抄録
Objective: Left ventricular mechanical dyssynchrony (LVMD) is associated with deterioration of systolic function and adverse clinical outcomes. This study investigated whether LVMD influenced subsequent cardiac events (CEs), including cardiac death, recurrent nonfatal myocardial infarction, hospitalization for heart failure, and ventricular tachycardia/ventricular fibrillation in patients with acute myocardial infarction (AMI).
Methods: Two hundred and six AMI patients aged 64 ± 11 years (163 men) who underwent successful percutaneous coronary intervention between April 1998 and December 2007 were enrolled. All patients received myocardial 99mTc-sestamibi or 99mTc-tetrofosmin perfusion imaging at rest, and the total defect score was calculated as the sum of the defect scores in 17 standard myocardial segments. Indicators of left ventricular (LV) function were acquired with quantitative gated SPECT software, including the LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), and LV ejection fraction (LVEF). Then the LVMD index was evaluated by using CardioGraf software.
Results: The follow-up period was 63 ± 31 months. Cardiac events (CEs) occurred in 30 patients, including 15 patients hospitalized for congestive heart failure, 8 patients with recurrent AMI, 4 patients with ventricular tachycardia, and 3 patients with cardiac death. These patients were classified as the CE group, while the other 176 patients without CEs formed the non-CE group. According to univariate analysis with the Cox proportional hazards model, the maximum creatine kinase, frequency of multivessel disease (2-vessel or 3-vessel disease), total defect score, LVEDV, LVESV, and dyssynchrony index were all significantly higher in the CE group than the non-CE group. In contrast, LVEF and the peak ejection rate were significantly lower in the CE group than in the non-CE group. Multivariate analysis showed that multivessel disease (p=0.003) and the LVMD index (p=0.047) were independent prognostic factors for CEs.
Conclusion: LVMD contributes to the risk of subsequent cardiac events in AMI patients.
