Cardiovascular Risk Factors and Events in Pancreas-Kidney Transplants

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.

Incidence, risk factors, and outcomes of stroke post-transplantation in patients receiving a steroid sparing immunosuppression protocol

Corticosteroid use after transplantation is associated with an increased incidence of cardiovascular events and death. Cerebrovascular disease is a common cause of morbidity and mortality post-renal transplantation; however, a dedicated analysis of cerebrovascular disease in recipients of a steroid sparing protocol has not been reported. The aim of this study was to examine the incidence, risk factors, and outcomes of CVA in transplant recipients receiving a steroid sparing protocol. We retrospectively analyzed 1237 patients who received a kidney alone or a simultaneous pancreas and kidney (SPK) transplant. Fifty-six of 1237 (4.53%) patients had a CVA post-transplant. All-cause mortality was significantly higher in the CVA group compared with the non-CVA group, OR: 3.4 (1.7-7.0), p < 0.001. Factors found to be associated with increased risk of CVA by multivariate analysis were older age, HR: 1.07 (1.04-1.09), p < 0.001; diabetes at the time of transplantation, HR: 2.83 (1.42-5.64), p = 0.003; corticosteroid use pre-transplant, HR: 3.27 (1.29-8.27), p = 0.013 and recipients of a SPK, HR: 4.03 (1.85-8.79), p < 0.001. This study has identified subgroups of patients who are at increased risk of CVA post-transplant in patients otherwise receiving a steroid sparing immunosuppression protocol.

A possible role for statin therapy in solitary pancreas transplantation?

INTRODUCTION

Statin use after renal transplantation improves long-term outcome and reduces the incidence of glomerulonephritis. With both anti-inflammatory and cardioprotective effects, statins may also improve outcomes in pancreas transplantation.

METHODS

A retrospective review at a single institution was undertaken. Patients who underwent solitary pancreas transplantation between 2001 and 2010 were identified. Multiple data points including recipient and donor demographics, patient and graft outcomes, and early use of statins were collected.

RESULTS

Sixty-eight patients underwent solitary pancreas transplantation within the study period. Eighteen patients (26%) were already on, or were prescribed, a statin at the time of hospital discharge; the 1-year death-censored graft survival was 81.25% for those that were on statins versus 72.9% for those without (P = NS). Excluding patients with early graft loss (<600 days) mean graft survival was 646 days longer for patients receiving statins (P = .02).

CONCLUSIONS

The use of statins in the solitary pancreas transplant patient may lead to improved outcomes. Whether this is owing to cardiovascular protection or to other factors not associated with lipid lowering remains unclear.