Article

A32 - Impella can Increase Flow to the False Lumen and Impair Distal Coronary Flow in a Pig Model of Coronary Dissection

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Citation:Interventional Cardiology Review 2019;14(3 Suppl 1):A32.

Correspondence: Taro Kariya, kariya-tky@umin.org

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Background: Coronary dissection (CD) sometimes compromises haemodynamics and requires circulatory support. Impella compromises coronary flow in a certain form of CD.

Hypothesis: The Impella 5.0 will help preserve kidney function in patients in cardiogenic shock and decompensated heart failure.

Methods: Left anterior descending (LAD) artery dissection was created in Yorkshire pigs (n=6) by guidewire-induced intimal scratch and deep engagement of a blunt-cut-tip guiding catheter. The impact of Impella on CD was evaluated with a coronary pressure wire and LV pressure–volume catheter. Impella CP was set to P0 (no support) or P8 (maximal support). LAD flow delay time (DT) was calculated as the difference of LAD and LCX filling times in the angiogram.

Results: CD was successfully induced in the proximal LAD of all pigs, with four of them displaying large initial flaps. One pig exhibited TIMI-1 grade flow (DT 1.07 seconds), while other pigs had TIMI-2 to 3 (0.20 ± 0.08 seconds). With Impella support, LV was unloaded, as evidenced by decreased LV end-diastolic pressure (23.2 ± 1.8 to 11.2 ± 2.8 mmHg, p=0.012), LV end-diastolic volume (136 ± 34 versus 102 ± 30 ml, p=0.029) and stroke work (6,452 ± 1,924 versus 4,989 ± 1,756 mmHg/ml, p=0.028). Maximal Impella support resulted in further delay of LAD flow in the pig with TIMI-1 (DT 2.53 seconds), whereas it remained similar in other pigs (DT 0.20 ± 0.14 seconds, p=1.00). LAD pressures distal to CD decreased in the pig with TIMI-1 (Pmax 36.7 to 29.6, Pmax 15.8 to 10.8, Pmean 22.9 to 17.1 mmHg), while they increased in other pigs (Pmax 127.6 ± 25.1 to 140.8 ± 29.7, p=0.022; Pmax 75.4 ± 27.6 to 100.7 ± 30.1, p=0.0006; Pmean 101.4 ± 23.1 to 117.0 ± 29.8 mmHg, p=0.013). The pressure of the false lumen increased after Impella support in the pig with further delay (Pmean 74.2–99.0 mmHg), suggesting increased flow into the false lumen during Impella support.

Conclusion: We successfully created a pig model of CD. Impella effectively unloaded LV in pigs with CD, but worsened coronary pressure and flow in one pig with a large flap and low TIMI flow grading.