The segment proximal to a myocardial bridge, which is frequently involved in atherosclerotic plaque formation, could serve as an independent and significant factor with a higher odds ratio than other major risk factors for arteriosclerosis, according to a study presented last week at the 94th annual meeting of the Radiological Society of North America (RSNA).
Takeshi Nakaura MD, from the departments of radiology at Kumamoto University School of Medicine in Kumamoto, Japan, and colleagues investigated whether myocardial bridging is an independent factor of atherosclerosis using coronary CT angiography (CCTA).
The investigators enrolled 98 patients with suspected coronary disease (mean age 67 years), who underwent a CT study on a 40-detector instrument (Brilliance-40 from Philips Healthcare). They reviewed the baseline characteristics (age, body mass index, smoking history, presence of hypertension, hypercholesterolemia and diabetes mellitus) and results of the CCTA in all patients.
Nakaura, who presented the findings, said that two radiologists evaluated the left anterior descending coronary artery (LAD) segments for the absence or presence of myocardial bridging and classified the coronary wall in the proximal LAD segment as negative or positive for plaque. After independent evaluation, they assigned a score to each finding by consensus.
They identified 43 instances of myocardial bridging in 36.7 percent of the patients—26.5 percent were located in the middle segment of the LAD, he reported.
By multivariate analysis, age, sex, the presence of hypertension and myocardial bridging were “statistically significantly associated with proximal LAD atherosclerosis.” Nakaura added that “the middle LAD bridging represented the highest risk for the development of coronary plaques in the proximal segment of the LAD.”
Based on their findings, Nakaura concluded that “myocardial bridging in the middle LAD may be a significant risk factor for atherosclerosis in the proximal LAD.”