High blood pressure and low blood pressure are perfectly identified cardio-vascular risk factors, especially in primary prevention. However, their respective role after myocardial infarction is uncertain, with few data available.

To compare cardio-vascular deaths and events after myocardial infarction between the different blood pressure levels observed during the first forty-eight hours.

We carried out an observational, prospective, monocentric study, including all consecutive patients admitted in Dijon’s Cardiologic Intensive Care Unit for myocardial infarction, between February 2012 and February 2014. Systolic blood pressure (SBP) was defined as the average of three measurements performed daily during the first two days of hospitalization. Mortality and cardiovascular events were collected during hospitalization and after a follow-up of 1 year.

Among 1153 patients enrolled, 920 were analyzed and divided into three groups: 75 patients with SBP less than or equal to 100mmHg, 731 patients with SBP of 101 to 140mmHg, 114 patients with SBP greater than 110mmHg. Age, BMI, LVEF and STEMI were predictive of a SBP below 100mmHg. Unadjusted analyses showed no difference between the three groups for in-hospital mortality from all causes (2.7% vs 2.2% vs 2.6%, p=0.769) and at 1 year (13.3% vs 9.3% vs 10.5%, p=0.513), and cardiovascular mortality at 1 year (6.7% vs 7.4% vs 7.9%, p=0.951). When adjusted, SBP less than or equal to 100mmHg did not significantly increase mortality (OR=2.145, 95% CI=0.969-4.747, p=0.060).

Hypotension within the first forty-eight hours after myocardial infarction is common. Our work established four predictors, but did not find relationship between blood pressure levels and in-hospital and long-term prognosis of patients. Further studies are needed to clarify the optimal blood pressure after acute coronary syndrome.