Abstract 2125: P Wave Morphology Is a Predictor of Poor Cardiac Outcome and Death in MADIT II Patients
The objective of the present study was to non-invasively analyse atrial electrophysiology to identify markers associated with increased risk of mortality and deterioration of heart failure in a high-risk population with advanced CHF and a history of acute myocardial infarction. Patients included in MADIT II with sinus rhythm at baseline were studied (n=802). Unfiltered and bandpass filtered signal-averaged P waves were analyzed to determine orthogonal P wave morphology, P wave duration and RMS20. The association between P wave parameters and data on the clinical course and cardiac events during a mean follow-up of 20 months was analyzed. P wave duration was 139±23 ms and the RMS20 was 1.9±1.1 μV. None of these parameters were significantly associated with poor cardiac outcome. Differences in P wave morphology were independently predictive of non-sudden cardiac death (HR 2.66; 95% CI 1.41–5.04, P=0.0027). In addition, in univariate analyses differences in P wave morphology were found to be associated with an increased risk of all-cause mortality (HR 1.35; 95%CI 1.01–1.81, P=0.042) and cardiac death (HR 1.54; 95%CI 1.10 –2.16, P=0.011) (figure⇓) In the present study the value of analyzing the P wave morphology in patients with previous myocardial infarction and CHF is demonstrated. Changes in P wave morphology were shown to be independently predictive of increased risk of non-sudden cardiac death. Furthermore, statistically significant associations between P wave morphology changes and all-cause mortality, cardiac death and CHF hospitalization was demonstrated.