Stefan W. Toennes

Adherence to Antihypertensive Medication in Treatment‐Resistant Hypertension Undergoing Renal Denervation

Background Adherence to medication has been repeatedly proposed to represent a major cause of treatment‐resistant hypertension (TRH); however, treatment decisions such as treating TRH with renal denervation depend on accurate judgment of adherence. We carefully analyzed adherence rates to medication before and after renal denervation and its effect on blood pressure (BP) control. Methods and Results Eighty patients with TRH were included in 2 prospective observational studies that assessed the difference of potential antihypertensive and nephroprotective effects of renal denervation. To compare prescribed with actual medication intake (representing a measure of adherence), we analyzed urine samples collected at baseline and at 6 months after renal denervation for antihypertensive compounds or metabolites (by liquid chromatography–mass spectrometry). In addition to office BP, 24‐hour ambulatory BP and central hemodynamics (central systolic pressure, central pulse pressure) were assessed. Informed consent for analyses of urine metabolites was obtained from 79 of 80 patients. Actual intake of all antihypertensive drugs was detected at baseline and at 6 months after renal denervation in 44 (56%) and 52 (66%) patients, respectively; 1 drug was missing in 22 (28%) and 17 (22%) patients, respectively, and ≥2 drugs were missing in 13 (16%) and 10 (13%) patients, respectively. At baseline, 24‐hour ambulatory BP (P=0.049) and central systolic BP (P=0.012) were higher in nonadherent patients. Adherence did not significantly change overall (McNemar‐Bowker test, P=0.362). An increase in adherence was observed in 21 patients, and a decrease was observed in 11 patients. The decrease in 24‐hour ambulatory BP was not different in those with stable adherence 6 months after renal denervation (n=41, −7±13 mm Hg) compared with those with increased adherence (n=21, −10±13 mm Hg) and decreased adherence (n=11, −7±14 mm Hg) (P>0.20). Our study is limited by the relatively small sample size and potentially by the specific health environment of our university center (Northern Bavaria, Germany). Conclusions Nonadherence to medication among patients with TRH was relatively low: ≈1 of 6 patients with TRH did not take ≥2 of the prescribed drugs. Adherence pattern did not change significantly after renal denervation and had no impact on the overall observed BP changes, supporting the concept that renal denervation is an effective treatment in patients with TRH. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifiers: NCT00888433, NCT01442883 and NCT01687725.

Factors leading to the degradation/loss of insulin in postmortem blood samples

Since lethal insulin injection has been used in murder and suicide cases, its non-ambiguous detection in postmortem, mostly hemolytic blood samples is still a problem. In the present study the stability of insulin and reasons for its loss in those blood samples were examined. When incubated with buffer, serum or with intact blood cell suspensions insulin concentrations were found to remain stable over time, but a significant loss of insulin was observed in hemolyzed blood samples. This was not due to an enzymatic cleavage, but predominantly to the presence of hemoglobin. Incubation of insulin with a hemoglobin solution containing the same hemoglobin content as hemolyzed blood caused a dramatic decrease of the insulin concentration. Degradation of insulin reached its maximum after 23 h of incubation. The charge state of the ferric ion of hemoglobin could not be held accountable for the insulin-loss, but rather the protein part of hemoglobin. Alkylation experiments using iodoacetamide suggested that the thiol groups of the globin molecule are involved in the insulin loss preventing degradation at least partially. The same was observed by lowering the pH to 2.7 in the incubation mixture. Two degradation products of insulin were identified by mass spectrometry such as modified insulin A and B chains with 4 (A chain) and 2 Da (B chain) lower masses. These results suggest that thiol groups of hemoglobin cause splitting of the disulfide bonds of insulin which immediately leads to the formation of new intramolecular disulfide bridges, a reaction which occurs in hemolytic blood and may explain the gradual loss of insulin in postmortem blood samples.

Use of lidocaine in endotracheal intubation. Blood and urine concentrations in patients and deceased after unsuccessful resuscitation

In toxicological analysis of postmortem samples the local anesthetic lidocaine is often identified. In most cases, lidocaine levels result from its use as aid in endotracheal intubation. The range of the drugs concentration in blood and urine was studied under controlled conditions from a cohort of cardiac surgery patients (n=35). Plasma concentrations 1 h after exposure to lidocaine in the range of the recommended 81 mg coating the endotracheal tube were less than 0.2 mg/l, its metabolite monoethylglycinxylidide (MEGX) less than 0.05 mg/l (median ratio 0.18, range 0.03-1.23). Also the concentrations of lidocaine and MEGX in urine samples were low (less than 1.2 and 0.1 mg/l, respectively) with MEGX/lidocaine ratios of 0.11 (median, range up to 1.2). These data were compared with results obtained by analyzing postmortem blood and urine samples of 18 deceased with a documented cardiopulmonary resuscitation attempt prior to death. Blood concentrations were in the same range (lidocaine median 0.07, range 0.02-1.07 mg/l; MEGX median 0.01, range <0.001-0.044 mg/l); besides low lidocaine concentrations in urine. MEGX was detected only in 2 out of 9 urine samples. The results of the present study confirm that lidocaine is absorbed in the trachea from the endotracheal tube coated with lidocaine containing gel. Postmortem quantitative results can be explained on the basis of the data obtained in the controlled study.

7B.01: FINAL ANALYSIS ON ADHERENCE TO ANTIHYPERTENSIVE MEDICATION IN TREATMENT RESISTANT HYPERTENSION (TRH) UNDERGOING RENAL DENERVATION (RDN).

Objective: Adherence to medication has been repeatedly proposed to represent a major cause of TRH and may affect the BP response to antihypertensive interventions. We assessed adherence rates in patients with TRH at baseline at 6 months after RDN and the potential impact BP response. Design and method: 80 patients with TRH have been included in two prospective observational follow-up studies (clinicaltrials.gov, NCT01442883 and NCT01687725) that focus on potential antihypertensive and nephroprotective effects of renal denervation (RDN). After ethical approval on 23.08.2013 we retrospectively approached each patient to give us informed consent for analyzing urine samples that had been collected at baseline and 6 months after renal denervation for toxicological urine analysis (by liquid chromatography-mass spectrometry analysis (LC-MS)) of antihypertensive compounds or metabolites. In addition to office BP, 24-h ambulatory BP (ABP) (Spacelab) and central hemodynamics (Sphygmocor) were assed as well. Results: Informed consent was obtained in 79 patients (mean age 60.4u200a±u200a10 years (ABP: 155u200a±u200a14/88u200a±u200a13 mmHg). All meds were detected at baseline in Nu200a=u200a44 or 56 % [6 month after RDN: in Nu200a=u200a52 or 66%] 1 med was missing in Nu200a=u200a22 or 28% [Nu200a=u200a17 or 22%],u200a>u200au200a=u200a2 meds in Nu200a=u200a13 or 16% [Nu200a=u200a10 or 13%] of whom Nu200a=u200a3 did not take any meds at all (pu200a=u200a0.049) and central systolic pressure (pu200a=u200a0.012) was higher in non-adherent patients (pu200a=u200a0.049). A shift analysis revealed that adherence remained the same in 47 subjects (in 35 Ss all meds, in 6 Ss 1 med missing and in 6 Ss >u200a=u200a2 meds missing), whereas in 21 Ss adherence increased and in 11 Ss decreased after RDN. Adherence did not significantly change (Mc Nemar-Bowker Test, pu200a=u200a0.362). The decrease in 24-h ABP was not different in those taking all medication at 6 months visit (-7u200a±u200a13 mmHg) compared to those with an increased (-10u200a±u200a13 mmHg) and decreased adherence (-7u200a±u200a14 mmHg) (all pu200a>u200a0.20). Conclusions: In our tertiary referral center in Northern Bavaria, Germany, non-adherence to medication in patients with TRH was relatively low. Adherence pattern did not change significantly and had no impact on the overall reported BP changes after RDN.

[LB.01.02] PHASE II RANDOMIZED SHAM-CONTROLLED STUDY OF RENAL DENERVATION FOR SUBJECTS WITH UNCONTROLLED HYPERTENSION – WAVE IV

Objective: The aim of this double blind randomized sham-controlled study was to verify the blood pressure (BP) lowering efficacy of externally delivered focussed ultrasound for renal denervation (RDN). Design and method: The WAVE IV study was an international, randomized (1:1), sham-controlled, double blind prospective clinical study carried out in 13 institutions. Patients (18–80 years of age) had true treatment resistant hypertension with office BP >u200a=u200a160u200ammHg whilst taking 3 or more antihypertensive medications. The treatment consisted of bilateral RDN using therapeutic levels of ultrasound energy and the sham consisted of bilateral application of diagnostic levels of ultrasound energy. The primary objective was change in office BP and secondary objective change in 24-hour ambulatory BP at 24 week follow-up visit. Results: An interim analysis showing lack of evidence of antihypertensive efficacy by the externally delivered focused ultrasound in the RDN group over the sham group prompted termination of the trial. Out of 239 screened patients, 81 were treated. Neither changes in office BP at 24 weeks (sham: −18.9u200a±u200a14 vs RDN: −13.2u200a±u200a20u200ammHg, pu200a=u200a0.133), nor changes in 24-hour ambulatory BP at 24 week follow-up visit (sham: −5.90u200a±u200a15 vs RDN: −7.11u200a±u200a13u200ammHg, pu200a=u200a0.770) differed between the two groups significantly. Of note, no safety signal was observed. Medication changes were less than 15% throughout the first follow-up period of 24 weeks. In a subset urinary toxicological analysis disclosed full adherence in 77% at baseline and 82% at 6 months. Post hoc analysis revealed that stricter criteria for stabilisation of BP at baseline were associated with a numerically greater change in 24-hour ambulatory BP in the RDN group than in the sham group. Systolic BP changes were numerically greater in patients with pulse pressure < 65 compared to those with pulse pressure >u200a=u200a65u200ammHg. Conclusions: Our data did not prove that antihypertensive efficacy of the externally delivered focused ultrasound for RDN was greater than the sham effect. Post-hoc analysis suggested that the predominance of treatment resistant hypertensive patients with stiff arteries, and less stringent stabilisation of baseline BP may have hampered our trial.

Lack of effects of a “sobering” product, “Eezup!”, on the blood ethanol and congener alcohol concentration

INTRODUCTIONnThe lifestyle product Eezup! appeared on the German market and promised to normalize energy metabolism. Among vitamins (B1, B2, B6, C, E and zinc), rice protein and fructose the addition of alcohol dehydrogenase and catalase enzymes is a novel approach. The product was advertised as capable of boosting the rate of alcohol elimination.nnnMETHODSnSeventeen subjects (11 men, 6 women, 19-58 years old), participated in a two-way crossover drinking study. Unfiltered wheat beer (4.4g% alcohol content) was drank within one hour to reach blood alcohol concentrations of 1‰ (1g/kg whole blood). On one day Eezup! was taken according to the manufacturers instructions before and after drinking which was substituted for a placebo on the second test day. Blood samples were taken during 9h and ethanol and congener alcohols were determined. A comparison of Cmax, tmax, area under the curve (AUC) for ethanol and congener alcohols, and the hourly elimination rate of ethanol (β60) was performed to investigate an effect of Eezup!.nnnRESULTSnEthanol concentrations (Cmax) were in the range of 0,63-1,00‰ (median 0,85‰) and 0.62-1.22‰ (median 0.84‰) in the placebo and Eezup! condition, respectively, and not statistically different. Also tmax (1-2.5h) and AUCs did not differ. The ethanol elimination rates were 0.16‰/h (0.14-0.19‰/h) and 0.17‰/h (0.14-0.22 ‰/h) in the placebo and Eezup! condition without significant difference. The pharmacokinetic parameters of the congener alcohols (1-propanol, isobutanol, 3-methyl-1-butanol, 2-methyl-1-butanol) as well as of methanol did also not differ.nnnCONCLUSIONSnThe results of the present study failed to show any effect of the sobering product Eezup! on the amount of ethanol and congener alcohols absorbed (Cmax, tmax, AUC) and on the ethanol elimination rate (β60).

Self-induced illegal abortion with Rivanol®: A medicolegal–toxicological case report

Approximately during the 30th week of pregnancy, a woman gave birth to a still-born child in a hospital. After first citing an extraneous cause for the premature still-birth, the woman later admitted to having self-induced the abortion by injecting the antiseptic Rivanol® (active agent: ethacridine lactate) through her abdominal wall into the amniotic cavity. The investigating authorities ordered an autopsy of the fetus along with additional toxicological investigations. To the naked eye, no obvious cause of death was apparent. The main autopsy findings were four skin defects (puncture/stabbing wounds) on the ball of the fetuss left thumb, with slight bleeding around the punctures and into the underlying fatty tissue, and a yellowish discoloration of the fetuss body surface, especially of the umbilical cord and fingernails. On basis of the results, the child would have been viable. Femoral vein blood and urine from the fetus were analyzed for ethacridine, as were an amniotic fluid sample and maternal blood and urine samples, which had been collected as evidence. The concentration of ethacridine in the amniotic fluid was 16mg/l. In the postmortem fetal blood and urine samples, the concentrations were 0.36mg/l and 0.34mg/l, respectively, while concentrations of 0.091mg/l and 0.42mg/l, respectively, were found in the serum and urine samples from the mother. In many countries, foremost in China, ethacridine lactate, to which both mother and child are exposed, is widely used as safe abortion method. Although the ethacridine concentrations found in blood and urine samples of the mother in our case are consistent with published values, we believe to be the first to report postmortem ethacridine concentrations in a fetus. While exposure to ethacridine is not toxicologically relevant for the mother, it is fatal for the fetus because it causes the placental decidua capsularis to separate from the decidua parietalis or decidua placentalis, respectively. Prostaglandins that are then produced induce labor. In medicolegal contexts, the proof for an abortion through the administration of ethacridine lactate lies in the typical yellow discoloration of the fetus in conjunction with the toxicological demonstration of the substance in fetal body fluids, and if possible also in maternal body fluids.