Relationship Between Level of Trimethylamine Oxide and the Risk of Recurrent Cardiovascular Events in Patients with Acute Myocardial Infarction

TL;DR

High levels of trimethylamine oxide (TMAO) and choline are linked to higher risks of heart events in patients who had a heart attack.

Contribution

This study shows choline has better predictive power than TMAO for cardiovascular risk in acute myocardial infarction patients.

Findings

TMAO levels were associated with increased risk of MACE, cardiac death, and recurrent MI.

Choline showed stronger predictive power for all-cause mortality than TMAO.

A choline pathway independent of TMAO contributes to cardiovascular risk.

Abstract

Background: This study investigated the value of trimethylamine oxide (TMAO) and its precursors in secondary prevention for patients with acute myocardial infarction (AMI). Methods: We retrospectively enrolled patients diagnosed with AMI. The associations of TMAO and its precursors with endpoint events were estimated by Cox proportional hazards models. Results: During a median follow-up of 6.4 years, 319 (32.0%) major adverse cardiovascular event (MACE) occurred in the 996 patients enrolled. After adjusting for traditional risk factors, the risk of MACE, cardiac death, and recurrent MI increased by 28% (HR 1.28, 95% CI 1.10–1.49), 44% (HR 1.44, 95% CI 1.12–1.84), and 27% (HR 1.27, 95% CI 1.04–1.55), respectively, per one increment in ln-transformed TMAO. After adjustment for the levels of its precursors, the relationship between TMAO and MACE was still significant. Choline was associated with MACEs, all-cause mortality, cardiac death, and risk of recurrent MI after adjusting for the levels of the remaining metabolites, in addition to traditional risk factors. The overall ability to predict all-cause mortality was better for the choline model than for the TMAO model (continuous NRI 0.185, p = 0.007; IDI 0.030, p = 0.020). Mediation effect analysis showed that the mediating effect of TMAO on choline and the risk of all-cause mortality was 11.39% (95% CI 0.0209–0.2200, p = 0.016), suggesting the existence of a choline activity pathway that is independent of the TMAO pathway. Conclusions: TMAO and choline were associated with an increased risk of MACE in patients with AMI, and choline had better predictive power.

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