Perfusion Pressure Cerebral Infarct (PPCI) trial - the importance of mean arterial pressure during cardiopulmonary bypass to prevent cerebral complications after cardiac surgery: study protocol for a randomised controlled trial

Abstract

BackgroundDebilitating brain injury occurs in 1.6–5 % of patients undergoing cardiac surgery with cardiopulmonary bypass. Diffusion-weighted magnetic resonance imaging studies have reported stroke-like lesions in up to 51 % of patients after cardiac surgery. The majority of the lesions seem to be caused by emboli, but inadequate blood flow caused by other mechanisms may increase ischaemia in the penumbra or cause watershed infarcts. During cardiopulmonary bypass, blood pressure can be below the lower limit of cerebral autoregulation. Although much debated, the constant blood flow provided by the cardiopulmonary bypass system is still considered by many as appropriate to avoid cerebral ischaemia despite the low blood pressure.Methods/designThe Perfusion Pressure Cerebral Infarct trial is a single-centre superiority trial with a blinded outcome assessment. The trial is randomising 210 patients with coronary vessel and/or valve disease and who are undergoing cardiac surgery with the use of cardiopulmonary bypass. Patients are stratified by age and surgical procedure and are randomised 1:1 to either an increased mean arterial pressure (70–80 mmHg) or ‘usual practice’ (40–50 mmHg) during cardiopulmonary bypass.The cardiopulmonary bypass pump flow is fixed and set at 2.4 L/minute/m2 body surface area plus 10–20 % in both groups.The primary outcome measure is the volume of the new ischaemic cerebral lesions (in mL), expressed as the difference between a baseline, diffusion-weighted, magnetic resonance imaging scan and an equal scan conducted 3–6 days postoperatively. Secondary endpoints are the total number of new ischaemic cerebral lesions, postoperative cognitive dysfunction at discharge and 3 months postoperatively, diffuse cerebral injury evaluated by magnetic resonance spectroscopy and selected biochemical markers of cerebral injury.The sample size will enable us to detect a 50 % reduction in the primary outcome measure in the intervention compared to the control group at a significance level of 0.05 and with a power of 0.80.DiscussionThis is the first clinical randomised study to evaluate whether the mean arterial pressure level during cardiopulmonary bypass influences the development of brain injuries that are detected by diffusion-weighted magnetic resonance imaging.Trial registrationClinicalTrials.gov, NCT02185885. Registered on 7 July 2014.Electronic supplementary materialThe online version of this article (doi:10.1186/s13063-016-1373-6) contains supplementary material, which is available to authorized users.

α7 nicotinic acetylcholine receptor agonist attenuates the cerebral injury in a rat model of cardiopulmonary bypass by activating the Akt/GSK3β pathway

“…Cerebral injury is a serious complication following the use of CPB in the cardiac surgery ( 2 , 22 , 23 ). This pathological lesion may be due to several aspects, including impaired cerebral perfusion and oxygenation, cerebral microemboli and SIRS ( 3 , 4 ).…”

Differences in regional cerebral oximetry during cardiac surgery for patients with or without postoperative cerebral ischaemic lesions evaluated by magnetic resonance imaging

“…The study protocol and primary outcome result has been published previously. 3,8 The PPCI trial was a single-centre, parallel group, 1:1 randomised trial investigating the effect of different MAP levels during CPB on cerebral complications after cardiac surgery.…”

“…All inclusion and exclusion criteria have been published previously. 8 In summary, all participants in the PPCI trial were 18 yr of age or older and undergoing elective or subacute coronary artery bypass grafting (CABG), heart valve surgery with the use of CPB, or both.…”

“…Detailed protocols for interventions, anaesthesia, and CPB procedures, and the primary outcome from the PPCI trial have been published previously. 3,8 DWI evaluated lesions and NIRS measurements were both prespecified outcomes in the PPCI trial and the data analysis exploring the association between NIRS readings and DWI measures was specified before initiation of analysis.…”

Erratum to: Perfusion Pressure Cerebral Infarct (PPCI) trial - the importance of mean arterial pressure during cardiopulmonary bypass to prevent cerebral complications after cardiac surgery: study protocol for a randomised controlled trial

“…Unfortunately, the original version of this article [1] contained an error. The listings “Excusion criteria” and “Inclusion criteria” are incorrect.…”