Studies have shown that human albumin undergoes a considerable reduction in its capacity to bind exogenous cobalt (Ischemia Modified Albumin (IMA); Ischemia Technologies, Denver, Colorado, USA), as measured by the albumin cobalt binding test, when exposed to an ischaemic insult. We have recently observed that plasma IMA levels increase soon after transient balloon inflation during percutaneous coronary intervention (PCI), even in the absence of considerable elevations of cardiac troponin.¹ Higher IMA levels have also been reported in patients with acute coronary syndrome attending the emergency department with recent-onset chest pain.² At present however, no data exist regarding the relationship between IMA and an accepted gold standard for myocardial ischaemia—that is, myocardial lactate extraction.³ We therefore sought to assess whether increased IMA plasma levels documented in patients after PCI correlate with an increased production of lactate by the myocardium.

METHODS

We simultaneously measured coronary sinus and arterial lactate concentrations and plasma IMA levels before and after balloon inflation in 10 patients with chronic stable angina undergoing PCI to the proximal left anterior descending coronary artery. The study protocol was approved by the local ethics committee, and informed written consent was obtained from all patients before study entry. Patients with signs or symptoms of acute or chronic ischaemic conditions, including stroke, transient ischaemic attack, leg claudication or shock, were not included. Blood was drawn for detecting IMA and lactate: (1) immediately before PCI, using arterial and venous sheaths; (2) 1 min after the last balloon inflation (arterial and coronary sinus measurements); (3) 5 min after PCI (arterial and coronary sinus …