RESUMEN
In the last 20 years clinical trials evaluating statins showed the importance of LDL-cholesterol lowering in decreasing the risk of cardiovascular disease. The efficacy of statin therapy has been well documented both in primary and secondary prevention, in patients with subclinical atherosclerosis and in those with average cholesterol levels. However, the so-called "residual risk" remains significant and new strategies are needed for reducing it, such as raising HDL-cholesterol levels. Recently, the JUPITER study demonstrated the efficacy of statins in reducing the risk in healthy subjects with elevated C-reactive protein levels, highlighting the potential protective mechanisms of these drugs. Different from the setting of primary and secondary prevention, the results of statin trials in patients with heart failure, end-stage renal disease and aortic stenosis have shown no benefit in terms of survival.
Asunto(s)
Enfermedades Cardiovasculares/prevención & control , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Estenosis de la Válvula Aórtica/prevención & control , Ensayos Clínicos como Asunto , Insuficiencia Cardíaca/prevención & control , Humanos , Factores de TiempoAsunto(s)
Aneurisma de la Aorta/diagnóstico , Rotura de la Aorta/diagnóstico , Transferencia de Embrión/métodos , Complicaciones Cardiovasculares del Embarazo/diagnóstico , Seno Aórtico , Enfermedad Aguda , Adulto , Diagnóstico Diferencial , Ecocardiografía Doppler , Ecocardiografía Transesofágica , Femenino , Humanos , Imagen por Resonancia Magnética , EmbarazoRESUMEN
While the beneficial effects of cardiac resynchronization therapy (CRT) on left ventricular (LV) systolic function have been demonstrated, no information is available regarding its effects on LV diastolic function during exercise. Using radionuclide angiography, we prospectively evaluated the effects of CRT on diastolic function at rest and during exercise in 15 patients consecutively referred for CRT. All patients underwent equilibrium Tc(99) radionuclide angiography with bicycle exercise performed (1) at baseline; (2) immediately after CRT implantation, in spontaneous rhythm and during CRT; and (3) after 3 months of biventricular stimulation. Diastolic function was assessed by measurements of peak filling rate (PFR). At baseline, activation of biventricular stimulation influenced PFR neither at rest (1.06 +/- 0.34 vs 1.07 +/- 0.50 mL/s during spontaneous rhythm, P = 0.9) nor during exercise (1.45 +/- 0.62 vs 1.33 +/- 0.48 mL/s, P = 0.3). At 3 months, improvements were observed in New York Heart Association functional class and systolic function. By contrast, no improvement in diastolic function was observed either at rest (PFR = 1.11 +/- 0.45 vs 1.07 +/- 0.50 mL/s in spontaneous rhythm at baseline, P = 0.6) or during exercise (1.23 +/- 0.50 vs 1.33 +/- 0.48 mL/s, P = 0.2). These observations indicate that the intermediate benefits conferred by CRT on LV systolic function at rest and during exercise were not accompanied by similar improvements in diastolic function.
Asunto(s)
Estimulación Cardíaca Artificial , Insuficiencia Cardíaca/terapia , Angiografía por Radionúclidos , Anciano , Diástole , Electrocardiografía , Tolerancia al Ejercicio , Femenino , Insuficiencia Cardíaca/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Resultado del Tratamiento , Función Ventricular IzquierdaRESUMEN
Atrial fibrillation and severe carotid artery stenosis are the most common causes of stroke. However, several patients recognize unusual cause for their cerebral ischemia. At the beginning of the last decade after the introduction of transesophageal echocardiography (TEE) and other imaging techniques, atheromatosis of the thoracic aorta has been recognized as an important source of stroke or systemic embolism. Formerly in the pre-TEE era, this entity was included into cryptogenic strokes. Notably, aortic atheromas are found in about one quarter of patients presenting with embolic events and their grading by TEE correlates with the risk of future embolism, especially if mobile lesions or superimposed thrombi are present. Unfortunately, the diagnosis of aortic atheroma is mostly established when an embolic event has already occurred. The aim of this paper is to review the current evidence for aortic atheroma as an important independent risk factor for stroke, and to discuss the potential therapeutic options. Unfortunately, randomized studies addressing the treatment of patients with severe aortic atheroma are not yet completed. Furthermore, although warfarin and statins look promising in several retrospective series, their results are by most controversial so far. In conclusion, although the diagnostic criteria and the negative prognostic significance of aortic atheroma are almost defined, its therapeutic options are far to be clear. Therefore, clinical trials addressing this relevant pathologic condition are urgently needed.
Asunto(s)
Aorta Torácica , Enfermedades de la Aorta/complicaciones , Aterosclerosis/complicaciones , Accidente Cerebrovascular/etiología , Anticoagulantes/uso terapéutico , Aorta Torácica/diagnóstico por imagen , Enfermedades de la Aorta/diagnóstico por imagen , Enfermedades de la Aorta/tratamiento farmacológico , Aspirina/uso terapéutico , Aterosclerosis/diagnóstico por imagen , Aterosclerosis/tratamiento farmacológico , Clopidogrel , Ensayos Clínicos Controlados como Asunto , Ecocardiografía Transesofágica , Fibrinolíticos/uso terapéutico , Estudios de Seguimiento , Humanos , Hipolipemiantes/uso terapéutico , Metaanálisis como Asunto , Oportunidad Relativa , Inhibidores de Agregación Plaquetaria/uso terapéutico , Pronóstico , Recurrencia , Factores de Riesgo , Ticlopidina/análogos & derivados , Ticlopidina/uso terapéutico , Factores de Tiempo , Warfarina/uso terapéuticoRESUMEN
In patients with heart failure and wide QRS complex, cardiac resynchronization therapy (CRT) is associated with improvement of symptoms and cardiac function. This study examined the effects of a 3-month period of CRT on left ventricular (LV) and right ventricular (RV) ejection fraction (EF) and on LV volumes, both at rest and during exercise. A CRT system was implanted in 15 patients with severe heart failure and wide QRS. Before implant and 3 months later, all patients underwent assessment of cardiac performance with equilibrium Tc(99) radionuclide angiography with imaging in the best septal left anterior oblique view. Exercise was performed on a bicycle ergometer. At 3 months, a significant improvement in New York Heart Association functional class was observed, and radionuclide angiography showed a significant decrease in LV volumes and a significant increase in LVEF at rest, as well as a significant increase in LVEF during exercise. The remodeling processes associated with CRT did not appear to include RV function, since RVEF did not improve, and changes in RVEF did not correlate with changes in LVEF, neither at rest nor during exercise.
Asunto(s)
Estimulación Cardíaca Artificial , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/terapia , Volumen Sistólico , Prueba de Esfuerzo , Femenino , Insuficiencia Cardíaca/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Ventriculografía con RadionúclidosRESUMEN
Various modalities of cardiac pacing have been proposed in the past to improve hemodynamics, either directly or indirectly. Some of these are conventional ways of cardiac stimulation, others such as biventricular or left ventricular pacing, represent dedicated pacing techniques. Left ventricular and biventricular pacing are successfully applied in those patients with congestive heart failure who have conduction disturbances (i.e. left bundle branch block) as they correct the ensuing intra- and interventricular dyssynchrony. This is the reason why these pacing modalities are described as cardiac resynchronization therapy. According to the results of a series of studies, the cardiac resynchronization therapy seems to have a favourable clinical impact in terms of quality of life, morbidity and hospitalization rate. On-going and future studies should assess the impact of resynchronization therapy on overall mortality and its cost-effectiveness profile in specific subgroups of patients. Other open issues regard (i) the convenience of using biventricular pacing as a pacing-alone therapy or in combination with ventricular defibrillation capability, especially for potential candidates to heart transplantation, and (ii) the ways to identify properly the responders to resynchronization therapy.