Blood pressure variability (BPV) has been mainly studied through the prism of congestive heart failure (CHF) and hypertension, but not in the setting of an acute coronary syndrome (ACS). The aim of the present study was to assess blood pressure variability (BPV) in patients hospitalized for myocardial infarction (MI).
We studied 211 patients (79.8% male; mean age 62.33 years) who were hospitalized because of ST-elevation myocardial infarction (STEMI) and Non ST–elevation myocardial infarction (NSTEMI). All patients underwent baseline estimation of clinical and laboratory parameters during their hospitalization. Additionally, BPV was estimated based on daily measurements of BP during hospitalization and with 24-hour ambulatory BP monitoring during the third day of hospital stay. The parameters of BPV analyzed were: a) standard deviation (SD) of systolic BP, b) SD of diastolic BP, c) the coefficient of variation (CV) of systolic BP and d) the average real variability (ARV) of systolic and diastolic BP.
From the total population, 28.9% had family history of cardiovascular disease, 67.3% were hypertensives, 27% had diabetes mellitus (DM), 58.8% were smokers and 23.7% had previous history of coronary artery disease. Regarding the type of myocardial infarction, 49.3% were admitted for STEMI and 78.5% had coronary revascularization. From the ambulatory BP, ARV SBP was 9.32 ± 2mmHg while NSTEMI patients demonstrated significantly higher values of ARV SBP compared to STEMI (9.72 ± 2 mmHg vs 8.9 ± 1.7 mmHg; p = 0.002). Using univariate analysis, the type of MI (STEMI and NSTEMI) was significantly related to ARV SBP (r = 0.215, p < 0.002). After multivariate regression analysis, ARV SBP remained significantly associated with the type of MI (b = 0.144; p = 0.042), independently of age, gender, history of hypertension, history of DM, history of chronic kidney disease (CKD) and low-density lipoprotein (LDL-C).
In patients admitted for MI there is a relationship between the ARV and the type of myocardial infarction. These findings suggest differential impact of hemodynamic load on the cardiovascular system in patients with STEMI and NSTEMI.
First Cardiology Clinic, Medical School, National and Kapodistrian University of Athens, Hippokration Hospital, Athens, GREECE