[Technical possibilities and limitations of mechanical circulatory support]

Ventricular assist devices (VAD) to support the left (LVAD), the right (RVAD) or both ventricles (BVAD) have emerged as one standard of care for advanced heart failure patients. Initially used to bridge patients to transplantation (BTT) they are now more frequently implanted as permanent support (destination therapy, DT). Bridge to recovery (BTR) is a valid option for only a small number of patients. Although there are different devices available, patient selection, preoperative and intraoperative management, and the timing of VAD implantation are the elements critical to successful circulatory support.

Reversibility of fixed pulmonary hypertension in left ventricular assist device support recipients

OBJECTIVE

Conflicting data still exist concerning the reversibility of secondary severe 'fixed' pulmonary hypertension (PH) by the use of left ventricular assist device (LVAD) support in terms of time necessary to provide a bridge to 'transplantability'.

METHODS

We retrospectively reviewed 145 patients with heart failure and severe PH treated by LVAD support between 2000 and 2009. There were 133 men (91.7%) and 12 women (8.3%) with a mean age of 52.95±12.01 years. Patients were divided into two groups depending on preoperative PH reversibility. Fixed PH was defined by a mean pulmonary arterial pressure (mPAP) >25 mmHg, a pulmonary vascular resistance (PVR) >2.5 Wood Unit (WU) and a transpulmonary gradient (TPG) >12 mmHg, despite pharmacological treatment.

RESULTS

Fifty-six patients had fixed PH (group A) and 89 reversible PH (group B). Only 27 patients of group A underwent right heart catheterization evaluation during LVAD support; the remaining 29 patients had other contraindications to heart transplantation (HTx). The 27 patients were divided into three subgroups on the basis of examination time during LVAD support: <6 months (11 patients), between 6 and 12 months (six patients) and >12 months (10 patients). The mPAP, PVR, and TPG decreased significantly during LVAD support (mPAP, 37.26±6.35 mmHg vs 21.00±7.51 mmHg, p=0.007; PVR, 3.49±1.47 WU vs 1.53±0.66 WU, p=0.000; and TPG, 15.04±5.22 mmHg vs 7.78±3.21 mmHg, p=0.019). A significant reduction of all parameters was observed during the first 6 months and later on there was no further decrease. There were no significant differences between the three subgroups (mPAP, p=0.680; PVR, p=0.723; and TPG, p=0.679) in terms of time of reversibility. LVAD support allowed 19 patients to be transplanted.

CONCLUSIONS

Patients with fixed PH can be treated with LVAD support. Our data suggest that 6 months after LVAD implantation it is possible to observe an important reduction of PH and evaluate the potential transplantability of patients. Longer support does not add any effect of LVAD on PH.