Relation of Electrocardiographic Abnormal P-Wave Axis With Stroke Mortality in the General Population

Abstract

The link between abnormal P-wave axis (aPWA) and incident ischemic stroke is well established. However, studies examining the association between aPWA and fatal stroke are rare. We hypothesized that aPWA is associated with fatal stroke. We examined the association of abnormal aPWA with stroke mortality in 7,359 participants (60.0 ± 13.4years, 51.9% women, 49.8% White) without cardiovascular (CV) disease (CVD) from the Third National Health and Nutrition Examination Survey. aPWA was defined as any value <0 or >75^°. The National Death Index was used to identify the date and cause of death. Cox proportional hazard analysis was used to examine the association between baseline aPWA with stroke mortality. Over a median follow-up of 14years, 189 stroke deaths occurred. During follow-up, stroke mortality was more common in those with aPWA than those without aPWA (3.5% vs 2.2%, respectively;p=0.002). In a multivariable-adjusted model, aPWA was associated with a 44% increased risk of stroke mortality (hazard ratio [HR] 95% confidence interval [CI] 1.44 [1.05 to 1.99]). This association was stronger in men than in women (HR 95% CI 2.29 [1.42 to 3.67] vs 1.00 [0.64 to 1.55]), respectively; p-interaction=0.04) and among non-Whites than Whites (HR 95% CI 2.20 [1.39 to 3.46] vs. 1.07 [0.68 to 1.69], respectively; p-interaction=0.09). The annualized stroke death rates/1,000 participants across levels of CHA2DS2-VASc scores were higher in those with than without aPWA. In conclusion, aPWA, a marker of atrial cardiopathy, is associated with an increased risk of stroke mortality, especially among men and non-Whites. Whether intensive risk factor modifications in those with aPWA would reduce the risk of stroke and thus, stroke mortality needs further investigation.