333 consecutive adult patients with a suspected first acute myocardial infarction were randomly assigned in a 1:1 ratio by computerised block randomisation to receive primary percutaneous coronary intervention with (n=166 patients) versus without (n=167) remote conditioning (intermittent arm ischaemia through four cycles of 5-min inflation and 5-min deflation of a blood-pressure cuff). Allocation was concealed with opaque sealed envelopes. Patients received remote conditioning during transport to hospital, and primary percutaneous coronary intervention in hospital. The primary endpoint was myocardial salvage index at 30 days after primary percutaneous coronary intervention, measured by myocardial perfusion imaging as the proportion of the area at risk salvaged by treatment; analysis was per protocol.Hey, lose blood flow to an arm to save a heart. Works for me.
Median salvage index was 0·75 (IQR 0·50—0·93, n=73) in the remote conditioning group versus 0·55 (0·35—0·88, n=69) in the control group, with median difference of 0·10 (95% CI 0·01—0·22; p=0·0333); mean salvage index was 0·69 (SD 0·27) versus 0·57 (0·26), with mean difference of 0·12 (95% CI 0·01—0·21; p=0·0333).
Remote ischaemic conditioning before hospital admission increases myocardial salvage, and has a favourable safety profile. Our findings merit a larger trial to establish the effect of remote conditioning on clinical outcomes.
Bøtker HE at al. "Remote ischaemic conditioning before hospital admission, as a complement to angioplasty, and effect on myocardial salvage in patients with acute myocardial infarction: a randomised trial" Lancet 27 February 2010 375: 727-734.