Plasma TMAO Combined With NT-proBNP Predicts Prognosis And Length Of Hospital Ization In Patients With Ischemia Heart Failure

BackgroundHeart failure(HF)has become a global epidemic of chronic end-stage cardiac disease in the past decades,with a high fatality rate even under optimal treatment.As a metabolite of intestinal microflora,trimethylamine n-oxide(TMAO)is closely related to many cardiovascular diseases.TMAO combined with NT-proBNP to predict prognosis,hospitalization cost and length of stay in ischemic heart failure(IHF)patients has been rarely reported.ObjectiveTo examine whether plasma TMAO combined with NT-proBNP is associated with the all-cause mortality and duration of hospitalization as well as hospital cost in IHF patients.MethodsThis prospective cohort study was conducted with 189 patients with a left ventricular ejection fraction<45%caused by CAD from March 2016 to December 2020.Baseline data,including demographics,comorbid conditions and laboratory inspection,were recorded.The cumulative rate of all-cause mortality was evaluated using the Kaplan-Meier method and compared between the groups according to the log-rank test.Relative risks were reported as hazard ratios and 95%confidence interval calculated using the Cox proportional-hazards analyses,with stepwise adjustment for covariables.Discrimination of the TMAO,NT-proBNP,TMAO combined with NT-proBNP models on all-cause mortality was further calculated by ROC curve,Harrell’s C index and Net reclassification index.Spearman correlation analysis was then performed to study the relationship between TMAO combined with NT-proBNP and duration of hospital stays and hospitalization costs.ResultsTMAO,in combination with NT-proBNP,improved all-cause mortality prediction in IHF patients when stratified as none,one or both biomarker(s)elevated,with the highest risk of all-cause mortality in both biomarkers elevated group(HR:3.62,95%CI:1.89-6.96,p<0.001).After stepwise adjusting for other covariables,both TMAO and NT-proBNP elevated group still remained statistically significant in predicting all-cause mortality.ROC curve analysis further confirmed that TMAO combined with NT-probNP strengthened the prediction of all-cause death risk(AUC:0.727,sensitivity:53.0%,specificity:83.1%).Discrimination of predictive model was strongest in TMAO combined with NT-proBNP group(C-statistic:0.83,95%CI:0.76-0.90;NRI:0.84,95%CI:0.18-1.49).In Spearman correlation analysis,both TMAO and NT-proBNP elevated is association with longer duration of hospitalization(r=0.191,p=0.009)but not higher hospital cost.ConclusionTMAO combined with NT-probNP further strengthened the prediction of all-cause mortality in patients with IHF,and those with elevated two biomarkers have the highest risk of mortality.IHF patients with elevated two biomarkers had longer hospital stays.