Impaired cerebrovascular reactivity as a risk marker for first-ever lacunar infarction - A case-control study

Background and Purpose-Functional assessment of small arteries and arteriol es could provide valuable information regarding the extent of diffuse arter iolosclerosis in patients with small-vessel disease. Therefore we attempted to clarify the role of cerebrovascular reactivity (CVR) as a risk marker f or first-ever symptomatic lacunar infarction. Methods-Forty-six patients with lacunar infarction and 46 sex- and age-matc hed control subjects were prospectively evaluated. Cerebral hemodynamics we re studied with transcranial Doppler ultrasonography. CVR was examined by c alculating the percent increase in mean flow velocity occurring after 15 mg /kg acetazolamide administration (Diamox test). Results-CVR was significantly (P<0.0001, Student's t test) lower in cases ( 50.0+/-12.7%) as compared with control subjects (65.2+/-12.4%). A multiple logistic regression analysis identified male sex (odds ratio [OR] 2.3, P=0. 02), age (OR 3.6, P<0.005), and the presence of lacunar infarction on magne tic resonance imaging (OR 5.3, P<0.001) as significant and independent fact ors associated with a reduction of CVR. Moreover, a cut-point of 55.6% (sen sitivity 67%, specificity 82%) was established as the threshold value for d istinguishing between pathological and normal CVR. CVR was significantly (P =0.02) lower in patients with multiple (46.38+/-12.6%) than with single (54 .83+/-11.58%) lacunar infarction. In addition, a trend of negative correlat ion was found between CVR and the number of lacunar infarctions (r=-0.26, P =0.08). In the multiple logistic model, history of hypertension (OR 7.24; 9 5% confidence interval 2.95 to 17.79) and CVR (OR 0.8;95% confidence interv al 0.81 to 0.93) emerge as significant and independent predictors of first- ever lacunar infarction. Conclusions-These data suggest that impaired CVR is a risk marker for first -ever lacunar infarction.