Exercise-induced ischemic preconditioning detected by sequential exercise stress tests: A meta-analysis

Abstract

Exercise-induced ischemic preconditioning (IPC) can be assessed with the second exercise stress test during sequential testing. Exercise-induced IPC is defined as the time to 1 mm ST segment depression (STD), the rate-pressure product (RPP) at 1 mm STD, the maximal ST depression and the rate-pressure product at peak exercise. The purpose of this meta-analysis is to validate the parameters used to assess exercise-induced IPC in the scientific community. A literature search was performed using electronic database. The main key words were limited to human studies, which were (a) ischemic preconditioning, (b) warm-up phenomenon, and (c) exercise. Meta-analyses were performed on the study-specific mean difference between the clinical measures obtained in the two consecutive stress tests (second minus first test score). Random effect models were fitted with inverse variance weighting to provide greater weight to studies with larger sample size and more precise estimates. The search resulted in 309 articles of which 34 were included after revision (1053 patients). Results are: (a) time to 1 mm ST segment depression increased by 91 s (95% confidence interval (CI): 75-108), p < 0.001; (b) peak ST depression decreased by -0.38 mm (95% CI: -0.66 to -0.10), p < 0.01; and (c) rate-pressure product at 1 mm STD increased by 1.80 × 10(3)mmHg (95% CI: 1.0-2.0), p < 0.001. This is the first meta-analysis to set clinical parameters to assess the benefit of exercise-induced ischemic preconditioning in sequential stress testing. The results of this first meta-analysis on the sequential stress test confirm what is presented in the literature by independent studies on exercise-induced ischemic preconditioning. From now on, the results could be used in further research to set standardized parameters to assess the phenomenon.

Association of Exercise Preconditioning With Immediate Cardioprotection

“…A meta-analysis, based on 34 studies and 1,053 patients, reported a significantly later onset of ST depression (91 s) and a decrease in peak ST depression (-0.38 mm) on the second exercise stress test during sequential testing. 25 This supports the ability of exercise to induce immediate attenuation of cardiac ischemia. Pre-clinical work found that warm-up angina requires a preceding period of ischemia, 26 which in turn activates pathways that protect the myocardium against ischemia.…”

Impact of eight weeks of repeated ischaemic preconditioning on brachial artery and cutaneous microcirculatory function in healthy males

“…16 Preconditioning effects of an exercise bout has also been shown previously on cardiac function in patients with coronary artery disease. 17 Early reports have raised concerns about the application of repeated IPC, suggesting repeated protocols may negate vascular protection. 18 Nevertheless, we found FMD was enhanced after 2-weeks (i.e.…”

Exercise-Induced Ischemic Preconditioning and the Potential Application to Cardiac Rehabilitation

“…In contrast, Tomai et al 15 recorded that the effect of the warm-up phenomenon completely disappears in 2 hours and the effects were positive if the time between exercise stress tests was 10 minutes. 10 Beyond those timelines, the effects of preconditioning fade to baseline results. In brief, the FWOP can be assessed when sequential stress testing is separated by 10 to 60 minutes and 24 ± 2 hours for the SWOP.…”

“…12 The initial transient ischemia generates molecules such as nitric oxide, adenosine, and reactive oxygen species leading to de novo (the synthesis of complex molecules from simple molecules) cardioprotective proteins, such as nitric oxide synthase, cyclo-oxygenase-2, and superoxide dismutase. 10 The effect of the FWOP is known to last about 60 minutes, and this is why the second stress test must be performed within this period. Exercise-induced IPC can trigger both the FWOP and the SWOP by an improved exercise/ischemic tolerance in patients.…”

“…[7][8][9] A recent meta-analysis by Lalonde et al 10 described IPC using sequential exercise tests and demonstrated that this produced the following significant changes during the second test: (1) an increase in time before the onset of 1 mm of ST-segment depression (STD); (2) a decrease in the maximal STD; (3) an increase in total exercise time; and (4) an increase in the rate-pressure product (RPP) at 1-mm STD ( Figure 1 ). [7][8][9] A recent meta-analysis by Lalonde et al 10 described IPC using sequential exercise tests and demonstrated that this produced the following significant changes during the second test: (1) an increase in time before the onset of 1 mm of ST-segment depression (STD); (2) a decrease in the maximal STD; (3) an increase in total exercise time; and (4) an increase in the rate-pressure product (RPP) at 1-mm STD ( Figure 1 ).…”