Disfunción microvascular, angina vasoespástica e isquemia silente

Abstract

Almost two thirds of patients with angina show no obstructive lesions on coronary angiography. It is important to rule out microvascular dysfunction or vasospastic angina in these patients. Microvascular dysfunction encompasses abnormalities in vessels smaller than 500μm. The capacity for correct vasodilation is lost and coronary flow cannot be increased in situations of stress causing ischaemia. In recent years, invasive diagnostic methods during catheterisation have been developed, the main method being coronary flow reserve. The aim of treatment is to improve endothelial function. ACE inhibitors/ARBs, beta-adrenergic-blocking drugs (BABs), and statins are recommended.Vasospastic angina is caused by vasoconstriction of the epicardial arteries or the arteries of microcirculation (microvascular dysfunction). It should be ruled out in patients with predominantly nocturnal rest angina. If suspected, provocation testing is indicated during catheterisation with acetylcholine, ergonovine or substance P. It responds to calcium antagonists and nitrates. ACE inhibitors and statins are also recommenced. BABs are contraindicated.Asymptomatic ischaemia is termed silent ischaemia. It is more frequent in diabetic patients. Diagnostic delay will determine prognosis.