# Total body water to lean body mass ratio predicts mortality in patients with chronic heart failure: a prospective, observational study

## TL;DR

A new biomarker combining body water and lean mass predicts mortality in heart failure patients better than existing tools.

## Contribution

Introduces the total body water to lean body mass ratio (TLR) as a novel composite biomarker for chronic heart failure prognosis.

## Key findings

- High TLR (≥0.783) was independently associated with increased all-cause and cardiovascular mortality.
- Patients with high TLR had worse nutritional status and higher mortality rates during a 1,200-day follow-up.
- TLR performed comparably to established biomarkers in predicting long-term outcomes in CHF patients.

## Abstract

Malnutrition and sodium water retention are some of the most common complications of chronic heart failure (CHF). To date, several parameters or risk stratification tools have been established to predict one’s volume or nutritional status. Unfortunately, there is no biomarker that may reflect both conditions, thus, in this study, we established a novel biomarker known as total body water (TBW) to lean body mass ratio (LBM) ratio (TLR). Accordingly, we also assessed the prognostic value of TLR in CHF patients.

A total of 401 consecutive patients with CHF from August 2019 to October 2021 were prospectively enrolled. TBW and LBM were obtained by InBody S10. The primary endpoint was long-term all-cause and cardiovascular mortality. The cut-off and prognostic value of TLR was determined by receiver operating characteristic curves and Cox regression analysis. Patients were then divided into two groups according to the cut-off value of TLR.

During a median follow-up of 1,200 days, the high-TLR group (TLR ≥ 0.783) was presented with a higher all-cause mortality (41.27% vs. 18.40%, p < 0.001) and cardiovascular mortality (28.57% vs. 13.68%, p < 0.001) compared to the low-TLR group (TLR < 0.783). Furthermore, patients in the high-TLR group tended to be older, presented with atrial fibrillation, had higher NYHA class, had a history of chronic kidney disease, had a higher level of N-terminal prohormone of brain natriuretic peptide, worse nutritional status, and a lower level of albumin (all p < 0.05). The Kaplan–Meier curves of the two group patients revealed that the cumulative all-cause and cardiovascular mortality were lower in patients with lower TLR (all log-rank p < 0.001). In the multivariate Cox proportional hazard analysis, TLR ≥ 0.783 was an independent predictor for both all-cause mortality (HR = 2.108, 95%CI 1.400, 3.173, p < 0.001) and cardiovascular mortality (HR = 2.044, 95%CI 1.264, 3.305, p = 0.004).

The TLR may serve as a novel composite biomarker that reflects both volume and nutritional status in CHF patients and is associated with long-term prognosis. Its prognostic performance appears comparable to several established biomarkers, though further validation is warranted.