Can Exercise Capacity Assessed by the 6 Minute Walk Test Predict the Development of Major Adverse Cardiac Events in Patients with STEMI after Fibrinolysis?

Background: To assess the added value of the 6 minute walk test distance (6MWTD) in the risk-stratification methods for patients with ST-segment elevation myocardial infarction (STEMI) treated with fibrinolysis. Methodology/Principal Findings: This is a prospective cohort study of one hundred consecutive patients with STEMI, who had received fibrinolysis, at Assuit University Hospital. All patients underwent 6MWT pre- discharge and were followed up for 3 months to monitor the incidence of major adverse cardiac events (MACE). Patients were divided into 3 groups according to the level of 6MWTD (level I.450 m, level II = 300–450 m and level III,300 m). Among the study population, the median 6MWT distance was 370 meters (interquartile range 162–462). The mean age was 60.9610.7 years, 71.9 % of them were males, 2/3 had anterior MI. only 10.5 % had successful thrombolysis. Compared to patients in level I (.450 m), patients in level III (,300 m) were more likely to have clinical risk factors as hypertension, diabetes and impaired renal function. The patient’s mean TIMI score was 3.462.2, the mean GRACE score was 150.5627.7. There was a significant negative correlation between the 6 MWTD and GRACE risk score (r =20.80, p,0.001). At 3 months of follow-up, 51 % had MACE including 16 % were dead. Multivariate logistic regression analysis identified that the GRACE risk score and 6MWT distance levels were the best predictors of the MACE at 3 month of follow up. The incidence of MACE was 4 times higher in patients with high GRACE risk score who couldn’t walk more than 300 meters (OR = 4.66, 95 % CI = 1.1–14.5, p = 0.006)