Risk stratification for complex ventricular arrhythmia complicating ST-segment elevation myocardial infarction.

OBJECTIVES: The primary aim of the study was to evaluate risk factors for ventricular fibrillation/sustained ventricular tachycardia (VF/VT) and to develop the risk score for prediction of VF/VT in patients with ST-segment elevation myocardial infarction (STEMI) treated invasively. The secondary aim was to assess the effect of VF/VT on mortality depending on timing of arrhythmia. PATIENTS AND METHODS: We analyzed 4363 consecutive patients with STEMI treated invasively. Among them, 163 patients with pre-reperfusion arrhythmia were excluded from the study. Group ventricular arrhythmias (VA) encompassed patients with VF/VT - those with reperfusion-induced arrhythmia were included into group VA1, whereas group VA2 consisted of patients with postreperfusion arrhythmia. The control group comprised patients free of VF/VT. RESULTS: VF or VT occurred in 313 (7.45%) patients - group VA1 encompassed 103 (32.9%) and group AV2 210 (67.1%) patients. Cardiogenic shock on admission [hazard ratio (HR) 3.5], new-onset atrial fibrillation (HR 2.1), incomplete revascularization (HR 1.7), prior myocardial infarction (HR 1.6) and symptom-to-balloon time more than 3 h (HR 1.3) were the independent predictors of VF/VT occurrence. In group VA2, the in-hospital and long-term mortality were 4- and 1.5-fold higher than in the arrhythmia-free population (20.5 vs. 4.5% and 36.2 vs. 22.6%, respectively; P<0.001). On the contrary, in group VA1, the long-term mortality was not significantly higher compared with the control group (26.2 vs. 22.6%; P=NS), whereas in-hospital mortality was almost three-fold increased (12.5 vs. 4.5%, respectively; P<0.001). CONCLUSION: The risk score based on simple clinical parameters might be useful for risk stratification for VF/VT in patients with STEMI. The predictive value of VF/VT was strongly dependent on timing of arrhythmia.

The risk of stroke in patients with acute myocardial infarction treated invasively.

BACKGROUND: To assess the incidence, clinical significance, and independent risk factors of stroke in patients with acute myocardial infarction (AMI) treated invasively. MATERIALS AND METHODS: We analyzed 2520 consecutive patients with AMI admitted between 2003 and 2007. Data on long-term follow-up were screened to identify patients who had stroke. RESULTS: During a median of 25.5 months, 52 patients (2.07%) had stroke. The cumulative risk of stroke was the highest during the first year (1.23%) and particularly within the first month after AMI (0.28%). Patients with stroke were at a significantly higher risk of developing major adverse cardiovascular events, including repeated AMI (26.9 vs. 14.6%, P<0.05) and death (40.4 vs. 13.6%, P<0.001). Previous stroke [hazard ratio (HR) 5.89], female sex (HR 2.60), glomerular filtration rate <60 ml/min/1.73 m (HR 1.92), and contrast nephropathy (HR 1.87, all P<0.05) were independent predictors of stroke. The receiver-operating curve calculated for the Contrast nephropathy, renal Insufficiency, Female, prior Stroke (CIFS) risk scale demonstrated a significant predictive value of this scale (area under curve 0.73, P<0.001). Patients with the lowest, median, and highest risk scores (<4, 4-5, ≥6 points, respectively) differed significantly with regard to stroke incidence (2.1 vs. 7.9 vs. 14.0%, respectively, P<0.05). CONCLUSION: The risk of stroke is the highest within the first month after AMI. Stroke is a marker of unfavorable outcome in this population. Independent risk factors for stroke after invasive treatment of AMI are different from those commonly perceived as stroke predictors. A risk scale based on sex, stroke history, and renal impairment is useful in risk stratification.