Cardiac Effects in Post-COVID-19 Heart Failure: A Systematic Review of Longitudinal Imaging- and Biomarker-Based Structural and Functional Remodeling.

COVID-19 has been linked to persistent cardiovascular sequelae, yet the trajectory of structural and functional cardiac changes beyond the acute phase remains unclear. This systematic review synthesizes longitudinal evidence on post-COVID cardiac remodeling assessed by imaging and biomarkers. Following PRISMA guidelines, we searched PubMed and Cochrane Library (January 2020-April 2025) for peer-reviewed studies enrolling adults (≥18 years) with polymerase chain reaction (PCR)/antigen-confirmed SARS-CoV-2 infection and reporting cardiac outcomes ≥ 12 weeks post-infection. Eligible outcomes included imaging-based abnormalities (cardiac magnetic resonance [CMR]: T1/T2 mapping, late gadolinium enhancement [LGE]; echocardiography: left ventricular ejection fraction [LVEF], LV/RV strain). Longitudinal trends of biomarkers (troponin, NT-proBNP, C-reactive protein [CRP]) were also studied. Risk of bias was assessed using joanna briggs institute (JBI) tools; synthesis followed synthesis without metaanalysis (SWiM) principles. Fifteen studies (n ≈ 166,000; 14 cohorts, 1 case report) were included. Across CMR cohorts, global systolic function was largely preserved, but tissue abnormalities were frequent early and improved over time: edema indices normalized by ~ 12 months, while LGE prevalence declined (e.g. 50%→19% in paired scans). However, residual non-ischemic scars and elevated T1/T2 persisted in symptomatic subgroups. Echocardiography showed normal LVEF, but subtle left ventricular global longitudinal strain (LV-GLS) impairment versus controls (e.g. -18.5% vs - 19.3%). Biomarker trends were heterogeneous: natriuretic peptide positivity persisted in patients with prior cardiovascular disease (CVD), while troponin and CRP generally normalized. Large population-based cohorts demonstrated sustained 12-month risk for heart failure, myocarditis, and major cardiovascular events, graded by acute severity. Most patients recover gross systolic function, yet subclinical myocardial changes and elevated population-level cardiovascular risk persist up to 1 year. These findings support risk-stratified follow-up, judicious use of advanced imaging, and preventive cardiology strategies.