Association of systolic and diastolic blood pressures with long-term outcomes after myocardial infarction

Background and Aims Blood pressure (BP) is the strongest predictor of cardiovascular diseases in the general population and is linearly associated with cardiovascular risk. Myocardial perfusion is dependent primarily on diastole. However, whether BP remains a predictor of long-term outcome after myocardial infarction (MI), and which BP index is more closely associated have not been elucidated. Methods Among 4788 MI survivors (89.8% men; mean age, 62.4 years) in the Kailuan Study, we compared systolic and diastolic BPs after MI in relation to the incident risk of all-cause mortality and composite cardiovascular events, including all-cause mortality, recurrent MI, hospitalization for heart failure and stroke, with multivariable adjustment. Results After a median follow-up of 7.5 years, 1355 participants died and 1939 experienced composite cardiovascular events. Both systolic and diastolic BPs were linearly associated with composite cardiovascular events and all-cause mortality by multivariable-adjusted restricted cubic spline curve analyses. The multivariable-adjusted hazard ratios of composite cardiovascular events in relation to 10 mm Hg-increment of BPs were 1.06 (95% CI: 1.04–1.08, P<0.001,Figure 1) for systolic and 1.07 (95% CI: 1.03–1.12, P=0.001,Figure 1) for diastolic BP. The adjusted hazard ratios for all-cause mortality were 1.06 (95% CI: 1.03–1.08, P<0.001,Figure 1) for systolic and 1.09 (95% CI: 1.04–1.15, P<0.001,Figure 1) for diastolic BP. In the multivariable-adjusted models including both systolic and diastolic BP, the composite cardiovascular events and all-cause mortality were associated with only systolic BP (P≤0.014,Figure 2), not diastolic BP (P≥0.25,Figure 2). Adding systolic BP to multivariable Cox models including diastolic BP significantly improved the AUC of the models (composite cardiovascular events: 0.0032, 95% CI: 0.0006 to 0.0058; all-cause mortality: 0.0015, 95% CI: –0.0006 to 0.0036). The subgroup analyses indicated that the association between systolic BP and outcomes was greater among individuals aged <60 years or hypertensive patients. Conclusions Systolic and diastolic BPs were linearly associated with composite cardiovascular events and all-cause mortality after MI. Systolic BP was more closely associated with adverse outcomes after MI than diastolic BP and should be targeted when managing BP among patients after MI.Figure 1Figure 2