# Discontinuous Doppler‐Derived Intrarenal Venous Flow Is a Predictor of Impaired Exercise Capacity Associated With Poor Prognosis in Patients With Acute Coronary Syndrome

## TL;DR

Discontinuous intrarenal venous flow predicts poor exercise capacity and worse outcomes in patients with acute coronary syndrome.

## Contribution

DIRVF is shown to independently predict impaired exercise capacity and prognosis in ACS patients.

## Key findings

- DIRVF was more common in patients with lower peak oxygen consumption.
- DIRVF was an independent predictor of peak VO2 <12 mL/min/kg.
- Adding DIRVF to clinical models improved prediction of impaired exercise capacity.

## Abstract

Doppler‐derived intrarenal venous flow (IRVF) has recently been used to assess renal congestion and intrarenal hemodynamics. Although several reports suggest that IRVF is useful for predicting the prognosis of patients with heart failure (HF), information is sparse for patients with acute coronary syndrome (ACS). Therefore, we performed a study to investigate the relationship between IRVF and peak oxygen consumption (VO2), which is associated with prognosis in patients with ACS.

We enrolled 80 patients with ACS. The prevalence of discontinuous IRVF (DIRVF) was higher in patients with peak VO2 less than the group median (13.2 mL/min/kg; 38% vs. 8%, p = 0.003). Multivariable logistic regression analyses indicated that DIRVF was the only independent predictor of peak VO2 <12 mL/min/kg (odds ratio 6.33, 95% confidence interval [CI] 1.28−31.1, p = 0.02). Median follow‐up was 366 days [189−513 days]. The occurrence of composite endpoints, including death from cardiovascular disease and unplanned hospitalization for HF, was significantly higher in patients with DIRVF than in those with continuous IRVF (p = 0.001). Moreover, according to receiver operating characteristic curves, the area under the curve obtained with basic clinical variables (age, sex, and log N‐terminal pro‐B‐type‐natriuretic peptide) was 0.72 (95% CI 0.60−0.83); this increased significantly to 0.84 (95% CI 0.75−0.93) when peak early diastolic mitral inflow velocity to early diastolic velocity ratio (E/e’) and DIRVF were added (p = 0.007).

DIRVF predicts impaired exercise capacity, which is associated with poor prognosis, in patients with ACS.

DIRVF was an independent predictor of impaired exercise capacity and poor prognosis in patients with ACS. Addition of DIRVF to a clinical variable‐based model improved its predictive ability for impaired exercise capacity in patients with ACS.