VADを用いた心移植のブリッジは問題がある

非常に重度の患者に対し緊急心移植までの間をVADでブリッジした場合の術後成績は移植まで従来の治療を行った患者と比較し不良である
Worse postoperative outcomes for critically ill patients bridged to urgent heart transplantation with VADs than with conventional therapy
非常に重度の患者に対し緊急心移植（～ status UNOS 1A）までの間をVADでブリッジした場合の術後成績は、移植まで従来の治療を行った患者と比較し有意に不良であるとの最近のSpanish National Heart Transplant Registry（スペイン心移植レジストリ）の結果が2011年European Society of Cardiology学会で発表された。研究者らは、2000～2009年に15のスペインの病院で緊急の高優先度心移植を施行された704人の重症心不全患者を対象とした施設レトロスペクティブスタディを行った。107人の患者が移植前に短期間のVADによる補助を受け、一方残りの597人は強心薬静脈内投与、侵襲的人工呼吸および/または大動脈内バルーンパンピングなどの従来通りの治療によりブリッジされた。埋め込まれたVADは58症例が体側パルス血流装置で47例は体外持続血流装置であった。興味深いことに、平均待機時間は非常に短く約5日間であり、これは非常によく整備されたスペインの高度緊急臓器調達および配置システムの特徴的な実態であった。移植前臨床状態および臓器機能はほぼ同等であったにも関わらず、VADでブリッジされた患者においては従来通りにブリッジされた患者と比較し、重度の術中出血発現率が高く、バイパス時間が長く、一次グラフト不全率が高く、結果として移植後生存率が低かった。
Full Text

Postoperative outcomes of severe heart failure patients bridged with short-term VADs to urgent (～ status UNOS 1A) heart transplantation are significantly worse than those of patients bridged with conventional support, recent data of the Spanish National Heart Transplant Registry suggest according to a presentation at the 2011 European Society of Cardiology Congress.

Spanish investigators led by Drs. Eduardo Barge-Caballero and Marisa Crespo-Leiro from the Hospital Universitario A Coruna conducted a multi-institutional retrospective study of 704 patients with critical heart failure, who underwent urgent, high-priority heart transplantation in 15 Spanish hospitals from January 2000 to December 2009. One hundred and seven patients had been supported with short-term VADs before transplantation, while the remaining 597 had been bridged with conventional therapy that included intravenous inotropes, invasive mechanical ventilation and/or intraaortic balloon pump. Implanted VADs were paracorporeal pulsatile-flow devices in 58 cases and extracorporeal continuous-flow ones in 47. Interestingly, mean waiting list time was extremely short, around 5 days, a characteristic fact of the well-organized Spanish high-emergency organ procurement and allocation system.

Despite fairly similar pre-transplant clinical status and end-organ function, VAD bridged patients showed a higher incidence of severe surgical bleeding, longer bypass times and higher rates of primary graft failure than conventionally bridged patients, resulting in a significantly reduced post-transplant survival.

In Dr. Barge-Caballero´s opinion, "our data suggest that routine short-term VAD implantation in stable patients awaiting high-emergency heart transplantation should not be recommended, at least in countries with expected short waiting list times, as this strategy might compromise heart transplant outcomes". For the main investigator of the study, "short-term VAD support as a bridge to high-emergency heart transplantation should be reserved for critically ill patients with a deteriorating hemodynamic status, in which conventional therapy is not enough to ensure adequate peripheral perfusion and to avoid irreversible end-organ damage".

Contributors are Drs. E. Barge-Caballero and M. Crespo-Leiro on behalf of the Spanish Group of Heart Transplant Teams.