Ivabradine Use in Refractory Unstable Angina: A Case Report

In this report, we describe the clinical results of ivabradine use in a patient with a serious form of unstable angina. For this patient, it was proposed that no other therapeutic, pharmacologic or surgical, option was available. The patient is a 75-year-old woman who presented with repeated episodes of retrosternal chest pain. She notably had a history of type II diabetes mellitus treated by insulin for several years and complicated by diabetic macro-angiopathy. ECG tracings recorded during these episodes showed abnormalities of the lateral repolarization phase of ischaemic nature. There was no measured increase in cardiac enzymes. She was transferred to our CCU with a diagnosis of unstable angina. In our CCU, the patient was treated with nitrates, metoprolol, aspirin, clopidogrel and atorvastatin at maximal sustainable doses. Following persistent clinical-instrumental instability, she was subjected to coronary angiography. This study revealed severe multi-vessel coronary artery disease not amenable to surgery or angioplasty revascularization. In addition to the therapy already provided, a beta-blocker (metoprolol 50 mgx2/die) and diltiazem (30 mgx2/die) were added despite their potentially dangerous and adverse chronotropic effects. Despite this treatment, the patients heart rate remained high (between 80 and 100 beats/min). This heart rate appeared to be the main driving cause of her anginal symptoms. At this point, the use of ivabradine seemed the only option, even though use would be off-label compared to current indications for the drugs use. We started with a low dose of 2.5 mg/b.i.d. and titrated up to 5 mg b.i.d. As we titrated, we witnessed a gradual reduction in heart rate. A consequent stabilization of her clinical pattern progressed into an almost unexpected asymptomatic state. After about a week of clinical observation, the patient recovered. After three months, she remains asymptomatic.