Clinical impact of blood pressure on cardiovascular death in patients 80 years and older following acute myocardial infarction: a prospective cohort study.

Numerous trials have shown that lowering blood pressure (BP) reduces cardiovascular risk and mortality, yet data about the impact of BP on cardiovascular death risk in patients aged ≥80 years with acute myocardial infarction (AMI) are sparse. This study explored the prognostic value of BP for cardiovascular death during the first 48 h after admission following AMI among patients aged ≥80 years. A total of 1005 patients ≥80 years with AMI were enrolled. Average BP parameters, including systolic, diastolic, and pulse BP, over the first 48 h after admission were calculated. The end point was cardiovascular death. Receiver operating curve (ROC) analysis was used to identify whether BP was relevant to cardiovascular death. The relationship between BP levels and cardiovascular death was evaluated by Cox regression models. ROC analysis showed that average diastolic blood pressure (aDBP), but not systolic and pulse BP, was relevant to cardiovascular death, and the optimal cutoff was 65 mmHg. During the 2.9-year follow-up, patients who died from a cardiovascular cause had lower aDBP levels than those who did not (p = 0.002). Patients with aDBP <65 mmHg had a 1.5-fold higher incidence of cardiovascular death than those with aDBP ≥65 mmHg (35.9% vs. 24.0%; p < 0.001). In multivariable regression analysis, low aDBP remained a strong and independent predictor of cardiovascular death (adjusted hazard ratio 1.907; 95% CI 1.303-2.792). aDBP was independently associated with cardiovascular death in patients aged ≥80 years with AMI, suggesting that aDBP may be a useful index to predict worse outcome in these patients.