Effect of caffeine on ventricular arrhythmia: a systematic review and meta-analysis of experimental and clinical studies

Aims The relationship between caffeineconsumption and the occurrence of arrhythmias remains controversial. Despite this lack of scientific evidence, counselling to reduce caffeineconsumption is still widely advised in clinical practice. We conducted a systematical review and meta-analysis of interventional studies of the caffeineeffects on ventricular arrhythmias. Methods and results The search was performed on Pubmed, Embase, and Cochrane database, and terms related to coffee, caffeine, and cardiac arrhythmias were used. Methodological quality was assessed based on The Cochrane Collaboration recommendations and the ARRIVE guidelines. There were 2016 citations retrieved on the initial research. After full-text assessment, seven human and two animal studieswere included in the meta-analysis. In animal studies, the main outcome reported was the ventricular fibrillation threshold. We observed a significant mean difference of −2.15 mA (95% CI −3.43 to −0.87; I 2 0.0%, P for heterogeneity = 0.37). The main outcome evaluated in human studies was the rate of ventricular premature beats (VPBs). The overall relative risk for occurrence of VPBs in 24 h attributed to caffeineexposure was 1.00 (95% CI 0.94–1.06; I 2 13.5%, P for heterogeneity = 0.32). Sensitivity analysis for caffeinedose, different designs, and subject profile was performed and no major differences were observed. Conclusion Our meta-analysis demonstrates that data from human interventional studies do not show a significant effect of caffeineconsumption on the occurrence of VBPs. The effects observed in animal studiesare most probably the result of very high caffeinedoses that are not regularly consumed in a daily basis by humans.