Ischemic Attack, TransientStrokePrognosisCerebrovascular DisordersCarotid StenosisEndarterectomy, CarotidAspirinRecurrenceCarotid Artery DiseasesCarotid Artery, InternalBrain IschemiaRisk FactorsProspective StudiesIntracranial Embolism and ThrombosisFollow-Up StudiesCerebral InfarctionIntracranial EmbolismTime FactorsCerebral AngiographyDipyridamoleTreatment OutcomeUltrasonography, Doppler, TranscranialPlatelet Aggregation InhibitorsMagnetic Resonance AngiographyAtrial FibrillationEchocardiography, TransesophagealRisk AssessmentCarotid ArteriesAnticoagulantsGreat BritainRetrospective StudiesReferral and ConsultationTomography, X-Ray ComputedSeverity of Illness IndexPredictive Value of TestsFibrinolytic AgentsCerebrovascular CirculationCohort StudiesPatient SelectionEnglandAge FactorsIncidenceVertebrobasilar InsufficiencyEmbolismAcute DiseaseMyocardial InfarctionMyocardial IschemiaMagnetic Resonance ImagingSurvival AnalysisCardiovascular DiseasesEndarterectomySurvival RateIntracranial ArteriosclerosisIschemiaInterrenal GlandComplement Membrane Attack ComplexNeurologyAmaurosis FugaxIntracranial Arterial DiseasesCerebral HemorrhageSecondary PreventionKaplan-Meier EstimateRiskPericarditis, TuberculousProportional Hazards ModelsMultivariate AnalysisTumor Markers, BiologicalCalciumCerebral ArteriesImmunohistochemistryBrainSulfinpyrazoneSeptember 11 Terrorist AttacksNeoplasm StagingArterial Occlusive DiseasesDisease ProgressionDiffusion Magnetic Resonance ImagingEmergency Medical Services