Severity of Coronary Artery Disease but Not Degree of Coronary Stenosis Is Correlated to Cerebrovascular Reactivity

BACKGROUND: A decade difference in peak incidences of coronary and cerebral ischemia assumes a protection of the brain vasculature. Therefore, we hypothesize that early indicators of cerebrovascular disease such as parameters of the neurovascular coupling show a higher correlation to coronary artery disease than morphologic parameters. METHODS: Stenotic degree (%) of coronary arteries (RCA, LCA, LAD, RCX) was determined together with the Gensini score by angiography in 96 patients (80 men; 62 +/- 10 years), which were grouped according to disease severity (sclerosis, 1-vessel disease (VD), 2-VD, 3-VD). Presence of internal carotid artery stenosis and left ventricular ejection fraction (LVEF) were established with duplex sonography. Resting and visually evoked hemodynamic responses were measured with transcranial Doppler ultrasound in both posterior cerebral arteries and expressed in terms of control system parameters. These were gain, natural frequency, attenuation, and rate time. Group differences and correlations between stenosis and parameters of vasoreactivity were tested. RESULTS: Groups differed in stenotic degree of coronary arteries, Gensini score, LVEF, carotid artery stenosis, resting flow velocity, and evoked responses (gain, p < 0.005; attenuation, p < 0.05). Stenosis of each coronary artery and LVEF were correlated to carotid artery stenosis but no association was found to cerebrovascular parameters. Only severity of coronary artery disease and the Gensini score were associated with disturbed cerebrovascular reactivity. Carotid artery stenosis was associated with decreased cerebrovascular parameters (attenuation, p < 0.05; rate time, p < 0.01). CONCLUSIONS: Although atherosclerosis is a systemic disease our data support concepts of a heterogeneous distribution of the disease indicating protection of brain vessels.