Heart Transplant Criteria: Rethinking Pulmonary Vascular Resistance

PHOENIX — High pulmonary vascular resistance (PVR) alone should not disqualify a person for heart transplantation, research suggested.

Based on data from the Organ Procurement and Transplantation Network, an elevated PVR was not actually predictive of excess 1-year mortality after heart transplantation, whereas a high transpulmonary gradient (TPG) was, reported Ahmed Zayed, MBBCh, of Staten Island University Hospital, Northwell Health, New York City.

Compared with transplant recipients who’d had low PVR and low TPG, the excess risk was observed in peers who had elevated TPG, whether with a low PVR (adjusted HR 1.15, 95% CI 1.04-1.28) or a high PVR (adjusted HR 1.18, 95% CI 1.08-1.28). A high PVR with low TPG was not significantly tied to greater post-transplant mortality (adjusted HR 1.06, 95% CI 0.92-1.23).

Similarly, as continuous variables, rising PVR did not correlate with rising deaths (adjusted HR 1.00 at 3 Wood Units, adjusted HR 0.94 at 8 Wood Units), while rising TPG did (adjusted HR 1.13 at 12 mmHg, adjusted HR 1.23 at 18 mmHg).

Zayed presented these findings during a poster session here at the Heart Failure Society of America annual meeting. The study manuscript was simultaneously published in JACC: Heart Failure.

Study Insights

The high PVR/low TPG phenotype was defined by low cardiac output and high filling pressures, indicating that its PVR elevation is a flow-dependent, mathematical artifact rather than fixed pulmonary vascular disease, so the donor right ventricle is not exposed to a high gradient.

The practical message for clinicians is simple and I think reassuring: a candidate with a high calculated PVR but a normal TPG probably shouldn’t be turned down on the PVR number alone. Conversely, a normal PVR in a high-output or LVAD [left ventricular assist device]-supported patient can be falsely reassuring, and an elevated gradient in that setting deserves real attention to reversibility and to protecting the donor right ventricle around the time of transplant.

Fuente: https://www.medpagetoday.com/meetingcoverage/hfsa/123354