title: Remote ischaemic conditioning and healthcare system delay in patients with ST-segment elevation myocardial infarction.
abstract: We investigated influence of remote ischaemic conditioning (RIC) on the detrimental effect of healthcare system delay on myocardial salvage in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI).
  
  
  
  A post-hoc analysis of a randomised controlled trial in patients with STEMI randomised to treatment with pPCI or RIC+pPCI. RIC was performed as four cycles of intermittent 5 min upper arm ischaemia and reperfusion. Healthcare system delay was defined as time from emergency medical service call to pPCI-wire. Myocardial salvage index (MSI) was assessed by single photon emission computerised tomography.
  
  
  
  Data for healthcare system delay and MSI were available for 129 patients. MSI was negatively associated with healthcare system delay in patients treated with pPCI alone (-0.003 decrease in MSI/min of healthcare system delay; 95% CI -0.005 to -0.001, r(2)=0.11, p=0.008) but not in patients treated with RIC+pPCI (-0.0002 decrease in MSI/min of healthcare system delay; 95% CI -0.001 to 0.001, r(2)=0.002, p=0.74). In patients with healthcare system delay ≤120 min, RIC+pPCI did not affect median MSI compared with pPCI alone (0.75 (IQR: 0.49-0.99) and 0.70 (0.45-0.94), p=1.00). However, in patients with healthcare system delay >120 min, RIC+pPCI increased median MSI compared with pPCI alone (0.74 (0.52-0.93) vs 0.42 (0.22-0.68), p=0.02). Adjusting for potential confounders did not affect the results.
  
  
  
  RIC as adjunctive to pPCI attenuated the detrimental effect of healthcare system delay on myocardial salvage in patients with STEMI, suggesting that the cardioprotective effect of RIC increases with the duration of ischaemia.
  
  
  
  NCT00435266; post-results.
authors.affiliation: Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.
authors.forename: Kasper
authors.initials: K
authors.lastname: Pryds
authors.affiliation: Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Christian Juhl
authors.initials: CJ
authors.lastname: Terkelsen
authors.affiliation: Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.
authors.forename: Astrid Drivsholm
authors.initials: AD
authors.lastname: Sloth
authors.affiliation: Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Kim
authors.initials: K
authors.lastname: Munk
authors.affiliation: Department of Nuclear Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Søren Steen
authors.initials: SS
authors.lastname: Nielsen
authors.affiliation: Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Michael Rahbek
authors.initials: MR
authors.lastname: Schmidt
authors.affiliation: Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Hans Erik
authors.initials: HE
authors.lastname: Bøtker
mesh_terms: D000368:Aged; D003718:Denmark; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D006801:Humans; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015428:Myocardial Reperfusion Injury / Q000209:etiology / Q000517:prevention & control; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000379:methods*; D000072657:ST Elevation Myocardial Infarction / Q000628:therapy*; D016879:Salvage Therapy / Q000379:methods; D016037:Single-Blind Method; D013997:Time Factors