Magnetic resonance imaging in patients with cardiac implantable electronic devices: A prospective study.

BACKGROUND: The number of patients with cardiac implantable electronic devices in whom magnetic resonance imaging (MRI) is indicated is constantly increasing. The potential risk of electromagnetic interference has limited its use and it is still contraindicated by the Food and Drug Administration in some cases. The aim of this study is to evaluate the safety and efficacy of MRI in these patients. METHODS: A prospective registry comprising patients with a pacemaker (PM) or implantable cardioverter-defibrillator (ICD), MRI-conditional or not, who were candidates for MRI (at 1.5 T) with no suitable alternative diagnostic technique. All devices were programmed before the procedure and patients were monitored throughout the test. Clinical, electrical, and technical parameters were evaluated before and after MRI. RESULTS: 147 MRI examinations (132 PM and 15 ICD) were performed. There were no clinical events or significant differences in the electrical parameters of the leads after MRI. A variation in the impedance of the ventricular leads was detected, although the difference was not clinically relevant. In one patient with a PM, a failure in release of the safety impulse was detected in the auto-threshold test, although the threshold was correctly determined. In 11 of the 17 thoracic MRIs, image artifacts were detected, preventing the diagnosis in two of them. CONCLUSIONS: In patients with cardiac implantable electronic devices, MRIs performed under a specific protocol has been shown to be safe in the short term even in the thoracic region, as well as interpretable in most cases.

Predictores de fibrilación auricular en pacientes con ictus embólico de origen indeterminado / Atrial fibrillation predictors in patients with embolic stroke of undetermined source

Antecedentes y objetivos: En el accidente cerebrovascular embólico de origen indeterminado (ESUS) la detección de fibrilación auricular (FA) conlleva un cambio de tratamiento y una reducción drástica en la incidencia de nuevos ictus. Es necesario determinar qué pacientes se benefician en mayor medida de una monitorización electrocardiográfica prolongada. Nuestro objetivo fue la búsqueda de predictores electrocardiográficos y ecocardiográficos de FA en pacientes con ESUS.Materiales y métodosSe diseñó un estudio observacional de cohortes en el que se incluyeron 95 pacientes consecutivos que ingresaron por ESUS en un hospital terciario. A todos se les realizó un electrocardiograma (ECG), un Holter electrocardiograma (Holter-ECG) de 24h y un ecocardiograma durante el ingreso. Se realizó un seguimiento presencial durante 2años mediante Holter-ECG de 24h, trimestral durante el primer año y semestral durante el segundo.ResultadosDurante el seguimiento se detectó FA en 11 pacientes (11,6%), siendo la tasa detección del 3,2% a los 6meses, del 7,4% a los 12meses y del 11,6% a los 18 y a los 24meses. Las variables que se relacionaron de forma independiente con el desarrollo de FA fueron la dilatación en grado moderado o severo de la aurícula izquierda (AI) (p=0,02), el bloqueo interauricular avanzado (BIA-A) (p=0,04) y la presencia de más de 1.000 extrasístoles auriculares (EA) en Holter-ECG de 24h (p=0,01).ConclusionesLa dilatación en un grado moderado o severo de AI, el BIA-A y la presencia de más de 1.000 EA en Holter-ECG de 24h se comportan como predictores independientes de FA en pacientes con ESUS. (AU)

Background and objectives: Atrial fibrillation (AF) detection in patients with embolic stroke of underdetermined source (ESUS) entails a change of medical treatment and a significant decrease in the incidence of new strokes. It is necessary to determine which patients would benefit more from prolonged electrocardiographic monitoring. Our aim was to find electrocardiographic and echocardiographic AF predictors in patients with ESUS.MethodsWe performed a cohort study that included 95 consecutive patients admitted to the hospital because of an ESUS. An electrocardiogram, each subject in the study underwent a 24-hour Holter-electrocardiogram (Holter-ECG) and an echocardiogram. A 2-year follow up was also conducted, with a 24-hour Holter-ECG every 3months for the first year, and every 6months during the second one.ResultsDuring the follow-up, AF was detected in 11 patients (11.6%), with a detection rate of 3.2% at 6months, 7.4% at 12months, and 11.6% at 18months as well as at 24months. The variables that were independently related to AF detection included moderate or severe left atrium dilation (P=.02), interatrial advanced block (P=.04) and more than 1000 premature atrial beats on 24-hour Holter-ECG (P=.01).ConclusionsModerate or severe atrial dilation, interatrial advanced block, and the presence of more than 1000 premature atrial beats on 24-hour Holter-ECG behave as AF predictors in patients with ESUS. (AU)

[Atrial fibrillation predictors in patients with embolic stroke of undetermined source]. / Predictores de fibrilación auricular en pacientes con ictus embólico de origen indeterminado.

BACKGROUND AND OBJECTIVES: Atrial fibrillation (AF) detection in patients with embolic stroke of underdetermined source (ESUS) entails a change of medical treatment and a significant decrease in the incidence of new strokes. It is necessary to determine which patients would benefit more from prolonged electrocardiographic monitoring. Our aim was to find electrocardiographic and echocardiographic AF predictors in patients with ESUS. METHODS: We performed a cohort study that included 95 consecutive patients admitted to the hospital because of an ESUS. An electrocardiogram, each subject in the study underwent a 24-hour Holter-electrocardiogram (Holter-ECG) and an echocardiogram. A 2-year follow up was also conducted, with a 24-hour Holter-ECG every 3months for the first year, and every 6months during the second one. RESULTS: During the follow-up, AF was detected in 11 patients (11.6%), with a detection rate of 3.2% at 6months, 7.4% at 12months, and 11.6% at 18months as well as at 24months. The variables that were independently related to AF detection included moderate or severe left atrium dilation (P=.02), interatrial advanced block (P=.04) and more than 1000 premature atrial beats on 24-hour Holter-ECG (P=.01). CONCLUSIONS: Moderate or severe atrial dilation, interatrial advanced block, and the presence of more than 1000 premature atrial beats on 24-hour Holter-ECG behave as AF predictors in patients with ESUS.

Assessment methods for aspirin-mediated platelet antiaggregation in type 2 diabetic patients: degree of correlation between 2 point-of-care methods.

AIMS: Impaired response to antiplatelet therapy in diabetic patients results in a higher incidence of drug-eluting stent thrombosis. This study determined the prevalence of high on-aspirin (AS) platelet reactivity in type 2 diabetic patients treated with percutaneous coronary intervention (PCI) using the VerifyNow Aspirin Assay (VN) and platelet function analyzer PFA-100 (PFA-100) and analyzed the correlation between both methods. METHODS: Type 2 diabetic patients (100) with non-ST-elevation acute coronary syndrome who underwent PCI and Xience V drug-eluting stent implantation were included in this study. After PCI, platelet antiaggregation mediated by acetylsalicylic acid was assessed by VN and PFA-100. The degree of correlation and concordance was then determined. RESULTS: When assayed with VN, 7% of the patients were nonresponders to aspirin (aspirin reaction units >550), and when assayed with PFA-10, 41% were nonresponders (closure time <193 seconds). Of the patients, 4% were nonresponders to aspirin according to VN but were sensitive to aspirin according to PFA-100, and 38% were sensitive to aspirin according to VN and nonresponders according to PFA-100. Overall, 55% of the patients were aspirin-sensitive in both methods. The Spearman's coefficient between VN and PFA-100 results was r = 0.09 (P = 0.35). The kappa index value was 0.0062 (P = 0.91). CONCLUSIONS: There is no concordance or correlation between the VN and PFA-100 results. Therefore, the use of these analyses should be restricted to clinical research, which limits its application in clinical practice.