PARIS – Worse long-term outcomes after high-emergency heart transplants in patients bridged to transplant with cardiac assist devices seem to be related to more complex transplant procedures for those patients rather than differences in patients or donors, a registry study suggests.
The study compared data on 107 patients who had been supported with short-term ventricular assist devices (VADs) and 597 patients supported with conventional therapy before high-emergency heart transplantation (defined by United Network for Organ Sharing status 1 criteria). Data came from 15 centers in the Spanish National Heart Transplant Registry in 2000-2009.
In the postoperative period, rates of primary graft failure and major bleeding were higher among VAD patients than among the conventional group (39% vs. 22%, and 33% vs. 23%, respectively). Furthermore, 22% in the VAD group and 14% in the conventional group required cardiac reoperation. These differences between groups were statistically significant, Dr. Eduardo Barge-Caballero and his associates reported in a press briefing at the annual congress of the European Society of Cardiology.
There was a trend toward higher risk of in-hospital death after surgery in the VAD group (36%) compared with the conventional group (27%), but this did not reach statistical significance. Approximately 60% of patients in the VAD group survived a year after transplantation compared with about 70% of patients in the conventional group.
Long-term survival rates differed significantly between groups by the first year after heart transplantation after adjustment for confounding variables, but the differences were not significant at 10 years of follow-up, said Dr. Barge-Caballero of Hospital Universitario A Coruña, Spain.
Concerns about potential adverse impacts of short-term VAD on outcomes after high-emergency heart transplantation have been cited previously. It has been suggested that these adverse impacts may have been caused by the VAD patients being in worse clinical condition, undergoing more difficult procedures with bleeding complications and infections caused by removal of the VAD, receiving less-desirable donor hearts, or being at a higher risk of rejection.
The current study, which compared the clinical characteristics of donor hearts and recipients in the VAD and conventional groups, concluded that donors were similar between groups and recipients were "not drastically different" between groups, Dr. Barge-Caballero said.
Two kinds of VADs were implanted: Forty-nine patients got extracorporeal continuous-flow devices, and 58 patients received paracorporeal pulsatile-flow devices. There was a trend toward a higher risk of bleeding with the paracorporeal pulsatile-flow devices, but there were not enough patients in each group to show a significant difference, he said.
Patients supported by VAD were significantly younger than were those receiving conventional bridge therapy (48 vs. 51 years, respectively) and were more likely to be female (37% vs. 17%) and to have had previous cardiac surgery (53% vs. 20%). Before VAD implantation, patients in the VAD group received higher doses of intravenous inotropes than did patients in the conventional group.
Measures of end-organ function such as creatinine and bilirubin were similar between groups. Donor organs were similar between groups in age, cold ischemia time, and other characteristics.
The surgical bypass time was significantly longer in the VAD group (156 minutes) than in the conventional group (133 minutes), which may reflect more complicated heart transplantation surgery in the VAD group, he suggested.
Patients spent a mean of only 5 days on bridge support with VAD or conventional bridge therapy, including intra-aortic balloon pump and/or IV inotropes, invasive mechanical ventilation, and dialysis.
Stable patients awaiting high-emergency heart transplantation in countries with short waiting lists should not routinely get VADs, Dr. Barge-Caballero suggested. Because of their risks, VADs should be reserved for critically ill patients who deteriorate when conventional therapy does not provide adequate peripheral perfusion to avoid irreversible end-organ damage.
"Routine implantation of a short-term VAD is not a good option for all patients undergoing a high-emergency heart transplantation," Dr. Barge-Caballero said. "It’s evident that if the patient is really not doing well, has severe hemodynamic instability, [and] is not well with conventional support, we have to implant a VAD. But it’s not, in our opinion, a good option for all patients."
Dr. Barge-Caballero said the investigators had no relevant conflicts of interest.