Resolution of Angina Pectoris and Improvement of the Coronary Flow Reserve after Ranolazine Treatment in a Woman with Isolated Impaired Coronary Microcirculation

In a 61-year-old woman with well controlled arterial hypertension, hypercholesterolemia, and smoke and suffering from recurrent angina pectoris despite angiographically normal epicardial coronary vessels and maximal therapy, the replacement of nitrates with novel antiangina drug ranolazine, after 6-month therapy, induced a complete relief of angina and a relevant rising of the transthoracic Doppler-derived coronary flow reserve (CFR). The present clinical case underlines therefore how in patients with chronic ischemic heart disease without epicardial coronary stenosis ranolazine can induce an improvement till the complete solution of the angina symptoms and a substantial increase of CFR as expression of the enhancement of the microvascular coronary function. The improvement of both symptoms and coronary microvascular function is strictly linked to the mechanism of action of the drug. Ranolazine induces in fact a reduction of the intracellular late sodium current that leads to a reduction of the intracellular calcium concentration thus producing a better myocardial diastolic relaxation process which in its turns enhances the myocardial perfusion. The ranolazine acts therefore as a lusitropic drug that improves the diastolic dysfunction and the segmental ischemia thus affecting one of the first steps of the ischemic cascade. 1. Introduction Chronic angina pectoris represents a common impairing disease that involves limitations in the work activities and affects the individual quality of life [1]. Though the revascularization procedures are developing day-by-day, still a relevant number of patients (up to 20%) keep showing the angina symptoms even if they have been undergone a percutaneous coronary angioplasty intervention (PCI) and/or coronary artery bypass and are treated by standard therapy (beta blockers, calcium antagonists, and nitrites) with the maximal dosage [2]. Although several causes might be considered as responsible of this frequent treatment failure, coronary microvascular impairment is one of the main determinant taking part as well to the development of the angina symptoms. In addition, the activity of the standard therapy is based on hemodynamic effects which involve the reduction of myocardial oxygen consumption while novel mechanisms of action might be used to support and enhance the anti-ischemic effect. Ranolazine, an example of a new class of antiangina drugs, has shown a good outcome despite the absence of hemodynamic effects with an increasing number of clinical experiences that certify its value in the chronic ischemic heart