Predictors of Mortality After Aortic Valve Replacement for Severe Aortic Stenosis: The Auckland Experience

Abstract

Background: Atrial fibrillation (Afib) may first be diagnosed only after presentation with heart failure or stroke. Identification of Afib by non-medical staff when measuring blood pressure (BP) may improve its’ detection in asymptomatic patients in primary care. The Pulsecor CardioScope is a user friendly automated sphygmomanometer previously validated for estimating central BP. Analysis of beat-to-beat variation in the pulsewave amplitude or RR interval could also be used to diagnose Afib. Methods: Patients presented for pre-clinic BP measurement and electrocardiogram (ECG) were recruited. ECG technicians performed BP measurement using Pulsecor and an ECG simultaneously. Pulse wave parameters calculated by Pulsecor were tested for performance in correctly classifying rhythm as Afib and Sinus via pulse rate variability (PRV) using √ mean[(period2−period1)2], pulse amplitude variation (PAV) using [max(pulse amplitude)−min(pulse amplitude)]/mean(pulse amplitude) and signal to noise ratio (SNR). Pulsecor analysis was performed blind to ECG results. Diagnoses of arrhythmias were confirmedbyCardiologyRegistrars interpreting corresponding ECGs. Results:Forty-fivepatients (meanage 70± 12 years; 71% men) with Afib on ECG, and 55 patients (mean age 60± 17 years; 44% men) with normal sinus rhythm. One hundred percent sensitivity to Afib was associated with a 13% false positive rate; 96% sensitivity with 7% false positive rate when using PRV for rhythm classification. PRV demonstrated the highest accuracy [Area under the curve (AUC)= 0.953] to detect Afib when comparing with PAV (AUC=0.844) and SNR (AUC=0.857). Conclusions: Pulsecor device can diagnose Afib with high sensitivity, and can be used to screen for Afib with BP measurement in primary care.