CONGRESS ABSTRACT

Background: The six-minute walk test (6MWT) is a reliable measure of exercise capacity in patients suffering from cardiovascular diseases. While the prognostic significance of a reduced six-minute walk distance (6MWD) is well-established, there remains a paucity of comprehensive data on the factors that predict performance on this test. Purpose: To evaluate the clinical predictors of 6MWT results and the prognostic significance of this test in patients with acute myocardial infarction (AMI).  Methods: Overall, 532 patients admitted to the Intensive Care Unit of the University Hospital of Trieste due to AMI were prospectively enrolled. The combined endpoint comprised all-cause mortality, re-infarction, and heart failure development. Results: The mean age of the cohort was 64 years, with 79% of patients being male and 86% presenting with STEMI. The mean 6MWD was 352±83 m. Patients with diabetes mellitus performed shorter distances than those without (356±82 Vs. 329±84 m, p<0.01). Furthermore, the 6MWD in women was found to be lower than that of men. Binary logistic regression analysis revealed that a 6MWD lower than the mean value was predicted by older age, female gender, diabetes mellitus, higher BMI, worse left ventricular ejection fraction (LVEF), and higher C-reactive protein levels, after correction for smoking and hypertension. During a mean follow-up period of 48 months, 147 patients (28%) reached the composite endpoint. Utilizing continuous hazard ratio analysis, 6MWD was linearly associated with the composite endpoint and a cut-off of 363 m was identified (Fig. 1A). At Kaplan-Meier analysis, patients with 6MWD below the cut-off had a higher probability of an adverse outcomes (p<0.01) (Fig. 1B). The findings of the Cox regression analysis further confirmed that a 6MWD below the cut-off was a predictor of adverse outcome (HR: 1.54, p=0.02), along with worse renal function, reduced LVEF, smoking and hypertension, adjusted for age, gender, diabetes, PCR and BMI. Conclusion: This study investigated the determinants of reduced 6MWD, which reflect underlying pathophysiological mechanisms that impair exercise performance. The 6MWD was confirmed as an independent predictor of adverse events, consistently with its established role as a prognostic marker. These findings emphasize the 6MWT value in clinical risk assessment and underscore the need to prioritize functional capacity in the management of patients with AMI.