Ivabradine in Patients with ST-Elevation Myocardial Infarction Complicated by Cardiogenic Shock: A Preliminary Randomized Prospective Study.

BACKGROUND AND OBJECTIVE: An elevated heart rate (HR) is an independent risk factor for mortality and morbidity in patients with acute heart failure (HF). The purpose of this study was to evaluate the impact of ivabradine, a selective HR-lowering agent, in patients with cardiogenic shock (CS) complicating ST-elevation acute myocardial infarction (AMI).

METHODS: Patients with post-AMI CS were randomized to standard treatment (SDT, 28 patients) or to standard treatment plus ivabradine (I + SDT, 30 patients). In the presence of orotracheal intubation (OTI), ivabradine was administered by nasogastric intubation. HR, BP, New York Heart Association (NYHA) class, NT-proBNP, left ventricular ejection fraction (LVEF) and diastolic function (LVDF) were monitored at specific times after the onset of AMI. The primary (surrogate) end-point was the in-hospital halving of plasma NT-proBNP levels. The secondary end-points were cardiovascular death, hospital re-admission for worsening HF, and clinical and haemodynamic improvement.

RESULTS: Treatment groups were statistically similar with regard to age, gender distribution, cardiovascular risk factors, number of diseased vessels and overall treated lesions, AMI site and occurrence of OTI. In-hospital mortality was double in the SDT group in comparison with the I + SDT group (14.3 vs. 6.7 %), but the difference was not statistically significant. HR, BP, NT-proBNP and LVEF favorably changed in both groups, but the change was more relevant in the I + SDT group. LVDF significantly changed only in the I + SDT group (p < 0.01). Patients in the I + SDT group did not experience adverse effects.

CONCLUSION: Ivabradine in CS complicating AMI is safe, is associated with a short-term favourable outcome and can be effectively administered by nasogastric intubation.