Pulsatile left ventricular assist device support as a bridge to decision in patients with end-stage heart failure complicated by pulmonary hypertension

Abstract

Background: Severe pulmonary hypertension (PH) in heart failure (HF) is a risk factor for adverse outcomes after heart transplantation (HTx). Left ventricular assist devices (LVADs) improve pulmonary hemodynamics, but our understanding of the degree of improvement and the effect on outcomes is still evolving.

Methods: We reviewed invasive pulmonary hemodynamics from 58 consecutive patients receiving LVAD support as a bridge to HTx from 1996 to 2003. The primary outcome was change in baseline transpulmonary gradient (TPG) during LVAD support and after HTx/recovery. The secondary outcome was post-HTx survival.

Results: All patients (age, 49 +/- 14 years, 79% male, 40% ischemic) received a pulsatile LVAD (median support, 97 days; interquartile range [IQR], 31-222). Hemodynamic measurements were obtained at baseline (median, 1 day; IQR, 1-3), during early (median, 1 day; IQR, 0-4) and late (median, 75 days; IQR, 24-186) LVAD support, and after HTx/recovery (median, 28 days; IQR, 17-40). Improvement in TPG occurred throughout LVAD support and was sustained after HTx/recovery. Levels of TPG reductions in patients with a baseline TPG in the highest quartile (14.1-26.0 mm Hg) were 8.6 +/- 3.5 vs 6.5 +/- 3.1 mm Hg in the lowest quartile (2.0-7.7 mm Hg) during LVAD support (p = 0.102), with 90% vs 100% 30-day post-HTx survival (P = 0.113).

Conclusion: Pulmonary hemodynamics and post-HTx survival were similar after pulsatile LVAD support in patients with and without pre-implant PH. LVAD support may be a useful strategy to reverse PH in carefully selected patients, thus improving candidacy for HTx.

Figure 1

Pulmonary hemodynamics in 58 patients at baseline and after left ventricular assist device (LVAD) support. Early improvements in hemodynamics were sustained during late support. The black, white, and striped bars represent baseline (median 1 day pre-implant), early (median 1 day post-implant) and late (median 75 days post-implant) LVAD support, respectively. Values are mean ± standard deviation. MPAP, mean pulmonary artery pressure (mmHg); TPG, transpulmonary gradient (mmHg); PVR, pulmonary vascular resistance (Wood units); ^*p < 0.001 compared with baseline; ^†p = 0.028 compared with early LVAD support.

Figure 2

Pulmonary hemodynamics in patients who survived to heart transplantation (n = 46) or myocardial recovery (n = 4) before, during, and after left ventricular assist device (LVAD) support. There were sustained improvements in hemodynamics after LVAD support. Grey, white, black, and striped bars represent baseline (median 2 days pre-implant), early (median 1 day post-implant), and late (median 75 days post-implant) LVAD support, and post-transplant/recovery (median 28 days post-explant), respectively. Values are mean ± standard deviation. MPAP, mean pulmonary artery pressure (mm Hg); TPG, transpulmonary gradient (mm Hg); PVR, pulmonary vascular resistance (Wood units); ^*p < 0.005 compared with baseline, ^†p = 0.004 compared with post-transplant/recovery.

Figure 3

Transpulmonary gradient (TPG) by quartiles of baseline value in patients surviving to heart transplantation/recovery after left ventricular assist device (LVAD) support. TPG improved in patients with severe pulmonary hypertension. Quartile 4, TPG 14.1–26 mm Hg; quartile 3, TPG 11.3–14.0 mm Hg; quartile 2, TPG 7.8 –11.2 mm Hg; quartile 1, TPG 2.0 –7.7 mm Hg; ^*P < 0.01, quartile 4 follow-up values compared with baseline; ^†p < 0.01, quartile 3 follow-up values compared with baseline; ^‡p < 0.01, quartile 2 follow-up values compared with baseline.

Figure 4

Transpulmonary gradients (TPG) during left ventricular assist device (LVAD) support among the 30 patients within the highest 2 quartiles of baseline values. Solid and dashed lines represent survivors and non-survivors to heart transplant/recovery, respectively. Highest quartiles are TPG 14.1–26 mm Hg (quartile 4) and TPG 11.3–14.0 mm Hg (quartile 3).

Figure 5

Pulmonary hemodynamics in 35 patients supported with a left ventricular assist device (LVAD) who survived to heart transplantation/recovery and received a pre-implant intra-aortic balloon pump. Improvements in transpulmonary gradient (TPG, mm Hg) and pulmonary vascular resistance (PVR, Wood units) were not sustained after transplant/recovery. Grey, white, black, and striped bars represent baseline (median 1 day pre-implant), early (1 day post-implant), and late (68 days post-implant) LVAD support, and post-transplant/recovery (27 days post-explant), respectively. Values are mean ± standard deviation. MPAP, mean pulmonary artery pressure (mm Hg); ^*p < 0.005 compared with baseline; ^†p = 0.012 compared with early LVAD support; ^‡p = 0.011 compared with late LVAD support.

Figure 6

Pulmonary hemodynamics in 15 patients supported with a left ventricular assist device (LVAD) who survived to heart transplantation/recovery and did not receive a pre-implant intra-aortic balloon pump. Early hemodynamic improvements were sustained after LVAD support. Grey, white, black, and striped bars represent baseline (median 2 days pre-implant), early (median 2 days post-implant) and late (median 75 days post-implant) LVAD support, and post-transplant/recovery (median 28 days post-explant), respectively. Values are mean ± standard deviation. MPAP, mean pulmonary artery pressure (mm Hg); TPG, transpulmonary gradient (mm Hg); PVR, pulmonary vascular resistance (Wood units); ^*p < 0.05 compared with baseline.