Contribution of impaired renal function to
cardiovascular risk prediction models in
renal transplant recipients
Benguzzi M, Mansell H, Hassan A, Elmoselhi H, Mainra R, Shoker A.
Contribution of impaired renal function to cardiovascular risk
prediction models in renal transplant recipients.
Abstract: Background: The Framingham risk score (FRS) and
cardiovascular risk calculator for renal transplant recipients (CRCRTR-
MACE) quantify cardiovascular risk in renal transplant recipients
(RTR). In contrast to the FRS, the CRCRTR-MACE includes serum
creatinine as a variable in the risk prediction equation.
Objective: To determine the influence of impaired renal function on
performances of the two equations.
Methods: A chart review of 270 RTR transplanted from 1979 to 2012.
High risk was defined at scores ≥20%. Standard statistical analyses
included multivariate analysis (MVA), stepwise analysis, and odds ratio
to estimate contributions of risk factors.
Results: Mean transplant duration was 9.51 Æ 6.65 yr. Mean eGFR was
59.19 Æ 28.26 mL/min/1.73 m
2
. FRS and CRCRTR-MACE scores of
least 20% were present in 9.3% and 24.8%, respectively, while 7.2% and
11.2% of RTR with eGFR ≥60 mL/min/1.73 m
2
were high risk,
respectively. Mean age, blood pressure, TC:HDL ratio, smoking, and
diabetes were evenly distributed in patients with varying eGFR. FRS
scores remained similar at wide eGFR range (≤30 mL/min/
1.73 m
2
–≥90 mL/min/1.73 m
2
), while CRCRTR-MACE scores
significantly increased as eGFR decreased.
Conclusions: CRCRTR-MACE identified more patients at high
cardiovascular risk, even in those with more favorable renal function,
suggesting a fundamental difference between the two calculators beyond
renal function.
Mowad Benguzzi
a
, Holly Mansell
b
,
Abubakar Hassan
b
, Hamdi
Elmoselhi
b
, Rahul Mainra
b
and
Ahmed Shoker
a,b,c
a
University of Saskatchewan, College of
Medicine,
b
St. Paul’s Hospital, Saskatchewan
Renal Transplant Program and
c
Department of
Medicine, University of Saskatchewan,
Saskatoon, SK, Canada
Key words: cardiovascular events –
cardiovascular risk factors – Framingham risk
score – GFR – kidney transplantation – MACE
Corresponding author: Ahmed Shoker, St.
Paul’s Hospital, Saskatchewan Renal
Transplant Program, 1702 20th Street West,
Saskatoon, SK, S7M 0Z9.
Tel.: 306-655-5934;
fax: 306-655-5959;
e-mail: ahmed.shoker@usask.ca
Conflict of Interest: None.
Accepted for publication 17 September 2014
Cardiovascular disease (CVD), a leading cause of
morbidity and mortality, remains a significant
challenge before and after kidney transplantation
(1). Both traditional risk factors (such as hyperten-
sion, weight gain, DM, and hyperlipidemia) and
non-traditional risk factors (such as impaired renal
transplant function) are believed to impart cardio-
vascular risk (2, 3). As global screening of total
burden of risk assists in predicting future cardio-
vascular events and tailoring preventative therapy,
researchers have attempted to develop, modify,
and validate prediction risk scores in kidney trans-
plant recipients (4). The Framingham Heart study
has generated risk prediction algorithms from the
general population based on traditional risk fac-
tors (5, 6). These factors (age, gender, blood pres-
sure, HDL cholesterol, diabetes, smoking history)
are common among renal transplant recipients
(RTR).
The negative impact of impaired renal function
on CVE is well known (7) and has been extensively
reviewed by Sarnak (8). It is confounded by the
increased prevalence of traditional risk factors in
patients with impaired renal function (9). Many
researchers will argue, however, that the effect of
diminished eGFR on CVD cannot be explained by
traditional factors alone (10, 11), and this has
sparked the search for non-traditional risk causes.
The relative contribution of increased traditional
risk versus impaired renal function has come to the
forefront of research to define the relative contri-
butions of increased traditional risks versus
impaired renal function on CVD scores and CVE
(11).
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© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Clin Transplant 2014: 28: 1383–1392 DOI: 10.1111/ctr.12466
Clinical Transplantation