Persistent macrovascular and microvascular dysfunction in patients with malignant hypertension

Abstract

Endothelial dysfunction is characteristic of patients with essential hypertension, but only limited data are available on different aspects of endothelial function in patients with malignant-phase hypertension. We investigated myocardial perfusion using real-time quantitative myocardial contrast echocardiography with concurrent assessment of macrovascular and microvascular endothelial damage/dysfunction in patients with previous malignant hypertension (but now in stable phase), who were compared with patients with treated "high-risk" hypertension (hypertension) and healthy controls. We measured flow (hyperemia)-mediated dilation and response to glyceryl trinitrate of brachial artery (ultrasound), microvascular (forearm) response to acetylcholine and sodium nitroprusside (laser Doppler), pulse wave velocity, circulating endothelial and endothelial progenitor cells in 15 patients with malignant hypertension, 40 matched patients with hypertension, and 40 healthy controls. Patients with malignant hypertension had impaired endothelial-dependant response to acetylcholine (P<0.001, but not to sodium nitroprusside) compared with hypertension and impaired reaction to both stimuli compared with healthy subjects (P<0.001). Patients with malignant hypertension had increased circulating endothelial cells (P=0.001), endothelial progenitors (P=0.008), and stiffness (P=0.003). Both hypertensive groups had impaired response to hyperemia and glyceryl trinitrate when compared with healthy controls (P<0.05). Both hypertensive groups had similar myocardial perfusion, which was significantly lower than in healthy controls. There were no significant differences in hyperemia and endothelium-independent stimuli between the 2 hypertensive groups. In conclusion, despite fairly well-controlled blood pressure, malignant hypertension patients had more pronounced abnormalities of macrovascular and microvascular function (which seem to be both endothelium dependent and endothelium independent) compared with patients with hypertension and healthy controls.