Prognostic value of ST-T abnormalities and left high R waves with cardiovascular mortality in Japanese (24-Year follow-up of NIPPON DATA80)

Little is known about the prognostic value of ST-segment depression and/or T wave (ST-T abnormalities) with or without left high R waves on electrocardiogram recorded at rest for death from cardiovascular disease (CVD) in Asian populations. Japanese participants without a history of CVD and free of major electrocardiographic (ECG) abnormalities were followed for 24 years. Subjects were divided into 4 groups based on baseline ECG findings: isolated left high R waves, isolated ST-T abnormalities, ST-T abnormalities with left high R waves, and normal electrocardiogram. Cox proportional hazard model was used to estimate risk of CVD mortality in groups with ECG abnormalities compared to the normal group. Of 8,572 participants (44.4% men, mean age 49.5 years; 55.6% women, mean age 49.4 years), 1,142 had isolated left high R waves, 292 had isolated ST-T abnormalities, and 128 had ST-T abnormalities with left high R waves at baseline. Multivariable-adjusted hazard ratios of ST-T abnormalities with left high R waves for CVD mortality were 1.95 (95% confidence interval 1.25 to 3.04) in men and 2.68 (95% confidence interval 1.81 to 3.97) in women. Isolated ST-T abnormalities increased the risk for CVD death by 1.66 times (95% confidence interval 1.01 to 2.71) in men and 1.62 times (95% confidence interval 1.18 to 2.24) in women. Association of ECG abnormalities with CVD mortality was independent of age, body mass index, systolic blood pressure, serum cholesterol, blood glucose, smoking and drinking, and antihypertensive medication. In conclusion, ST-T abnormalities with or without left high R waves on electrocardiogram recorded at rest constitute an independent predictor of CVD mortality in Japanese men and women.