Xue L, et al. - Researchers examined patients with coronary heart disease to determine the incidence as well as the prognostic significance of Chlamydia pneumoniae infection (CP). This study included a case group, including 92 patients with coronary heart disease who had percutaneous coronary intervention, as well as a control group which included 50 healthy people. A high CP infection rate was observed in patients with coronary heart disease. A higher incidence of CP infection was observed among patients at grade III (66.7%) vs those at grade I or II (17.6% and 30.8%, respectively). In regard to the severity of the coronary artery lesions and postoperative prognosis of patients, the degree of infection was considered relevant. This was indicative of a possible significance of CP infection as a factor influencing the incidence and prognosis of coronary heart disease.