OBJECTIVETo explore the risk and protective factors for the occurrence of myocardial ischemia-reperfusion injury (MIRI) during primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI).

METHODSClinical and angiographic data of 228 AMI patients in whom the infarct-related arteries (IRA) were successfully revascularized by primary PCI were analyzed retrospectively. MIRI was defined if the following conditions existed after PCI: severe bradycardia with hypotension, or lethal ventricular arrhythmias requiring electrical cardioversion, or IRA antegrade flow < or = TIMI 2 grade flow without angiographic evidence of thrombus, emboli, dissection or spasm. Multivariate logistic regression was used to identify independent relative factors among 18 clinical and angiographic factors for occurrence of MIRI.

RESULTSMultivariate logistic regression analysis showed that independent risk factors for MIRI were the time intervals from AMI onset to IRA reflow < or = 6 h (P = 0.014), inferior infarction localization (P = 0.006), IRA antegrade flow prior to PCI < or = TIMI 1 grade (P = 0.028), multivessel lesions (P = 0.063) and renal insufficiency (P = 0.067). Pre-infarction angina was found to be an independent protective factor (P = 0.005).

CONCLUSIONSShort time intervals from AMI onset to IRA revascularization, inferior wall infarction location, low IRA antegrade flow prior to PCI, multivessel lesions and renal insufficiency may promote the occurrence of MIRI during primary PCI, whereas pre-infarction angina may be a cardioprotective factor attenuating MIRI.

Adult ; Aged ; Aged, 80 and over ; Angioplasty, Balloon, Coronary ; adverse effects ; Female ; Humans ; Logistic Models ; Male ; Middle Aged ; Myocardial Infarction ; therapy ; Myocardial Reperfusion Injury ; etiology ; Retrospective Studies

OBJECTIVETo investigate the clinical implications of reperfusion arrhythmias during primary percutaneous coronary intervention (PCI) for patients with acute myocardial infarction (AMI).

METHODSData from 228 AMI patients in whom the infarct-related artery (IRA) were successfully recanalized by primary PCI were retrospectively analyzed. The 228 patients were divided into 2 groups: myocardial ischemia-reperfusion injury (MIRI) group (n=119) in whom MIRI events occurred within minutes after successful recanalization of IRA, and non-MIRI group (n=109). The 119 patients in MIRI group were further divided into 3 subgroups: severe bradycardia with hypotension (brady-arrhythmia subgroup), lethal ventricular arrhythmias requiring electrical cardioversion (tachy-arrhythmia subgroup), and IRA antegrade flow less than or equal to TIMI 2 grade without angiographic evidence of abrupt closure (no-reflow subgroup).

RESULTS(1) Clinical and angiographic data: Compared with non-MIRI group, MIRI group was characterized by more inferior infarct location, shorter ischemic duration, more frequently right coronary artery as IRA, more diseased vessels, more often TIMI 0 grade of initial antegrade flow in IRA, less pre-infarction angina, more renal insufficiency, and higher in-hospital mortality (13.4% vs. 4.6%, P=0.021). (2) The peak CK level was remarkably lower in brady-arrhythmia subgroup than that in non-MIRI group (2010 IU/L vs. 2521 IU/L, P=0.039). The peak CK or CK-MB level was notably higher in no-reflow subgroup than in non-MIRI group (4573 IU/L, 338 IU/L, respectively, P=0.000). (3) Left ventricular ejection fraction in no-reflow subgroup was significantly lower than in non-MIRI group (38.7% +/- 8.3% vs. 51.2% +/- 8.1%, P=0.000), left ventricular end-diastolic volume in no-reflow subgroup was greater than that in tachy-arrhythmia subgroup [(135 +/- 32) ml vs. (105 +/- 19) ml, P=0.029].

CONCLUSIONReperfusion arrhythmias may imply the existence of much survived myocardium and do not enhance myocardial damage, while no-reflow increases myocardial injury and induces permanent impairment of cardiac function.

Arrhythmias, Cardiac ; complications ; Cell Survival ; Humans ; Myocardial Infarction ; therapy ; Myocardial Reperfusion ; Myocardial Reperfusion Injury ; etiology ; Myocardium ; enzymology ; Retrospective Studies