Complex Heart Rate Control in Patients with Acute Coronary Syndrome

One of the main factors influencing a short-term and remote prognosis of patients, who experienced acute myocardial infarction, is heart rate. Ivabradine usage decreases HR at the expense of inhibition of electric activity of the sinoatrial node (Keith-Flack node) resulting in reduction of heart rhythm, increase of diastolic time during perfusion as a result of decreased oxygen supply to the myocardium without any harmful changes – arterial pressure values, coronary blood supply and contractile capacity of the myocardium. Materials and methods. 135 patients with ACS were included into the study. The possibility to improve treatment and clinical-prognostic role of ACS reduction was assessed with Ivabradine usage. Pharmacological therapy correlated with national recommendations concerning management of patients with ACS. The rates of HR, BP, ECG indices were assessed after admission to the hospital: during an acute period (on the 2-4th day, the 3rd day on an average), during subacute period (on the 14th day) of staying in the hospital. The patients were divided into two groups: the one included patients receiving Bisoprolol with the aim to control HR (group І, 93 patients), and another one – patients receiving Bisoprolol in the combination with Ivabradine (group ІІ, 42 patients). Analysis of the main parameters of the clinical-instrumental examination was not indicative of reliable differences between the patients of the examined groups at the beginning of treatment. The target levels of SP and DP were achieved in all the patients of the examined groups. The patients with complicated course of ACS (subgroup A) demonstrated reliably lower decrease of HR, than those without variant angina and/or relapse of MI (subgroup B) during all the stages of the hospital investigation. Similar dynamics of HR changes can be found in both groups of HR correction. Maximal decrease of HR was found since the first days of the study, which was similar for both groups of comparison. Considering selective decrease of HR without loss of the myocardial contractility, Ivabradine can be recommended as an effective agent to treat ACS without decrease of ejection fraction. Monotherapy with Bisoprolol is indicative of an effective control of the heart rhythm in patients with ACS, but after a combined therapy with Ivabradine and Bisoprolol better results were found during the first 3-4 days of treatment. Insufficient decrease of HR in patients with ACS during the first 3-7 days of hospitalization is associated with an increased risk of post-infarction angina or relapse of myocardial infarction.