Dual Cardiotoxicity of Capecitabine: Coronary Vasospasm and QT Prolongation in a Patient With Gastric Adenocarcinoma

Dominguez-Linares A.; Nieto-Dolores A.K.; Ayala-Bustamante L.E.; Valencia Hernandez H.A.; Ruiz-Mori E.; Gonzalez-Trejo A.; Guerra E.C.; Acosta-Gutierrez G.H.; Ponce-Acosta C.; Espinola-Zavaleta N. · JACC: Case Reports (2026) · DOI: 10.1016/j.jaccas.2025.106252

Resumen

Background: Fluoropyrimidines such as 5-fluorouracil and its oral prodrug capecitabine are widely used in treating gastrointestinal malignancies but are associated with potentially severe cardiotoxicity. Case Summary: We present the case of a 67-year-old woman with resected gastric adenocarcinoma (pT4apN1) treated with adjuvant XELOX (capecitabine plus oxaliplatin). On the fifth day of the first cycle, she developed severe oppressive chest pain and acute dyspnea. Electrocardiogram showed repolarization changes and QT prolongation, while echocardiography demonstrated preserved ejection fraction. Coronary computed tomography ruled out obstructive disease, and symptoms resolved after drug withdrawal, supporting diagnosis of capecitabine-induced coronary vasospasm. Chemotherapy was safely reintroduced under cardiologic prophylaxis. Conclusions: This case illustrates the dual cardiotoxicity of capecitabine, with both vasospastic angina and QT prolongation.

Instituciones: Universidad de San Martín de Porres