Luis Estevan Ianhez

Coronary Angiography Is the Best Predictor of Events in Renal Transplant Candidates Compared With Noninvasive Testing

Abstract—Guidelines for the detection of coronary artery disease (CAD) and assess of risk in renal transplant candidates are based on the results of noninvasive testing, according to data originated in the nonuremic population. We evaluated prospectively the accuracy of 2 noninvasive tests and risk stratification in detecting CAD (≥70% obstruction) and assessing cardiac risk by using coronary angiography (CA). One hundred twenty-six renal transplant candidates who were classified as at moderate (≥50 years) or high (diabetes, extracardiac atherosclerosis, or clinical coronary artery disease) coronary risk underwent myocardial scintigraphy (SPECT), dobutamine stress echocardiography, and CA and were followed for 6 to 48 months. The prevalence of CAD was 42%. The sensitivities and negative predictive values for the 2 noninvasive tests and risk stratification were <75%. After 6 to 48 months, there were 18 cardiac events, 9 fatal. Risk stratification (P =0.007) and CA (P =0.0002) predicted the crude probability of surviving free of cardiac events. The probability of event-free survival at 6, 12, 24, 36, and 48 months were 98%, 98%, 94%, 94%, and 94% in patients with <70% stenosis on CA and 97%, 87%, 61%, 56%, and 54% in patients with ≥70% stenosis. Multivariate analysis showed that the sole predictor of cardiac events was critical coronary lesions (P =0.003). Coronary angiography may still be necessary for detecting CAD and determining cardiac risk in renal transplant candidates. The data suggest that current algorithms based on noninvasive testing in this population should be revised.

Blood pressure and the risk of complex arrhythmia in renal insufficiency, hemodialysis, and renal transplant patients☆

Complex arrhythmia is frequent in hemodialysis patients but it is not clear if this is a consequence of dialysis or uremia or is secondary to the hemodynamic and cardiovascular alterations often associated with chronic renal failure. The incidence of complex ventricular arrhythmia (frequent multiform premature beats, couplets, and runs) in 31 subjects who had their uremic status recently corrected by renal transplant (Group 1) and in 23 predialysis (Group 2) and 73 hemodialysis (Group 3) chronic renal failure patients were studied with 24-h Holter monitoring. Patients were not receiving antiarrhythmic drugs or digitalis and significant coronary artery disease was excluded by clinical and noninvasive methods. Complex arrhythmia was two times more frequent in dialysis patients but the difference did not reach statistical significance (Group 1: 16%; Group 2: 17%; Group 3: 34%; chi2 4.9, P = .086). The stepwise model of logistic regression analysis identified systolic blood pressure (odds ratio 1.015, 95% confidence interval [CI] 1.001-1.027, P = .03) and left ventricular systolic dysfunction (odds ratio 7.04, 95% CI 1.3-36.7, P = .02) as the only factors that independently influenced the probability of complex arrhythmia. Age, gender, race, diabetes, smoking status, body mass index, diastolic blood pressure, serum creatinine, hematocrit, left ventricular mass index, and use of diuretics, beta-blockers, angiotensin converting enzyme (ACE) inhibitors, sympatolytics, and calcium channel blockers did not influence the occurrence of complex arrhythmia. The data indicate that blood pressure and myocardial dysfunction are more important determinants of complex arrhythmia than dialysis or uremia in chronic renal disease patients.

KIDNEY TRANSPLANTATION: THE USE OF LIVING DONORS WITH RENAL ARTERY LESIONS

PURPOSE A shortage of organs for transplantation has forced surgeons to optimize the use of marginal organs, such as kidneys with arterial disease. We present a retrospective study of the outcome of donors with renal artery disease and recipients of kidneys from living related and unrelated donors. MATERIALS AND METHODS Kidneys with vascular abnormalities from healthy living donors were grafted into 11 recipients. These kidney transplants comprised 1.8% of those performed at our institution. The vascular abnormalities were aneurysms in 3 cases, atherosclerotic lesions in 4 and fibromuscular dysplasia in 4. After nephrectomy all abnormalities were corrected under hypothermic conditions during bench surgery except in 3 cases of ostial atherosclerotic plaque, which was left in the donors. The renal artery was anastomosed to the external iliac artery in 5 cases and to the internal iliac artery in 6. The ureter was reimplanted using an extravesical technique. RESULTS All patients had immediate diuresis and no delayed post-transplant graft dysfunction was observed. One patient died of an unrelated cause and 3 had post-transplant graft function loss due to acute vasculopathy in 1, post-diarrhea with acute arterial thrombosis in 1 and recurrence of the hemolytic-uremic syndrome in 1. All remaining patients are well with median serum creatinine of 1.4 mg./dl. (normal 0.4 to 1.4). All donors are well and normotensive with normal renal function. CONCLUSIONS The use of kidneys with arterial disease from living donors with unilateral disease is safe. Complete informed consent regarding the risks and benefits by donor and recipient is mandatory.

Histological outcome of acute cellular rejection in kidney transplantation after treatment with methylprednisolone.

BACKGROUND Several studies comparing the response of acute cellular rejection (ACR) episodes to different corticosteroid regimens have been conducted. However, in most of them, the histological evaluation of the infiltrate and its correlation with clinical response was not studied. The clinical and histological outcomes of 37 episodes of ACR treated with methylprednisolone (MP) were studied, with the aim to determine how long the infiltrate takes to be cleared after therapy. METHODS A total of 37 patients with biopsy-proven ACR were treated with 8 or 16 mg of MP/kg/day. Allograft biopsies were repeated at 5 and 10 days after the end of corticotherapy. Clinical and histological outcomes were compared. RESULTS Six patients were excluded; 15 (48.4%) patients responded to therapy; the mean serum creatinine of these patients reached normal levels in the 2 weeks that followed treatment. Nine patients (60%) of this group had signs of ACR on biopsies done 5 days after corticotherapy, and four (26.7%) maintained them on the 10th day. Among 16 patients with no clinical response, none reached normal serum creatinine levels; 15 (93.7%) had signs of rejection 5 days after treatment and maintained them on the 10th day. Histological signs of ACR disappeared in 73.3% of patients with clinical response 10 days after therapy, but in only 6.3% of patients with no response (P=0.001). CONCLUSIONS Biopsies performed 5 days after treatment show a high incidence of features of ACR; such features take on average 10 days to disappear in nearly 75% of cases with successful therapy with MP.

EXTRAPERITONEAL ACCESS FOR KIDNEY TRANSPLANTATION IN CHILDREN WEIGHING 20 KG. OR LESS

PURPOSE We present our experience with kidney transplantation in children weighing 20 kg. or less. Surgery was done via extraperitoneal access while preserving the peritoneal cavity intact with special attention given to technical feasibility and the complication rate. MATERIALS AND METHODS Included in our study were 46 children with a median age of 7 years weighing 20 kg. or less (mean 16.6), of whom 16 weighed less than 15 kg. (median 13.2). The 25 boys and 21 girls underwent a total of 49 kidney transplants, including 2 in 3 during the study. Donors were living related in 44 cases and cadaveric in 5. Surgical access was obtained by making a J-shaped pararectal incision in a curvilinear fashion from the symphysis pubis to near the costal border. RESULTS Mean hospital stay was 22.9 days (range 6 to 83) and mean followup was 55.8 months (range 12 to 131). All patients received water on day 1 and food on day 2 postoperatively. In 6 patients 7 surgical complications developed, including urinary fistula in 2, superficial wound infection in 2 and vascular complications in 3 (renal vein thrombosis, stenosis and renal artery kinking in 1 each). Only 1 graft was lost due to a surgical complication. CONCLUSIONS There are many advantages to using extraperitoneal access without an increase in surgical complications or technical difficulty. Absent gastrointestinal complications, an easier way to perform percutaneous biopsy, treatment of any surgical complication with no need for repeat laparotomy and the possibility of using the peritoneal cavity when dialysis is needed postoperatively are attractive justifications for extraperitoneal access.

Renal transplantation using external continent urinary diversion.

A 29-year-old man born with bladder exstrophy presented with end stage renal failure many years after ileal conduit diversion. Bilateral nephrectomy and continent external urinary diversion were performed, and 1.5 months later a cadaveric kidney was grafted into the right iliac fossa. The patient was well at 18 months with a serum creatinine level of 1.2 mg./dl. and he was completely dry with 4 or 5 daily catheterizations. Although followup is still short, renal transplantation with drainage into an external continent urinary diversion permits excellent quality of life and good renal function. Therefore, this alternative is worth consideration whenever other reconstructive alternatives are not possible in candidates for renal transplantation.

Validation of a strategy to diagnose coronary artery disease and predict cardiac events in high-risk renal transplant candidates.

BackgroundWe validated a strategy for diagnosis of coronary artery disease (CAD) and prediction of cardiac events in high-risk renal transplant candidates (at least one of the following: age ≥50 years, diabetes, cardiovascular disease). MethodsA diagnosis and risk assessment strategy was used in 228 renal transplant candidates to validate an algorithm. Patients underwent dipyridamole myocardial stress testing and coronary angiography and were followed up until death, renal transplantation, or cardiac events. ResultsThe prevalence of CAD was 47%. Stress testing did not detect significant CAD in 1/3 of patients. The sensitivity, specificity, and positive and negative predictive values of the stress test for detecting CAD were 70, 74, 69, and 71%, respectively. CAD, defined by angiography, was associated with increased probability of cardiac events [log-rank: 0.001; hazard ratio: 1.90, 95% confidence interval (CI): 1.29–2.92]. Diabetes (P=0.03; hazard ratio: 1.58, 95% CI: 1.06–2.45) and angiographically defined CAD (P=0.03; hazard ratio: 1.69, 95% CI: 1.08–2.78) were the independent predictors of events. ConclusionThe results validate our observations in a smaller number of high-risk transplant candidates and indicate that stress testing is not appropriate for the diagnosis of CAD or prediction of cardiac events in this group of patients. Coronary angiography was correlated with events but, because less than 50% of patients had significant disease, it seems premature to recommend the test to all high-risk renal transplant candidates. The results suggest that angiography is necessary in many high-risk renal transplant candidates and that better noninvasive methods are still lacking to identify with precision patients who will benefit from invasive procedures.

Twenty-four hour blood pressure profile and left ventricular hypertrophy early after renal transplantation.

Background: Left ventricular hypertrophy is common in renal transplant patients but the factors influencing its development remain to be determined. The present investigation was conducted to study the effect of blood pressure load on the left ventricular mass of recently transplanted patients using 24-h ambulatory blood pressure monitoring (ABPM). Methods: We studied 30 renal transplant (RT) patients (36.1 ± 13.7 years old, 11 males, 26 Whites, 4 diabetics, 15 under antihypertensive medication, 21 recipients of cadaver donors, and all treated with steroids, cyclosporin and azathioprine and with adequate (serum creatinine< 1.8 mg/100 ml) renal function). The median duration of dialysis treatment before transplant was 37 months, and the studies were performed during the first 40 days post-transplantation. Blood pressure was measured after a 15-min rest (casual blood pressure) and during a 24-h period with a SpaceLabs™ apparatus. Echocardiograms were obtained from all patients. Results: Mean left ventricular mass index (LVMI) was 153 ± 44 g/m2; casual systolic and diastolic BP (mmHg) was 152 ± 25 and 92 ± 13, whereas systolic and diastolic 24-h BP was 133 ± 12 and 85 ± 8, respectively. The systolic sleeping BP/awake systolic BP (SSBP/ASBP) ratio was 0.94 ± 0.07, and 73% of the patients did not show a significant (>10%) fall of systolic blood pressure during sleep. Multivariate analysis showed that awake systolic blood pressure was the only variable that independently influenced LVMI after adjusting for confounding factors (regression coefficient = 0.49, p = 0.01). Casual systolic and diastolic BP, sleeping systolic and diastolic blood pressure, 24-h heart rate, age, race, gender, smoking, body mass index, duration of dialysis, diabetes, antihypertensive and immunosuppressive drugs and levels of hematocrit, creatinine and serum lipids did not correlate with LVMI. Conclusion: The data indicate that left ventricular hypertrophy during the early post-transplant period is mainly influenced by awake blood pressure load. They also suggest that ABPM may be more useful in the diagnosis and management of post-transplant hypertension than casual BP. The findings emphasize the importance of rigid blood pressure control in renal transplant recipients.

Influence of coronary artery disease assessment and treatment in the incidence of cardiac events in renal transplant recipients

De Lima JJG, Gowdak LHW, de Paula FJ, Arantes RL, Ianhez LE, Ramires JAF, Krieger EM. Influence of coronary artery disease assessment and treatment in the incidence of cardiac events in renal transplant recipients.
Clin Transplant 2010: 24: 474–480.
© 2009 John Wiley & Sons A/S.