Early left heart decompression protects the lungs in a canine model of acute left heart failure being treated with venoarterial extracorporeal membrane oxygenation.

Background: Nearly 30% of patients who undergo venoarterial extracorporeal membrane oxygenation (VA-ECMO) suffer pulmonary edema, which increases mortality risk. Left heart decompression is widely considered an effective way to counter left ventricular dilatation during VA-ECMO, but whether decompression can protect the lung or improve prognosis is unclear. We investigated this question using a canine model of acute left heart failure being treated through VA-ECMO. Methods: The left anterior descending artery was ligated in 12 beagles to induce acute heart failure, and starting 1 h later, animals were treated using femoral-femoral VA-ECMO for 3 h. In half the animals, left heart decompression was initiated concurrently with VA-ECMO. In the other half, decompression was initiated 1 h after VA-ECMO began. The "early decompression" and "late decompression" groups were compared in terms of pulmonary function, cardiac function, hemodynamics, histopathology and inflammatory responses. Results: Early initiation of decompression led to significantly higher PaO Conclusion: Left heart decompression, when initiated as soon as possible during VA-ECMO, can protect pulmonary function by alleviating inflammatory responses in the lung, improving hemodynamics and lowering ventricular filling pressure.