Electrocardiographic myocardial injury and stroke mortality in the general population.

Background: Recent evidence suggests a link between myocardial infarction and stroke risk, but it is unclear whether such risk exists with electrocardiographic myocardial injury in otherwise healthy individuals. Therefore, we explored the association of myocardial injury with stroke mortality in participants free of cardiovascular disease.

Methods: This analysis included 6017 participants (58.4 ± 13.4 years, 54.1% women, 50.3% white) from the Third National Health and Nutrition Examination Survey. Cardiac infarction/injury score (CIIS), a weighted scoring system composed of several electrocardiographic waveform components related to myocardial injury and ischemia, was used to define myocardial injury. Stroke mortality was ascertained using the National Death Index during follow-up. Multivariable adjusted Cox proportional hazard analysis was used to examine the association between baseline myocardial injury and risk of stroke mortality.

Results: Over a median follow-up of 14 years, 152 stroke deaths occurred. Stroke mortality was more common in those with than those without myocardial injury (3.8% vs. 2.1%, respectively; p = 0.0003). In a model adjusted for potential confounders, the myocardial injury was associated with a 44% increased risk of stroke mortality (HR (95%CI):1.44(1.02-2.03)). In a similar model, each 1 CIIS score point increase was associated with a 2% increase in the risk of stroke mortality (HR (95%CI):1.02 (1.00-1.04), p = 0.01).

Conclusions: Electrocardiographic myocardial injury in cardiovascular disease-free adults is associated with an increased risk of stroke mortality suggesting a potential link between asymptomatic myocardial injury and risk of cardiac thromboembolism. Whether screening and management of myocardial injury would reduce such risk requires further investigation.