This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Chen-Scarabelli, C. Articles by Taggart, D. P. Search for Related Content PubMed PubMed Citation Articles by Chen-Scarabelli, C. Articles by Taggart, D. P. Related Collections CT and MRI CV surgery: coronary artery disease Acute myocardial infarction

(Circulation. 2004;110:e36.)
© 2004 American Heart Association, Inc.

Correspondence

Myocardial Injury and Cardiac Troponin I Release After Off-Pump Versus On-Pump Coronary Surgery

Carol Chen-Scarabelli, MSN, APRN, BC, CCRN

Division of Cardiology, VA Ann Arbor, Ann Arbor, Mich, carol.chen-scarabelli@med.va.gov

Tiziano M. Scarabelli, MD, PhD

Wayne State University, Division of Cardiology, St John Hospital and Medical Center, Detroit, Mich, Tiziano.Scarabelli@stjohn.org

An extract of the first 250 words of the full text is provided, because this article has no abstract.

In a recent study by Selvanayagam and colleagues aimed at evaluating reversible and irreversible myocardial injury in patients undergoing off-pump (OP-) versus on-pump (P-) coronary artery bypass surgery (CABG),¹ the authors documented a similar incidence and magnitude of new irreversible myocardial injury in both groups, despite the greater release of cardiac troponin I (cTnI) after P-CABG. These findings raise questions about not only the clinical significance of increased cTnI levels after P-CABG, but also the higher degree of cardioprotection allegedly supplied by OP-CABG.

The extent of cTnI release does not necessarily correlate with occurrence or magnitude of irrevocable myocardial injury. Although the inaccuracy of cTnI levels in the "quantification" of postsurgical myocardial infarction seems to be mainly related to the "washout phenomenon," the lack of correlation between cTnI release and occurrence of irreversible myocardial injury may be ascribed to iatrogenic stressors, intrinsic to the P-CABG surgical approach, and not typically associated with enduring myocardial injury. Release of cTnI after P-CABG was detected in bypass patients in the absence of ischemic conditions,² as well as associated with myocardial stunning³ (a common occurrence after P-CABG), and elevated preload, independently of cardiac ischemia.⁴ This release, potentially occurring in cardiopulmonary bypass together with that inevitably associated with surgical manipulations, may possibly explain higher, though benign, cTnI levels, detected in P-CABG versus OP-CABG. Reperfusion, whether pharmacologically or mechanically achieved, results in earlier and augmented cTnI release versus no reperfusion. This was substantiated by a recent study showing that P-CABG had graft patency rates significantly greater . . . [Full Text of this Article]

Joseph B. Selvanayagam, MBBS, FRACP; Steffen E. Petersen, MD; Jane M. Francis, DCRR, DNM; Matthew D. Robson, PhD; Attila Kardos, MD, PhD; Stefan Neubauer, MD, FRCP; David P. Taggart, MD, PhD

Oxford University, John Radcliffe Hospital, Oxford, UK, stefan.neubauer@cardiov.ox.ac.uk