Angiographically evident atherosclerotic stenosis associated with myocardial bridging and risk factors for the artery stenosis located proximally to myocardial bridging.

OBJECTIVE: The purpose of this study was to determine the prevalence of coronary angiographically evident atherosclerotic stenosis associated with myocardial bridging (MB) and to explore related risk factors of coronary artery stenosis located proximally to MB. METHODS: Overall, 603 patients with MB-mural coronary arteries (MB-MCAs) diagnosed by angiography initially were enrolled in this observational study during May 2004 to May 2009. One-way ANOVA, t-test, Pearson correlation test and stepwise multiple regression analysis were performed to explore related risk factors. RESULTS: Totally 644 MB-MCAs were examined. Prevalence of lesions located distally to MBs was significantly lower than those proximally to MBs [36 (5.9%) vs. 382 (62.4%), p<0.001]. Diastolic vessel diameters in MB segments were significantly smaller than reference segments p<0.001. Ulcer-like lesion was found in MB-MCA in 1 patient. Multivariate analysis suggested that vascular bifurcation lesions, the degree of narrowing and the number of diseased coronary vessels of non-MB-MCA arteries, age, low-density lipoprotein cholesterol (LDL-C)/high density lipoprotein cholesterol (HDL-C), male, course of diabetes, and systolic narrow rate (SNR) of MB-MCAs were positively related with the narrow degree of the first coronary artery stenosis (FCAS) located proximally to MBs (all p<0.05). Vascular bifurcation lesions, the degree of narrowing and the number of diseased coronary vessels of non-MB-MCA arteries, age, LDL-C/HDL-C, male, diabetes and dyslipidemia were positively related with the narrow degree of the most severe coronary artery stenosis(MSCAS) located proximally to MB (all p<0.05). CONCLUSION: The intramural and distal portions of a bridged artery are not the forbidden zone of artery atherosclerosis formation. SNR of MB-MCA may be one of the important decision factors to coronary artery stenosis located proximally to MB.

[Imaging and clinical characteristics of patients with coronary artery stenosis located proximally to myocardial bridging].

OBJECTIVE: To explore the imaging and clinical characteristics and related risk factors of patients with coronary artery stenosis located proximally to myocardial bridging. METHODS: This study enrolled 603 patients with angiography evidenced myocardial bridging-mural coronary artery between May 2004 to May 2009. Angiographic and clinic data were collected according to uniform protocol and standard questionnaires were used to obtain patients' demographic and clinical information. Univariate and multivariate analysis were performed to explore related risk factors. RESULTS: Chest pain was present in 247 cases (41.0%). Dynamic ST-T changes were found in 229 cases (38%). A total of 644 myocardial bridging-mural coronary arteries were detected including 382 (62.4%) segments located proximally to myocardial bridging. Diastolic vessel diameters in the myocardial bridging segment were significantly smaller than reference segments (all P < 0.01). Stepwise multiple regression analysis suggested that vascular bifurcation lesions, the degree of narrowing and the number of diseased coronary vessels of non- myocardial bridging-mural coronary arteries, age, LDL-C/HDL-C, male gender, diabetes, and systolic narrow rate of myocardial bridging-mural coronary arteries were positively related with the narrowing degree of the first coronary artery stenosis located proximally to myocardial bridging (P < 0.05 or P < 0.01). Vascular bifurcation lesions, the degree of narrowing and the number of diseased coronary vessels of non- myocardial bridging-mural coronary arteries, age, LDL-C/HDL-C, male, diabetes and dyslipidemia were positively related with the narrowing degree of the most severe coronary artery stenosis located proximally to myocardial bridging (P < 0.05 or P < 0.01). CONCLUSIONS: Myocardial ischemia is common in patients with myocardial bridging and the artery segments located proximally to myocardial bridging are prone to stenosis. Systolic narrow rate of myocardial bridging-mural coronary arteries is one of major determinants of coronary artery stenosis located proximally to myocardial bridging. Whereas the other coronary heart disease risk factors are likely to play more important roles.

[Clinical predictive factors of coronary artery stenosis located distally to myocardial bridging].

OBJECTIVE: To explore the clinical predictive factors of coronary artery stenosis located distally to myocardial bridging (MB). METHODS: A total of 603 patients with MB-mural coronary artery (MB-MCA) diagnosed by angiography initially were enrolled during May 2004 to May 2009. Their angiographic and clinical data were collected according to an uniform protocol. And standard questionnaires were used to acquire demographic information and clinical examinations. Univariate and multivariate analysis were performed to explore the related clinical predictive factors. RESULTS: A total of 644 MB-MCAs were detected. Diastolic vessel diameters in MCAs were significantly smaller than those in reference segments ( (2.29 ± 0.39) vs (2.48 ± 0.40) mm, P < 0.001) . Lesions located distally to MB detected in 36 patients were significantly fewer than those proximally to MB in 382 patients (5.9% vs 62.4%, P < 0.001) . Univariate analysis suggested that the narrowing degree of vessel located proximally to MB, the narrowing degree and the number of diseased coronary vessels of non-MB-MCAs and course of hypertension were positively correlated with the narrowing degree of vessel located distally to MB (all P < 0.05) . Multivariate Logistic regression analysis suggested that the number of cigarettes per day, the narrowing degree of diseased coronary vessels of non-MB-MCAs, the narrowing degree of vessel located proximally to MB and diastolic narrow rate of MCA were positively correlated with the occurrence of coronary artery stenosis located distally to MB (all P < 0.05) . Their standardized coefficients (ß) were 0.763, 0.727, 0.420 and 0.403 respectively. And the corresponding Exp (ß) were 2.146 (1.089-4.229) , 2.070 (1.371-3.125) , 1.521 (1.050-2.204) and 1.496 (1.094-2.045) . CONCLUSION: The number of cigarettes per day, the narrowing degree of diseased coronary vessels of non-MB-MCAs, the narrowing degree of vessel located proximally to MB and diastolic narrowing rate of MCA are likely to be important clinical predictive factors of coronary artery stenosis located distally to MB.