IMPORTANCE: The frequency and clinical phenotypes of cardiotoxic events in chimeric antigen receptor (CAR) T-cell recipients remain poorly understood given that landmark approval trials typically exclude patients with high-risk cardiovascular profiles and data from nontrial settings are scarce. OBJECTIVE: To summarize the prevalence of adverse cardiovascular events among adults receiving CAR T-cell therapies for advanced hematologic malignant neoplasms. DATA SOURCES: MEDLINE, Embase, Cochrane Library, and Google Scholar were systematically searched from database inception until February 26, 2024. STUDY SELECTION: Observational studies were included if they comprised adult CAR T-cell recipients with advanced hematologic malignant neoplasms and if they systematically evaluated cardiovascular complications. DATA EXTRACTION AND SYNTHESIS: Extraction of prespecified parameters related to the patient population, study design, and clinical events was performed at the study level by 2 independent reviewers in accordance with the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline. Meta-analysis of single proportions was conducted using random-effect models with Freeman-Tukey double arcsine transformations to calculate pooled prevalence estimates. Sensitivity analysis was performed using generalized linear mixed models with logit transformations. MAIN OUTCOMES AND MEASURES: Ventricular and supraventricular arrhythmias, heart failure events, reduction in left ventricular ejection fraction, myocardial infarction, and cardiovascular and all-cause mortality. RESULTS: Thirteen studies comprising 1528 CAR T-cell recipients (median [IQR] age, 61 [58.7-63.0] years; 1016 males [66%]; 80% patients with lymphoma) were included. The median (IQR) duration of follow-up was 487 (294-530) days. On random-effects meta-analysis, we observed a pooled prevalence of 0.66% (95% CI, 0.00%-2.28%) for ventricular arrhythmia, 7.79% (95% CI, 4.87%-11.27%) for supraventricular arrhythmia, 8.68% (95% CI, 2.26%-17.97%) for left ventricular dysfunction, 3.87% (95% CI, 1.77%-6.62%) for heart failure events, 0.62% (95% CI, 0.02%-1.74%) for myocardial infarction, and 0.63% (95% CI, 0.13%-1.38%) for cardiovascular death. The pooled prevalence of all-cause mortality was 30.01% (95% CI, 19.49%-41.68%). Sensitivity analyses generated similar findings. CONCLUSIONS AND RELEVANCE: This meta-analysis found a low prevalence of ventricular arrhythmia, myocardial infarction, and cardiovascular death among CAR T-cell recipients over a short-term to midterm follow-up. Left ventricular dysfunction and supraventricular arrhythmia were the most commonly reported cardiovascular complications, suggesting that cardiovascular surveillance strategies should focus on decreases in ejection fraction and supraventricular arrhythmia.