La fibrilación auricular es cada vez más frecuente por el envejecimiento de la población. Si no se trata generalmente produce palpitaciones, fatiga (entendida como cansancio), disnea de esfuerzo y mareos.
Se sabe que frenar la respuesta ventricular con agentes controladores de frecuencia mejorar los síntomas y probablemente reduce complicaciones futuras. Esta es la estrategia actual en la fibrilación auricular, ya que se ha demostrado que intentar retornar al paciente a ritmo sinusal como medida inicial no disminuye la mortalidad, ni la tasa de accidentes cerebrovasculares, ni los síntomas. 2 . La idea extendida era que había que controlar a los pacientes a frecuencias cardiacas por debajo de 80 latidos por minutos. Esto se basa en:
• La extrapolación de experiencias que demuestran que una frecuencia cardiaca elevada (en ritmo sinusal, lo cual ya es poco extrapolable) se asocia a peor pronóstico.
• La ablación con colocación de marcapasos simultánea mejora los síntomas de los pacientes y su calidad de vida.
Sin embargo, experiencias previas de los studios AFFIRM y RACE (estudios diseñados para comparar la estrategia de control de ritmo frente a la de control de frecuencia) no demostraron la ventaja de un control de frecuencia más estricto. En el estudio CIBIS II, en el subrupo de pacientes en insuficiencia cardiaca que tenían fibrilación auricular el bisoprolol no disminuyó la tasa de mortalidad ni de ingreso hospitalario.
Resumen en inglés. Venticular Rate Control must not always to be tight in atrial fibrillation
Although it is well recognized that controlling heart rate may improve symptos of atrial fibrillation (palpitations, fatigue, dizziness, shortness of breath) and may improve prognosis. Today it is preferred to control heart rate instead of trying to recover sinus rhythm, since this last strategy has not showed to improve prognosis (same rate of death or strokes or quality of life). It was believed that heart rate should be kept under 80 bpm (given the fact that sinus tachycardia has been related to bad prognosis, and that ablation with simultaneous pacing improve symptoms and quality of life). Because of these considerations the ideal ventricular response rate in atrial fibrillation has been considered to be under 80 bpm.
Both the AFFIRM and the RACE study did not show any positive effect of tight versus less tight control of ventricular rate. In patients with heart failure, bisoprolol failed to lower deaths or hospitalizations rates in patients with atrial fibrillation
In the RACE II trial (Rate Control Efficacy in Permanent Atrial Fibrillation: a Comparison between Lenient versus Strict Rate Control II) no clinical benefit (death, heart failure or symptoms) was found after 2 years of tight (< 80 bpm) ventricular rate control (with bet-blocker or calcium blocker therapy) versus less tight control (< 110 bpm). The only relevant objection to this conclusion is the short follow-up period, because rapid ventricular rates may take years to result in cardiac damage (tachycardia-related cardiomyopathy).
Bibliografía
Editorial del NEJM link
Van Gelder IC, Van Veldhuisen DJ, Crijns HJ, et al. RAte Control Efficacy in permanent atrial fibrillation: a comparison between lenient versus strict rate control in patients with and without heart failure: background, aims, and design of RACE II. Am Heart J 2006;152:420. link
Wood MA, Brown-Mahoney C, Kay GN, Ellenbogen KA. Clinical outcomes after ablation and pacing therapy for atrial fibrillation: a meta-analysis. Circulation 2000;101:1138-1144. link
Fuster V, Rydén LE, Cannom DS, et al. ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines (writing committee to revise the 2001 guidelines for the management of patients with atrial fibrillation) developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society. J Am Coll Cardiol 2006;48:e149-e246. link
Reynolds MR, Lavelle T, Essebag V, Cohen DJ, Zimetbaum P. Influence of age, sex, and atrial fibrillation recurrence on quality of life outcomes in a population of patients with new-onset atrial fibrillation: the Fibrillation Registry Assessing Costs, Therapies, Adverse events and Lifestyle (FRACTAL) study. Am Heart J 2006;152:1097-1103. link
Cooper HA, Bloomfield DA, Bush DE, et al. Relation between achieved heart rate and outcomes in patients with atrial fibrillation (from the Atrial Fibrillation Follow-up Investigation of Rhythm Management [AFFIRM] Study). Am J Cardiol 2004;93:1247-1253. link
The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) Investigators. A comparison of rate control and rhythm control in patients with atrial fibrillation. N Engl J Med 2002;347:1825-1833. link
Groenveld HF, Crijins HJGM, Rienstra M, Van den Berg MP, Van Veldhuisen DJ, Van Gelder IC. Does intensity of rate control influence outcome in persistent atrial fibrillation? Data of the RACE study. Am Heart J 2009;158:785-791. link
Lechat P, Hulot JS, Escolano S, et al. Heart rate and cardiac rhythm relationships with bisoprolol benefit in chronic heart failure in CIBIS II Trial. Circulation 2001;103:1428-1433. link
Van Gelder IC, Groenveld HF, Crijns HJGM, et al. Lenient versus strict rate control in patients with atrial fibrillation. N Engl J Med 2010. DOI: 10.1056/NEJMoa1001337. link
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