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. 2019 Apr 11:12:1756286419842698.
doi: 10.1177/1756286419842698. eCollection 2019.

Evaluation of a clinical score for predicting atrial fibrillation in cryptogenic stroke patients with insertable cardiac monitors: results from the CRYSTAL AF study

Susan X Zhao  1 , Paul D Ziegler  2 , Michael H Crawford  3 , Calvin Kwong  4 , Jodi L Koehler  2 , Rod S Passman  5
Affiliations

Evaluation of a clinical score for predicting atrial fibrillation in cryptogenic stroke patients with insertable cardiac monitors: results from the CRYSTAL AF study

Susan X Zhao et al. Ther Adv Neurol Disord. .

Abstract

Background: The HAVOC score was previously developed to predict the risk of atrial fibrillation (AF) after cryptogenic stroke (CS) or transient ischemic attack (TIA). The purpose of this study was to apply the HAVOC score to patients who received insertable cardiac monitors (ICMs) in the CRYSTAL AF study.

Methods: All patients from the CRYSTAL AF study who received an ICM were included. HAVOC score (one point each for peripheral vascular disease and obesity with body mass index >30, two points each for hypertension, age ⩾ 75, valvular heart disease, and coronary artery disease, 4 points for congestive heart failure) was computed for all patients. The primary endpoint was AF detection by 12 months of ICM monitoring.

Results: A total of 214 patients who received ICM were included. AF was detected in 40 patients while the remaining 174 patients were AF negative. The HAVOC score was significantly higher among patients with AF [median 3.0 with interquartile range (IQR) 2-4] than those without AF [median 2.0 (IQR 0-3)], p = 0.01. AF increased significantly across the three HAVOC score groups: 11% in Group A (score 0-1), 18% in Group B (score 2-3), and 32 % in Group C (score ⩾ 4) with p = 0.02.

Conclusions: The HAVOC score was shown in this post hoc analysis of CRYSTAL AF to successfully stratify AF risk post CS or TIA. The 11% AF rate in the lowest HAVOC score group highlights the significance of nontraditional contributors to AF and ischemic stroke.

Keywords: atrial fibrillation; cryptogenic stroke; insertable cardiac monitor; risk stratification; transient ischemic attack.

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Conflict of interest statement

Conflict of interest statement: PDZ and JLK are employees and shareholders of Medtronic, Inc. RSP reports speaker fees from Medtronic and Biotronik. SXZ, CK, and MHC report no relationships relevant to the contents of this paper to disclose.

Figures

Figure 1.
Figure 1.
Study flowchart of patients who received insertable cardiac monitors (ICMs) in the CRYSTAL AF study.
Figure 2.
Figure 2.
Time-to-event analysis of insertable cardiac monitor (ICM)-detected atrial fibrillation (AF) based on HAVOC scores.
Figure 3.
Figure 3.
Schematic diagram depicting relationships between atrial fibrillation, ischemic stroke, and their contributing factors.
See this image and copyright information in PMC

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