Ticagrelor-Induced Prolongation of the QTc Interval

Area of Science:

• Cardiology
• Pharmacology
• Clinical Medicine

Background:

• Ticagrelor is a Class I antiplatelet agent recommended for patients undergoing percutaneous coronary angioplasty (PTCA).
• While ticagrelor is associated with various cardiac conduction defects, evidence linking it to QTc prolongation was previously lacking.
• This study addresses the potential for ticagrelor to induce QTc prolongation.

Observation:

• A 64-year-old male, post-PTCA, received ticagrelor and had a baseline QTc of 402 ms.
• After 1.5 months, the patient presented with dyspnea, and ECG showed a QTc of 468 ms.
• Ticagrelor was discontinued, and the patient was switched to clopidogrel, with other medications remaining unchanged.

Findings:

• Following ticagrelor discontinuation and switch to clopidogrel, the patient's QTc interval normalized to 425 ms within a month.
• The Naranjo algorithm indicated a probable association between ticagrelor and QTc prolongation (score of 6).
• This case represents the first reported instance of ticagrelor-induced QTc prolongation.

Implications:

• This case highlights a potential, previously unreported adverse effect of ticagrelor.
• Clinicians should consider ticagrelor-induced QTc prolongation in patients presenting with relevant symptoms and ECG changes.
• Further research is warranted to confirm the causality and prevalence of QTc prolongation associated with ticagrelor.