Global prevalence of myocardial fibrosis among individuals with cardiometabolic conditions: a systematic review and meta-analysis

AIMS: Cardiometabolic conditions including hypertension, diabetes, hyperlipidaemia, and obesity are significant risk factors for cardiovascular diseases. Myocardial fibrosis (MF) is a complication and final common pathway of these conditions, potentially leading to heart failure, arrhythmias, and sudden death. Existing reviews explored pathophysiological changes and treatment of MF, but the global prevalence of MF among individuals with cardiometabolic conditions remains limited. This review aims to evaluate the global prevalence of MF in individuals with cardiometabolic conditions and explore factors influencing its prevalence. METHODS AND RESULTS: CINAHL, Cochrane Library, Embase, PubMed, ProQuest Theses and Dissertations, Scopus, and Web of Science were systematically reviewed until January 2024. Studies included individuals with hypertension, type 2 diabetes mellitus, hyperlipidaemia, and obesity, with MF prevalence assessed via biopsy or late gadolinium enhancement-cardiac magnetic resonance (LGE-CMR). Meta-analysis was conducted using jamovi, and factors associated with MF were synthesized narratively. This review is registered on PROSPERO, CRD42024544632. The meta-analysis included 52 articles involving 5921 individuals. A total of 32.7% of individuals with cardiometabolic conditions developed MF, with hypertension demonstrating the highest prevalence [35.2% (95% CI: 25.5-45.0)]. Biopsy-based studies reported a higher prevalence [75.6% (95% CI: 53.6-97.6)] compared to LGE-CMR studies [26.8% (95% CI: 20.6-33.0)]. Key factors associated with MF included increased LV mass/LV hypertrophy, reduced LV function, and myocardial stiffness. CONCLUSION: This first global review estimates that one-third of individuals with cardiometabolic conditions develop MF, with the prevalence expected to rise. Standardized CMR measures cut-offs are needed to address prevalence inconsistencies. Future research should explore MF prevalence using diverse samples, combined CMR measures, considering socio-demographic and clinical factors for more accurate estimates. LAY SUMMARY: About one in three people with high blood pressure, diabetes, high cholesterol, and obesity develop myocardial fibrosis (MF)-a type of heart tissue scarring that disrupt normal heart function, increasing the risk of heart failure, life-threatening heart rhythms, and even death.Different methods to assess MF (such as biopsies vs. heart imaging) led to variations in reported rates, largely due to limitations in heart imaging for detecting certain types of MF.Future research should explore how common MF is across different populations. Using a combination of advanced heart imaging techniques and considering patient characteristics such as medical history and clinical details could help provide more accurate insights into this condition and how to manage it.