Postconditioning the Human Heart

Abstract

Background-In animal models, brief periods of ischemia performed just at the time of reperfusion can reduce infarct size, a phenomenon called postconditioning. In this prospective, randomized, controlled, multicenter study, we investigated whether postconditioning may protect the human heart during coronary angioplasty for acute myocardial infarction. Methods and Results-Thirty patients, submitted to coronary angioplasty for ongoing acute myocardial infarction, contributed to the study. Patients were randomly assigned to either a control or a postconditioning group. After reperfusion by direct stenting, control subjects underwent no further intervention, whereas postconditioning was performed within 1 minute of reflow by 4 episodes of 1-minute inflation and 1-minute deflation of the angioplasty balloon. Infarct size was assessed by measuring total creatine kinase release over 72 hours. Area at risk and collateral blood flow were estimated on left ventricular and coronary angiograms. No adverse events occurred in the postconditioning group. Determinants of infarct size, including ischemia time, size of the area at risk, and collateral flow, were comparable between the 2 groups. Area under the curve of creatine kinase release was significantly reduced in the postconditioning compared with the control group, averaging 208 984Ϯ26 576 compared with 326 095Ϯ48 779 (arbitrary units) in control subjects, ie, a 36% reduction in infarct size. Blush grade, a marker of myocardial reperfusion, was significantly increased in postconditioned compared with control subjects: 2.44Ϯ0.17 versus 1.95Ϯ0.27, respectively (PϽ0.05). Conclusions-This

Adverse Effects on β‐Adrenergic Receptor Coupling: Ischemic Postconditioning Failed to Preserve Long‐Term Cardiac Function

“…Therapeutically, application at the time of reperfusion is an appropriate intervention option, meaning that in routine clinical practice IPoC is the preferred protective strategy 6, 7…”

One-year outcome of the sevoflurane in acute myocardial infarction randomized trial

“…Further, patients with larger infarcts or those with an anterior MI are more likely to benefit from such an intervention. 5,6,27,32 Indeed, in our initial study, there was a trend toward a stronger effect of sevoflurane in patients with an anterior MI on assessing myocardial injury by release of cardiac enzymes. 20 In the current study, we did not observe an overall clinically meaningful effect of sevoflurane on the long-term assessment of LV function, myocardial scarring, or hibernating myocardium.…”

“…3 Several studies performed in the setting of STEMI have shown the effectiveness of this intervention. 4,5 However, other recent studies, including a study published by our group, did not show clinical benefit from ischemic conditioning, suggesting that the precise mode of applying ischemic conditioning should be explored further. 6,7 In particular, it seems that it is important to apply the ischemic conditioning intervention as early as possible.…”

“…The median [interquartile range] amount of scarring at six months was 0% [0 -8] in the sevoflurane group and 2.5% [0 -7.1] in control group (mean difference, -0.1%; 95% CI, -4.6 to 4.4; P = 0.700). The mean (SD) percentage of hibernating myocardium was similar in both groups 0% [0,5] (mean difference, -1.3%; 95% CI, -3.4 to 0.9; P = 0.259). The mean (SD) ejection fraction at one year increased compared with baseline by 8.0 (9.1)% (P \ 0.001).…”

Postconditioning against ischaemia-reperfusion injury: ready for wide application in patients?

“…In these studies, it was reported that interrupting reperfusion (with four cycles of 1-min low pressure inflations and deflations of the angioplasty balloon immediately after direct stenting of the infarct-related artery) improved myocardial reperfusion, reduced myocardial infarct size both acutely and at six months, and improved left ventricular ejection fraction up to 7% (percent points) at one year. [5][6][7] Table 1 gives an overview of the clinical trials to date using IPOC in AMI. Although the results of these trials using surrogate endpoints (including ejection fraction, enzyme release, etc.)…”