Abstract 12849: Invasive Assessment of Hemodynamic Effect of Ivabradine in Post ST Segment Elevation Myocardial Infarction Associated Sinus Tachycardia

Abstract

Introduction: Post MI tachycardia is associated with increase in cardiac morbidity and mortality. We aimed to assess efficacy and safety of ivabradine to control heart rate in post MI tachycardia patients in whom beta-blockers were intolerant. Hypothesis: We hypothesized that ivabradine in post MI tachycardia patients effectively control heart rate without deteriorating effects on hemodynamics. Methods: STEMI patients with sinus tachycardia (heart rate >120/min) who had intolerance to beta blocker were enrolled. Important exclusions were cardiogenic shock, second /third-degree atrioventricular block, Killip class III/ IV. Patient’s invasive hemodynamic parameters such as MAP (Mean Arterial Pressure), iSV (indexed Stroke Volume), CVP (Central Venous Pressure), cardiac output and cardiac index were measured with help of Edwards LifeSciences Flotrac monitor. Patients received ivabradine till heart rate control (<100/min.) was achieved. The primary objectives were to study ivabradine efficacy to achieve target heart rate, and its effects on hemodynamic parameters and secondary objectives were to assess any adverse events. Results: Mean age was 52.7 ± 9.8 years and 29 (81%) were male. At enrolment, mean heart rate, MAP, iSV and CVP was 128.92±3.3bpm, 87.31±10.46mmHg, 28.19±7.85ml/m 2 , 6.35±2.61 mmHg respectively. At target heart rate ≤1oo/min (mean 96.57±5.29bpm), MAP, iSV and CVP were 82.71±13.70 mmHg (P=0.559), 1.11±6.33ml/m 2 (P=0.087) and 7.7±2.54 mmHg (P=0.122) showed no significant changes. However, cardiac output and cardiac index dropped to 5.22± 1.00 L/min (P=0.005) and 2.96±0.60 L/min/m 2 (P=0.005) but within physiological limits. None of the patient reported hypotension, arrhythmia, heart failure or in-hospital mortality. Conclusions: Invasive hemodynamic evaluation showed oral ivabradine is effective and safe alternative to control heart rate in uncomplicated post MI sinus tachycardia patients who had intolerance to beta-blockers.