Abstract
Cycles of ischemia and reperfusion induced with a pressure cuff on a skeletal muscle, also know as remote ischemic preconditioning (RIPC), appears to improve performance in different time-trial events in healthy individuals. Our primary goal was to assess the effect of RIPC in heart failure (HF) patients' functional capacity using the six-minute walk test (6MWT). A randomized crossover design comparing RIPC (4 × five-minutes of upper arm ischemia) to the SHAM procedure was done in 15 patients prior to a 6MWT. The primary outcome measure was the total distance walked in a standardized 6MWT (20m corridor). Metabolic and hemodynamic responses were measured using gas exchange analysis with a portable metabolic analyzer and peripheral skeletal muscle oxygen saturation (smO(2)) with near-infrared spectroscopy. The total distance travelled during 6MWT was not significantly different between the RIPC (347 ± 63 m) and the SHAM procedure (352 ± 65 m; p = 0.514). Relative oxygen uptake did not change when comparing interventions: 10.26 ± 2.01 ml/kg/min vs 10.69 ± 2.51 ml/kg/min (RIPC vs SHAM, respectively, p = 0.278). As well, no significant differences were observed for heart rate, respiratory exchange ratio, smO(2), and ventilation. Even though HF patients tolerated well the RIPC intervention, it did not provide any significant improvement in functional capacity and other physiological parameters in our sample of patients.