The Impact of Remote Ischaemic Preconditioning on Cardiac Biomarker and Functional Response to Endurance Exercise

Abstract

Remote ischemic preconditioning (RIPC; repeated short reversible periods of ischemia) protects the heart against subsequent ischemic injury. We explored whether RIPC can attenuate post‐exercise changes in cardiac troponin T (cTnT) and cardiac function in healthy individuals. In a randomized, crossover design, 14 participants completed 1‐h cycling time trials (TT) on two separate visits; preceded by RIPC (arms/legs, 4 × 5‐min 220 mmHg), or SHAM‐RIPC (20 mmHg). Venous blood was sampled before and 0‐, 1‐, and 3‐h post‐exercise to assess high sensitivity (hs‐)cTnT and brain natriuretic peptide (NT‐proBNP). Echocardiograms were performed at the same time points to assess left and right ventricular systolic (ejection fraction; EF and right ventricular fractional area change; RVFAC, respectively) and diastolic (early transmitral flow velocities; E) function. Baseline hs‐cTnT was not different between RIPC and SHAM. Post‐exercise hs‐cTnT levels were consistently lower following RIPC (18 ± 3 vs 21 ± 3; 19 ± 3 vs 23 ± 3; and 20 ± 2 vs 25 ± 2 ng/L at 0, 1 and 3‐h post‐exercise, respectively; P < 0.05). There was no main effect of time, trial, or interaction for NT‐proBNP and left ventricular EF or RVFAC (all P < 0.05). A main effect of time was evident for E which transiently declined immediately after exercise to a similar level in both trials (0.85 ± 0.04 vs 0.74 ± 0.04 m/s, respectively; P < 0.05). In summary, RIPC was associated with lower hs‐cTnT levels after exercise but there was no independent effect of RIPC for NT‐proBNP or LV systolic and diastolic function. The lower hs‐cTnT levels after RIPC suggests that further research should evaluate the role of ischemia in exercise‐induced elevation in hs‐cTnT.