title: Isolated insular strokes and plasma MR-proANP levels are associated with newly diagnosed atrial fibrillation: a pilot study.
abstract: BACKGROUND
  In this study, we assessed the relationship of insular strokes and plasma MR-proANP levels with newly diagnosed atrial fibrillation (NDAF).
  
  
  METHODS
  This study is based on a prospective acute stroke cohort (http://www.clinicaltrials.gov, NCT00390962). Patient eligibility was dependent on the diagnosis of acute ischemic stroke, absence of previous stroke based on past medical history and MRI, no history of AF and congestive heart failure (cohort A) and, additionally, no stroke lesion size ≥ 20 mL (sub-cohort A*). AF, the primary endpoint, was detected on 24-hour electrocardiography and/or echocardiography. Involvement of the insula was assessed by two experienced readers on MRI blinded to clinical data. MR-proANP levels were obtained through a novel sandwich immunoassay. Logistic-regression-models were fitted to estimate odds ratios for the association of insular strokes and MR-proANP with NDAF. The discriminatory accuracy of insular strokes and MR-proANP was assessed by a model-wise comparison of the area under the receiver-operating-characteristics-curve (AUC) with known predictors of AF.
  
  
  RESULTS
  104 (cohort A) and 83 (cohort A*) patients fulfilled above-mentioned criteria. Patients with isolated insular strokes had a 10.7-fold higher odds of NDAF than patients with a small ischemic stroke at any other location. The AUC of multivariate logistic regression models for the prediction of NDAF improved significantly when adding stroke location and MR-proANP levels. Moreover, MR-proANP levels remained significantly elevated throughout the acute hospitalization period in patients with NDAF compared to those without.
  
  
  CONCLUSIONS
  Isolated insular strokes and plasma MR-proANP levels on admission are independent predictors of NDAF and significantly improve the prediction accuracy of identifying patients with NDAF compared to known predictors including age, the NIHSS and lesion size. To accelerate accurate diagnosis and enhance secondary prevention in acute stroke, higher levels of MR-proANP and insular strokes may represent easily accessible indicators of AF if confirmed in an independent validation cohort.
authors.affiliation: Institute of Neuropathology, University Hospital Zurich, Zurich, Switzerland; Department of Neurology, University Hospital Basel, Basel, Switzerland.
authors.forename: Karl
authors.initials: K
authors.lastname: Frontzek
authors.affiliation: Department of Neurology, University Hospital Basel, Basel, Switzerland; Department of Neurology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Felix
authors.initials: F
authors.lastname: Fluri
authors.affiliation: University Hospital of Psychiatry, Zurich, Switzerland.
authors.forename: Jakob
authors.initials: J
authors.lastname: Siemerkus
authors.affiliation: Medical University Clinic, Cantonal Hospital Aarau, Aarau, Switzerland.
authors.forename: Beat
authors.initials: B
authors.lastname: Müller
authors.affiliation: Department of Neurology, University Hospital Mannheim, Mannheim, Germany.
authors.forename: Achim
authors.initials: A
authors.lastname: Gass
authors.affiliation: Department of Endocrinology, University Hospital Basel, Basel, Switzerland.
authors.forename: Mirjam
authors.initials: M
authors.lastname: Christ-Crain
authors.affiliation: Department of Neurology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Mira
authors.initials: M
authors.lastname: Katan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000097:blood* / Q000175:diagnosis* / Q000209:etiology; D009320:Atrial Natriuretic Factor / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D020521:Stroke / Q000097:blood* / Q000150:complications*
chemical_list: C552580:midregional pro-atrial natriuretic peptide, human; D009320:Atrial Natriuretic Factor