The prognostic value of the Incremental Shuttle Walk Test in Chagas cardiomyopathy

Abstract

Purpose

To verify the value of the Incremental Shuttle Walk Test (ISWT) distance to identify patients with Chagas cardiomyopathy (ChC) at risk of adverse cardiovascular events.

Methods

Fifty-two patients with ChC (51 ± 6 years) were evaluated by ISWT, echocardiography, Cardiopulmonary Exercise Testing, and Human Activity Profile (HAP) Questionnaire. Patients were prospectively followed for 44 ± 10 months. The combined endpoint was cardiac death/heart transplant/stroke. The prognostic value of ISWT was verified by the Cox regression, and the ISWT was adjusted for age, sex, left ventricular ejection fraction (LVEF), and minute ventilation/carbon dioxide production relationship (VE/VCO₂ slope).

Results

At the final follow-up, 11 patients (21%) had experienced the endpoint event. When adjusted for age, sex, LVEF, and VE/VCO₂ slope, only ISWT distance (HR 0.99, 95% confidence interval (CI): 0.98–0.99; p = 0.026) and VE/VCO₂ slope (HR 0.93, 95% CI: 0.87–0.99; p = 0.044) remained as independent predictors of adverse cardiovascular events in patients with ChC. The optimal cutoff point for identifying poor prognosis was the ISWT distance less than 440 m (AUC = 0.72). There was a significant difference (p = 0.032) in the number of events between the groups with low ISWT distance (≤440 m) and high (>440 m) ISWT distance.

Conclusions

The ISWT is a valuable tool with potential value in the prognostic evaluation of patients with ChC.

Implications for rehabilitation

• Patients with Chagas cardiomyopathy showed functional impairment since the early stages of heart disease.

• The Incremental Shuttle Walk Test (ISWT) can be a valuable and inexpensive tool in the risk stratification of the patients.

• The ISWT distance is an independent predictor of adverse cardiovascular event.

• The ISWT distance of 440m is the optimal cut-off point in the identification of patients at risk for adverse cardiovascular events.

Keywords:

• Chagas disease
• Chagas cardiomyopathy
• exercise test
• exercise tolerance
• evaluation
• prognosis

Disclosure statement

No potential conflict of interest was reported by the authors.