO(2 PEAK). RESULTS: Speckle tracking strain RV strain exhibited the closest association with CMR RV ejection fraction. Indices of RV function demonstrated weak correlation with 6-minute walk distance, but basal RV strain rate by tissue velocity imaging had good correlation with VO(2 PEAK). CONCLUSION: Strain by speckle tracking echocardiography and strain rate by tissue velocity imaging may offer complementary information in the evaluation of RV contractility and its functional effects.
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Ecocardiografía/métodos , Diagnóstico por Imagen de Elasticidad/métodos , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/diagnóstico por imagen , Imagen por Resonancia Cinemagnética/métodos , Disfunción Ventricular Derecha/diagnóstico por imagen , Disfunción Ventricular Derecha/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Volumen SistólicoRESUMEN
AIMS: To determine whether the extent of myocardial fibrosis by late-gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR), and echocardiographic ventricular dyssynchrony are independently associated with response to medical therapy in patients with newly diagnosed idiopathic dilated cardiomyopathy (DCM). Myocardial fibrosis and ventricular dyssynchrony are frequent findings in DCM. Previous studies focused on patients with established cardiomyopathy; however, the degree of myocardial fibrosis and ventricular dyssynchrony at presentation and their role in perpetuating left ventricular (LV) dysfunction in DCM remains unclear. Those studies of individuals with long-standing DCM did not characterize patients early in the disease course, and may not have included those with significant improvement in LV function. Thus factors contributing to LV recovery are uncertain. METHODS AND RESULTS: Consecutive patients with a new diagnosis of DCM [LV ejection fraction (EF) ≤45%] made within the preceding 2 weeks were recruited. Patients underwent LGE-CMR, echocardiography, 6-minute walk testing, cardiopulmonary exercise testing, and blood sampling for measurement of serum amino-terminal pro-brain natiuretic peptide (NT-pro-BNP) concentration at baseline. Baseline patient characteristics were compared with a cohort of healthy volunteers. Myocardial fibrosis by LGE-CMR was quantified, identified by experienced observers blinded to patient outcome. Left ventricular systolic function was reassessed after 5 months of optimal medical therapy. Sixty-eight patients with DCM and 19 healthy volunteers were studied. DCM patients were studied a median 12.5 days following diagnosis. Compared with healthy controls, DCM patients exhibited greater inter- and intra-ventricular dyssynchrony. Twenty-four per cent of DCM patients exhibited LGE at diagnosis. Among DCM patients with LGE, the mean fibrosis mass was 2.2 ± 1.3 g. On multivariate analysis, strain dyssynchrony index, and fibrosis mass were independently associated with change in the LVEF over time (P≤ 0.001). Late-gadolinium enhancement cardiovascular magnetic resonance conferred additive value for modelling change in the LVEF beyond clinical and echocardiographic dyssynchrony parameters. CONCLUSION: The extent of myocardial fibrosis is independently associated with lack of response to medical therapy in new-presentation DCM, and LGE-CMR may thus be an important risk-stratifying investigation in these patients. Accurate risk stratification may permit more targeted pharmacological and device therapies for patients with newly diagnosed DCM.