RESUMEN
BACKGROUND: Nearly half of the patients with hypereosinophilic syndrome (HES) have cardiovascular involvement, a major cause of mortality. COVID-19 infection can lead to cardiac involvement, negatively impacting the clinical course and prognosis. We reported two patients with HES complicated by COVID-19, with cardiac involvement and valve replacement. CASE PRESENTATION: Our first patient was a 27-year-old woman admitted due to dyspnea and signs of heart failure. She had severe mitral stenosis and mitral regurgitation on the echocardiogram. Corticosteroid therapy improved her symptoms initially, but she deteriorated following a positive COVID-19 test. A repeated echocardiogram showed right ventricular failure, severe mitral regurgitation, and torrential tricuspid regurgitation and, she underwent mitral and tricuspid valve replacement. Our second patient was a 43-year-old man with HES resulted in severe tricuspid stenosis, which was improved with corticosteroid treatment. He underwent tricuspid valve replacement due to severe valvular regurgitation. He was admitted again following tricuspid prosthetic mechanical valve thrombosis. Initial workups revealed lung involvement in favor of COVID-19 infection, and his PCR test was positive. CONCLUSION: COVID-19 infection can change the clinical course of HES. It may result in a heart failure exacerbation due to myocardial injury and an increased risk of thrombosis in prosthetic valves or native vessels due to hypercoagulability.