The Value of Computed Tomography-Derived Coronary Artery Calcification Score in Coronary Artery Disease Detection in Asymptomatic Hemodialysis Patients

Background. We evaluated the value of coronary artery calcification (CAC) score in coronary artery disease (CAD) detection in asymptomatic hemodialysis (HD) patients by evaluating the association among CAC score, exercise electrocardiography (EECG), and Thallium-201 dipyridamole scintigraphy. Correlation between aortic pulse wave velocity (PWV) and CAC score was also evaluated. Methods. CAC score was assessed with conventional computed tomography in 40 patients. Thirty patients completed EECG and 25; those with a positive CAC score and/or a positive EECG performed Thallium dipyridamole scintigraphy. Carotid-femoral PWV was assessed in all patients. Results. There was no association among CAC score and EECG or Thallium dipyridamole scintigraphy. In contrast, CAC score was correlated with aortic PWV. Conclusion. The previous results question the role of CAC score in the detection of CAD in asymptomatic HD patients. The correlation between CAC score and aortic PWV raises the possibility that CAC score represents more an indicator of coronary artery medial wall calcification than a marker of CAD.     

Early-onset coronary artery disease after pediatric kidney transplantation: implicating the angiogenesis inhibitor, endostatin

Pediatric kidney transplant recipients have a higher rate of coronary artery disease (CAD) as adults. The angiogenesis inhibitor, endostatin, has been implicated in the development of atherosclerosis. Endostatin levels will vary between adult patients who received a kidney transplant as a child. We conducted a study in young adult patients who had undergone pediatric kidney (n = 12) or liver transplantation (n = 8). Coronary arterial calcification was measured using electron beam CT. Values were compared with age-matched control subjects from an epidemiologic database. Serum endostatin levels were measured using enzyme-linked immunosorbent assay. Risk factors for atherosclerosis were assessed. Kidney transplant recipients had a higher rate of CAD compared with liver transplant recipients (33 vs 0%, P = 0.03). Mean (± standard error of mean) serum endostatin levels were higher in kidney transplant recipients compared with liver transplant recipients (26 ± 7 vs 14 ± 3 ng/mL, P = 0.04) and control subjects (26 ± 7 vs 11 ± 1 ng/mL, P = 0.01). Pediatric kidney transplantation is associated with a higher rate of adult-onset CAD compared with liver transplantation. Endostatin levels were greater in kidney transplant recipients compared with liver transplant recipients and healthy control subjects. Endostatin may play a role in the development of atherosclerosis after kidney transplantation and may serve as a biomarker for atherosclerotic disease.     

Coronary artery calcification is related to coronary atherosclerosis in chronic renal disease patients: a study comparing EBCT-generated coronary artery calcium scores and coronary angiography.

BACKGROUND: Coronary artery calcification (CAC) measured by electron beam computed tomography (EBCT) correlates with plaque burden, vessel stenosis and is predictive of future cardiac events in the general population. Extensive CAC has been described recently in dialysis cohorts. For the first time we studied the relationship between CAC and coronary angiographic findings in patients with chronic renal failure, on dialysis and after renal transplantation. METHODS: We studied 46 patients who all had an EBCT-derived Agatston coronary calcium score and a diagnostic coronary angiogram within a 12-month period. The mean age was 55.7+/-13.2 (SD) years (range 29-80). The mean duration of dialysis was 54.4 months (range 1-372). RESULTS: The mean CAC was 2370+/-352.8. The mean CAC in patients with an abnormal coronary angiogram (n = 35) was 2869.6+/-417.9, while that in patients with a normal coronary angiogram (n = 11) was 559.4+/-255.1 (P = 0.001 for the inter-mean comparison). Total CAC correlated with the number of diseased vessels (P = 0.0001) and with severity of atherosclerosis in all the vessels (P = 0.0001). The individual coronary artery calcification score correlated well with the severity of atherosclerotic coronary disease (P<0.0001 for all) in the left anterior descending, right coronary and circumflex arteries. Running a multivariate regression analysis for atherosclerosis burden, we found that the only predictor was CAC (r = 0.34, P = 0.0001). CONCLUSION: CAC is common and more severe in patients with chronic kidney disease. Although in chronic kidney disease patients CAC can occur in the absence of occlusive coronary atherosclerosis, our data suggest that, as in the general population, CAC in chronic kidney disease patients is associated with obstructive atherosclerosis and may therefore be associated with a worse outcome.     

Combined off-pump coronary bypass grafting without heparin and liver transplantation: A novel approach to a complex dilemma

Cardiac disease is a leading cause of early mortality for patients undergoing liver transplantation (LT), and severe coronary artery disease (CAD) is usually considered a contraindication for LT in patients with cirrhosis. Incidence of CAD in LT candidates has increased in recent years. While stable patients might be candidates for percutaneous interventions, patients with decompensated liver failure, or critical coronary lesions present a therapeutic challenge, and are often not considered candidates for LT. We present the case of a 60 year old male patient with decompensated liver failure, and critical CAD, who received successful combined off-pump coronary bypass grafting without heparin and LT using ex vivo normothermic liver perfusion machine. This approach represents a novel strategy to offer LT to this very selective group of patients.     

Graft function 5-7 years after renal transplantation in early childhood

BACKGROUND: Low recipient age is still a risk factor for graft failure after kidney transplantation (Tx). Detailed prospective reports on long-term graft function in small children after renal Tx are still lacking. METHODS: Forty-nine kidney allograft recipients who received transplants before the age of 5 years were followed prospectively. The most common disease was congenital nephrotic syndrome of the Finnish type. Twenty patients were recipients of living related donors (LRD), and 29 were cadaveric kidney (CAD) recipients. All patients received triple immunosuppression. Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), sodium, urate, and potassium handling, and concentrating capacity were studied for up to 7 years after Tx. RESULTS: Patient survival 7 years after Tx was 100% for LRD and 96% for CAD recipients. Graft survival was 94% for LRD and 79% for CAD recipients (P=NS) and 89% and 83% for children >2 years and <2 years of age at Tx, respectively (P=NS). Five years after Tx, GFR was 70 vs. 64 and ERPF was 380 vs. 310 ml/min/1.73 m2 for LRD and CAD recipients, respectively (P=NS). Mean absolute GFR remained stable. GFR was lower in children who received transplants at <2 years than in children who received transplants at >2 years of age, 54 vs. 75 ml/min/1.73 m2 (P=0.02). Sodium handling remained intact, but hyperuricemia was seen in 43-67%; 17-33% showed abnormal handling of potassium; and most patients had a subnormal concentrating capacity. CONCLUSIONS: Excellent long-term graft survival and good graft function can be achieved with triple immunosuppression, even in young CAD kidney recipients.     

Coronary calcium in adults with type 1 diabetes: a stronger correlate of clinical coronary artery disease in men than in women

We studied the relationship of coronary artery calcification (CAC), a marker of coronary atherosclerosis, with prevalent clinical coronary artery disease (CAD) and established cardiovascular disease (CVD) risk factors in a type 1 diabetic population. At the 10-year follow-up examination of the Pittsburgh Epidemiology of Diabetes Complications (EDC) Study cohort, 302 adults (mean age 38.1 +/- 7.8 years) received electron beam tomography (EBT) scanning of the heart and a clinical examination. Clinical CAD was defined as a confirmed history of myocardial infarction (MI), angiographic stenosis > or =50%, Pittsburgh EDC Study physician-diagnosed angina, or ischemic electrocardiogram (ECG). CAC correlated with most CVD risk factors. CAC had 84 and 71% sensitivity for clinical CAD in men and women, respectively, and 100% sensitivity for MI or obstructive CAD. A CACS cut point of 400 was the most efficient coronary calcium correlate of CAD. In subjects with angina only, CAC sensitivity was 83% in men and 46% in women. In logistic regression, CAC, ECG R-R variation, peripheral vascular disease, and Beck Depression Inventory independently correlated with prevalent CAD in men and overall. Except for CAC, the same variables independently correlated with CAD in women, and age also entered the model. CAC was an independent correlate of MI or obstructive CAD in both sexes and was the strongest independent correlate in men, but CAC was not independently associated with angina and ischemic ECG in either sex. It is concluded that EBT-detected CAC is strongly correlated with CAD in type 1 diabetes-particularly in men.     

The value of computed tomography-derived coronary artery calcification score in coronary artery disease detection in asymptomatic hemodialysis patients

BACKGROUND: We evaluated the value of coronary artery calcification (CAC) score in coronary artery disease (CAD) detection in asymptomatic hemodialysis (HD) patients by evaluating the association among CAC score, exercise electrocardiography (EECG), and Thallium-201 dipyridamole scintigraphy. Correlation between aortic pulse wave velocity (PWV) and CAC score was also evaluated. METHODS: CAC score was assessed with conventional computed tomography in 40 patients. Thirty patients completed EECG and 25; those with a positive CAC score and/or a positive EECG performed Thallium dipyridamole scintigraphy. Carotid-femoral PWV was assessed in all patients. RESULTS: There was no association among CAC score and EECG or Thallium dipyridamole scintigraphy. In contrast, CAC score was correlated with aortic PWV. CONCLUSION: The previous results question the role of CAC score in the detection of CAD in asymptomatic HD patients. The correlation between CAC score and aortic PWV raises the possibility that CAC score represents more an indicator of coronary artery medial wall calcification than a marker of CAD.     

The use of cadaver kidneys for transplantation in young children

The role of cadaver kidney transplantation in the management of end-stage renal disease in young children is controversial. To assess the current risk-benefit ratio of cadaver first and second kidney transplants in recipients under 6 years of age, we compared the outcome of 19 transplants performed between 1984 and 1989 using a quadruple-drug regimen (Minnesota antilymphocyte globulin, azathioprine, prednisone, cyclosporine) with the outcome of 25 transplants performed prior to 1984 without the use of cyclosporine at a single institution. Twenty-five transplants were in children under the age of 3 years. In the last decade patient survival has significantly improved. One-year patient survival improved from 53% before 1979 to 90% since 1979 (P less than 0.05). The use of the quadruple-drug regimen since 1984 was associated with a significant improvement in one-year cadaver graft function from 40% before 1979 to 78% in recipients under 6 years of age, and from 22% to 82% in recipients under 3 years of age (P less than 0.05). With the quadruple-drug regimen, one-year and four-year graft function rates for children under 6 years of age were 83% for first cadaver transplants and 72% for second cadaver transplants, which were essentially the same results as in older children and adults. Children who received kidneys from donors over 4 years of age achieved the best result, with 87% one-year graft function compared with 50% for kidneys from donors under 4 years old. In 15 children with successful transplants, 8 (53%) showed accelerated growth, 5 (33%) had normal-velocity growth, and only 2 children (14%) with suboptimal renal function had poor growth following transplantation. Therefore, we believe that with a quadruple-drug immunosuppressive protocol, cadaver renal transplantation using kidneys from adults or pediatric donors over 4 years old is an acceptable form of treatment in young children with end-stage renal disease for whom there are no suitable living-related donors.     

Coronary risk stratification in patients with end-stage lung disease.

BACKGROUND: Significant coronary artery disease (CAD) has been a contraindication for listing patients for lung transplantation. We hypothesize that coronary risk stratification can help identify a sub-set of patients who need additional diagnostic tools and intervention. METHODS: We performed a retrospective review of 72 consecutive patients who underwent lung transplantation at our institution from 1995 to 2000. Further, a review of patients who are currently listed for transplantation yielded 48 patients. We then identified the various risk factors for CAD, the diagnostic tools used, and pre-operative intervention. Risk factors identified included smoking history, diabetes, hypertension, hypercholesterolemia, CAD, congestive heart failure, age >50, and arrhythmias. Based on these risk factors, the patients were then classified into 2 groups: low risk (< or =1 risk factors) and high risk (> or =2 risk factors). We identified the patients in each group who underwent coronary angiography (CA), those with angiographic evidence of CAD, and those who received pre-operative intervention. RESULTS: Of the 72 patients who underwent lung transplantation, 48 were identified as at high risk for CAD. Of these, 5 patients had CAD diagnosed before surgery using CA, and 1 patient received pre-operative intervention. Of the 48 patients currently on the lung transplant list, we identified 28 patients as high risk for CAD, 12 of whom were noted to have CA, and 2 of whom received pre-operative intervention. CONCLUSIONS: Although CAD was once a contraindication for lung transplantation, pre-operative risk stratification allows identification of CAD with CA in a high-risk group. We believe that by using appropriate pre-operative cardiac intervention, patients with severe CAD could successfully undergo lung transplantation.     

Congenital coronary artery fistulas: clinical considerations and surgical treatment

BACKGROUND: Coronary artery fistulas are uncommon abnormalities that can cause significant cardiac morbidity. Indications for operation vary, particularly, for asymptomatic patients. Early surgical correction is indicated because of the high incidence of late symptoms and complications. METHODS: From January 1981 to December 2001, all 15 patients who underwent surgical management of congenital coronary artery fistulas at the Tri-Service General Hospital, Taipei, Taiwan, China were included in the present retrospective study. RESULTS: Twelve patients were symptomatic at the time of the diagnosis. Coronary artery fistulas involved the right coronary artery in five patients, left coronary artery in nine, and both the right and the left coronary arteries in one. Coronary artery fistula drained into the right ventricle in seven patients, right atrium in three, pulmonary artery in two, left ventricle in one, left atrium in two, and coronary venous sinus in one. The value of pulmonary blood flow/systemic blood flow ranged from 0.98 to 2.1. Six patients had associated cardiac anomalies. All patients received surgical correction. Nine patients received cardiopulmonary bypass during operation. There was zero operative mortality and operative morbidity was low. All patients had a stable condition and were asymptomatic during a mean postoperative follow-up of 13.3 years. CONCLUSIONS: Early surgical treatment for coronary artery fistulas is safe and effective. The risk of operative correction appears to be considerably less than the potential for development of serious and potentially fatal complications, even in asymptomatic patients.     

Graft thrombosis in pediatric renal transplant recipients. A report of the North American Pediatric Renal Transplant Cooperative Study

Data from the North American Pediatric Renal Transplant Cooperative Study were analyzed to determine the incidence and possible causes of graft thrombosis in pediatric renal transplant recipients. Between January 1987, and November 1989, 1045 renal transplants in recipients less than 18 years of age were registered in the study, including 484 living-related donor and 561 cadaver donor transplants. There were 213 graft failures (67 LRD, 146 CAD), and of these 27 were caused by thrombosis (8 LRD, 19 CAD). Thrombosis occurred in 2.6% of all transplants and accounted for 22.5% (27/120) of all graft failures that occurred in the first 60 days following transplantation. Among the LRD recipients, there were 24 graft failures in those less than 6 years of age, and 7 of these were due to thrombosis, compared to 1 thrombosis in 43 graft losses in recipients greater than 6 years (P less than 0.01). In recipients less than 6 years old, the thrombosis rate for those who received transplants without prior dialysis was 4/32 (12.5%) versus 3/109 (2.8%) with prior dialysis. Among the CAD recipients, age of the recipient did not influence graft thrombosis. Donor age, however, was strongly associated with the risk of thrombosis, as was cold storage time. Donor age and cold storage time were not independently distributed within the population, with longer cold storage times required for younger donors. Both factors, however, independently affected outcome. Other factors, including prior nephrectomy, prior transplant, center size, and use of cyclosporine were not associated with increased risk of thrombosis in LRD or CAD recipients. We conclude that graft thrombosis is an important cause of renal graft loss in children. In LRD transplants the risk of graft thrombosis is increased in recipients less than 6 years old, and preliminary data suggest that the lack of prior dialysis may be associated with thrombotic risk in these patients. CAD transplant recipients who receive grafts from young donors, particularly those with long cold storage time, are at increased risk for graft failure due to thrombosis.     

Ventricular arrhythmia in incident kidney transplant recipients: prevalence and associated factors

Cardiovascular mortality in kidney transplant recipients has shown to be substantially elevated particularly in the first year of transplantation. Complex ventricular arrhythmia (VA) has been pointed as one of the etiologies of sudden death. The aim of this study was to evaluate the prevalence of VA and to investigate the factors associated with their occurrence in incident kidney transplant recipients. A total of 100 incident kidney transplant recipients were included in the study (39.7 ± 10.1 years, 55% male, 43.6 ± 10.1 days of transplantation, 66% living donors). All the patients underwent 24 h electrocardiogram, echocardiogram and multi‐slice computed tomography. Thirty percent of the patients had VA. Left ventricular hypertrophy was observed in 57% of the patients while heart failure was found in 5%. Coronary artery calcification (CAC) was observed in 26 patients, from which 31% had severe calcification. The group of patients with VA was predominantly male, had been on dialysis therapy for a longer time and had more coronary calcification. In the multiple logistic regression analysis, male gender and CAC score were independently associated with the presence of VA. In conclusion, kidney transplant recipients exhibited a high prevalence of VA and the factors associated with its occurrence were the male gender and the presence of CAC.     

Use of multidetector computed tomography for evaluating coronary artery disease in patients undergoing dialysis

Aim: Cardiovascular disease is the most common cause of death in patients undergoing dialysis. The accuracy of multidetector computed tomography (MDCT) for detecting coronary disease has not been determined, and little information is available regarding the performance of MDCT in patients undergoing dialysis. Methods: Twenty‐nine patients undergoing dialysis were analyzed and MDCT and coronary angiography (CAng) were performed consecutively. The coronary arteries were divided into four segments for analysis. We compared the significant stenosis lesions (≥50% luminal narrowing) identified by MDCT with those found by CAng. The total coronary artery calcium (CAC) score was determined by summing the individual lesion scores from each of the coronary branches. Results: One hundred and sixteen coronary artery branches in 29 patients were analyzed. The sensitivity, specificity, and positive and negative predictive values of MDCT for detecting significant coronary artery stenosis (≥50% stenosis) were 68%, 94%, 71% and 93%, respectively. The CAC scores were significantly higher in subjects with coronary artery disease (CAD) (514.0 ± 493.6 vs 254.3 ± 375.3, P = 0.05). The severe CAC score (>500) was related to the presence of significant CAD (P = 0.05) and the sensitivity and specificity for detecting significant CAD were 50% and 80%, respectively. Conclusion: MDCT is a useful and non‐invasive approach for detecting or excluding CAD in patients undergoing dialysis.     

Effect of lipid modification on progression of coronary calcification

Coronary artery calcification (CAC) reflects the anatomic presence of coronary atherosclerosis and the relative burden of coronary artery disease (CAD). Higher levels of CAC are seen in the presence of CAD risk factors, older age, and chronic kidney disease. The lipid profile (primarily low HDL cholesterol, elevated triglycerides, elevated LDL cholesterol, and elevated total cholesterol) are important factors in the calcification process. The annual progression of CAC can be reduced from 25 to 30% to 0 to 6% with LDL cholesterol reduction caused by statins and possibly sevelamer. At treated LDL cholesterol levels somewhere below 100 mg/dl, several sources of data suggest the anatomic burden of CAD, including CAC, regresses. Additional supportive studies indicate that carotid intimal medial thickness and the volume of coronary atheroma also can be reduced by LDL cholesterol reduction in concert with elevation of HDL cholesterol. This article reviews the data in support of altering the natural history of CAC with lipid modification.     

Screening for silent ischemia with coronary artery calcium and nuclear stress testing in nondiabetic patients prior to kidney transplant

Whether coronary artery calcium (CAC) screening in pretransplant patients may help predict silent myocardial ischemia is unknown. Accordingly, we performed CAC imaging on 46 nondiabetic patients awaiting kidneytransplant. All patients underwent multidetector computed tomography imaging for CAC quantification, and a vasodilator myocardial perfusion stress (MPS) test was performed only in patients with a total CAC score>300 or>100 in a single coronary artery. The mean patient's age was 46+/-14 years and the median dialysis vintage was 33 months (interquartile range 19-53). The median CAC score was 82 (interquartile range 0-700) and correlated with patients' age (p=0.006) and dialysis vintage (p=0.02). Nineteen patients qualified for MPS, but 5 refused the test. Of the remaining 14 patients, 7 patients had normal scans and 7 showed a minimal perfusion defect in the inferoposterior segment of the left ventricle. At the time of writing, 12 patients have undergone successful kidney transplantation without untoward complications. CAC screening does not appear to be associated with silent ischemia in pretransplant patients. Though CAC is extensive in dialysis patients, calcium may be associated with nonobstructive atherosclerotic lesions or calcification of the media layer of the vessel wall.     

Cardiac operations in patients with functioning renal allografts

The Transplant Service at the University of Minnesota Hospitals has performed over 2,000 kidney transplants. Fourteen of these patients have developed cardiac conditions necessitating surgical intervention at intervals of 9 to 144 months (mean 67 months) following their transplantation. These individuals had a mean age of 42 years, and five (36%) were diabetic. All patients had functioning renal allografts with preoperative serum creatinine levels ranging from 1.0 to 1.8 mg/100 ml (mean 1.4 mg/100 ml). Ten patients underwent aorta-coronary saphenous vein bypass grafting. One patient underwent bypass grafting and concomitant left ventricular aneurysmectomy. Native valvular endocarditis developed in two patients. One had tricuspid valve debridement for fungal endocarditis and the other had aortic valve replacement for bacterial endocarditis. The final patient had calcific aortic stenosis and coronary artery disease necessitating aortic valve replacement and coronary bypass. Two patients (14%) died perioperatively. One was a young woman with juvenile-onset diabetes and preinfarction angina who died suddenly several days after the operation; at autopsy, she was found to have an occluded graft to the right coronary artery and extensive infarction. The other was a 54-year-old woman with calcific aortic stenosis, coronary artery disease, and unstable angina who died perioperatively of uncontrollable arrhythmias. Autopsy suggested that she may have had an unsuspected infarction 1 to 2 days before the operation. The remaining 12 patients had uneventful postoperative courses and returned to Class I functional status from a cardiac standpoint. There has been one late death (7%), 45 months after successful coronary artery bypass grafting, as a result of complications attendant to a perforated gastric ulcer. The remaining 11 patients are alive and well at intervals of 8 to 93 months (mean 31 months) after operation. Postoperative serum creatinine levels at hospital discharge averaged 1.6 mg/100 ml, not significantly changed from preoperative levels. Cardiac operations can be performed safely in patients with functioning renal allografts. Patient survival is acceptable and preservation of renal function has been uniformly successful in surviving patients.     

Determinants of Coronary Artery Calcification Progression in Renal Transplant Recipients

Coronary artery calcification (CAC) is associated with increased atherosclerotic burden and cardiovascular events. The objective of this study was to determine the natural history and risk factors associated with CAC progression in a cohort of incident asymptomatic renal transplant recipients with no history of coronary revascularization. Electron-beam computed tomography was performed in 82 subjects at time of transplantation and at least 1 year later. Mean (SD) and median CAC score increased for all subjects from 392.4 (747.9) and 75.8 at time of transplant to 475.3 (873.5), (p = 0.002[log]) and 98.9 (p < 0.001), respectively. Most subjects (89%) with no calcifications remained without calcification. Mean annualized rate (SD) of CAC score change was 52.5 (150) with a median of 0.5. Average yearly percent change was 67.3 (409.6) with a median of 1.4. In multivariate analysis, diastolic blood pressure at 3 months post-transplant, Caucasian race, glomerular filtration rate at 3.0, months post-transplant, body mass index and baseline CAC score were independent predictors of annualized rate of CAC change. There is significant progression of CAC post-renal transplantation in most subjects. Progression is most likely to occur in white patients and is associated with clinical factors such as blood pressure, body mass index, renal function and baseline CAC score.     

Extent and Severity of Coronary Disease and Mortality in Patients with End-Stage Renal Failure Evaluated for Renal Transplantation

The purpose of this study is to explore the relationship between coronary artery disease (CAD), transplantation status and subsequent mortality in end-stage renal disease (ESRD) patients undergoing evaluation for renal transplantation. Two hundred fifty-three ESRD patients at high risk for CAD underwent coronary angiography as part of a renal transplant evaluation. The cohort was divided into three groups: Group 1 (n = 127) had no vessels with ≥50% stenosis, Group 2 (n = 56) had one vessel with ≥50% stenosis and Group 3 (n = 70) had two or more vessels with ≥50% stenosis. Long-term survival was determined; median follow-up was 3.3 years. The baseline characteristics were similar except for older age and higher proportion of diabetes mellitus, dyslipidemia and peripheral vascular disease in Groups 2 and 3 patients as compared to Group 1. Survival was worse in Group 3 compared to Group 1 (p < 0.0001). Each of the three subgroups had better survival with renal transplantation than those who did not undergo transplantation (p < 0.0001). Although the degree of CAD is related to subsequent mortality, transplantation is associated with better survival regardless of the extent and severity of CAD. Thus, the presence of CAD should not exclude ESRD patients from consideration for this therapy.     

Validation of a screening protocol for identifying low-risk candidates with type 1 diabetes mellitus for kidney with or without pancreas transplantation

BACKGROUND: Certain clinical risk factors are associated with significant coronary artery disease in kidney transplant candidates with diabetes mellitus. We sought to validate the use of a clinical algorithm in predicting post-transplantation mortality in patients with type 1 diabetes. We also examined the prevalence of significant coronary lesions in high-risk transplant candidates. METHODS: All patients with type 1 diabetes evaluated between 1991 and 2001 for kidney with/without pancreas transplantation were classified as high-risk based on the presence of any of the following risk factors: age >or=45 yr, smoking history >or=5 pack years, diabetes duration >or=25 yr or any ST-T segment abnormalities on electrocardiogram. Remaining patients were considered low risk. All high-risk candidates were advised to undergo coronary angiography. The primary outcome of interest was all-cause mortality post-transplantation. RESULTS: Eighty-four high-risk and 42 low-risk patients were identified. Significant coronary artery stenosis was detected in 31 high-risk candidates. Mean arterial pressure was a significant predictor of coronary stenosis (odds ratio 1.68; 95% confidence interval 1.14-2.46), adjusted for age, sex and duration of diabetes. In 75 candidates who underwent transplantation with median follow-up of 47 months, the use of clinical risk factors predicted all eight deaths. No deaths occurred in low-risk patients. A significant mortality difference was noted between the two risk groups (p = 0.03). CONCLUSIONS: This clinical algorithm can identify patients with type 1 diabetes at risk for mortality after kidney with/without pancreas transplant. Patients without clinical risk factors can safely undergo transplantation without further cardiac evaluation.     

Elevated concentrations of cardiac troponins are associated with severe coronary artery calcification in asymptomatic haemodialysis patients.

BACKGROUND: Elevated concentrations of cardiac biomarkers, such as troponins and natriuretic peptides, have been shown to be predictive of poorer long-term cardiovascular outcomes in stable patients with end-stage renal disease (ESRD). However, little is known about the relationship between elevated concentrations of these cardiac markers and underlying coronary artery pathology in these patients. The aim of the present study was to investigate associations between coronary artery calcification (CAC) and the concentrations of cardiac biomarkers in ESRD patients. METHODS: We conducted a cross-sectional study of 38 asymptomatic patients (median age, 54 years; 26 males, 12 females; diabetic, 39%) who were undergoing chronic haemodialysis. In these patients, pre-dialysis circulating concentrations of cardiac troponin T (cTnT), cardiac troponin I (cTnI), creatine kinase-MB (CK-MB) and B-type natriuretic peptide (BNP) were measured. We quantified the level of CAC by multirow spiral computed tomography to obtain a CAC score. CAC scores > or = 400 were defined as being indicative of severe CAC. RESULTS: Severe CAC was detected in 17 patients (45%). The degree of CAC severity was positively associated (P < 0.05) with cTnT concentrations. Thus, 15% of patients had severe CAC in the lowest tertile of cTnT, 50% had severe CAC in the middle third, and 69% in the highest third. Similarly, the degree of severity of CAC was positively associated (P < 0.01) with cTnI concentrations across concentration categories. In contrast, there was no association between the degree of CAC severity and the concentrations of either BNP or CK-MB. A logistic regression analysis revealed that elevated concentrations of cTnT (> or = median vs or = 0.1 ng/ml vs 相似文献