ARTERIAL CALCIFICATION AND NOT LUMEN STENOSIS IS HIGHLY CORRELATED WITH ATHEROSCLEROTIC PLAQUE BURDEN IN HUMANS - A HISTOLOGIC-STUDY OF 723CORONARY-ARTERY SEGMENTS USING NONDECALCIFYING METHODOLOGY

Objectives. This study was designed to evaluate whether calcium deposi tion in the coronary arteries is related to atherosclerotic plaque bur den and narrowing of the arterial lumen. Background, Many studies have recently documented the feasibility of electron beam computed tomogra phy to detect and quantify coronary artery calcification in patients, Although these studies suggest a general relation between calcificatio n and severity of coronary artery disease, the value of coronary calci um in defining atherosclerotic plaque and coronary lumen narrowing is unclear, Previous pathologic comparisons have failed to detail such a relation in identical histologic sections, This finding may be due to atherosclerotic remodeling.Methods. A total of 37 nondecalcified coron ary arteries were processed, sectioned at 3-mm intervals (723 sections ) and evaluated by computer planimetry and densitometry. Results. A si gnificant relation between calcium area and plaque area was found on a per-heart basis (n = 13, r = 0.87, p < 0.0001), per-artery basis (lef t anterior descending coronary artery [LAD]: 13, r = 0.89, p < 0.0001; left circumflex coronary artery [LCx]: n = 11, r = 0.7, p < 0.001; ri ght coronary artery [RCA]: n = 13, r = 0.89, p < 0.0001) and per-segme nt basis (n = 723, r = 0.52, p < 0.0001), In contrast, a poor relation existed between residual histologic lumen area and calcium area for i ndividual hearts (r = 0.48, p = NS), individual coronary arteries (LAD : r = 0.59, p = NS; LCx: r = 0.10, p = NS; RCA: r = 0.59, p = NS) and coronary segments (r = 0.07, p = NS), Longitudinal changes in external elastic lamina areas, were highly correlated with changes in plaque a rea values (r = 0.60, p < 0.0001), whereas lumen area did not correlat e with plaque size change (r = 0.01, p = NS). Conclusions. Coronary ca lcium quantification is an excellent method of assessing atherosclerot ic plaque presence at individual artery sites, Moreover, the amount of calcium correlates with the overall magnitude of atherosclerotic plaq ue burden, This study suggests that the remodeling phenomenon is the l ikely explanation for the lack of a good predictive value between lume n narrowing and quantification of mural calcification. (C) 1998 by the American College of Cardiology.