Document Detail


Chronic stable ischaemia protects against myocyte damage during beating heart coronary surgery.
MedLine Citation:
PMID:  15082281     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVES: Many patients with coronary artery disease demonstrate chronic resting ischaemic myocardial dysfunction. We have investigated whether this ischaemia influences the myocardial damage caused by the period of coronary occlusion involved in beating heart surgery. METHODS: Thirty-three patients with chronic stable angina and normal left ventricular ejection fraction were studied. To make our model clinically appropriate, we included patients with a wide range of ischaemic times, ages and in a subset of 10 patients a surgical preconditioning protocol. Myocyte injury was assessed from venous Troponin T release measured on days 1, 2, and 3. We used intraoperative transoesophageal M mode echocardiograms and simultaneous high-fidelity left ventricular pressure to assess whether patients were demonstrating the functional effects of ischaemia (asynchronous regional contraction with reduced mechanical function). RESULTS: Patients demonstrated the functional effects of resting ischaemia and 17 did not. Patients with resting ischaemia had lower preoperative values of regional peak power and work and all three variables increased significantly with surgery. Venous Troponin T levels at 48 and 72 h postoperatively were lower in those with preoperative resting ischaemia (median (interquartile range) 0.13 (0.08-0.20) vs 0.21 (0.13-0.69) for 48 h and 0.10 (0.08-0.19) vs 0.26 (0.12-0.51) for 72 h). Stepwise multiple linear regression of total postoperative troponin release (measured as the area under the curve of troponin release) demonstrated two independent determinants (R squared for model 0.40): longer ischaemic time, and increasing values of cycle efficiency. The surgical ischaemic preconditioning protocol and preoperative collaterals were not independent determinants. CONCLUSIONS: In patients with chronic coronary artery disease, stable preoperative ischaemia may thus represent a naturally occurring form of myocardial protection, whose presence reduces Troponin T release after beating heart surgery. This protection is different in nature from classical ischaemic preconditioning.
Authors:
Gerald Carr-White; Tat Koh; Anthony DeSouza; Elizabeth Haxby; Michael Kemp; James Hooper; Derek Gibson; John Pepper
Publication Detail:
Type:  Clinical Trial; Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery     Volume:  25     ISSN:  1010-7940     ISO Abbreviation:  Eur J Cardiothorac Surg     Publication Date:  2004 May 
Date Detail:
Created Date:  2004-04-14     Completed Date:  2004-06-10     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8804069     Medline TA:  Eur J Cardiothorac Surg     Country:  England    
Other Details:
Languages:  eng     Pagination:  772-8     Citation Subset:  IM    
Affiliation:
Department of Academic Cardiac Surgery, Royal Brompton and Harefield Hospitals NHS Trust, Sydney Street, London, UK. g.carr-white@virgin.net
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MeSH Terms
Descriptor/Qualifier:
Aged
Cardiopulmonary Bypass
Collateral Circulation
Coronary Artery Bypass / methods*
Coronary Disease / surgery*
Echocardiography, Transesophageal / methods
Female
Humans
Ischemic Preconditioning, Myocardial*
Male
Middle Aged
Muscle Cells / pathology*
Preoperative Care / methods
Troponin T / blood
Ventricular Function, Left
Chemical
Reg. No./Substance:
0/Troponin T

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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