Structural and functional alterations of the intramyocardial coronary arterioles in patients with arterial hypertension

B Schwartzkopff, W Motz, H Frenzel, M Vogt, S Knauer, B E Strauer
1993 Circulation  
Background. In hypertensive patients with angina pectoris, the coronary vasodilator reserve is frequently impaired despite a normal coronary angiogram. Experimental data indicate that structural alterations of the intramyocardial coronary vasculature contribute to an increased minimal coronary resistance and a diminished coronary flow reserve. Methods and Results. In 14 patients (10 men and 4 women) with arterial hypertension and 8 normotensive subjects, minimal coronary resistance and
more » ... stance and vasodilator reserve (dipyridamole: 0.5 mg/kg body wt, gas chromatographic argon method) were determined after the angiographic exclusion of relevant coronary artery disease. Coronary reserve was depressed in hypertensive patients (2.7+2.3 vs 4.6+ 1.3, P<.05) due to increased minimal coronary resistance (0.64±0.30 vs 0.24±0.05 mm Hg * min * 100 g * mL-', p<0.002). In right septal biopsies, mean external arteriolar diameter (21.6+2.3 vs 17.2±2.5 ,um, P<.001), mean arteriolar wall area (271+61 vs 172±62 ,um2, P'.01), percent medial wall area (69.9+4.0 vs 66.0+3.2%oW, Pc.05), mean periarteriolar fibrosis area (216+ 122 vs 104±68 gm2, P'.05), and volume density of total interstitial fibrosis (3.6+ 1.8 vs 1.9±0.5Vvo fibrosis, Pc.05) were increased in hypertensive patients compared with normotensive subjects. Minimal coronary resistance correlated with %W (r=.6, Pc.003) and Vv% fibrosis (r=.62, P<.002). Left ventricular mass index (111±21 vs 97±17 g/m2, P=NS) and left ventricular end-diastolic pressure (12±6 vs 8±3 mm Hg, P=NS) did not correlate significantly with minimal coronary resistance. In multivariate analysis, both %oW and Vv% fibrosis explained half of the variability of minimal coronary resistance (r2=.5, P_.002). Conclusions. Structural remodeling of the intramyocardial coronary arterioles and the accumulation of fibrillar collagen are decisive factors for a reduced coronary dilatory capacity in patients with arterial hypertension and angina pectoris in the absence of relevant coronary artery stenoses. (Circulation. 1993;88:993-1003.) KEY WoRDs * hypertension * coronary reserve, arteriolar wall thickening, fibrosis
doi:10.1161/01.cir.88.3.993 pmid:8353927 fatcat:63i22axs5vh4rgbpirhvmnvj5m