麻豆传媒

One center's heart transplant volume grew substantially following a move to accept donor hearts more liberally, among other strategic changes, researchers reported.

The restructuring of the advanced heart failure program at Yale New Haven Hospital in Connecticut included a change in donor selection philosophy. Heart size mismatches were better tolerated, as were donors of higher age and high-risk donors (predominantly due to prior drug use), though hepatitis C virus-positive donors continued to not be accepted.

Annual volume increased from 12.3 heart transplants per year before the changes (Sept. 1, 2014 to Aug. 31, 2018) to 58 per year afterward (Sept. 1, 2018 to Aug. 31, 2019), according to Harlan Krumholz, MD, SM, director of the Center for Outcomes Research and Evaluation at Yale New Haven, and colleagues.

The study, published , showed that when annual case volumes were counted in years starting from July 1 and ending June 30, case volume increased by 374% during this period at Yale, whereas four other regional centers had volume changes ranging from -10% to +68%.

"The volume increase at our center was associated with accepting hearts from older donors with more comorbidities that were refused by more centers, and offering opportunities to recipients with higher acuity (i.e., receiving extracorporeal membrane oxygenation or an intra-aortic balloon pump requiring heart-kidney transplants)," the team noted. "These observations may be applicable to other centers contemplating increasing the use of donor hearts."

Survival at 180 days was similar between heart transplant recipients before and after the changes at Yale (87.8% vs 89.7%). Mortality while on the waiting list was also statistically no different (2.8 deaths per year vs 3 deaths per year, respectively).

Yale's strategic changes went beyond greater donor heart acceptance to include a change in the surgical directorship in the advanced heart failure service, hospital funding for a dedicated procurement surgeon and additional transplant coordinator, and increased surgical attending physician involvement in pretransplant listing and rounding on inpatients awaiting transplant.

Notably, these changes occurred in mid-August 2018, coinciding with implementation of the new United Network for Organ Sharing (UNOS) donor heart allocation system. The new rules made people on temporary mechanical circulatory support a high priority and have been criticized for the potential for hospitals to game the new system.

"Our study suggests that strategic and service structure changes led by new surgical leadership coinciding with change in the UNOS allocation system may have substantially increased the acceptance of donor heart offers and transplant volume while maintaining comparable unadjusted short-term outcomes," the investigators concluded.

"Breaking out of traditional, more conservative practice patterns associated with donor and recipient selection is not easy when transplant centers are heavily regulated and measured by publicly reported outcomes," according to an by Jason Bjelkengren, RN, BSN, and Todd Dardas, MD, MS, of the University of Washington in Seattle.

Clinical and financial risks include rising mortality and hospitals going on probation and potentially losing the credential to perform transplants, Krumholz's group noted.

"Nonetheless, for programs that are willing to expend resources and embark on concerted systematic improvement, heart transplant volumes can be increased," Bjelkengren and Dardas wrote.

The way to do that, they said, is not to seek more unconventional donors (e.g., hepatitis C-positive donors in remote areas, donation after cardiac death) but rather to accept donors with risk factors previously seen as unfavorable.

"For early adopters, an increase in transplant rates can be expected and maintained with ongoing quality monitoring and measured discourse in the case of adverse events," the commentators continued. "Quality improvement efforts ... have the greatest potential to permanently switch the norms in donor and donor-recipient matching away from inappropriate conservatism and toward increased heart transplant rates."

The study included 107 patients who underwent heart transplant surgery at Yale New Haven Hospital. Before the institutional changes, the proportion of transplant recipients who were women was 40.8%, and median age was 57. After the changes, the proportion of women fell to 32.8%, with median age staying at 57 years.

Several measures pointed to the greater acceptance of organ offers, the researchers said:

• Overall offer acceptance rate increased (from 6.4% before the changes to 20.5% after, P<0.001)

• Donor hearts with more prior refusals were accepted (from 3.0 refusals to 16.5, P<0.001)

• Donor hearts from older donors were increasingly accepted (from a median age of 30 to 40, P<0.001)

• Recipients spent less time on the waiting list (from a median 242 days to 41 days, P<0.001)

The finding that older hearts were increasingly used for transplant "suggests that previously held concepts about what constitutes a 'usable donor' were perhaps inaccurate or inflated based on a binary treatment of risk factors as good or bad, creating a false dichotomy," commented Bjelkengren and Dardas.

Following the institutional changes, more patients were supported on temporary circulatory assist devices preoperatively (24.1% vs 0, P<0.001).

Moreover, there was a greater number of people undergoing left ventricular assist device implant or heart transplant (69 vs 42 patients per year). "The exact cause of this increase is difficult to isolate but likely involves publicity regarding the increase in the propensity for transplants at our center," the researchers suggested.

Limitations of the study, they said, included the lack of longer-term data on survival and the risk of late consequences such as allograft vasculopathy.

"This is a pre-post cohort study and a causal relationship between the program change and patient characteristics or case volume was not ascertained," Krumholz and co-authors wrote. "However, the program changes coincided with the expected change in donor heart characteristics and increase in the case volume, suggesting that the observed changes were indeed associated with the program change."

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