Valvular Heart Disease and Heart Failure in the Post-COVID-19 Era: A Narrative Review of Mechanisms, Diagnosis, Differential Assessment, and Clinical Outcomes

Background/Objectives: Cardiovascular involvement is among the most consequential sequelae of SARS-CoV-2 infection. Myocardial injury, arrhythmia, and thromboembolic disease have been characterized in depth, yet the relationship between COVID-19 and valvular heart disease (VHD), and its interplay with heart failure (HF), has received comparatively limited synthesis. This narrative review consolidates current evidence on the mechanisms, diagnosis, differential assessment, and clinical outcomes linking acute and post-acute COVID-19 to valvular dysfunction and to incident or worsening heart failure, with emphasis on practical implications for cardiologists and internists. Methods: We searched PubMed, Scopus, and Web of Science (January 2020–January 2026) for studies on valvular dysfunction, heart failure, myocardial injury, and endothelial pathology in SARS-CoV-2 infection, and synthesized findings narratively. Results: Convergent pathways—endothelial injury, systemic hyperinflammation, micro- and macrovascular thrombosis, and pressure–volume overload—contribute to functional and, less frequently, structural valvular changes. Available evidence suggests that clinically relevant post-COVID valvular abnormalities are more often secondary/functional (mitral and tricuspid regurgitation) than primary structural lesions, although dedicated prospective valvular studies remain scarce. Pre-existing severe VHD markedly worsens acute COVID-19 prognosis. Elevated NT-proBNP, troponin, and interleukin-6 consistently predict decompensation and mortality, and a substantial minority of survivors show persistent fibrotic pulmonary changes and restrictive ventilatory defects on follow-up (pulmonary rather than cardiac findings). Conclusions: Post-COVID valvular dysfunction appears, on currently available but largely indirect evidence, predominantly functional and inflammation-related, and may overlap with HFpEF phenotypes in selected patients when objective diagnostic criteria are fulfilled. Biomarker-guided, multimodality follow-up is reasonable in high-risk survivors, and prospective longitudinal studies with standardized valvular endpoints remain a priority. Dedicated longitudinal evidence on valvular outcomes specifically remains very limited.