L’ús d’escales clíniques en els ictus isquèmics secundaris a fibril·lació auricular

Abstract

AF is the most common cardiac arrhythmia in clinical practice, and is a well-known risk factor for cardiogenic embolism. These cardioembolic strokes are frequent and associated with a substantial increased risk of morbidity and mortality. However the risk of stroke and thromboembolism in AF patients is not homogeneous. Different risk factors such as advancing age, hypertension and diabetes mellitus, among others, contribute to the annual thromboembolic risk. Various stroke risk-stratification schemes have been developed for people with AF. The CHADS2 was probably the most often used because of its simplicity. But in 2010 a new scale was published: CHA2DS2-VASc. The first purpose of this thesis was to evaluate how CHADS2 classifies a cohort of patients previous to its first ischemic stroke and compare this risk stratification if the CHA2DS2-VASc scale would have been used. The results of this study showed that this new scale reclassifies a lot of patients out of the category of low-intermediate risk, into a category in which anticoagulation would have been indicated. Studies like ours changed recommendations of both European and U.S guidelines towards the use of the CHA2DS2-VASc score as the main scheme to assess patientís stroke risk. The second objective of our thesis was to evaluate the use of this new scale, not only for risk stratification, but also as prognosis tool in patients who suffered a stroke. We found that each point increase in the scale is associated with a 36% increase in the risk for poor 90-day outcome, independently of stroke severity. In both works, we found a low use of anticoagulation in primary prevention for high risk patients, despite its well-established protective effect, that we were able to replicate. Our research is also orientated towards the detection of a new paroxysmal atrial fibrillation (pAF) in stroke patients, since undetected pAF would lead to a suboptimal secondary prevention with antiplatelet agents. Therefore in the third work, in our cohort with unselected patients, who were admitted in the stroke unit, we detected 11.2% of pAF until de three-month visit. We analyzed which are the clinical risk factors associated to this new diagnosis in a bivariate and afterwards a multivariate analysis (which were advancing age, female sex, initial stroke severity and previous history of congestive heart failure). From this analysis we obtained a risk for new pAF detection for each vascular risk profile, that we represented into two risk charts for easy and immediately interpretation at patientís arrival.

Date of Award	28 Oct 2015
Original language	Catalan
Supervisor	Jaume Roquer (Director) & Adolfo Diez Perez (Tutor)