Suspicious index in Lyme carditis: Systematic review and proposed new risk score

Abstract

Background Lyme carditis (LC), an early manifestation of Lyme disease that most commonly presents as high‐degree atrioventricular block (AVB), usually resolves with antibiotic treatment. When LC is not identified as the cause of AVB, a permanent pacemaker may be inappropriately implanted in a reversible cardiac conduction disorder. Hypothesis The likelihood that a patient's high‐degree AVB is caused by LC can be evaluated by clinical characteristics incorporated into a risk stratification tool. Methods A systematic review of all published cases of LC with high‐degree AVB, and five cases from the authors' experience, was conducted. The results informed the development of a new risk stratification tool, the Suspicious Index in LC (SILC) score. The SILC score was then applied to each case included in the review. Results Of the 88 cases included, 51 (58%) were high‐risk, 31 (35.2%) intermediate‐risk, and 6 (6.8%) low‐risk for LC according to the SILC score (sensitivity 93.2%). For the subset of 32 cases that reported on all SILC variables, 24 (75%) cases were classified as high‐risk, 8 (25%) intermediate‐risk, and 0 low‐risk (sensitivity 100%). Specificity could not be assessed (no control group). Notably, 6 of the 11 patients who received permanent pacemakers had reversal of AVB with antibiotic treatment. Conclusion The SILC risk score and COSTAR mnemonic (constitutional symptoms; outdoor activity; sex = male; tick bite; age < 50; rash = erythema migrans) may help to identify LC in patients presenting with high‐degree AVB, and ultimately, minimize the implantation of unnecessary permanent pacemakers.

Lyme carditis presenting as atrial fibrillation

“…Results of a systematic review in January 2019 of all published cases of Lyme carditis with high-degree AVB by Besant et al stimulated the development of a risk stratification tool called the Suspicious Index in Lyme Carditis (SILC) score utilising the acronym COSTAR (constitutional symptoms, outdoor activities, male sex, tick bite, age <50 and erythema migrans rash) (figure 5). Our patient’s calculated SILC score is 9 indicating a high likelihood for Lyme carditis 11…”

Chest palpitations in a teenager as an unusual presentation of Lyme disease: case report

“…Steroids do not appear to shorten the time course of Lyme carditis and are not routinely recommended [17]. For situations in which the diagnosis of LD may be uncertain, a risk score algorithm, the "Suspicious Index in Lyme Carditis (SILC)" has been developed to help predict outcomes and direct management [18]. Although developed for adult patients, calculation of the SILC risk score and accompanying "COSTAR" mnemonic (constitutional symptoms; outdoor activity; sex = male; tick bite; age < 50; rash = erythema migrans) may help to identify Lyme carditis in children presenting with high-degree AVB, and ultimately, may help minimize the implantation of unnecessary permanent pacemakers (since treatment with antibiotics can lead to resolution of AVB, obviating the need for pacing).…”

A Practical Approach to the Diagnosis of Lyme Borreliosis: From Clinical Heterogeneity to Laboratory Methods

“…The involvement of the heart is observed in 4-10% of patients with LB, of whom 90% have Lyme carditis (90,91 If heart involvement in LB is suspected, a cardiological examination is suggested. The following investigations should be addressed: 12-channel ECG and 24-h ECG Holter (query: rhythm analysis, PQ interval, QRS width, ectopic beats), chest X-ray (question: heart size, congestion); echocardiography (diameter, ejection fraction, abnormal wall movement, pericardial effusion); cardiac MRI, and in selected cases myocardial biopsy for histological examination and cultural isolation of Borrelia (96).…”