Association between average systolic blood pressure during the acute phase and mortality in very elderly (≥80 years) patients with acute myocardial infarction

Background The optimal blood pressure (BP) target during acute myocardial infarction (AMI) in patients aged ≥ 80 years is undefined. We aimed to assess the association between average acute-phase BP and mortality in this population. Methods This prospective study included consecutive patients aged ≥ 80 years who were admitted for AMI to the coronary care unit of Peking University Third Hospital between 2013 and 2023. Patients with cardiogenic shock or cardiac arrest at admission were excluded. The in-hospital BPs of each patient were collected and the average in-hospital systolic BP (aSBP) and diastolic BP (aDBP) were calculated for analysis. The primary outcome was 1-year all-cause mortality. Results A total of 872 patients were analyzed (mean age 84.2 years, 59.3% male) and 208 patients (23.9%) died within 1 year post-discharge. The association between aSBP and the primary outcomes followed an inverse J-shape curve. Multivariate logistic regression models revealed that compared with aSBP < 120 mm Hg, the risk of 1-year all-cause mortality was reduced by 57% (OR, 0.43; 95% CI, (0.24, 0.78), P  = 0.006) in the group of aSBP > 130 mm Hg. The group of 120 to 130 mm Hg showed a trend towards lower mortality risk (OR, 0.86; 95% CI, 0.52–1.43; P  = 0.566), but it did not reach statistical significance. The benefit of aSBP ≥ 130 mm Hg was more pronounced in men, patients aged > 85 years, those without diabetes or chronic kidney disease, and those with STEMI or hypertension. The relationship between aDBP and primary outcomes followed a U-shape curve. Patients with aDBP at 60 to 70 mm Hg showed a non-significant trend toward a lower risk. Further multi-center RCTs are warranted to validate our findings and provide evidences for the optimized BP management for very elderly patients in the acute phase of AMI. Conclusion Among the very elderly with AMI, an in-hospital average SBP higher than130 mm Hg was significantly associated with a lower risk of 1-year all-cause mortality compared with those having lower aSBP levels.