Background: Unmasking the residual cardiovascular risk is a major research challenge in the attempt to reduce cardiovascular disease (CVD) morbidity and mortality. Mounting evidence suggests that a high circulating level of trimethylamine N-oxide is a new potential CVD risk factor. We performed a systematic review of the published studies to clarify the association between circulating high levels of TMAO and cardiovascular events.
Methods: Studies evaluating the association between TMAO and CVD events were searched by electronic databases up to December 2018. Pooled results were expressed as risk ratio (RR) with 95% pertinent confidence interval (CI).
Results: Three studies for a total of 923 patients at high/very high CVD risk were included in our analysis. Overall, a high TMAO level was associated with both major adverse cardiovascular events (RR = 2.05; 95% CI 1.61-2.61) and all-cause mortality (RR = 3.42; 95% CI 2.27-5.15).
Conclusions: Our findings support a role of high TMAO levels in predicting CVD events. High levels of TMAO may be a new CVD risk factor, potentially useful to better plan personalized CVD prevention strategies.
Keywords: Cardiovascular events; Gut microbiota; Trimethylamine oxide.