OBJECTIVES: The purpose of this research was to examine the prognostic value of ST-segment changes(concordant ST-segment elevation and/or precordial V1 to V3 ST-segment depression) during presumed-new left bundle bran...OBJECTIVES: The purpose of this research was to examine the prognostic value of ST-segment changes(concordant ST-segment elevation and/or precordial V1 to V3 ST-segment depression) during presumed-new left bundle branch block(LBBB) in patients receiving fibrinolytic therapy. BACKGROUND: These patients are often considered high-risk, but their outcome is not well-defined. METHODS: The Hirulog and Early Reperfusion or Occlusion(HERO)-2 trial compared bivalirudin with heparin in patients receiving streptokinase for ST-segment elevation or presumed-new LBBB. Each patient with LBBB was matched with a control(with normal intraventricular conduction) for age, gender, pulse rate, systolic blood pressure, Killip class, and region. RESULTS: A total of 300 patients had LBBB(92 with and 208 without ST-segment changes) and 15,340 had normal conduction. Acute myocardial infarction(AMI) occurred in 80.7%of LBBB patients and 88.7%of controls(p=0.006). ST-segment changes were specific(96.6%) but not sensitive(37.8%) for enzymatic diagnosis of AMI. Mortality at 30 days was similar in LBBB patients with ST-segment changes(21.7%) and controls(25.0%, p=0.563), but lower in LBBB patients without ST-segment changes than in controls(13.5%vs. 21.6%, p=0.022). In the whole HERO-2 cohort, the LBBB patients with ST-segment changes had higher mortality than patients with normal conduction(odds ratio OR 1.37, 95%confidence interval CI 0.78 to 2.42). The LBBB patients without ST-segment changes had lower mortality than patients with normal conduction(OR 0.52, 95%CI 0.33 to 0.80). CONCLUSIONS: ST-segment changes during LBBB are specific for the diagnosis of AMI and predict 30-day mortality; LBBB patients without ST-segment changes have lower adjusted 30-day mortality than those with normal conduction. Trials are required to determine the best treatment for high-risk and low-risk patients with LBBB.展开更多
文摘OBJECTIVES: The purpose of this research was to examine the prognostic value of ST-segment changes(concordant ST-segment elevation and/or precordial V1 to V3 ST-segment depression) during presumed-new left bundle branch block(LBBB) in patients receiving fibrinolytic therapy. BACKGROUND: These patients are often considered high-risk, but their outcome is not well-defined. METHODS: The Hirulog and Early Reperfusion or Occlusion(HERO)-2 trial compared bivalirudin with heparin in patients receiving streptokinase for ST-segment elevation or presumed-new LBBB. Each patient with LBBB was matched with a control(with normal intraventricular conduction) for age, gender, pulse rate, systolic blood pressure, Killip class, and region. RESULTS: A total of 300 patients had LBBB(92 with and 208 without ST-segment changes) and 15,340 had normal conduction. Acute myocardial infarction(AMI) occurred in 80.7%of LBBB patients and 88.7%of controls(p=0.006). ST-segment changes were specific(96.6%) but not sensitive(37.8%) for enzymatic diagnosis of AMI. Mortality at 30 days was similar in LBBB patients with ST-segment changes(21.7%) and controls(25.0%, p=0.563), but lower in LBBB patients without ST-segment changes than in controls(13.5%vs. 21.6%, p=0.022). In the whole HERO-2 cohort, the LBBB patients with ST-segment changes had higher mortality than patients with normal conduction(odds ratio OR 1.37, 95%confidence interval CI 0.78 to 2.42). The LBBB patients without ST-segment changes had lower mortality than patients with normal conduction(OR 0.52, 95%CI 0.33 to 0.80). CONCLUSIONS: ST-segment changes during LBBB are specific for the diagnosis of AMI and predict 30-day mortality; LBBB patients without ST-segment changes have lower adjusted 30-day mortality than those with normal conduction. Trials are required to determine the best treatment for high-risk and low-risk patients with LBBB.
