Cytomegalovirus and coronary stenosis. Coronary stenosis

(narrowing of the artery supply to the heart muscle) is a direct cause of heart disease. A theory suggests that chronic cytomegalovirus

(CMV) infection narrows coronary vessels and leads to coronary heart disease. To test this theory, 75 patients undergoing angioplasty were followed for 6 months following their procedure. The 49 patients who were seropositive for CMV experienced an average luminal diameter reduction of 1.24 mm (s1 = 0.83 mm). In contrast, the 26 patients who were seronegative for CMV experienced an average luminal reduction of 0.68

(s2 = 0.69).k Test whether this mean difference in luminal reduction is significant. Show all hypothesis-testing steps. Do the data support the hypothesis that chronic CMV virus infection plays a role in coronary luminal reduction?