Frequency and clinical significance of ischemic preconditioning during percutaneous coronary intervention

We sought to examine the short- and long-term clinical consequences of ischemic preconditioning (IP) during percutaneous coronary intervention (PCI).

Ischemic preconditioning has been demonstrated in animal models to significantly diminish the extent of myocardial necrosis consequent to coronary occlusion. Surrogate markers of ischemic injury (ST segment shift, lactate release, creatine kinase release) in humans have been shown to be similarly diminished with IP elicited during PCI. There are no studies of the frequency of inducibility of IP during PCI, nor are there longer-term data on the clinical relevance of IP.

A total of 382 patients underwent elective PCI employing a previously validated protocol to elicit IP. Procedural, in-hospital, and one-year outcomes were recorded.

Ischemic preconditioning was elicited in 80% of patients and was associated with a significant reduction in the likelihood of in-hospital adverse cardiac events (IP group, 12.1%; non-IP group, 44.1%; p < 0.0001). Women and diabetic patients were less likely to exhibit IP. By one year, patients failing to manifest IP were at significantly greater risk of post-discharge death or non-fatal myocardial infarction (MI) (non-IP group, 25.9%; IP group, 11.1%; p < 0.002). Failure to manifest IP was significantly and independently associated with an increased risk of death or non-fatal MI by one year.

Clinically relevant short- and long-term cardioprotection can be found in association with IP during PCI. In-hospital adverse ischemic events are significantly diminished in patients with IP, as are the risks of death or non-fatal MI at one year. Failure to elicit IP during PCI serves as an independent marker of increased risk of future ischemic events.