Flávio Jota de Paula

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.

Screening for significant coronary artery disease in high-risk renal transplant candidates.

BackgroundRenal transplant candidates are at an increased risk for coronary artery disease (CAD), a strong predictor of cardiovascular events [major adverse coronary events (MACE)]. Coronary angiography is a costly, risky, invasive procedure. We sought to determine clinical predictors of significant CAD (stenosis ≥70%) in high-risk renal transplant candidates. MethodsClinical evaluation and coronary angiography were performed in 301 patients (57±8 years, 73% men) on hemodialysis for 32 months (median). Patients were followed-up for 22 months (median). Inclusion criteria were diabetes (type 1 or 2), evidence of cardiovascular disease, or age ≥50 years. Risk factors included hypertension (93.7%), overweight/obesity (54.3%), dyslipidemia (44.9%), diabetes (42.1%), and smoking (24.3%). Cardiovascular disease was found as follows: peripheral arterial disease (PAD) (31.2%), angina (28.1%), stroke (12.9%), myocardial infarction (MI) (10.3%), and heart failure (9.3%). ResultsSignificant CAD was found in 136 individuals (45.2%). Diabetes [odds ratio (OR)=1.82; 95% confidence interval (CI)=1.08–3.07], PAD (OR=2.50; 95% CI=1.44–4.37), and previous MI (OR=7.75; 95% CI=3.03–23.98) were associated with significant CAD. The prevalence of significant CAD increased with the number of clinical predictors from 26% (none) to 100% (all present) (P<0.0001). The incidence of fatal/nonfatal MACE increased two, four, and sixfold in those with diabetes, PAD, or previous MI, respectively (P<0.0001). ConclusionsIn high-risk patients with end-stage renal disease, the prevalence of CAD and the incidence of MACE were high. Significant CAD or cardiovascular complications were not related to the majority of classic risk factors. Patients with diabetes, PAD, or previous MI are at higher risk of CAD, MACE, or both and, thus, must be referred for invasive diagnostic procedures.

Treatment of coronary artery disease in hemodialysis patients evaluated for transplant-a registry study.

Background. We assessed the results of a noninvasive therapeutic strategy on the long-term occurrence of cardiac events and death in a registry of patients with chronic kidney disease (CKD) and coronary artery disease (CAD). Methods. We analyzed 519 patients with CKD (56±9 years, 67% men, 67% whites) on maintenance hemodialysis with clinical or scintigraphic evidence of CAD by using coronary angiography. Results. In 230 (44%) patients, coronary angiography revealed significant CAD (lumen reduction≥70%). Subjects with significant CAD were kept on medical treatment (MT; n=184) or referred for myocardial revascularization (percutaneous transluminal coronary angioplasty/coronary artery bypass graft—intervention; n=30) according to American College of Cardiology/American Heart Association guidelines. In addition, 16 subjects refused intervention and were also followed-up. Event-free survival for patients on MT at 12, 36, and 60 months was 86%, 71%, and 57%, whereas overall survival was 89%, 71%, and 50% in the same period, respectively. Patients who refused intervention had a significantly worse prognosis compared with those who actually underwent intervention (events: hazard ratio=4.50; % confidence interval=1.48–15.10; death: hazard ratio=3.39; % confidence interval 1.41–8.45). Conclusions. In patients with CKD and significant CAD, MT promotes adequate long-term event-free survival. However, failure to perform a coronary intervention when necessary results in an accentuated increased risk of events and death.

Mycophenolate mofetil may protect against Pneumocystis carinii pneumonia in renal transplanted patients

Pneumocystis carinii pneumonia (PCP) is usually prevented in transplanted patients by prophylactic trimethoprim-sulfamethoxazol (TMS). Mycophenolate mofetil (MMF) has been shown to have a strong protective effect against PCP in rats. This effect is also suggested in humans by the absence of PCP in patients receiving MMF. After January 1998 MMF has been used with no TMS prophylaxis in renal transplanted patients. In azathioprine (AZA) treated patients TMS prophylaxis was maintained. The incidence of PCP was analyzed in both groups. Data were collected in order to have a minimum 6-month follow-up. Two hundred and seventy-two patients were eligible for analysis. No PCP occurred either in patients under MMF without TMS prophylaxis nor in patients under AZA. MMF may have an effective protective role against PCP as no patient under MMF, despite not receiving TMS coverage, developed PCP. A larger, controlled, trial is warranted to consolidate this information.

Clinical features and outcomes of tuberculosis in kidney transplant recipients in Brazil: a report of the last decade

Among kidney transplant recipients (KTRs), tuberculosis is one of the most common opportunistic infections and is associated with high morbidity and mortality. The aim of this study was to describe the incidence, clinical features, and prognosis of tuberculosis in KTRs.

Cardiac MRI for Detection of Unrecognized Myocardial Infarction in Patients With End-Stage Renal Disease: Comparison With ECG and Scintigraphy

OBJECTIVE The purposes of this study were to use the myocardial delayed enhancement technique of cardiac MRI to investigate the frequency of unrecognized myocardial infarction (MI) in patients with end-stage renal disease, to compare the findings with those of ECG and SPECT, and to examine factors that may influence the utility of these methods in the detection of MI. SUBJECTS AND METHODS We prospectively performed cardiac MRI, ECG, and SPECT to detect unrecognized MI in 72 patients with end-stage renal disease at high risk of coronary artery disease but without a clinical history of MI. RESULTS Fifty-six patients (78%) were men (mean age, 56.2 +/- 9.4 years) and 16 (22%) were women (mean age, 55.8 +/- 11.4). The mean left ventricular mass index was 103.4 +/- 27.3 g/m(2), and the mean ejection fraction was 60.6% +/- 15.5%. Myocardial delayed enhancement imaging depicted unrecognized MI in 18 patients (25%). ECG findings were abnormal in five patients (7%), and SPECT findings were abnormal in 19 patients (26%). ECG findings were false-negative in 14 cases and false-positive in one case. The accuracy, sensitivity, and specificity of ECG were 79.2%, 22.2%, and 98.1% (p = 0.002). SPECT findings were false-negative in six cases and false-positive in seven cases. The accuracy, sensitivity, and specificity of SPECT were 81.9%, 66.7%, and 87.0% (not significant). During a period of 4.9-77.9 months, 19 cardiac deaths were documented, but no statistical significance was found in survival analysis. CONCLUSION Cardiac MRI with myocardial delayed enhancement can depict unrecognized MI in patients with end-stage renal disease. ECG and SPECT had low sensitivity in detection of MI. Infarct size and left ventricular mass can influence the utility of these methods in the detection of MI.

Underuse of American College of Cardiology/American Heart Association Guidelines in Hemodialysis Patients

Patients with end-stage renal disease (ESRD) are at high risk for cardiovascular disease (CVD) and therefore should be treated according to ACC/AHA Guidelines. Scant data are available concerning the actual use of cardioprotective drugs in this population. The use of angiotensin-converting enzyme inhibitors (ACE-I), β-blockers, aspirin, and statins was assessed in 271 (72% males, 66% Caucasians) high-risk ESRD patients on hemodialysis. The study population comprised 27% smokers, 95% with hypertension, 38% with diabetes, and 44% with dyslipidemia; 44% of patients had overt CVD at baseline, including 9% with heart failure, 9% with prior myocardial infarction, and 3% with previous myocardial revascularization. One-third of all patients were not receiving any cardioprotective drugs; among those patients who were, 42% were on one drug, 21% were on two, 3.7% were on three, and 1.5% were on four. The most prescribed agent was ACE-I (35.8%), followed by aspirin (30.6%), and β-blockers (28.0%). The use of statins was remarkably and significantly low (4.1%) (p < 0.001), even in the higher risk subgroups (patients with diabetes or macrovascular disease). ACE-I plus aspirin was the most prescribed combination (8.5%). Cardioprotective agents recommended for risk-factor modification by the ACC/AHA Guidelines for their well-established efficacy in the general population were underutilized in this cohort of high-risk hypertensive hemodialysis patients, despite an elevated prevalence of clinically evident CVD. Speculatively, this fact may be relevant to better understand the known increased cardiovascular morbidity-mortality associated with chronic renal disease.

Doença cardiovascular e fatores de risco cardiovascular em candidatos a transplante renal

OBJECTIVE To determine the prevalence of cardiovascular disease (CVD) and traditional risk factors in patients with chronic renal failure undergoing evaluation for inclusion on the renal transplantation list. METHODS One hundred ninety-five patients with dialytic chronic renal failure underwent clinical evaluation and complementary tests and were compared with a group of 334 hypertensive patients paired for age. The Framingham equations were used for calculating the absolute risk (AR). The relative risk (RR) was calculated based on the absolute risk of the low-risk Framingham cohort. RESULTS Thirty-seven percent of the patients had some sort of cardiovascular disease on the initial evaluation, peripheral vascular disease (23%) being the most prevalent. Patients with cardiovascular disease were excluded. Regarding traditional risk factors, a significant difference was observed in systolic blood pressure and total cholesterol (greater in the hypertensive group), and in the prevalence of men, diabetes, and smoking, which were greater in the chronic renal failure group. The latter had a greater degree of left ventricular hypertrophy, lower diastolic blood pressure, and a lower prevalence of familial history of cardiovascular disease and obesity. The relative risk for cardiovascular disease in patients with chronic renal failure was greater compared with that in the Framingham control population, but it did not differ from that observed in the group of hypertensive individuals. CONCLUSION The prevalence of cardiovascular disease and traditional risk factors is high among candidates for renal transplantation; the Framingham equations do not adequately quantify the real cardiovascular risk, and other risk factors specific for that population should contribute for their greater cardiovascular risk.

The role of myocardial scintigraphy in the assessment of cardiovascular risk in patients with end-stage chronic kidney disease on the waiting list for renal transplantation

BACKGROUND The usefulness of stress myocardial perfusion scintigraphy for cardiovascular (CV) risk stratification in chronic kidney disease remains controversial. We tested the hypothesis that different clinical risk profiles influence the test. METHODS We assessed the prognostic value of myocardial scintigraphy in 892 consecutive renal transplant candidates classified into four risk groups: very high (aged≥50 years, diabetes and CV disease), high (two factors), intermediate (one factor) and low (no factor). RESULTS The incidence of CV events and death was 20 and 18%, respectively (median follow-up=22 months). Altered stress testing was associated with an increased probability of cardiovascular events only in intermediate-risk (one risk factor) patients [30.3 versus 10%, hazard ratio (HR)=2.37, confidence interval (CI) 1.69-3.33, P<0.0001]. Low-risk patients did well regardless of scan results. In patients with two or three risk factors, an altered stress test did not add to the already increased CV risk. Myocardial scintigraphy was related to overall mortality only in intermediate-risk patients (HR=2.8, CI 1.5-5.1, P=0.007). CONCLUSIONS CV risk stratification based on myocardial stress testing is useful only in patients with just one risk factor. Screening may avoid unnecessary testing in 60% of patients, help stratifying for risk of events and provide an explanation for the inconsistent performance of myocardial scintigraphy.

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.