急性心筋梗塞患者の慢性期における冠動脈攣縮誘発試験の結果と影響因子について

Quantitative Assessment for Angiographic Results of Coronary Spasm Provocation Test Performed among Japanese Patients in the Chronic Stage of Acute Myocardial Infarction

要旨　急性心筋梗塞(AMI)患者における冠攣縮の影響は日本人で大きいことが示されているが，個々の患者における関連の程度については不明な点が多い．今回，AMI患者60例でアテノロールが冠攣縮に及ぼす影響を調べた当施設の研究の中で，エルゴノビン負荷試験の結果を再評価し，責任冠動脈(IRA)と非IRA(non-IRA)で比較検討した．負荷試験による冠動脈狭小化は11～100%と様々で，IRA，non-IRAとも同様であった．単変量解析で，IRAにおける負荷陽性因子は，IRAがどの冠動脈であるかであった．また，non-IRAにおけるそれは，冠動脈疾患の家族歴のないことと非糖尿病，発症時のIRAへの側副血行路の発達となった．多変量解析でIRAでは，右冠動脈の梗塞(p＝0.001)，非糖尿病(p＝0.035)が，non-IRAでは，家族歴なし(p＝0.004)と側副血行路の発達(p＝0.011)が関連因子となった．AMI慢性期の冠攣縮反応は症例によって広くばらつきがあり，IRAとnon-IRAでは異なる背景が関連していることが示唆された．

Background:Coronary vasospasm is thought to play an important role in the pathogenesis of acute myocardial infarction(AMI) in many Japanese patients. However, it is not well known how much this phenomenon influences in individual patients.

Methods:The results of the ergonovine provocation test in our previous study, in which the influence of atenolol upon Japanese patients(26 patients with and 34 without atenolol)with acute myocardial infarction were investigated, were reassessed by analyzing the degree of vasomotor tone observed in the infarct-related artery(IRA)(60 cases)and the non-IRA(54 cases)during the test.

Results:Percent stenosis produced by the test was similarly variable between 11% and 100% for IRA and between 12% and 100% for non-IRA. Univariate analysis showed that the index IRA itself(p＝0.013)is related to the reaction of IRA and absence of family history of coronary heart disease(CHD)(p＝0.012), absence of diabetes(p＝0.037), and well developed collateral circulation towards the infarct region on emergency angiogram(p＝0.032)are related to that of non-IRA. Multivariate analysis revealed right coronary artery as IRA(p＝0.001)and absence of diabetes(p＝0.035)as independent predictors of IRA vasoconstriction. In contrast, absence of family history of CHD(p＝0.004)and well developed collateral circulation(p＝0.011)were selected as independent predictors of non-IRA vasoconstriction.

Conclusions:Response to ergonovine is variable in the chronic stage of AMI. Underlying conditions promoting coronary vasoconstriction appear to be different between IRA and non-IRA.