Remote Ischaemic preconditioning reduces myocardial injury in patients undergoing cardiac surgery with cold blood cardioplegia:a randomised controlled trial

Vinod Venugopal ¹, Derek J Hausenloy ¹, Andrew Ludman ¹, Carmelo Di Salvo Mr², Shyam Kolvekar ², John Yap ², David Lawrence ², Guilio Bognolo ² and Derek M Yellon ^1*

¹ The Hatter Cardiovascular Institute, University College London Hospital & Medical School, United Kingdom
² The Heart Hospital, UCLH, United Kingdom

^* To whom correspondence should be addressed. E-mail: d.yellon{at}ucl.ac.uk.

Accepted 23 September 2008

Abstract

Objective: Remote ischaemic preconditioning (RIPC) induced by brief limb ischaemia reduces myocardial injury in coronary artery bypass (CABG) surgery patients receiving predominantly cross-clamp fibrillation for myocardial protection. However, cold-blood cardioplegia is the more commonly used method worldwide. This study was designed to assess whether RIPC is cardioprotective in CABG patients receiving cold-blood cardioplegia.

Design: Single centre, single-blinded, randomised controlled trial.

Setting: Tertiary referral hospital in London.

Patients: Adults patients (18-80 years) undergoing elective CABG surgery with or without concomitant aortic valve surgery with cold-blood cardioplegia. Patients with diabetes, renal failure (serum creatinine >130 mmol/L), hepatic or pulmonary disease, unstable angina or myocardial infarction within the last 4 weeks were excluded.

Interventions: Patients were randomised to receive either RIPC (n=23) or control (n=22) following anaesthesia. RIPC comprised three 5-min cycles of right forearm ischaemia, induced by inflating a blood pressure cuff on the upper arm to 200mmHg, with an intervening 5 min reperfusion. The control group had a deflated cuff placed on the upper arm for 30min.

Main outcome measures: Serum troponin-T was measured pre-operatively and at 6, 12, 24, 48 and 72 hours post-surgery and the area under the curve (AUC72hrs) calculated.

Results: RIPC reduced absolute serum troponin-T release by 42.4% (AUC72hours 31.53±24.04 µg/L.72hrs in RIPC vs 18.16±6.67µg/L.72hrs in control; 95% CI 2.4–24.3; p=0.019).

Conclusions: Remote ischaemic preconditioning induced by brief ischaemia of the arm reduces myocardial injury in CABG patients receiving cold-blood cardioplegia making this non-invasive cardioprotective technique widely applicable clinically.