© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Clin Transplant 2015: 29: 971–977 DOI: 10.1111/ctr.12616
Clinical Transplantation
Coronary events in obese hemodialysis patients before and after renal transplantation De Lima JJG, Gowdak LHW, de Paula FJ, Muela HCS, David-Neto E, Bortolotto LA. Coronary events in obese hemodialysis patients before and after renal transplantation. Abstract: We examined the impact of obesity (BMI ≥30 kg/m2, n = 357) on prognosis in 1696 hemodialysis (HD) patients before and after renal transplantation (TX). End-points were coronary events, composite cardiovascular (CV) events, and death. Obese HD patients were older (55.9 9.2 vs. 54.2 11), had more diabetes (54% vs. 40%), dyslipidemia (49% vs. 30%), altered myocardial scan (38% vs. 31%), myocardial infarction (MI) (16% vs. 10%), coronary intervention (11% vs. 7%), higher total cholesterol (186 52 vs. 169 47), and triglycerides (219 167 vs. 144 91). Obese undergoing TX had more dyslipidemia (46% vs. 31%), angina (23% vs. 14%), MI (18% vs. 5%), increased total cholesterol (185 56 vs. 172 48), and triglycerides (237 190 vs. 149 100). Obesity was independently associated with coronary events (log-rank = 0.008, HR 2.55% CI 1.27–5.11) and death (log-rank 0.046, HR 1.52, % CI 1.007–2.30) in TX but not in HD. Obese HD patients had more risk factors and ischemic heart disease, but these characteristics did not interfere with prognosis. In TX patients, obesity predicts coronary events and death.
Jose Jayme G. De Limaa, Luis Henrique W. Gowdaka, Flavio J. de Paulab, Henrique Cotchi S. Muelaa,c, Elias DavidNetob and Luiz A. Bortolottoa a ~o Paulo Heart Institute (InCor), University of Sa Medical School, bRenal Transplant Unit, Urology, Hospital das Clınicas, University of ~o Paulo Medical School, Sa ~o Paulo,Brazil Sa and cFaculty of Medicine, Agostinho Neto University, Luanda, Angola
Key words: chronic kidney disease – hemodialysis – ischemic heart disease – obesity – renal transplantation Corresponding author: Jose J.G. De Lima, MD, PhD, Heart Institute (InCor), Rua Eneas ~o Paulo, SP, Carvalho Aguiar 44 05403-000 Sa Brazil. Tel.: +55 11 26615084; fax: 26615482; e-mail:
[email protected] Conflict of interest: None. Accepted for publication 11 August 2015
In patients on hemodialysis (HD), obesity is not associated with adverse cardiovascular events (CVE) events and death and may even be protective (1, 2). On the other hand, in patients undergoing renal transplantation (TX), obesity has been shown to be an independent risk factor for delayed graft function (DGF) (3, 4) and reduced graft (4, 5) and patient survival (5). It is unclear how TX could turn obesity from a survival advantage in dialysis to a risk factor endangering survival. A plausible explanation is that the impact of CV risk factors, frequent in obese, such as diabetes, dyslipidemia, and hypertension, has different effects on outcome before and after TX. However, it is still debatable whether TX increases the incidence of CV events in obese HD patients. In our center, we started a prospective, observational study intended to determine the best clinical and CV investigation for the detection of coronary
artery disease (CAD) and prediction of CV events in patients on the kidney transplant waiting list (6). In this retrospective cohort study, the database and data collected during follow-up were used to evaluate the relationship between obesity and prognosis in HD patients on the waiting list before and after renal transplantation. We intended to verify whether and why traditional CV risk factors present in obese patients could have a different impact on prognosis before and after TX. We took particular interest in coronary events, as they are an important cause of major CV events in dialysis and in transplanted patients. Patients and methods
This investigation was approved by the institutional ethics committee and conducted according to the Declaration of Helsinki. All subjects
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provided a signed, written informed consent at entry into the study. Between 1998 and 2014, 1696 adult (≥18 yr old) patients with chronic kidney disease (CKD) on maintenance HD, scheduled to receive their first engraft from a deceased donor, were referred for CV risk assessment before inclusion on kidney transplant waiting lists. All patients underwent a pre-specified comprehensive CV risk evaluation as reported elsewhere (6, 7). Briefly, we obtained from all patients a medical history and performed a physical examination with special interest in CV risk factors and previous and/or current cardiovascular disease (CVD). We also performed routine laboratory tests, resting 12-lead electrocardiography, transthoracic echocardiography, and myocardial perfusion scanning by singlephoton emission computed tomography (SPECT) Tc99 m sestamibi after pharmacological stress with dipyridamole or adenosine. In 2.3% of patients, results of SPECT were considered inadequate. In those cases, the tests were repeated. Patients considered at high risk for CAD (age ≥50 yr, or diabetes, types 1 or 2), or having CVD, such as angina, previous myocardial infarction (MI) or stroke, left ventricular dysfunction, or extracardiac atherosclerosis, or having non-invasive testing suggestive of CAD, were eligible for coronary angiography. Significant CAD was arbitrarily defined as luminal stenosis ≥70% in one or more epicardial arteries by visual estimation from two independent experts. All data were prospectively recorded in a computerized database. Allocation of deceased donor kidneys was centrally directed on the basis of a computerized algorithm, as reported (7). Body mass index (weight in kilograms divided by height in square meters) was calculated from data collected, at the time of inclusion in the list, on a day between two consecutive dialysis sections performed no more than 48-h from each other to reduce the interference of fluid overload. Patients were classified as obese and non-obese by BMI cutoff ≥30 kg/m2. Smokers comprised current and past tobacco users. Hypertension was defined as systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg (average of three consecutive readings taken between two consecutive dialysis sessions). Dyslipidemia was defined as total cholesterol and/or triglycerides ≥200 mg/dL. We used the Framingham study as a reference to define hypercholesterolemia. Because there is no guideline to define hypertriglyceridemia in dialysis patients, we used the median of our data. Diabetes (types 1 and 2) was defined according to American Diabetes Association guidelines. CV disease was defined by at least one of the following: heart failure, previous MI or stroke, coronary intervention
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(surgical/percutaneous), and arterial vascular disease. Heart failure was defined as New York Heart Association functional Class III or IV or ejection fraction
