AF in cryptogenic stroke – Cardiology MCQ – Answer

AF in cryptogenic stroke – Cardiology MCQ – Answer

CRYSTAL AF trial used implantable cardiac monitor to detect AF. Percentage of AF detected at 3 years – Correct answer: d) 30%

CRYSTAL AF (Cryptogenic Stroke and Underlying Atrial Fibrillation) trial randomized 441 patients with cryptogenic stroke with no evidence of AF on 24 hour monitoring. At six months AF was noted in 8.9% of study group vs 1.4% in the control group, which became 12.$% and 2% at 12 months, using an implantable cardiac monitor [1]. At 3 years, the detection rate was 30% with the implantable cardiac monitor while it was only 3% in the control group [2].

This study high lights the fact that a 24 hour Holter monitoring grossly underestimates the occurrence of AF in those with cryptogenic stroke. Guidelines recommend a minimum of 72 hour ECG monitoring  in patients with transient ischemic attack (TIA) or ischemic stroke to screen for AF [3].

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Reference

1. Sanna T, Diener HC, Passman RS, Di Lazzaro V, Bernstein RA, Morillo CA, Rymer MM, Thijs V, Rogers T, Beckers F, Lindborg K, Brachmann J; CRYSTAL AF Investigators. Cryptogenic stroke and underlying atrial fibrillation. N Engl J Med. 2014 Jun 26;370(26):2478-86.
2. Brachmann J, Morillo CA, Sanna T, Di Lazzaro V, Diener HC, Bernstein RA, Rymer M, Ziegler PD, Liu S, Passman RS. Uncovering Atrial Fibrillation Beyond Short-Term Monitoring in Cryptogenic Stroke Patients: Three-Year Results From the Cryptogenic Stroke and Underlying Atrial Fibrillation Trial. Circ Arrhythm Electrophysiol. 2016 Jan;9(1):e003333.
3. Kirchhof P, Benussi S, Kotecha D, Ahlsson A, Atar D, Casadei B, Castella M, Diener HC, Heidbuchel H, Hendriks J, Hindricks G, Manolis AS, Oldgren J, Popescu BA, Schotten U, Van Putte B, Vardas P; ESC Scientific Document Group. 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS. Eur Heart J. 2016 Oct 7;37(38):2893-2962.