Hahnemann University Hospital will close its heart transplant program on May 26, the Center City institution's chief executive Michael P. Halter announced Monday in an email to medical staff and employees.

"The reason for the closure of the Heart Transplant Program is due to low activity, despite ongoing efforts to enhance the program. The decision does not reflect the high-quality care that has been provided to our patients," Halter's note said.

Hahnemann, which said in a separate emailed statement that the closure was voluntary, performed just two heart transplants in each of the last two years, according to data from the U.S. Department of Health and Human Services.

By comparison, the Hospital of the University of Pennsylvania led the region, performing 65 transplants last year and 64 transplants in 2015.

Under regulations from the Centers for Medicare and Medicaid Services, centers are expected to perform an average of at least 10 transplants per year to maintain skills to safely perform the complicated procedure.

After a seven-month hiatus, Jefferson Health announced in September that it would resume heart transplants. It performed one transplant last year, and none so far this year, according to the HHS data.

Temple University Hospital has gained share, climbing from two heart transplants in 2011 to 23 last year.

Hahnemann's program peaked at 39 transplants in 1997, a year after Vanguard founder and former chief executive John C. Bogle received a heart transplant there. His surgeons, Rohinton Morris and Louis Samuels, are now at Jefferson.

Hahnemann also said it will voluntarily end its program that implants left ventricular assist devices, which are pumps that aid weakened hearts while patients are waiting for a transplant. Hahnemann did not respond to a question about whether there would be job losses because of the closures.

Publicly-traded Tenet Healthcare Corp. owns Hahnemann and has been trying to sell the money-losing Center City institution, as well as St. Christopher's Hospital for Children in North Philadelphia.

Separately, the Drexel University College of Medicine, which uses Hahnemann as its main teaching hospital, announced to faculty Monday that it will close its Department of Radiation Oncology at the end of June.

"We operate in a very difficult environment of progressively insufficient revenue in the face of high costs of operation; this situation inevitably leads to significant losses for the practice plan and the College," Daniel V. Schindlow, dean of the Drexel College of Medicine and senior vice president for medical affairs, wrote in an email to faculty.

He said the "losses detract from maintaining the necessary fiscal health to meet our mission of educating medical and graduate students, engaging in research, and providing cost-efficient patient services where they are needed most."