The role of therapy with aminoglycoside in the outcomes of kidney transplant recipients infected with polymyxin- and carbapenem-resistant Enterobacteriaceae

Kidney transplant recipients are at risk for infections due to carbapenem-resistant Enterobacteriaceae (CRE). Polymyxin-resistant CRE (PR-CRE) infections are especially difficult to treat. The aim of this study was to characterize PR-CRE infections among kidney transplant recipients and identify risk factors for treatment failure. This retrospective cohort study involved all kidney transplant recipients with PR-CRE infection between 2013 and 2017 at our center. Minimal inhibitory concentrations for polymyxin B were determined by broth microdilution. Carbapenem-resistant genes (bla_KPC, bla_NDM, and bla_OXA-48), aminoglycoside-resistance genes, and polymyxin-resistant gene mcr-1 were identified by polymerase chain reaction. All but one of the 47PR-CRE infections identified were due to Klebsiella pneumoniae. The most common type of infection (in 54.3%) was urinary tract infection (UTI). Monotherapy was used in 10 cases. Combined treatment regimens included double-carbapenem therapy in 19 cases, oral fosfomycin in 19, and amikacin in 13. Treatment failure occurred in 21 cases (45.7%). Clinical success was achieved 78.9% of patients who used aminoglycosides versus 37.0% of those who not used this drug (p = 0.007). Multivariate analysis showed diabetes mellitus to be a risk factor for treatment failure; amikacin use and UTI were found to be protective. Nine strains were RmtB producers. Although aminoglycosides constitute an important therapeutic option for PR-CRE infection, the emergence of aminoglycoside resistance could have a major impact on the management of CRE infection.

Evaluation of a protocol for coronary artery disease investigation in asymptomatic elderly hemodialysis patients

BACKGROUND

Coronary artery disease (CAD) is prevalent in older patients on dialysis, but the prognostic relevance of coronary assessment in asymptomatic subjects remains undefined. We tested the usefulness of a protocol, based on clinical, invasive, and noninvasive coronary assessment, by answering these questions: Could selecting asymptomatic patients for coronary invasive assessment identify those at higher risk of events? Is CAD associated with a worse prognosis?

METHODS

A retrospective study including 276 asymptomatic patients at least 65 years old on the waiting list, prospectively evaluated for CAD and followed up until death or renal transplantation, were classified into two groups: 1) low-risk patients who did not undergo coronary angiography (n=63) and 2) patients who did undergo angiography (n=213). The latter group was reclassified into patients with significant CAD or normal angiograms/nonsignificant CAD.

RESULTS

CAD (≥70% stenosis) occurred in 124 subjects (58%). The incidence of death by any cause, coronary death, and major cardiovascular (CV) events were similar in patients selected or not for angiography and in those with or without significant CAD. Myocardial revascularization (surgical/percutaneous) was performed in only 21/276 patients (7.6%) and did not result in a reduction in mortality.

CONCLUSION

In older patients on renal replacement therapy, the prevalence of CAD was high, but coronary investigation was not useful as a risk stratification tool and also resulted in a rather small proportion of patients eligible for intervention. Therefore, in the elderly, coronary investigation should not be considered routine in asymptomatic patients.

Coronary events in obese hemodialysis patients before and after renal transplantation

We examined the impact of obesity (BMI ≥30 kg/m(2) , n = 357) on prognosis in 1696 hemodialysis (HD) patients before and after renal transplantation (TX). End-points were coronary events, composite cardiovascular (CV) events, and death. Obese HD patients were older (55.9 ± 9.2 vs. 54.2 ± 11), had more diabetes (54% vs. 40%), dyslipidemia (49% vs. 30%), altered myocardial scan (38% vs. 31%), myocardial infarction (MI) (16% vs. 10%), coronary intervention (11% vs. 7%), higher total cholesterol (186 ± 52 vs. 169 ± 47), and triglycerides (219 ± 167 vs. 144 ± 91). Obese undergoing TX had more dyslipidemia (46% vs. 31%), angina (23% vs. 14%), MI (18% vs. 5%), increased total cholesterol (185 ± 56 vs. 172 ± 48), and triglycerides (237 ± 190 vs. 149 ± 100). Obesity was independently associated with coronary events (log-rank = 0.008, HR 2.55% CI 1.27-5.11) and death (log-rank 0.046, HR 1.52, % CI 1.007-2.30) in TX but not in HD. Obese HD patients had more risk factors and ischemic heart disease, but these characteristics did not interfere with prognosis. In TX patients, obesity predicts coronary events and death.

Recipient of kidney from donor with asymptomatic infection by Paracoccidioides brasiliensis

The increase in solid organ transplantations may soon create a rise in the occurrence of endemic fungal diseases, such as paracoccidioidomycosis, due to the lack of rigorous screening of donors from endemic areas. Here we present the first case of an immunocompetent and asymptomatic kidney donor who had Paracoccidioides brasiliensis infected-adrenal tissue but no glandular dysfunction.

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

 

BACKGROUND

The best strategy for pre-transplant investigation and treatment of coronary artery disease (CAD) is controversial.

METHODS

We evaluated 167 renal transplant recipients before transplantation to determine the incidence of cardiac events and death. We performed clinical evaluations and myocardial scans in all patients and coronary angiography in select patients.

RESULTS

Asymptomatic patients with normal myocardial scans (n=57) had significantly fewer cardiac events (log-rank=0.0002) and deaths (log-rank=0.0005) than did patients with abnormal scans but no angiographic evidence of CAD (n=76) and individuals with CAD (n=34) documented angiographically. CAD increased the probability of events (HR=2.27, % CI 1.007-5.11; p=0.04). The incidence of cardiac events (log-rank=0.349) and deaths (log-rank=0.588) was similar among patients treated medically (n=23) or by intervention (n=11).

CONCLUSION

Asymptomatic patients with normal myocardial scans had a better cardiac prognosis than did patients with or without CAD and positive for myocardial ischemia. Patients with altered scan and CAD had the poorer outcome. Guideline-oriented medical treatment is safe and yields results comparable to coronary intervention in renal transplant patients with CAD. The data do not support preemptive myocardial revascularization for renal transplant candidates.

Myocardial scintigraphy and clinical stratification as predictors of events in renal transplant candidates

BACKGROUND

We tested the hypothesis that the universal application of myocardial scanning with single-photon emission computed tomography (SPECT) would result in better risk stratification in renal transplant candidates (RTC) compared with SPECT being restricted to patients who, in addition to renal disease, had other clinical risk factors.

METHODS

RTCs (n=363) underwent SPECT and clinical risk stratification according to the American Society of Transplantation (AST) algorithm and were followed up until a major adverse cardiovascular event (MACE) or death.

RESULTS

Of the 363 patients, 79 patients (22%) had an abnormal SPECT scan and 270 (74%) were classified as high risk. Both methods correctly identified patients with increased probability of MACE. However, clinical stratification performed better (sensitivity and negative predictive value 99% and 99% vs. 25% and 87%, respectively). High-risk patients with an abnormal SPECT scan had a modest increased risk of events (log-rank = 0.03; hazard ratio [HR] = 1.37; 95% confidence interval [95% CI], 1.02-1.82). Eighty-six patients underwent coronary angiography, and coronary artery disease (CAD) was found in 60%. High-risk patients with CAD had an increased incidence of events (log-rank = 0.008; HR=3.85; 95% CI, 1.46-13.22), but in those with an abnormal SPECT scan, the incidence of events was not influenced by CAD (log-rank = 0.23). Forty-six patients died. Clinical stratification, but not SPECT, correlated with the probability of death (log-rank = 0.02; HR=3.25; 95% CI, 1.31-10.82).

CONCLUSION

SPECT should be restricted to high-risk patients. Moreover, in contrast to SPECT, the AST algorithm was also useful for predicting death by any cause in RTCs and for selecting patients for invasive coronary testing.

Coronary angiography is the best predictor of events in renal transplant candidates compared with noninvasive testing

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 (>or=70% obstruction) and assessing cardiac risk by using coronary angiography (CA). One hundred twenty-six renal transplant candidates who were classified as at moderate (>or=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 >or=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.