Abstract 14614: The Automatically Assessed P-wave Notch Predicts Cardiovascular Events in Patients With Cardiovascular Risks: The Japan Morning Surge Home Blood Pressure (J-HOP) Study

Abstract

Background: The notched P-wave characteristics is associated with atrial remodeling. However, the relationship between notched P-wave characteristics and long-term cardiovascular events remains unclear. Hypothesis: We hypothesized that the notched P-wave would be associated with cardiovascular events. Methods: We enrolled 810 subjects from the J-HOP Study who had ≥1 of four cardiovascular risk factors. Twelve-lead electrocardiography was conducted, and the peak-to-peak distance in the M-shape was calculated automatically using a 12-lead ECG Analysis system (Fukuda Denshi, Tokyo). We compared two definitions: P waves were defined as "notched" if the peak-to-peak distance in the M-shape was ≥20 msec or ≥40 msec in lead II. The primary endpoints were fatal/nonfatal cardiovascular events: myocardial infarction, stroke, hospitalization for heart failure, and aortic dissection. We assessed the left atrial diameter and left ventricular mass index (LVMI) by echocardiography. Results: The mean follow-up period was 101±34 months, and 85 cardiovascular events occurred. When we defined a notched P wave as ≥20msec in the M shape (n=92), a notched P wave was a significant predictor of cardiovascular events after adjustment for age, gender, and comorbidity (hazard ratio 1.80, 95%CI: 1.06-3.05). When we defined a notched P wave as ≥40msec in the M shape (n=25), the hazard ratio of cardiovascular events in the notched P-wave group was significantly borderline after adjustment for covariates (hazard ratio 2.23, 95%CI: 0.90-5.56). The left atrial diameter and LVMI in the patients in the notched P-wave group (≥20 msec in the M shape) were significantly higher than those in the control group (left atrial dia. 38.8±5.9 vs. 36.8±5.0 mm, p=0.001; LVMI 103.9±27.7 vs. 96.3±25.7 g/m 2 , p=0.010). Conclusion: The automatically assessed notched P wave was associated with cardiovascular events, left atrial enlargement and left ventricular hypertrophy.