Morphology-Voltage-P-wave duration (MVP) score in prediction of incident atrial fibrillation in an elderly epidemiologic cohort

Abstract

Background Interatrial block (IAB) on electrocardiography (ECG) and reduced P wave voltage reflect atrial abnormalities which may contribute to development of atrial fibrillation (AF). Purpose We aimed to assess the value of a recently proposed ECG risk score that combines the morphology, voltage and length of the P wave (MVP score) for prediction of incident AF in a prospective population-based setting. Material and methods The study population is based on the large, prospective Malmö Preventative Project (MPP) cohort. We included subjects without a history of AF, with a readable ECG in sinus rhythm and an echocardiography performed in 2002–2006 (n=983, mean age 70±5 years, 38% females). Median follow-up was 4.2 (IQR 3.7–4.8) years. ECGs were digitally processed using the Glasgow algorithm. Advanced IAB (aIAB) was defined as a P-wave ≥120 ms and biphasic morphology (+/−) in inferior leads, partial IAB (pIAB) as P-wave ≥120 ms and a monophasic positive morphoology in inferior leads. MVP score was calculated based on the P-wave morphology in inferior leads, voltage in lead 1, and P-wave duration (Table 1).Incident AF events (n=66, 7%) were obtained from the Swedish Hospital Discharge Register and Cause of Death Register. Cox regression analysis and Kaplan Meier curve analysis were used to study the association of echocardiographic and P-wave characteristics with the risk of new onset AF. Results At baseline the mean MVP score was 1±1, none of the subjects had MVP score above 4. MVP score correlated with left atrial (LA) area: Pearson r=0.192, p<0.001. After adjustment for age, gender and LA enlargement expressed as LA area >20 cm2, new onset AF was associated with MVP score 4 (HR 6.17, 95% CI 1.76–21.64 compared to those with MVP score <4, Figure 1). Neither aIAB (univariate HR 1.93 CI 95% 0.82–4.56), nor pIAB (univariate HR 1.16 CI 95% 0.52–2.55) predicted incident AF. Conclusion In a population-based elderly epidemiological cohort, the ECG-based MVP score was significantly associated with incident AF, independently of LA enlargement. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): The Swedish Heart-Lung Foundation