Minor Electrocardiographic ST-T Change and Risk of Stroke in the General Japanese Population

BACKGROUND: Minor ST-T changes are frequently observed on the electrocardiogram (ECG), but the risk of stroke associated with such changes is unclear. METHODS AND RESULTS: In 10,642 subjects from the Japanese general population, we evaluated minor and major ST-T changes (major ST depression ≥0.1 mV) on ECGs obtained at annual health examinations. At baseline, minor ST-T changes were found in 10.7% of the subjects and 0.5% had major ST-T changes. Minor ST-T changes were associated with older age, female gender, higher systolic blood pressure, presence of hyperlipidemia, and use of antihypertensive medication. There were 375 stroke events during the follow-up period (128.7±28.1 months). In all subjects, minor ST-T changes (HR, 2.10; 95% CI: 1.57-2.81) and major ST-T changes (HR, 8.64; 95% CI: 4.44-16.82) were associated with an increased risk of stroke, but the stroke risk associated with minor ST-T changes had borderline significance after adjustment for conventional risk factors (P=0.055). In subgroup analysis, the risk of stroke was significantly associated with minor ST-T changes in subjects who had hyperlipidemia (HR, 1.75; 95% CI: 1.15-2.67) compared to those without hyperlipidemia (HR, 1.01; 95% CI: 0.64-1.59; P for interaction=0.016), even after adjustment for ECG-diagnosed left ventricular hypertrophy. CONCLUSIONS: Minor ST-T changes were particularly associated with a higher risk of stroke in subjects with hyperlipidemia and this association was independent of electrocardiographic left ventricular hypertrophy.