Objectives: Renal transplant recipients may present with transplant-specific risk factors related to end-stage renal disease. Although cardiovascular disease-related deaths may be reduced in renal transplant recipients, this disease is still the leading cause of death in patients with a functioning allograft. In this study, our aim was to determine the incidence of cardiovascular events after renal transplant.
Materials and Methods: This observational retrospective cohort study analyzed renal transplant recipients seen at Başkent University Hospital from 2014 to 2017. Posttransplant cardiovascular events were defined as presence of myocardial infarction, percutaneous coronary interventions, new-onset angina, and death. Patient characteristics, traditionals cardiovascular risk factors, routine biochemistry, and other comorbidities were included in our analyses.
Results: In total, 56 renal transplant recipients older than 18 years were included (mean age of 48.4 ± 11.3 years; 21.4% were female patients). In the patient group, 14.2% had coronary artery disease pretransplant, and 1 patient had an acute myocardial infarction. Mean time from transplant to incidence of cardiovascular events (as shown by coronary angiography) was 9.34 ± 5.2 years. Thirty-six recipients (64.2%) had a cardiovascular event during this posttransplant period, and 6 patients who developed cardiovascular events were women. Five patients (8.9%) required bypass surgery after coronary angiography. Stent implantations were needed in 14 patients. The remaining patients received medical treatment decisions. Twenty-one patients had no acute or chronic cardiovascular events. One patient died because of noncardiac reasons (pulmonary aspergillosis). Two patients died after cardiac surgery, and 1 patient died because of decompensated heart failure.
Conclusions: The presence of symptoms of cardiovascular disease is an important prognostic marker that requires cardiac evaluation. As with the general population, modifiable risk factors can reduce the incidence of cardiovascular events in renal transplant recipients.
Key words : Coronary angiography, Coronary artery disease, End-stage renal disease, Kidney transplantation
Cardiovascular disease (CVD) is the most common cause of death in patients with end-stage renal disease. Although some studies have documented a significant reduction in CVD after renal transplant, CVD is still the major cause of death in renal transplant patients.1
In addition to transplant-specific risk factors related to end-stage renal disease, conventional cardiovascular risk factors, such as hyperlipidemia, hypertension, and diabetes, are common in transplant recipients,2,3 partly because of immunosuppressive drugs. These factors are associated with adverse outcomes.4 Thus, aggressive management of these risk factors may reduce the incidence of CVD in this population.
In this study, our aim was to determine the incidence of cardiovascular events after kidney transplant in our center.
Materials and Methods
This study was an observational retrospective follow-up study over a 3-year period. We reviewed clinical records of 56 renal transplant patients at Başkent University Hospital between 2014 and 2017.
Posttransplant cardiovascular events were defined as presence of myocardial infarction, invasive coronary artery therapy (coronary balloon angioplasty, stents, and bypass surgery), new-onset angina, congestive heart failure, and death.
We recorded laboratory parameters, and these included white blood counts, hemoglobin, platelet counts, sodium levels, potassium levels, and creatinine levels. In addition, left ventricular ejection fraction, left atrial size, and tricuspid systolic annular excursion were recorded.
In this study, we collected data of 56 kidney transplant patients with CVD; mean age was 48.4 ± 11.3 years, and 78.6% of patients were men. The most common comorbidity was hypertension (75%). The baseline characteristics of the study group are shown in Table 1.
Coronary angiography was performed in 62.5% of these patients. The average time from transplant to percutaneous coronary intervention (PCI) or coronary angiography was 9.34 ± 5.2 years. A normal coronary artery was observed in 7.14% of patients. In the patient group, 14.2% had coronary artery disease before transplant and 1 patient had an acute myocardial infarction. Of the 56 patients with CVD, 25% had stent implantation, 3.5% had unsuccessful coronary intervention, and 8.9% had history of coronary artery bypass surgery. Medical treatment decisions were undertaken for 21.4% of patients. Cardiovascular disease was the cause of death in 5.3% of the renal transplant recipients.
The presence of cardiovascular events after renal transplant was closely related to conventional cardiovascular risk factors such as male sex, recipient age, hypertension, hyperlipidemia, smoking, and diabetes.
For renal transplant recipients, coronary heart disease is the leading risk factor affecting long-term survival. Several epidemiologic studies have identified factors associated with increased death or illness due to CVD after kidney transplant. These studies showed that cardiovascular risk factors in the general population (eg, high blood pressure, hyperlipidemia, and smoking) are also predictive of events in the transplant population.4,5
It is difficult to determine the possible effects of therapeutic interventions in retrospective cross-sectional analyses. In an examination of cardiovascular death rate in kidney transplant patients, death was significantly reduced over both the short-term and long-term posttransplant periods.1 Similarly, in our study, the rate of cardiovascular death after transplant was low (5.3%). A low mortality rate due to CVD in the transplant population occurred despite increased comorbidity rates from other causes in the recipients. As shown previously, good renal function is associated with a reduction in cardiovascular death.6
After renal transplant, nearly 40% of patients have an adverse cardiovascular event and have a high likelihood of receiving coronary revascularization.7 In our study, both cardiovascular events and PCI incidence were lower than this rate.
Presently, most hospitals do not want to perform coronary angiography for kidney transplant patients. This is because coronary angiography may affect the function of the transplanted kidney by the contrast agent. One study confirmed that renal transplant recipients with coronary artery stenosis are more likely to die if they receive conventional treatment using drugs compared with those who receive revascularization (PCI or coronary bypass surgery).8 We suggest that patients with typical clinical symptoms or suspected CVD should be examined by coronary angiography and treated with PCI.
Numerous associations have been reported between immunosuppressive drugs and CVD risk factors. The CVD risk factors examined in our study are limited; therefore, correlations between lipid levels or factors such as blood pressure and CVD measurements cannot be analyzed here.
Currently, CVDs are a leading cause of noncardiac morbidity and mortality in patients before and after renal transplant. This increased cardiovascular risk may be associated with conventional and nontraditional risk factors. The presence of symptoms of CVD is an important prognostic marker that requires cardiac evaluation. Further studies assessing clinical outcomes are needed to guide management of coronary artery disease in these patients.
Volume : 18
Issue : 1
Pages : 70 - 72
DOI : 10.6002/ect.TOND-TDTD2019.P18
From the 1Department of Cardiology and the 2Department of General Surgery,
Başkent University Faculty of Medicine, Ankara Hospital, Ankara, Turkey
Acknowledgements: The authors have no sources of funding for this study and have no conflicts of interest to declare.
Corresponding author: Emir Karaçağlar, Başkent University Hospital, Ankara, Turkey
Phone: +90 535 3441523
Table 1. Baseline Characteristics and Cardiovascular Risk Factors of Kidney Transplant Recipients (N = 56)