Does Repeated Measurement of a 6-Min Walk Test Contribute to Risk Prediction in Children with Dilated Cardiomyopathy?

Marijke H. van der Meulen, Susanna den Boer, Gideon J. du Marchie Sarvaas, Nico A. Blom, Arend D.J. ten Harkel, Hans M.P.J. Breur, Lukas A.J. Rammeloo, Ronald Tanke, Willem A. Helbing, Eric Boersma, Michiel Dalinghaus*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

A single 6-min walk test (6MWT) can be used to identify children with dilated cardiomyopathy (DCM) with a high risk of death or heart transplantation. To determine if repeated 6MWT has added value in addition to a single 6MWT in predicting death or heart transplantation in children with DCM. Prospective multicenter cohort study including ambulatory DCM patients ≥ 6 years. A 6MWT was performed 1 to 4 times per year. The distance walked was expressed as percentage of predicted (6MWD%). We compared the temporal evolution of 6MWD% in patients with and without the study endpoint (SE: all-cause death or heart transplantation), using a linear mixed effects model. In 57 patients, we obtained a median of 4 (IQR 2–6) 6MWTs per patient during a median of 3.0 years of observation (IQR 1.5–5.1). Fourteen patients reached a SE (3 deaths, 11 heart transplantations). At any time during follow-up, the average estimate of 6MWD% was significantly lower in patients with a SE compared to patients without a SE. In both patients groups, 6MWD% remained constant over time. An absolute 1% lower 6MWD% was associated with an 11% higher risk (hazard) of the SE (HR 0.90, 95% CI 0.86–0.95 p < 0.001). Children with DCM who died or underwent heart transplantation had systematically reduced 6MWD%. The performance of all patients was stable over time, so repeated measurement of 6MWT within this time frame had little added value over a single test.

Original languageEnglish
Pages (from-to)223-229
Number of pages7
JournalPediatric Cardiology
Volume41
Issue number2
DOIs
Publication statusPublished - 1 Feb 2020

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