Does risk stratification using clinical history variables predict sudden arrhythmic death and cardiac death in patients with ventricular tachycardia or ventricular fibrillation after myocardial infarction?
Four simple clinical history variables can accurately stratify the risk of sudden and non-sudden cardiac death in patients with ventricular tachyarrhythmias after myocardial infarction.
Multivariate analysis using 70 variables in 200 patients who suffered from ventricular tachycardia or ventricular fibrillation after myocardial infarction detected eleven variables that were associated with an increased risk of sudden arrhythmic death and cardiac death during a mean follow-up period of 2 years. Four of the II variables came from the patient's clinical history: (1) cardiac arrest at the time of the first spontaneous episode of arrhythmia, (2) New York Heart Association functional class for dyspnoea = III, (3) ventricular tachycardia or ventricular fibrillation occurring early (after 3 days and within 2 months) after myocardial infarction, (4) multiple myocardial infarctions before the first episode of ventricular tachyarrhythmia. Total mortality, incidence of sudden arrhythmic death and of non-sudden cardiac death increased with an increasing number (zero, one, two, three, four) of variables seen in individual patients. Patients with zero or one variable had an incidence of sudden death of 2·8% and a 4·2% incidence of non-sudden cardiac death at 26 months, while patients with more than two variables had a 13·5% and a 20·3% incidence respectively of sudden and non-sudden cardiac death. The strongest predictor of sudden death was the occurrence of cardiac arrest during the first spontaneous episode of ventricular arrhythmia. The strongest predictor of non-sudden cardiac death was the New York Heart Association functional class. The use of the four variables to stratify risk revealed seven subgroups of patients with incidences of sudden death ranging from 0 to 28%. Two questions from the clinical history revealed a subgroup of patients with a 0% incidence of sudden death at 26 months which constituted 40% of the total population (patients without cardiac arrest at the time of their first ventricular tachycardia which occurred >2 months after myocardial infarction). The same questions from the clinical history allowed the classification of patients into four different subgroups which showed incidences of cardiac death ranging from 4 to 42%. The clinical history allows accurate classification and risk stratification of patients with ventricular tachycardia or ventricular fibrillation after myocardial infarction. These data from the clinical history are necessary for interpretation of the results of antiarrhythmic treatment in these patients. They are also valuable in the interpretation of apparent beneficial or deleterious effects of new forms of antiarrhythmic treatment, because of the different prognosis of the different subgroups of patients presenting with ventricular tachyarrhythmias after myocardial infarction.
Brugada et al. (1989) studied this question.