Association between pulse pressure and cardiovascular disease in renal transplant patients

Novel options for failing allograft in kidney transplanted patients to avoid or defer dialysis therapy

PURPOSE OF REVIEW

Despite improvement in short-term renal allograft survival in recent years, renal transplant recipients (RTR) have poorer long-term allograft outcomes. Allograft function slowly declines with periods of stable function similar to natural progression of chronic kidney disease in nontransplant population. Nearly all RTR transitions to failing renal allograft (FRG) period and require transition to dialysis. Conservative chronic kidney disease management before transition to end-stage renal disease is an increasingly important topic; however, there is limited data in RTR regarding how to delay dialysis initiation with conservative management.

RECENT FINDINGS

Since immunological and nonimmunological factors unique to RTR contribute to decline in allograft function, therapies to slow progression of FRG should take both sets of factors into account. Renal replacement therapy either incremental dialysis or rekidney transplantation should be explored. This required taking benefits and risks of continuing immunosuppressive medications into account when allograft nephrectomy may be necessary.

SUMMARY

FRG may benefit from various interventions to slow progression of worsening allograft function. Until there are stronger evidence to guide interventions to preserve renal function, extrapolating evidence from nontransplant patients and clinical judgment are necessary. The goal is to provide individualized care for conservative management of RTR with FRG.

Nutritional management in renal transplant recipients: A transplant team opportunity to improve graft survival

AIMS

The nutritional management of renal transplant recipients (RTR) represents a complex problem either because the recovery of renal function is not complete and for the appearance of "unavoidable" metabolic side effects of immunosuppressive drugs. Nevertheless, it remains a neglected problem, whereas an appropriate dietary intervention could favorably affect graft survival.

DATA SYNTHESIS

Renal transplantation is associated with steroids and calcineurin inhibitors administration, liberalization of diet after dialysis restrictions, and patients' better quality of life. These factors predispose, from the first months after surgery, to body weight gain, enhanced post transplant diabetes, hyperlipidemia, metabolic syndrome, with negative consequences on graft outcome. Unfortunately, specific guidelines about this topic and nutritional counseling are scarce; moreover, beyond the low adherence of patients to any dietary plan, there is a dangerous underestimation of the problem by physicians, sometimes with inadequate interventions. A prompt and specific nutritional management of RTR can help prevent or minimize these metabolic alterations, mostly when associated with careful and repeated counseling.

CONCLUSIONS

A correct nutritional management, possibly tailored to enhance patients' motivation and adherence, represents the best preventive maneuver to increase patients' life and probably improve graft survival, at no cost and with no side effects.

Pulse Pressure and Outcome in Kidney Transplantation: Results From the Collaborative Transplant Study

BACKGROUND

Systolic blood pressure (SBP) and diastolic blood pressure (DBP) are important predictors of graft and patient survival in renal transplantation. Pulse pressure (PP), the difference between systolic and diastolic pressure, has been associated with cardiovascular and renal morbidity in nontransplant epidemiological studies and clinical trials.

METHODS

In this large retrospective analysis of prospectively collected data, transplant recipients from 1995 to 2015 were examined for patient and death-censored graft survival.

RESULTS

In 43 006 recipients, a higher 1-year PP was significantly associated with inferior 10-year patient and death-censored graft survival. In patients 60 years or older, SBP but not DBP was associated with 10-year survival, an effect that was pronounced in patients with a normal SBP of <140 mm Hg and an increased PP of 60 mm Hg or greater, highlighting the superior impact of PP on survival in elderly recipients. In recipients 60 years or older, higher PP was associated with increased mortality due to circulatory system diseases but not to infection or cancer. The combination of PP 60 mm Hg or greater and high SBP of 140 mm Hg or greater showed the strongest association with death-censored graft survival across all age groups.

CONCLUSIONS

We found convincing evidence that PP 1-year posttransplant is predictive of patient survival, especially in elderly recipients with normal SBP. Combined analysis of SBP and PP showed that high PP confers additional predictive information for patient survival beyond that derived from analysis of SBP alone. With regard to prediction of death-censored graft survival, the combination of high SBP and high PP showed the best correlation across all age groups.

Association Between GLCCI1 Promoter Polymorphism (Rs37972) and Post-Transplant Hypertension in Renal Transplant Recipients

BACKGROUND/AIMS

Post-transplant hypertension is highly prevalent in renal transplant recipients and is a risk factor for graft loss, cardiovascular disease and death. Glucocorticoid is used to prevent rejection, but simultaneously increases the risk of post-transplant hypertension. The glucocorticoid-induced transcript 1 (GLCCI1) promoter polymorphism (rs37972) has been reported to be associated with response to glucocorticoid therapy in asthma. We therefore examined the association between GLCCI1 promoter polymorphism and post-transplant hypertension in renal transplant recipients.

METHODS

We conducted a retrospective cohort study of renal transplantation at a single university hospital from October 2003 to January 2014. Fifty consecutive adult recipients were analyzed, with clinical data retrieved from a prospectively collected database. Genotyping was carried out using genomic DNA derived from recipient's blood. GLCCI1 immunoreactivity in vascular endothelial cells was quantitatively analyzed by immunohistochemical staining of recipients' native kidney biopsy-specimens. The primary outcome measure was post-transplant hypertension.

RESULTS

Post-transplant hypertension was observed in 14/17 (82%) of recipients with CC, 18/20 (90%) with CT, and 2/13 (15%) with TT genotype. CC/CT genotype was significantly associated with post-transplant hypertension, even after adjustment for covariates (odds ratio, 10.6; 95% confidence intervals, 1.32 to 85.8; P = 0.026). In addition, we observed that GLCCI1 immunoreactivity in arteriolar endothelial cells was higher in kidney specimens obtained from recipients with a CC/CT genotype than a TT genotype (P = 0.021).

CONCLUSION

GLCCI1 promoter polymorphism rs37972 may be associated with post-transplant hypertension.

Evaluation of the efficacy and safety of endovascular management for transplant renal artery stenosis

OBJECTIVES

To evaluate the safety and efficacy of endovascular intervention with angioplasty and stent placement in patients with transplant renal artery stenosis.

METHODS

All patients diagnosed with transplant renal artery stenosis and graft dysfunction or resistant systemic hypertension who underwent endovascular treatment with stenting from February 2011 to April 2016 were included in this study. The primary endpoint was clinical success, and the secondary endpoints were technical success, complication rate and stent patency.

RESULTS

Twenty-four patients with transplant renal artery stenosis underwent endovascular treatment, and three of them required reinterventions, resulting in a total of 27 procedures. The clinical success rate was 100%. All graft dysfunction patients showed decreased serum creatinine levels and improved estimated glomerular filtration rates and creatinine levels. Patients with high blood pressure also showed improved control of systemic blood pressure and decreased use of antihypertensive drugs. The technical success rate of the procedure was 97%. Primary patency and assisted primary patency rates at one year were 90.5% and 100%, respectively. The mean follow-up time of patients was 794.04 days after angioplasty.

CONCLUSION

Angioplasty with stent placement for the treatment of transplant renal artery stenosis is a safe and effective technique with good results in both the short and long term.

Regression of asymptomatic cardiomyopathy and clinical outcome of renal transplant recipients: a long-term prospective cohort study

BACKGROUND

Asymptomatic left ventricular hypertrophy (LVH) is highly prevalent and associated with an adverse outcome in renal transplant recipients (RTRs). Nonetheless, there are currently no available studies analyzing the effect of LVH regression on solid clinical endpoints in these patients.

METHODS

This study is the prospective observational extension of two randomized controlled trials aimed at assessing the effect of active intervention on post-transplant LVH in RTRs. We evaluated the incidence of a composite of death and any cardiovascular (CV) or renal event in 60 RTRs in whom LVH regression was observed and in 40 whose LVH remained unchanged or worsened.

RESULTS

During an 8.4 ± 3.5-year follow-up, 8 deaths, 18 CV events and 6 renal events occurred in the entire cohort. Multivariable analysis showed that age [hazard ratio (HR) 1.07, 95% confidence interval (CI) 1.03-1.12 each 1 year, P = 0.002] and LVH regression (HR 0.42, 95% CI 0.22-0.87, P = 0.019) were significant predictors of the composite endpoint. Kaplan-Meier estimates showed better survival rates in patients in whom actual LVH regression was achieved (P < 0.001, log-rank test). Age (HR 1.09, 95% CI 1.03-1.15 each 1 year, P = 0.004), better graft function (HR 0.95, 95% CI 0.91-0.99 each 1 mL/min/1.73 m(2) increase in estimated glomerular filtration rate, P = 0.03) and LVH regression (HR 0.41, 95% CI 0.22-0.79, P = 0.01) were significant predictors of the CV endpoint. Patients with a left ventricular mass index decrease also showed better cardiac event-free survival (P = 0.0022, log-rank test).

CONCLUSIONS

This is the first study to demonstrate that LVH regression, regardless of the therapeutic strategy adopted to achieve it, portends better long-term clinical outcome in RTRs.

Serum osteoprotegerin is associated with pulse pressure in kidney transplant recipients

Pulse pressure (PP) reflects increased large artery stiffness, which is caused, in part, by arterial calcification in patients with chronic kidney disease. PP has been shown to predict both cardiovascular and cerebrovascular events in various patient populations, including kidney transplant (KTX) recipients. Osteoprotegerin (OPG) is a marker and regulator of arterial calcification, and it is related to cardiovascular survival in hemodialysis patients. Here we tested the hypothesis that OPG is associated with increased pulse pressure. We cross-sectionally analyzed the association between serum OPG and PP in a prevalent cohort of 969 KTX patients (mean age: 51 +/- --13 years, 57% male, 21% diabetics, mean eGFR 51 +/- 20 ml/min/1.73 m2). Independent associations were tested in a linear regression model adjusted for multiple covariables. PP was positively correlated with serum OPG (rho = 0.284, p < 0.001). Additionally, a positive correlation was seen between PP versus age (r = 0.358, p < 0.001), the Charlson Comorbidity Index (r = 0.232, p < 0.001), serum glucose (r = 0.172, p < 0.001), BMI (r = 0.133, p = 0.001) and serum cholesterol (r = 0.094, p = 0.003). PP was negatively correlated with serum Ca, albumin and eGFR. The association between PP and OPG remained significant after adjusting for multiple potentially relevant covariables (beta = 0.143, p < 0.001). We conclude that serum OPG is independently associated with pulse pressure in kidney transplant recipients.

Doppler indexes of left ventricular systolic and diastolic flow and central pulse pressure in relation to renal resistive index

BACKGROUND

The cardio-renal interaction occurs via hemodynamic and humoral factors. Noninvasive assessment of renal hemodynamics is currently possible by assessment of renal resistive index (RRI) derived from intrarenal Doppler arterial waveforms as ((peak systolic velocity - end-diastolic velocity)/peak systolic velocity). Limited information is available regarding the relationship between RRI and cardiac hemodynamics. We investigated these associations in randomly recruited subjects from a general population.

METHODS

In 171 participants (48.5% women; mean age, 52.2 years), using pulsed wave Doppler, we measured RRI (mean, 0.60) and left ventricular outflow tract (LVOT) and transmitral (E and A) blood flow peak velocities and its velocity time integrals (VTI). Using carotid applanation tonometry, we measured central pulse pressure and arterial stiffness indexes such as augmentation pressure and carotid-femoral pulse wave velocity.

RESULTS

In stepwise regression analysis, RRI independently and significantly increased with female sex, age, body weight, brachial pulse pressure, and use of β-blockers, whereas it decreased with body height and mean arterial pressure. In multivariable-adjusted models with central pulse pressure and arterial stiffness indexes as the explanatory variables, we observed a significant and positive correlation of RRI only with central pulse pressure (P < 0.0001). Among the Doppler indexes of left ventricular blood flow, RRI was significantly and positively associated with LVOT and E peak velocities (P ≤ 0.012) and VTIs (P ≤ 0.010).

CONCLUSIONS

We demonstrated that in unselected subjects RRI was significantly associated with central pulse pressure and left ventricular systolic and diastolic Doppler blood flow indexes. Our findings imply that in addition to the anthropometric characteristics, cardiac hemodynamic factors influence the intrarenal arterial Doppler waveform patterns.

Clinical characteristics of resistant hypertension in renal transplant patients

Hypertension is a prevalent complication that occurs in 80-85% of all kidney transplant recipients. The pathogenesis of post-transplant hypertension is multifactorial and includes pre-transplant hypertension, donor hypertension, renin secretion from the native kidney, graft dysfunction, recurrent disease and immunosuppressive treatment. Hypertension negatively affects transplant and patient survival outcomes; cardiovascular disease (CVD) is the leading cause of morbidity and mortality in patients with chronic renal disease and after successful renal transplantation. Hypertension is a well-known risk factor for CVD and it is frequently associated with other CVD risk factors. Despite increased awareness of the adverse effects of hypertension in both graft and patient survival, long-term studies have shown that arterial hypertension in the transplant population has not been adequately controlled. Resistant hypertension (RH) is defined as office blood pressure (oBP) that remains above goal (oBP ≥ 140/90 or 130/80 mmHg) in patients with diabetes or chronic kidney disease despite the concurrent use of three antihypertensive agents, at full doses, one of them being a diuretic. Despite studies in the general population and the high prevalence of hypertension in renal transplant patients, data about RH are very scarce and the prevalence of RH in renal transplant patients is unknown and could be associated with a worse prognosis.

Hypertension following kidney transplantation

The majority of patients become hypertensive following kidney transplantation. Its occurrence is associated not only with increased fatal and nonfatal cardiovascular events but also with decreased allograft survival. This review summarizes the current knowledge of the epidemiology, etiology, pathophysiology, and management of post-transplant hypertension.

Evolution of causes of mortality in renal transplantation in the last 10 years

INTRODUCTION

Improvements in immunosuppressive therapy have significantly changed results of organ transplantation. The aim of this study was to review the causes of mortality among our renal transplant population.

METHODS

This study population included 750 patients who underwent kidney transplantation between 1970 and 2007. During the follow-up, we recorded all causes of death and major cardiovascular events: stroke, myocardial infarction, angina pectoris, and cardiac death were considered major adverse cardiovascular events (MACE) The occurrence of MACE was related to wellestablished cardiovascular risk factors-age, sex, arterial blood pressure, diabetes, renal function, cardiovascular body mass index, history, or dyslipidemia measured at 6 months, as well as 5 and 10 years after transplantation. At these times we also calculated the INDANA, Framingham, and ltalian Heart Project scores.

RESULTS

The median follow-up was 63 months and mean age was 45 +/- 11 years. The median waiting time for transplant was 34 months. During follow up, 22 patients (6.1%) developed MACE, with 2 (0.55%) events within 6 months 10 (3.1%) between 6 months and 5 years, and 10 (6.5%) between 5 and 10 years. The INDANA score at all the time periods was significantly different among patients with vs without MACE (P < .0001), whereas no significant difference was observed using the Framinghan or the Italian Heart Project scores (P < .11).

CONCLUSION

Our study indicated that the INDANA scoring system better predicted the risk of MACE as approved to the Framinghan or Italian Heart Project systems. The INDANA score might be used to plan selective cardiovascular screening among recipients.

Similar lipid profile but improved long-term outcomes with sirolimus after cyclosporine withdrawal compared to sirolimus with continuous cyclosporine

Renal transplant recipients show an increased risk of cardiovascular disease compared with a nontransplant population. Herein we have shown an analysis of a randomized controlled trial wherein 525 patients receiving a first or second (9.7%) renal allograft from a deceased (89.1%), a living-related (7.8%), or a living-unrelated donor (3.1%) received sirolimus (SRL), cyclosporine (CsA), and steroids (ST) at the time of transplantation with randomization at 3 months after transplantation of 430 eligible patients to continue on SRL-CsA-ST or to have CsA withdrawn with increased SRL trough targets (SRL-ST group). Graft survival, patient survival, and renal function at 5 years were analyzed by average fasting total cholesterol (<or=200 or >200 mg/dL) and triglyceride (<or=240 or >240 mg/dL) subgroups. At 5 years, total, high-density lipoprotein (HDL), and low-density lipoprotein [LDL] cholesterol and triglyceride values were similar between the groups. Statins ( approximately 80% of patients of both groups) were most effective to lower cholesterol ( approximately 50 mg/dL; P < .001; both groups), and fibrates ( approximately 25% of patients of both groups) were most effective to decrease triglycerides ( approximately 100 mg/dL; P < .001; both groups). Renal function and blood pressure were significantly better with SRL-ST. Hypercholesterolemia and hypertriglyceridemia were associated with reduced graft survival, patient survival, and calculated GFR, but the only significant difference was lower graft survival among SRL-CsA-ST patients with hypertriglyceridemia. Cardiovascular-related deaths were reported in 3.7% and 2.8% of patients in the SRL-CsA-ST and SRL-ST groups, respectively. In conclusion, when compared with continuous SRL-CsA-ST, CsA withdrawal at 3 months followed by SRL-ST significantly improved glomerular filtration rate (GFR) and blood pressure without a further increase in lipid parameters or an incidence of untoward effects from hyperlipidemia, despite a 2-fold higher SRL exposure.

Early high pulse pressure is associated with graft dysfunction and predicts poor kidney allograft survival

BACKGROUND

Pulse pressure (PP), which reflects the pulsatile component of the blood pressure (BP), is known as a major predictor of cardiovascular events and death. In the elderly and type 2 diabetic patients, PP is associated with low glomerular filtration rate and albuminuria. Because kidney allograft survival is closely related to BP levels, we investigated the impact of early high PP, systolic, diastolic, and mean arterial BP on kidney allograft survival.

METHODS

Renal hemodynamic and function studies using isotopic methods were prospectively performed in 493 renal transplant patients at 3 months posttransplantation to determine the impact of the different BP components on allograft survival using a proportional hazard model.

RESULTS

After a median follow-up of 6.3 years, 91 allografts were lost. High PP was associated with high systolic, diastolic, and mean arterial pressure, heart rate, recipient age, glycemia, and low glomerular filtration rate. Moreover, PP emerged as the strongest BP component influencing overall and death-censored kidney allograft survival.

CONCLUSION

High PP is an early marker of poor allograft outcome that could be corrected by therapeutic intervention.

Antiphospholipid antibodies after renal transplantation and cardiovascular disease

BACKGROUND

The aim was to assess the presence of pre- or post-transplant serum antiphospholipid antibodies (APA) and its association with the development of cardiovascular disease (CVD) in renal transplantation.

METHODS

We studied 138 patients transplanted with a cadaver kidney graft between 1990 and 1998 and with a graft functioning for longer than one yr. One pre-transplant sample and another obtained after transplantation from our serum bank were analyzed. The ELISA used were set up in our laboratory, following established international guidelines, and results were confirmed in three different runs.

RESULTS

23.9% and 31.2% of patients had pre- and post-transplant positive titers of APA, respectively. 16% developed those antibodies de novo after transplantation. Post-transplant CVD was observed in 20.3% of patients but they were not associated with the production of APA in the whole population studied. However, multivariate analysis demonstrated an increased risk (RR 2.27; p = 0.02) for CVD when APA were produced after acute rejection.

CONCLUSIONS

The presence of serum APA alone was not an independent risk factor for CVD after kidney transplantation. Nonetheless, in kidney recipients who produced APA de novo after acute rejection, the control of cardiovascular risk factors must be intensified.

Risk factors for cardiovascular events after successful renal transplantation

BACKGROUND

Cardiovascular disease is a frequent cause of morbidity after renal transplantation. The aims of this study were to evaluate the incidence of cardiovascular events and to identify the main risk factors for cardiovascular complications and mortality in 2071 white adults with a renal transplant functioning for at least 1 year.

METHODS

Clinical events, routine biochemistry, and prescribed drugs at month 1, month 6, and yearly after transplantation were analyzed.

RESULTS

The incidence of cardiovascular events increased over time. At 15 years after transplantation, only 47% of surviving patients had not experienced any cardiovascular event. Risk factors associated with cardiovascular complications were male gender (P=0.04), age (P<0.0001), arterial hypertension before transplantation (P<0.0001), longer pretransplant dialysis (P<0.0001), cardiovascular event before transplantation (P<0.0001), older era of transplantation (P=0.0009), center-specific effect (P=0.003), posttransplant diabetes mellitus (P=0.01), increased pulse pressure after transplantation (P=0.02), intake of corticosteroids (P=0.016), intake of azathioprine (P=0.016), lower serum albumin after transplantation (P=0.004), and higher serum triglyceride levels after transplantation (P=0.007). The risk of death was increased in patients with low or elevated hematocrit, while it was minimal with values around 38%.

CONCLUSIONS

The occurrence of fatal and nonfatal cardiovascular events after successful renal transplantation not only relates to baseline cardiovascular risk factors present at transplantation, but also to immunosuppressive drugs and posttransplantation traditional and nontraditional risk factors.

Role of Pulse Pressure on Cardiovascular Risk in Chronic Kidney Disease Patients: Figure 1

Epidemiologic studies have emphasized the close relationship between high BP and cardiovascular disease (CVD). Recently published prospective studies have focus on systolic and pulse pressure (PP). Systolic BP seems to be a more important factor than diastolic BP on cardiovascular and all-cause mortality in older patients. PP reflects stiffness of the large arteries and increases with age. Increasingly, PP is recognized as an independent predictor of myocardial infarction, congestive heart failure, and cardiovascular death, even in hypertensive patients who undergo successful antihypertensive drug therapy, especially in older individuals. Chronic kidney disease (CKD) is a major public health problem. The progression of kidney disease and its associated cardiovascular complications are the major causes of morbidity and mortality. This holds true for all stages of kidney disease, including ESRD that requires renal replacement therapy. Most of the traditional CVD risk factors are highly prevalent in CKD, and several nontraditional factors also are associated with atherosclerosis in CKD. The burden of hypertension is present at all stages of CKD. Several studies have shown that PP is a reliable prognostic factor for mortality and CVD in patients who have CKD and are on hemodialysis and in renal transplant patients. The purpose of this review is to show the importance of PP on cardiovascular risk in patients with CKD, including kidney transplant recipients.