Effect of different diastolic blood pressure levels on the prognosis of patients with heart failure after acute myocardial infarction

Aims This study aims to investigate the effect of different diastolic blood pressure levels at discharge on the prognosis of patients with heart failure after acute myocardial infarction. Methods This study included 642 patients hospitalized in the Department of Cardiology of Langfang People's Hospital who were diagnosed with heart failure after acute myocardial infarction between March 2017 and October 2022. Patients were divided according to diastolic blood pressure (DBP) at discharge into three groups: 70 mmHg ( n = 122), 70–80 mmHg ( n = 221), and 80 mmHg ( n = 299) groups. The follow-up period was 12 months after discharge. The primary endpoint was a composite of all-cause mortality and all-cause readmission during follow-up. Secondary endpoints included the composite endpoint of cardiac death and cardiac readmission, as well as all-cause mortality, cardiac death, all-cause readmission, cardiac readmission, and heart failure-related readmission. Results During the follow-up period, there were no significant differences among the three groups in the incidence of the primary endpoint (a composite of all-cause mortality and all-cause readmission) or secondary endpoints (the composite endpoint of cardiac death and cardiac readmission, all-cause mortality, cardiac death, all-cause readmission, cardiac readmission, and heart failure readmission) ( P 0.05). Cox regression analysis, adjusted for variables showing differences in the univariate analysis, showed that patients in the 70–80 mmHg group had a significantly higher risk of the primary endpoint than those in the 70 mmHg group (HR: 2.078, 95% CI: 1.009–4.280, P = 0.047). Compared with the 70 mmHg group, patients in the 80 mmHg group exhibited an increased risk of the primary endpoint (HR: 2.808, 95% CI: 1.216–6.481, P = 0.016), the composite endpoint of cardiac death and cardiac readmission (HR: 3.765, 95% CI: 1.393–10.176, P = 0.009), all-cause readmission (HR: 2.850, 95% CI: 1.197–6.789, P = 0.018), and cardiac readmission (HR: 3.376, 95% CI: 1.234–9.237, P = 0.018), with no significant differences observed for the remaining outcome measures. No significant differences in outcome indices were found between the 80 mmHg and 70–80 mmHg groups ( P 0.05). Conclusion Different DBP levels at discharge in patients with heart failure after AMI are useful for patient prognosis evaluation. Maybe patients with heart failure after AMI with a low DBP (70 mmHg) at discharge have a lower risk of all-cause mortality and all-cause readmission. Notably, the study population had a relatively high mean left ventricular ejection fraction, and a higher number of patients in the DBP 70 mmHg group were treated with MRAs. Since MRAs themselves have blood pressure-lowering effects, their use may have influenced the results and prognosis. Therefore, until these findings are confirmed by further trials, active reduction of diastolic blood pressure should be approached with caution. This conclusion requires validation through large-scale randomized studies.