Cardiovascular prognostic impact of missense vs nonmissense lamin A/C variants: A systematic review and meta-analysis

Background: Variants in the LMNA gene, responsible for laminopathies, are associated with severe cardiovascular outcomes, including arrhythmias and heart failure (HF). However, the differential prognostic impact of missense vs nonmissense variants remains unclear. Objective: The primary end point of this systematic review and meta-analysis was to compare the cardiovascular outcome defined as combined malignant ventricular arrhythmias (MVAs) and HF among patients with missense vs nonmissense variants in the LMNA gene. Secondary outcomes included a comparison of MVAs and HF-related events analyzed separately. Methods: A systematic search of PubMed, Ovid MEDLINE, and Cochrane Library was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Meta-analyses were performed using fixed or random effects models, depending on heterogeneity. PROSPERO identifier: CRD42024584721. Results: 12 studies comprising 1818 participants were included. Of these, 969 had missense variants, and 849 had nonmissense variants. The nonmissense group showed a significantly higher rate of cardiovascular events (30.5% vs 21.3%; odds ratio [OR] 2.22; P < .001). MVAs were more frequent in nonmissense carriers (25.5% vs 18.9%; OR 2.37; P < .001). Although limited by the small number of studies (n = 5) and single-study bias, the incidence of HF-related severe events seemed similar between the groups (18.2% vs 23.9%; OR 0.956; P = .801). Conclusion: Nonmissense LMNA variants are associated with worse cardiovascular outcomes, particularly arrhythmic events, whereas HF-related events seem comparable between nonmissense and missense variants.