Ticagrelor therapy and atrioventricular block: Do we need to worry?

Abstract

Ticagrelor is a potent, direct P2Y12 antagonist with rapid onset of action and intense platelet inhibition, indicated in patients with acute coronary syndromes (ACS). This drug is usually well tolerated, but some patients experience serious adverse effects: Major bleeding; gastrointestinal disturbances; dyspnoea; ventricular pauses > 3 s. Given the unexpected high incidence of bradyarrhythmias, a PLATO substudy monitored this side effect, showing that ticagrelor was associated with an increase in the rate of sinus bradycardia and sinus arrest compared to clopidogrel. This side effect was usually transient, asymptomatic and not associated with higher incidence of severe atrioventricular (AV) block or pacemaker needs. A panel of experts from Food and Drug Administration did not consider bradyarrhythmias a serious problem in clinical practice and, accordingly, current labeling of the drug does not give any precaution or contraindication regarding this issue. However, recently some articles have described ACS patients with high-degree, life-threatening, AV block requiring drug discontinuation and, in some cases, pacemaker implantation. In this paper, we describe and discuss five published case reports of severe AV block following ticagrelor therapy and two other cases managed in our Hospital. The analysis of literature suggests that, although rarely, ticagrelor can be associated with life-threatening AV block. Caution and careful monitoring are required especially in patients with already compromised conduction system and/or treated with AV blocking agents. Future studies, with long-term rhythm monitoring, would help to define the outcome of patients at higher risk of developing this complication.

Cyclical sinus bradycardia and atrioventricular block induced by ticagrelor

“…Few reports of clinically significant ticagrelor-related bradycardia requiring drug discontinuation have been published. 8 To the best of our knowledge, we report the first case of severe sinus respiratory arrhythmia combined with AV block after ticagrelor loading. Cheyne-Stokes respiration frequently occurs in patients with congestive heart failure 9 and has been associated with exaggerated respiratory heart rate variations.…”

Heart Block Caused by Ticagrelor Use in a Patient Who Underwent Adenosine Diastolic Fractional Reserve Assessment: A Case Report

“…The conduction abnormalities induced are often asymptomatic without the need for a permanent pacemaker [ 1 ]. The abnormalities are sometimes even transient and resolve with discontinuation of ticagrelor [ 7 ]. However, a minority of patients did require pacemaker placement due to persistent sinoatrial disease, like the patient reported here [ 8 ]; however, unlike our patient, most of the patients requiring a pacemaker had some underlying conduction abnormality [ 7 ].…”

Isolated right ventricular myocardial infarction: a case report

“…Ticagrelor a potent P2Y12 inhibitor is recommended as first-line antithrombotic agent in addition to Aspirin in acute coronary syndrome; however, it may exert a deleterious effect in patients already presenting with symptomatic bradycardia causing atrioventricular block published in few case reports. 9 , 10 …”