A Practical and Effective Approach for the Prevention of Ischemia-Reperfusion Injury after Acute Myocardial Infarction: Pressure-Regulated Tepid Blood Reperfusion
DOI:
https://doi.org/10.1532/HSF98.20071052Abstract
Background. The prevention of perioperative ischemia-reperfusion injury is of critical importance, and this issue becomes more important in patients undergoing an early emergent revascularization procedure after an acute myocardial infarction. In this study, we sought to test the hypothesis that our simplified pressure-controlled initial reperfusion technique would be protective against ischemia-reperfusion injury in this subgroup of patients.
Methods. The data of 20 patients (group I) who underwent an emergent coronary artery bypass grafting procedure were analyzed and compared with the results of 37 patients (group II) underwent an innovative reperfusion technique. In group I patients, the operation was carried out using standard techniques. In group II, after the completion of all anastomoses, reperfusion was initiated before rewarming with a pressure of 20 to 25 mmHg and continued for a 2-minute period. Systemic blood pressure was then gradually increased to 40 mmHg and the aortic root was perfused at this pressure for another 2-minute period. Following the completion of the second low-pressure reperfusion period, cardiopulmonary bypass flow was regulated to preoperatively calculated values until systemic temperature reached 37°C.
Results. Both groups showed significant differences in terms of cardiac output, arrhythmia rates, and biochemical parameters. Spontaneous sinus rhythm recurred more frequently in group II (P < .01, 86% versus 45%). Atrial fibrillation attacks were observed in 5 and 3 patients in groups I and II, respectively. All patients were medically converted to sinus rhythm with amiadarone and/or ?-blockers. Persistent electrocardiographic changes indicating postoperative myocardial infarction occurred in 5 patients in group I and in 1 patient in group II (P = .003). Postoperative enzyme levels were found to be lower in group II patients and the differences became statistically significant at the end of 24 hours.
Conclusion. These results indicate that our controlled initial reperfusion technique is effective in the prevention of ischemia-reperfusion injury. We advocate the use of this innovative technique as an alternative to complex controlled aortic root reperfusion with the guidance of the early promising results of this study.
References
Allen BS, Buckberg GD, Fontan FM, et al. 1993. Superiority of controlled surgical reperfusion versus percutaneous transluminal coronary angioplasty in acute coronary occlusion. J Thorac Cardiovasc Surg105:864-84.nAllen BS, Rosenkranz ER, Buckberg GD, et al. 1989. Studies on prolonged regional ischemia. VI. Myocardial infarction with left ventricular power failure: a medical/surgical emergency requiring urgent revascularization with maximal protection of remote muscle. J Thorac Cardiovasc Surg98:691-703.nAmbrosio G, Weisman HF, Manisi JA, Becker LC. 1989. Progressive impairment of regional myocardial perfusion after initial restoration of postischemic blood flow. Circulation80:1846.nDavies JE, Digerness SB, Killingsworth CR, et al. 2005. Multiple treatment approach to limit cardiac ischemia-reperfusion injury. Ann Thorac Surg80:1408-16.nEdwards FH, Bellamy RF, Burge JR, et al. 1990. True emergency coronary artery bypass surgery. Ann Thorac Surg49:603-10.nFogelson BG, Nawas SI, Law WR. 2000. Mechanisms of myocardial protection in adenosine-supplemented cardioplegia: myofilament and metabolic responses. J Thorac Cardiovasc Surg119:601-9.nGarlick PB, Davies MJ, Hearse DJ, Slater TF. 1987. Direct detection of free radicals in the reperfused rat heart using electron spin resonance spectroscopy. Circ Res61:757-60.nHolman WL, Skinner JL, Killingsworth CR, et al. 2000. Controlled post-cardioplegia reperfusion: mechanism for attenuation of reperfusion injury. J Thorac Cardiovasc Surg119:1093-101.nJulia PI, Partington MT, Buckberg GD. 1991. Studies of controlled reperfusion after ischemia. XXI. Reperfusate composition: superiority of blood cardioplegia over crystalloid cardioplegia in limiting reperfusion damage—importance of endogenous oxygen free radical scavengers in red blood cells. J Thorac Cardiothorac Surg101:303-13.nLi G, Sullivan JA, You JM, Hall RI. 1998. Effect of pressure on myocardial function after 6-hour preservation with blood cardioplegia. Ann Thorac Surg65:115-24.nMehta JL, Lichols WW, Donnelly WH, Lawson DL, Saldeen TGP. 1989. Impaired canine coronary vasodilator response to acetylcholine and bradykinin after occlusion-reperfusion. Circ Res64; 43.nNishida M, Kuzuya T, Hoshida S, et al. 1990. Polymorphonuclear leucocytes induced vasoconstriction in isolated canine coronary arteries. Circ Res66:253.nOkamoto F, Allen BS, Buckberg GD, Bugyi H, Leaf J. 1989. Studies of controlled reperfusion after ischemia. XIV. Reperfusion conditions: importance of ensuring gentle versus sudden reperfusion during relief of coronary occlusion. J Thorac Cardiovasc Surg92:613.nQuillen JE, Sellke FW, Brooks LA, Harrison DG. 1990. Ischemia-reperfusion impairs endothelium dependent relaxation of coronary microvessels but does not affect large arteries. Circulation82:586.nRosenfeld FL, Rabinov M, Newman M. 1987. Coronary blood flow and myocardial metabolism during reperfusion after hypothermic cardioplegia in the dog. Eur J Cardiothorac Surg1:91.nSawatari K, Kadoba K, Bergner KA, Mayer JE Jr. 1991. Influence of initial reperfusion pressure after hypothermic cardioplegic ischemia on endothelial modulation of coronary tone in neonatal lambs: impaired coronary vasodilator response to acetylcoline. J Thorac Cardiovasc Surg101:777.nSchlensak C, Doenst T, Kobba J, Beyersdorf F. 1999. Protection of acutely ischemic myocardium by controlled reperfusion. Ann Thorac Surg68:1967-70.nUs MH, Ogus NT, Yildirim T, et al. 2004. Reperfusion strategy after regional ischaemia: simulation of emergency revascularization and effects of integrated cardioplegia on myocardial resuscitation. J Int Med Res32:304-11.nVane Jr, Anggard EE, Botting RM. 1990. Regulatory functions of the vascular endothelium. N Engl J Med323:27.nYan Y, Davani S, Chocron S, Kantelip B, Muret P, Kantelip JP. 2001. Effects of L-arginine administration before cardioplegic arrest on ischemia-reperfusion injury. Ann Thorac Surg72:1985-90.n
