Role of Ischemic Preconditioning and Inflammatory Response in the Development of Malignant Ventricular Arrhythmias After Reperfused ST-Elevation Myocardial Infarction
Received 16 January 2009; received in revised form 8 April 2009; accepted 4 May 2009. published online 29 June 2009.
Abstract
Background
Sustained ventricular tachycardia and ventricular fibrillation (VT/VF) are major complications of ST-elevation myocardial infarction (STEMI), even in the era of reperfusion therapy. We sought to clarify the determinants of VT/VF after reperfused STEMI.
Methods and Results
Consecutive STEMI patients treated with primary percutaneous coronary intervention (n=457) were divided into 2 groups by the presence or absence of VT/VF during hospitalization. Serum C-reactive protein (CRP) level and peripheral white blood cell (WBC) count were serially measured. VT/VF was observed in 54 patients (12%). Prior infarction was more common and preinfarction angina was less in patients with VT/VF than those without. Peak CRP level (P < .0001), WBC count on admission (P=.008), and maximum WBC count (P=.0014) were higher in patients with VT/VF than those without. VT/VF, especially VT/VF later than 48hours after onset, was associated with greater left ventricular (LV) dimension during convalescence. Kaplan-Meier curves and log-rank test revealed VT/VF to be a significant determinant of long-term major adverse cardiac events. Multivariate analysis revealed that prior infarction, absence of preinfarction angina, and peak CRP ≥10mg/dL were independent determinants of VT/VF.
Conclusions
Lack of ischemic preconditioning, enhanced inflammatory response, and subsequent LV dysfunction are related to the development of VT/VF after STEMI.
1Division of Cardiology, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
Correspondence to: Toshihisa Anzai, MD, Division of Cardiology, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. Tel: +81-3-5363-3793; Fax: +81-3-3353-2502.
Supported by the Global Center of Excellence (G-COE) Program at Keio University (H.K.) and the Medical School Faculty and Alumni Grant from Keio University Medical Science Fund (T.A.).
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