Reviews of the Latest Published Research
Summaries and commentaries from the section editors and invited reviewers present a clinical context for practitioners' application of the latest published research relevant to care of patients with pulmonary hypertension. In this issue, newly-appointed section editor Ioana Preston, MD, comments on a recent publication related to use of LVADs as a bridge to transplant.
Citation: Advances in Pulmonary Hypertension 10, 1; 10.21693/1933-088X-10.1.14
Citation: Advances in Pulmonary Hypertension 10, 1; 10.21693/1933-088X-10.1.14
Mikus E, Stepanenko A, Krabatsch T, Loforte A, Dandel M, Lehmkuhl HB, Hetzer R, Potapov EV. Reversibility of fixed pulmonary hypertension in left ventricular assist device support recipients. Eur J Cardiothorac Surg. 2011; Feb 25. [Epub ahead of print]
The presence of pulmonary hypertension in patients with left heart failure awaiting heart transplant is associated with increased morbidity and mortality post transplant. More specifically, the presence of a pulmonary vascular resistance (PVR) greater than 2.5 Wood Units (WU) and a transpulmonary gradient (TPG) greater than 12 mm Hg after pharmacological tests or continuous administration of inotropic agents are contraindications for heart transplant. Left ventricular assist devices (LVADs) provide a bridge to “transplantability,” but their effect on pulmonary hypertension secondary to left heart failure has not been thoroughly investigated.
In this retrospective review, authors evaluated 145 patients with heart failure and severe pulmonary hypertension (PH) who received LVAD support between 2000 and 2009. The majority of patients received a continuous-flow device and none required a right ventricular assist device. Patients considered to have “fixed” PH had a mean pulmonary arterial pressure (mPAP) >25mmHg, a PVR >2.5 WU, and a TPG > 12mmHg, despite optimized pharmacological treatment. Mean age was 52.95±12.01 years and 92% were men. Fifty-six patients (39%) had fixed PH and 89 (61%) reversible PH. Among patients with fixed PH, 27 (48%) did not have contraindications for heart transplant and underwent right heart catheterization during LVAD support. The 27 patients were divided into three subgroups on the basis of length of LVAD support: <6 months (11 patients), between 6 and 12 months (6 patients), and >12 months (10 patients). The hemodynamic parameters of the 27 patients were compared before and during LVAD support. The mPAP, PVR, and TPG decreased significantly during LVAD support: (mPAP dropped from 37 ± 6.3 mmHg to 21.0 ± 7.5 mmHg, p = 0.007; PVR decreased from 3.49 ± 1.47 WU to 1.53 ± 0.66 WU, p = 0.000; and TPG decreased from 15.0 ± 5.2 mmHg to 7.7 ± 3.2 mmHg, p = 0.019). There were no significant differences in hemodynamics among the three subgroups. Of 27 patients, 19 underwent heart transplant after an average of 564 ± 292 days. Two of them died of sepsis (8 and 32 days post transplant, respectively). Medium-term post-transplant survival of patients with fixed and reversible PH treated by LVAD support was similar.
This retrospective review suggests that treatment with LVAD is associated with a reduction in PH that failed pharmacologic therapy and improves the chance to heart transplant. In addition, post-transplant survival in those patients with improved pulmonary hemodynamics seems to be similar to those with reversible PH receiving LVAD support. LVAD support of longer than 6 months does not seem to add any further hemodynamic benefit. Although this is a retrospective study from a single center of highly selected patients, it suggests that fixed PH associated with end-stage heart failure can be improved in some patients to the degree that heart transplant can be safely approached. In addition, the proper time of the assessment of response seems to be at 6 months.
Ioana Preston, MD
Nick Kim, MD
Contributor Notes