Prognostic value of P-wave morphology in general population

AIMS

To evaluate the prognostic significance of novel P-wave morphology descriptors in general population.

METHODS AND RESULTS

Novel P-wave morphology variables were analyzed from orthogonal X-, Y-, Z-leads of the digitized electrocardiogram using a custom-made software in 6906 middle-aged subjects of the Mini-Finland Health Survey. A total of 3747 (54.3%) participants died during the follow-up period of 24.3 ± 10.4 years; 379 (5.5%) of the study population succumbed to sudden cardiac death (SCD), 928 (13.4%) to non-SCD (NSCD) and 2440 (35.3%) patients to non-cardiac death (NCD). In univariate comparisons, most of the studied P-wave morphology parameters had a significant association with all modes of death (P from <0.05 to <0.001). After relevant adjustments in the Cox multivariate hazards model, P-wave morphology dispersion (PMD) still tended to predict SCD [hazard ratio (HR): 1.006, 95% confidence interval (CI): 1.000-1.012, P = 0.05) but not NSCD (HR: 0.999, 95% CI: 0.995-1.003, P = 0.68) or NCD (HR: 0.999, 95% CI: 0.997-1.001, P = 0.44). The P-wave maximum amplitude in the lead Z (P-MaxAmp-Z) predicted SCD even after multivariate adjustments (HR: 1.010, 95% CI: 1.005-1.015, P = 0.0002) but also NSCD (HR: 1.005, 95% CI: 1.002-1.009, P = 0.0005) and NCD (HR: 1.002, 95% CI: 1.000-1.005, P = 0.03).

CONCLUSION

Abnormalities of P-wave morphology are associated with the risk of all modes of death in general population. After relevant adjustments, PMD was still closely associated with the risk of SCD but not with NSCD or NCD. P-MaxAmp-Z predicted SCD even after adjustments, however, it also retained its association with NSCD and NCD.

Prognostic significance of P-wave morphology in patients with coronary artery disease

INTRODUCTION

The prognostic significance of P-wave morphology in patients with coronary artery disease (CAD) is not well-known.

METHODS

A total of 1946 patients with angiographically verified CAD were included in the Innovation to reduce Cardiovascular Complications of Diabetes at the Intersection (ARTEMIS) study. The P-wave morphology could be analyzed in 1797 patients.

RESULTS

During 7.4 ± 2.0 years, a total of 168 (9.3%) patients died or experienced resuscitation from sudden cardiac arrest (SCA), 43 (2.4%) patients experienced sudden cardiac death (SCD) or were resuscitated from SCA, 37 (2.1%) patients succumbed to non-SCD (NSCD), and 88 (4.9%) patients to noncardiac death (NCD). Of the P-wave parameters, the absolute P-wave residuum (PWR), the heterogeneity of the P-wave morphology (PWH), and the P-wave duration (Pdur) had the closest univariate association with the risk of SCD/SCA (0.0038 ± 0.0026 vs 0.0022 ± 0.0017, P < .001; 11.0 ± 5.2 vs 8.6 ± 3.6, P < .01; 142.7 ± 16.9 vs 134.8 ± 14.3 milliseconds, P < .01; SCD/SCA vs no SCD/SCA, respectively). After adjustments with factors that were associated with the risk of SCD/SCA, such as diabetes, smoking, left bundle branch block, high-sensitivity C-reactive protein, and high-sensitivity troponin T, PWR (P < .001), PWH (P < .05), and Pdur (P < 0.01) still predicted SCD/SCA but not non-sudden cardiac death. When these parameters were added to the SCD/SCA clinical risk model, the discrimination and reclassification accuracy of the risk model increased significantly (P < .05, P < .001) and the C-index increased from 0.745 to 0.787.

CONCLUSION

The P-wave morphology parameters independently predict SCD/SCA in patients with CAD.