Low Systolic Blood Pressure and Mortality in Elderly Patients After Acute Myocardial Infarction

Abstract

Background Optimal blood pressure in elderly patients after acute myocardial infarction is still a matter of debate. In a prospective observational study, we aimed to identify optimal systolic blood pressure during the 48 first hours after admission for acute myocardial infarction and its prognostic value for cardiovascular mortality. Methods and Results From the Observatoire des Infarctus de Côte d'Or survey, all consecutive patients aged >75 years admitted for an acute myocardial infarction in a coronary care unit from 2012 to 2015 and discharged alive were included (n=814). Exclusion criteria were in‐hospital death, cardiogenic shock, and end‐stage renal disease. Average systolic blood pressure ( aSBP ) values over the first 48 hours after admission were recorded, and the population was dichotomized into 2 groups: low aSBP group (<125 mm Hg) and control group ( aSBP ≥125 mm Hg). When compared with patients without cardiovascular death at 1‐year follow‐up, patients who died from a cardiovascular cause had higher rate of cardiovascular risks factors, including age, diabetes mellitus, comorbidities, and cardiovascular history. They had higher rates of low body mass index (<21 kg/m 2 ) and more elevated Global Registry of Acute Coronary Events risk score. Patients with aSBP <125 mm Hg had a 2‐fold risk of 1‐year cardiovascular death (47 [12.0%] versus 28 [6.6%]; P =0.008). By multivariable logistic regression analysis, low aSBP (odds ratio [95% CI ], 1.91 [1.07–3.41]) remained a strong and independent predictor of 1‐year cardiovascular mortality. Conclusions In our large population‐based study in elderly patients with acute myocardial infarction, low aSBP was an independent and powerful predictor of 1‐year cardiovascular mortality. Early aSBP measurement could help to improve risk stratification. Moreover, our results may suggest an optimal blood pressure target in elderly patients.