Hyperkalemia: Major but still understudied complication among heart transplant recipients

Abstract

Hyperkalemia is a recognized and potentially life-threatening complication of heart transplantation. In the complex biosystem created by transplantation, recipients are susceptible to multiple mechanisms for hyperkalemia which are discussed in detail in this manuscript. Hyperkalemia in heart transplantation could occur pre-transplant, during the transplant period, or post-transplant. Pre-transplant causes of hyperkalemia include hypothermia, donor heart preservation solutions, conventional cardioplegia, normokalemic cardioplegia, continuous warm reperfusion technique, and ex-vivo heart perfusion. Intra-transplant causes of hyperkalemia include anesthetic medications used during the procedure, heparinization, blood transfusions, and a low output state. Finally, post-transplant causes of hyperkalemia include hemostasis and drug-induced hyperkalemia. Hyperkalemia has been studied in kidney and liver transplant recipients, but there is limited data on the incidence, causes, management, and prevention in heart transplant recipients. Hyperkalemia is associated with an increased risk of hospital mortality and readmission in these patients. This review describes the current literature pertaining to the causes, pathophysiology, and treatment of hyperkalemia in patients undergoing heart transplantation and focuses primarily on post-heart transplantation.

The Association Between Tacrolimus Levels and Hyperkalemia in Allograft Recipients Who Underwent Heart or Lung Transplantation in New Orleans, USA Between 2013 and 2019: A Single-Center Retrospective Study

“…Although recognized as a life-threatening complication, the literature supporting the link between tacrolimus and hyperkalemia is limited to mechanistic reviews and case reports in cardiothoracic transplantation [ 11 , 14 ]. A retrospective study in kidney transplant patients found increased hyperkalemia in patients taking tacrolimus vs cyclosporine [ 17 ].…”

“…Clinical intervention for hyperkalemia typically occurs before potassium levels reach 5.5 mmol/L in heart and lung transplantation due to risk of life-threatening arrhythmias. After cardiac surgery, the optimum range is often defined as 3.8–4.3 mmol/L [ 11 ]. Therefore, we chose 5.0 mmol/L as our defined breakpoint for hyperkalemia.…”

“…Elevated potassium levels frequently occur after transplantation, and prompt pharmacologic management is paramount to prevent cardiac arrhythmias associated with severe hyperkalemia [ 10 ]. Hyperkalemia presents a life-threatening complication comprising different mechanisms, including drug-induced hyperkalemia [ 11 ]. Yamada et al found that 1 in every 6 transplant patients experienced hyperkalemia in the acute care setting, which was associated with a 3-fold increase in hospital mortality [ 10 ].…”