Remote ischemic conditioning reduces myocardial infarct size and edema in patients with ST-segment elevation myocardial infarction

JACC Cardiovasc Interv. 2015 Jan;8(1 Pt B):178-188. doi: 10.1016/j.jcin.2014.05.015. Epub 2014 Sep 17.

Abstract

Objectives: This study aimed to determine whether remote ischemic conditioning (RIC) initiated prior to primary percutaneous coronary intervention (PPCI) could reduce myocardial infarct (MI) size in patients presenting with ST-segment elevation myocardial infarction.

Background: RIC, using transient limb ischemia and reperfusion, can protect the heart against acute ischemia-reperfusion injury. Whether RIC can reduce MI size, assessed by cardiac magnetic resonance (CMR), is unknown.

Methods: We randomly assigned 197 ST-segment elevation myocardial infarction patients with TIMI (Thrombolysis In Myocardial Infarction) flow grade 0 to receive RIC (four 5-min cycles of upper arm cuff inflation/deflation) or control (uninflated cuff placed on upper arm for 40 min) protocols prior to PPCI. The primary study endpoint was MI size, measured by CMR in 83 subjects on days 3 to 6 after admission.

Results: RIC reduced MI size by 27%, when compared with the MI size of control subjects (18.0 ± 10% [n = 40] vs. 24.5 ± 12.0% [n = 43]; p = 0.009). At 24 h, high-sensitivity troponin T was lower with RIC (2,296 ± 263 ng/l [n = 89] vs. 2,736 ± 325 ng/l [n = 84]; p = 0.037). RIC also reduced the extent of myocardial edema measured by T2-mapping CMR (28.5 ± 9.0% vs. 35.1 ± 10.0%; p = 0.003) and lowered mean T2 values (68.7 ± 5.8 ms vs. 73.1 ± 6.1 ms; p = 0.001), precluding the use of CMR edema imaging to correctly estimate the area at risk. Using CMR-independent coronary angiography jeopardy scores to estimate the area at risk, RIC, when compared with the control protocol, was found to significantly improve the myocardial salvage index (0.42 ± 0.29 vs. 0.28 ± 0.29; p = 0.03).

Conclusions: This randomized study demonstrated that in ST-segment elevation myocardial infarction patients treated by PPCI, RIC, initiated prior to PPCI, reduced MI size, increased myocardial salvage, and reduced myocardial edema.

Keywords: acute myocardial infarction; cardiovascular magnetic resonance; myocardial edema; primary percutaneous coronary intervention; remote ischemic conditioning; reperfusion injury.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Biomarkers / blood
  • Coronary Angiography
  • Edema, Cardiac / blood
  • Edema, Cardiac / diagnosis
  • Edema, Cardiac / etiology
  • Edema, Cardiac / prevention & control*
  • England
  • Female
  • Humans
  • Ischemic Preconditioning, Myocardial / adverse effects
  • Ischemic Preconditioning, Myocardial / methods*
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Myocardial Infarction / blood
  • Myocardial Infarction / diagnosis
  • Myocardial Infarction / therapy*
  • Myocardium / pathology
  • Percutaneous Coronary Intervention / adverse effects
  • Predictive Value of Tests
  • Time Factors
  • Treatment Outcome
  • Troponin T / blood
  • Upper Extremity / blood supply*

Substances

  • Biomarkers
  • Troponin T