Heart Care Info - Heart Disease Prevention & Treatment

Response to Letter Regarding Article," Remote Ischemic Preconditioning in Human Coronary Artery Bypass Surgery: From Promise to Disappointment?"

RS Bonser, IA Rahman, JG Mascaro, RP Steeds... - Circulation, 2011 - Am Heart Assoc Kluwer Health, 351 West Camden Street, Baltimore, MD 21202-2436. Phone: 410-528-4050. Permissions: Permissions & Rights Desk, Lippincott Williams & Wilkins, a division of Wolters ... Response to Letter Regarding Article, Remote Ischemic Preconditioning in ...

We thank Dr Heling et al for their interest in our article.1 Their letter raises the question of whether pain is a prerequisite for remote ischemic preconditioning (RIPC), and reflects on the utility of RIPC as a protective adjunct in the anesthetized patient, particularly when volatile anesthetic agents are used.

Some of the earliest clinical studies reporting a protective effect of RIPC were undertaken in anesthetized cardiac surgical patients.2,–,4 The single-blinded coronary artery bypass grafting studies3,4 suggested a promising major reduction in troponin release. We developed a scrupulous double-blinding technique to avoid inadvertent bias and applied an identical RIPC stimulus. Similar fractions of patients received volatile anesthetics and preoperative statins in the reported study as in its predecessors. Disappointingly, perhaps, we did not find differences in troponin release, and we were unable to establish any differences in postoperative cardiac function between RIPC and placebo. We thus concluded that RIPC, with the stimulus used, failed to fulfill its promise in myocardial protection in the setting of coronary artery surgery performed on bypass with cardioplegic arrest. Nevertheless, by adding the query sign in the title and considering caveats within the discussion, we did not exclude an RIPC benefit in other situations, including higher-risk patients, a different RIPC stimulus mass, or within cardiac conditions in which the potential for myocardial necrosis rather than reversible injury was likely to be higher, such as ST-elevation myocardial infarction.