Search

Administration of positively charged amino acids has been introduced to reduce the nephrotoxicity of targeted radiopeptide therapy (TRT). However, the amino acid solution may have side effects, including hyperkalaemia. The aim of this study was to evaluate the frequency and the magnitude of hyperkalaemia in neuroendocrine tumour (NET) patients undergoing TRT.Enrolled in the study were 31 patients with NET eligible for TRT with [(90)Y-DOTA(0),Tyr(3)]octreotide ((90)Y-DOTATOC). Their mean age was 54 ± 14 years. Of these 31 patients, 21 (67%) were referred for the first treatment cycle, while 10 (33%) were referred for a subsequent therapy cycle. Patients were treated with therapeutic doses of (90)Y-DOTATOC ranging from 7,030 to 35,520 MBq. To inhibit tubular reabsorption of (90)Y-DOTATOC, 1 l of physiological saline solution containing 25 g of arginine hydrochloride and 25 g of lysine hydrochloride was given over 4 h starting 1 h before (90)Y-DOTATOC injection. All patients underwent a standard biochemical blood analysis at baseline, and 4 h and 24 h after the beginning of the amino acid infusion.ANOVA repeated measures showed a significant overall effect on K(+) levels over time (F = 118.2, df = 2, P0.0001). Mean serum levels of K(+) were 4.00 ± 0.33 mmol/l at baseline, 5.47 ± 0.57 mmol/l at 4 h, and 4.38 ± 0.63 mmol/l at 24 h after the beginning of the infusion. Post-hoc analysis showed that K(+) levels at 4 h were significantly (P0.05) higher than at baseline. K(+) levels at 24 h were significantly (P0.05) lower than at 4 h but they were still significantly (P0.05) higher than K(+) levels at baseline. On a subject-by-subject basis, none of the 31 patients had increased K(+) levels at baseline. At 4 h, 24 of the 31 patients (77%) had K(+) levels above the normal range, and 6 patients (19%) experienced severe hyperkalaemia (K(+) ≥ 6 mmol/l). All patients with increased K(+) levels were clinically asymptomatic. At 24 h, only 4 patients (13%) had increased K(+) serum levels. The magnitude of the increase in K(+) levels between baseline and 4 h was relatively homogeneous over the whole group (1.41 ± 0.50 mmol/l) and it was not related (linear regression, P0.05) to baseline K(+) levels. Intravenous administration of 40 mg furosemide 1 h after the beginning of the amino acid infusion did not have a significant effect on K(+) levels (P0.05). No clinical characteristic was predictive for the increase in K(+) levels (chi-squared test, P0.05).Hyperkalaemia is a frequent, potentially life-threatening side effect of basic amino acid infusion during TRT. K(+) levels 4 h after the beginning of the infusion should be monitored in patients at risk of complications, such as those with heart disease and those with risk factors for nephrotoxicity.

Aims Several high-sensitivity cardiac troponin (hs-cTn) assays have recently been developed. It is unknown which hs-cTn provides the most accurate prognostic information and to what extent early changes in hs-cTn predict mortality. Methods and results In a prospective, international multicentre study, cTn was simultaneously measured with three novel [high-sensitivity cardiac Troponin T (hs-cTnT), Roche Diagnostics; hs-cTnI, Beckman-Coulter; hs-cTnI, Siemens] and a conventional assay (cTnT, Roche Diagnostics) in a blinded fashion in 1117 unselected patients with acute chest pain. Patients were followed up 2 years regarding mortality. Eighty-two (7.3%) patients died during the follow-up. The 2-year prognostic accuracy of hs-cTn was most accurate for hs-cTnT [area under the receivers operating characteristic curve (AUC) 0.78 (95% CI: 0.73–0.83) and outperformed both hs-cTnI (Beckman-Coulter, 0.71 (95% CI: 0.65–0.77; P = 0.001 for comparison), hs-cTnI (Siemens) 0.70 (95% CI: 0.64–0.76; P < 0.001 for comparison)] and cTnT 0.67 (95% CI: 0.61–0.74; P < 0.001 for comparison). Absolute changes of hs-cTnT were more accurate than relative changes in predicting mortality, but inferior to presentation values of hs-cTnT. Combining changes of hs-cTnT within the first 6 h with their presentation values did not further improve prognostic accuracy. Similar results were obtained for both hs-cTnI assays regarding the incremental value of changes. Hs-cTn concentrations remained predictors of death in clinically challenging subgroups such as patients with pre-existing coronary artery disease, impaired renal function, and patients older than 75 years. Conclusion High-sensitivity cardiac Troponin T is more accurate than hs-cTnI in the prediction of long-term mortality. Changes of hs-cTn do not seem to further improve risk stratification beyond initial presentation values.

Aims To examine the diagnostic accuracy of sensitive cardiac troponin (cTn) assays in elderly patients, since elevated levels with sensitive cTn assays were reported in 20% of elderly patients without acute myocardial infarction (AMI). Methods and results In this multi-centre study, we included 1098 consecutive patients presenting with symptoms suggestive of AMI, 406 (37%) were >70 years old. Measurement of three investigational sensitive cTn assays [Roche high-sensitive cTnT (hs-cTnT), Siemens cTnI-Ultra, and Abbott-Architect cTnI) and the standard assay (Roche cTnT) was performed in a blinded fashion. The final diagnosis was adjudicated by two independent cardiologists. Acute myocardial infarction was the adjudicated final diagnosis in 24% of elderly patients. Among elderly patients without AMI, baseline cTn levels were elevated above the 99th percentile in 51% with Roche hs-cTnT, in 17% with Siemens TnI-Ultra, and 13% with Abbott-Architect cTnI. The diagnostic accuracy as quantified by the area under the receiver operating characteristic (ROC) curve (AUC) was significantly greater for the sensitive cTn assays compared with the standard assay (AUC for Roche hs-cTnT, 0.94; Siemens cTnI-Ultra, 0.95; and Abbott-Architect cTnI, 0.95 vs. AUC for the standard assay, 0.90; P < 0.05 for comparisons). The best cut-offs for the sensitive cTn-assays determined by the ROC-curve in elderly patients differed clearly from those in younger patients. Furthermore, the prognostic value regarding 90-day mortality varied among the sensitive cTn assays. Conclusion Sensitive cTn assays have high diagnostic accuracy also in the elderly. Mild elevations are common in elderly non-AMI patients, therefore the optimal cut-off levels are substantially higher in elderly as compared with younger patients. Furthermore, sensitive cTn assays yielded different prognostic value (ClinicalTrials.gov number, [NCT00470587][1]). [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00470587&atom=%2Fehj%2Fearly%2F2011%2F02%2F28%2Feurheartj.ehr033.atom