軽症の冠動脈疾患であっても糖尿病患者では高リスクとなる（Abstract SSM03-04）

心臓CT血管造影は心イベントの高リスク患者を同定する
Cardiac CT angiography identifies diabetic patients who are at higher risk for cardiac events
糖尿病患者はたとえ軽症の冠動脈疾患であっても心筋梗塞または他の重大な有害心イベントの相対リスクは重症の1枝狭窄病変の糖尿病患者と同等である、とのスタディ結果が2014年Radiological Society of North America年次集会で発表された。研究者らは、Coronary CT Angiography Evaluation For Clinical Outcomes（CONFIRM）レジストリにおける、CCTAにより冠動脈の動脈硬化の範囲を検出及び判定された糖尿病患者1,823人のデータを解析した。スタディ対象の男女（年齢中央値61.7歳）は、冠動脈疾患なし、軽症冠動脈疾患（50%未満の冠動脈狭窄）、または狭窄病変（50%以上の冠動脈狭窄）に分類された。5.2年間の追跡期間中に246例が死亡し（スタディ対象全体の13.5%）、295例（30.3%）が心筋梗塞や冠動脈血行再建術施行などの重大な有害心イベント（MACE）を発症した。CCTAで判断された狭窄病変および軽症の冠動脈疾患があるか、または狭窄病変および冠動脈疾患がないかが患者の死亡およびMACEに関連した。軽症冠動脈疾患患者の死亡またはMACEの相対リスクは、1枝狭窄病変患者と同等であった。
Full Text

According to a new long-term study, diabetic patients with even mild coronary artery disease face the same relative risk for a myocardial infarction or other major adverse cardiac events as diabetics with serious single-vessel obstructive disease. Results of the study were presented at the 2104 annual meeting of the Radiological Society of North America (RSNA).

Researchers at the University of British Columbia and St. Paul's Hospital in Vancouver analyzed data from the Coronary CT Angiography Evaluation For Clinical Outcomes: An International Multicenter (CONFIRM) Registry, which was developed to examine the prognostic value of cardiac computed tomography angiography (CCTA) for predicting adverse cardiac events related to coronary artery disease. The registry, which has CCTA data on 40,000 patients from 17 centers around the world, now has five-year follow-up data on 14,000 patients.

"The CONFIRM Registry is the largest long-term data set available and allowed us to evaluate the long-term prognostic value of CCTA in diabetic patients," said study co-author Jonathan Leipsic, M.D., vice chairman of the Department of Radiology at the University of British Columbia.

The researchers analyzed data on 1,823 diabetic patients who underwent CCTA to detect and determine the extent of atherosclerosis in the coronary arteries.  Men and women (median age 61.7) in the study were categorized as having no coronary artery disease, mild disease (less than 50 percent of coronary artery narrowed), or obstructive disease (more than 50 percent artery obstruction). Over a 5.2-year follow-up period, there were 246 deaths, representing 13.5 percent of the total study group.

Major adverse cardiovascular event (MACE) data was available on 973 patients. During the follow-up period, 295 (30.3 percent) of the patients experienced a MACE such as a myocardial infarction or coronary revascularization.

The researchers found that both obstructive and mild, or non-obstructive, coronary artery disease as determined by CCTA were related to patient deaths and MACE. Most importantly, the study found that the relative risk for death or MACE for a patient with mild coronary artery disease was comparable to that of patients with single vessel obstructive disease.

"Until now, two-year follow-up studies suggested that a diabetic patient with mild or non-obstructive coronary artery disease had a lower risk of major adverse cardiovascular events and death than patients with obstructive disease," said co-author Philipp Blanke, M.D., radiologist at the University of British Columbia and St. Paul's Hospital. "Our five-year follow-up data suggests that non-obstructive and obstructive coronary artery disease as detected by cardiac CTA in diabetic patients are both associated with higher rates of mortality."

Dr. Leipsic said researchers need a better understanding of the evolution of plaque in the arteries and patient response to therapies.

"Cardiac CT angiography is helpful for identifying diabetic patients who are at higher risk for heart events, who may benefit from more aggressive therapy to help modify that risk," added Dr. Leipsic.

Co-authors on the study include Bruce Precious, M.D., Sasi R Ganga Raju, M.B.Ch.B., Iksung Cho, M.S., Hyuk-Jae Chang, M.D., Fay Lin, M.D., Stephan Achenbach, M.D., Daniel S. Berman, M.D., Matthew J. Budoff, M.D., Tracy Q. Callister, M.D., Mouaz Al-Mallah, M.D., Filippo Cademartiri, M.D., Ph.D., Kavitha M. Chinnaiyan, M.D., Benjamin Chow, M.D., Allison Dunning, M.S., Augustin Delago, M.D., Todd C. Villines, M.D., Martin Hadamitzky, M.D., Jorg Hausleiter, M.D., Leslee Shaw, Ph.D., Philipp A. Kaufmann, M.D., Ricardo C. Cury, M.D., Gudrun Feuchtner, M.D., Yong-Jin Kim, M.D., Erica Maffei, M.D., Gilbert Raff, M.D., Gianluca Pontone, M.D., Daniele Andreini, M.D., Hugo M. Marques, M.D., Ronen Rubinshtein, M.D., Millie Gomez, M.D., and James K. Min, M.D.