4極リードによりCRT合併症が減少する（Presentation #887）

MORE CRT：心臓再同期療法において4極リードは2極リードよりも優れている
MORE CRT: Quadripolar lead better than bipolar option in cardiac resynchronization therapy

心臓再同期療法（CRT）の際の2極リードの代わりに4極左室（LV）リードを用いることにより、6か月後の合併症を減少させる可能性があるとの予備的なホットラインセッションの結果が2014年European Society of Cardiology Congressで発表された。MORE-CRTスタディには、13か国63施設のCRT予定の心不全患者1,068人が組み入れられた。患者（68歳前 後）は1:2の比率で2極リード（コントロール；348人）または4極リード（720人）を用いてCRTを施行される群にランダムに割り付けられた。6か月後に、4極リードを用いられた患者は2極リードを用いられた患者と比較し、術中および術後LVリード関連合併症から成る複合エンドポイントが生じない確率が有意に高く（85.97%対76.86%、p=0.0001）、40.8%の相対的リスク軽減（RRR）が認められた。この有益性は主に、4極リード群において術中合併症が50%以上減少した（5.98%対13.73%、p<0.0001、RRR 56.4%）ことによるものであった。4極リード群ではまた、術後合併症も少なかったが、この差は統計学的に有意ではなかった。4極リードは一般的なペーシング合併症を有効に管理する選択肢を増やし、したがってCRTの能力を改善する、と筆者らは結論付けている。

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Use of a quadripolar left ventricular (LV) lead instead of a bipolar option during cardiac resynchronization therapy (CRT) can decrease complications at six months according to preliminary Hot Line results presented at ESC Congress 2014.

The MORE-CRT (More Options available with a quadripolar LV lead pRovidE in-clinic solutions to CRT challenges) trial "demonstrates the safety and efficiency of the quadripolar lead technology in providing more options to manage CRT patients," noted the study's lead investigator Giuseppe Boriani, M.D., Ph.D., from the University of Bologna, Italy.

The CRT device is implanted under the skin with "leads" or wires going into the heart. "However, in up to 10% of heart failure patients LV lead placement is not successful because of anatomical challenges, phrenic nerve stimulation or poor electrical measurements," explained Professor Boriani.

"Quadripolar pacing was developed with the aim of overcoming some of these barriers, but until now it has never been tested in a large, prospective, randomized trial," he added.

The MORE-CRT study included 1 068 heart failure patients scheduled for CRT from 63 centers in 13 countries. Patients (aged approximately 68 years) were randomized in a 1:2 ratio to undergo CRT with either a bipolar lead (controls; n=348) or a quadripolar lead (n=720).

The study showed that at six months, compared to controls, patients with quadripolar leads were significantly more likely to be free from a composite endpoint of both intra- and post-operative LV lead-related complications (85.97% vs. 76.86%, P=0.0001) – a relative risk reduction (RRR) of 40.8%.

The driver of this benefit was mainly intra-operative complications which were reduced by more than 50% in the quadripolar group, noted Professor Boriani (5.98% vs. 13.73%, P<0.0001, RRR 56.4%).

There were also fewer post-operative complications in the quadripolar group, but the difference was not statistically significant.

In conclusion, Professor Boriani said the quadripolar lead "provides more options to effectively manage common pacing complications, as compared to systems based on bipolar leads; hence, improving the efficiency of CRT".

The study was funded by St. Jude Medical.

Professor Boriani reported speaker fees from St. Jude, Medtronic, Boston and Boehringer for lectures at international conferences.