併用療法により心臓施術後の片頭痛が減少する (CS 01)

CANOA：クロピドグレルとアスピリンの併用により心房中隔欠損症に対するカテーテル閉鎖術後の片頭痛の発現および回数が減少する
CANOA: Clopidogrel plus aspirin reduces occurrence and number of migraines following transcatheter closure of an atrial septal defect
クロピドグレルとアスピリンの併用を3か月間行うことで心房中隔欠損症（ASD）に対するカテーテル閉鎖術を施行された患者の片頭痛の頻度が減少した、とのCANOA試験の結果が2015年American Heart Association学会で発表され同時にJAMAに掲載された。カテーテルを用いたASD閉鎖術後患者の約15%において片頭痛発作の新規発症が認められ、初回エピソードの多くは施術後数日から数週間以内に発症すると報告されている。研究者らは、ASD閉鎖術の適応で片頭痛歴のない患者171人を抗血小板薬2剤併用療法（アスピリン＋クロピドグレル［クロ ピドグレル群］、84人）または抗血小板薬単剤療法（アスピリン＋プラセボ［プラセボ群］、87人）にランダムに割り付け、カテーテルを用いたASD閉鎖術後3か月間追跡した。クロピドグレル群では施術後3か月以内の1か月当たりの片頭痛平均日数がプラセボ群よりも減少し（0.4日対1.4日）、片頭痛発作頻度が低かった（クロピドグレル群9.5%対プラセボ群22%）。片頭痛発現患者においては、クロピドグレル群の方が重症度が低かった。
Full Text

Three months of clopidogrel plus aspirin was associated with a reduced frequency of migraine in patients who had undergone transcatheter closure of an atrial septal defect (ASD) in the CANOA study.

Josep Rodes-Cabau, M.D., of Laval University, Quebec City, Canada, and colleagues randomly assigned 171 patients with an indication for ASD closure and no history of migraine to receive dual antiplatelet therapy (aspirin + clopidogrel [the clopidogrel group], n = 84) or single antiplatelet therapy (aspirin + placebo [the placebo group], n = 87) for 3 months following transcatheter ASD closure. This JAMA study is being released to coincide with its presentation at the American Heart Association's Scientific Sessions 2015.

Occurrence of new-onset migraine attacks has been reported in approximately 15 percent of patients following transcatheter ASD closure, with the majority of initial episodes occurring within the days to weeks following the procedure. Aspirin is often prescribed for 6 months following the procedure. Preliminary studies have suggested an association with a lower incidence and severity of migraine headaches following ASD closure when ticlopidine or clopidogrel is added to aspirin treatment.

The CANOA researchers found that patients in the clopidogrel group had a reduced average number of monthly migraine days within the 3 months following the procedure (0.4 days) vs. the placebo group (1.4 days) and a lower incidence of migraine attacks (9.5 percent for the clopidogrel group vs. 22 percent for the placebo group). Among patients with migraines, those in the clopidogrel group had less-severe migraine attacks (zero patients with moderately or severely disabling migraine attacks vs. 37 percent [7 patients] in the placebo group). No significant increase in adverse events was observed with the use of dual vs. single antiplatelet therapy.

"Further studies are needed to assess generalizability and durability of this effect," the authors write.

This study was funded by unrestricted grants from Sanofi and St. Jude Medical and a grant from the Foundation of the Quebec Heart and Lung Institute.