Ambulatory blood pressure monitoring, 2D-echo and clinical variables relating to cardiac events in ischaemic cardiomyopathy following cardioverter-defibrillator implantation

Abstract

Evaluation of ambulatory blood pressure monitoring (ABPM), two-dimensional (2D) echo and clinical variables in predicting cardiac death and acute decompensated heart failure in patients with ischaemic cardiomyopathy and receiving a cardioverter-defibrillator implantation. We studied 180 consecutive patients (169 men) on an out-patient basis, with systolic dysfunction (ejection fraction ≤35%) and previous myocardial infarction. All received a cardioverter defibrillator (ICD) (116 dual chamber, 36 monocameral and 28 biventricular), for primary prevention of sudden death and standard medical therapy for heart failure. Mean follow-up was 11.7 months. Two-dimensional echo was performed just before ICD implantation, ABPM and haematological samples 2 weeks later. Age, ejection fraction, creatinine, haemoglobin concentration, mean 24-h systolic blood pressure, mean 24-h diastolic blood pressure, mean 24-h heart rate, brain natriuretic peptide, QRS duration, % paced beats, ventricular scar, biventricular pacing, sex and diabetes were considered. Cox proportional hazards regression analysis was used to explore the relationship between events. ROC curves were built for each independent variable. Events occurred in 47 patients (26%); 7 deaths for refractory heart failure and 40 hospitalizations for acute decompensated heart failure. Low mean 24-h systolic blood pressure [hazard ratio 0.96, 95% confidence interval (CI) 0.93-0.99, P = 0.02], high creatinine (hazard ratio 1.61, 95% CI 1.06-2.47, P = 0.01), low haemoglobin concentration (hazard ratio 0.81, 95% CI 0.65-0.99, P = 0.04) and older age (hazard ratio 1.04, 95% CI 1.01-1.08, P = 0.02) were independent predictors of events. Ambulatory systolic blood pressure, haemoglobin, creatinine and age can stratify risk of death and acute decompensated heart failure in patients with ischaemic cardiomyopathy and ICD in whom 2D-echo ejection fraction is not predictive.