Evaluation of Type 1 Diabetics for Simultaneous Pancreas-Kidney Transplantation With Regard to Cardiovascular Risk

Major Adverse Cardiovascular Events Following Simultaneous Pancreas and Kidney Transplantation in the United Kingdom

OBJECTIVE

People with type 1 diabetes and kidney failure have an increased risk for major adverse cardiovascular events (MACE). Simultaneous pancreas and kidney transplantation (SPKT) improves survival, but the long-term risk for MACE is uncertain.

RESEARCH DESIGN AND METHODS

We assessed the frequency and risk factors for MACE (defined as fatal cardiovascular disease and nonfatal myocardial infarction or stroke) and related nonfatal MACE to allograft failure in SPKT recipients with type 1 diabetes who underwent transplantation between 2001 and 2015 in the U.K. In a subgroup, we related a pretransplant cardiovascular risk score to MACE.

RESULTS

During 5 years of follow-up, 133 of 1,699 SPKT recipients (7.8%) experienced a MACE. In covariate-adjusted models, age (hazard ratio 1.04 per year [95% CI 1.01-1.07]), prior myocardial infarction (2.6 [1.3-5.0]), stroke (2.3 [1.2-4.7]), amputation (2.0 [1.02-3.7]), donor history of hypertension (1.8 [1.05-3.2]), and waiting time (1.02 per month [1.0-1.04]) were significant predictors. Nonfatal MACE predicted subsequent allograft failure (renal 1.6 [1.06-2.6]; pancreas 1.7 [1.09-2.6]). In the subgroup, the pretransplant cardiovascular risk score predicted MACE (1.04 per 1% increment [1.02-1.06]).

CONCLUSIONS

We report a high rate of MACE in SPKT recipients. There are a number of variables that predict MACE, while nonfatal MACE increase the risk of subsequent allograft failure. It may be beneficial that organs from hypertensive donors are matched to recipients with lower cardiovascular risk. Pretransplant cardiovascular risk scoring may help to identify patients who would benefit from risk factor optimization or alternative transplant therapies and warrants validation nationally.

Coronary Microvascular Dysfunction Predicts Long-Term Outcome in Simultaneous Pancreas-Kidney Transplantation

BACKGROUND

Patients with diabetes are at increased cardiovascular risk. Simultaneous pancreas-kidney transplantation (SPKT) is the treatment of choice in patients with type 1 diabetes mellitus and diabetic nephropathy. We assessed coronary flow reserve (CFR) by transthoracic echocardiography as a marker of major adverse cardiac events (MACE) in SPKT patients.

METHODS

We studied 48 consecutive SPKT patients (28 male, age at SPKT 54 ± 8 years). Time from transplantation was 8.5 ± 3 years. Follow-up was 4.6 ± 1.8 years. Coronary flow velocity in the left anterior descending coronary artery was detected by Doppler echocardiography at rest and during adenosine infusion. CFR was the ratio of hyperemic diastolic flow velocity (DFV) to resting DFV. A CFR ≤ 2 was considered abnormal and a sign of coronary microvascular dysfunction. MACE were cardiac death, myocardial infarction, and heart failure.

RESULTS

CFR was 2.55 ± 0.8. CFR was ≤2 in 13 (27%) patients. CFR was lower in SPKT patients with MACE (2.1 ± 0.7 vs 2.7 ± 0.8, P = .03) and patients with MACE had a higher incidence of CFR ≤ 2 (P = .03). Time from transplantation was shorter in patients with MACE (P < .0001). Patients with CFR ≤ 2 had a lower MACE-free survival (P = .03). CFR ≤ 2 predicted the risk of MACE (P = .007) independently from coronary artery disease and metabolic control. However, this predicted role is lost when adjusted for the time from transplantation, which plays a protective role (P = .001).

CONCLUSIONS

In SPKT, CFR ≤ 2 may be a reliable marker for MACE, independent of coronary artery disease diagnosis. However, this role seems to be reduced over time. This finding suggests a gradual reduction of cardiovascular risk in SPKT patients.

Current concepts in the simultaneous transplantation of kidney and pancreas

Diabetes mellitus (DM) represents an enormous health care concern for the United States and other countries. According to the American Diabetes Association in 2007, there were more than 23 million Americans living with diabetes. This is a 13.5% increase from 2005, likely representing increases in Type II DM (DMII). Diabetes mellitus results when the beta cells of the pancreas are unable to produce sufficient insulin to prevent hyperglycemia. Simultaneous pancreas and kidney transplantation, or SPK, may be indicated for patients that have experienced renal failure as a complication of DM (either type I or type II). Until recently, technical failure represented a significant impediment to the success of pancreas transplantation. At the turn of the century, however, both renal and pancreatic graft survival dramatically improved. Immunologic and nonimmunologic causes of graft failure continue to challenge inpatient and outpatient management. With vigilance in the ICU postoperatively and in the clinic, SPK can provide significant benefit both in patient survival and quality of life.