Secondary prevention implantable cardioverter-defibrillator (ICD) therapy in octogenarians: effective and safe

Aims

Implantable cardioverter-defibrillator is well established for secondary prevention, but there is a lack of studies showing efficacy and safety in the elderly. The current study compared the outcome of octogenarians after ICD implantation to other age groups.

Methods

Data was achieved from a local ICD registry. Patients who received ICD implantation for secondary prevention were included. All-cause mortality, appropriate ICD therapy and acute adverse events requiring surgical intervention were compared between different age groups.

Results

519 patients were enrolled. 34 patients were ≥80 years. Over a median follow-up of 35 months after ICD implantation 129 patients (annual mortality rate 5.0%) died, including 16 patients in the age group ≥80 years (annual mortality rate 9.4%). Mortality rate in the age group ≥80 years was significantly higher than in the age groups ≤69 years (p<0.001) but no difference could be seen compared to age groups 70–79 y. Age at the time of ICD implantation was an independent predictor of all-cause mortality (p<0.001). 29.7% of patients had appropriate ICD therapy with no difference between age groups. Acute adverse events leading to surgical intervention were low (n=13) and not age-related.

Conclusion

Age is an independent predictor of mortality after ICD implantation for secondary prevention. No difference in mortality rate could be seen between octogenarians and other elderly from 70 – 79 years. Appropriate ICD therapy and acute adverse events leading to surgical intervention were not age-related. Implantable cardioverter-defibrillator for secondary prevention seems to be an effective and safe therapy in octogenarians.

Funding Acknowledgement

Type of funding sources: None.

A Consistent BGK Model with Velocity-Dependent Collision Frequency for Gas Mixtures

We derive a multi-species BGK model with velocity-dependent collision frequency for a non-reactive, multi-component gas mixture. The model is derived by minimizing a weighted entropy under the constraint that the number of particles of each species, total momentum, and total energy are conserved. We prove that this minimization problem admits a unique solution for very general collision frequencies. Moreover, we prove that the model satisfies an H-Theorem and characterize the form of equilibrium.

Prevalence and characterization of hypoadrenocorticism in dogs with signs of chronic gastrointestinal disease: A multicenter study

Background

Dogs with hypoadrenocorticism (HA) frequently show signs of gastrointestinal disease (SGD). The prevalence of dogs presented for chronic SGD with HA is unknown.

Objectives

The aims of this study were to determine the prevalence of HA in dogs with chronic SGD and to identify clinical and laboratory variables for HA in this population.

Animals

One hundred fifty‐one dogs with chronic SGD.

Methods

In this multicentered prevalence study a standardized workup was performed in prospectively enrolled dogs with SGD > 3 weeks duration. Basal serum cortisol concentration was measured in every dog with ACTH stimulation test (ACTHST) if basal serum cortisol concentration was <3 μg/dL.

Results

Basal serum cortisol concentration was <3 μg/dL in 80/151 (53%) dogs, <2 μg/dL in 42/151 (28%) dogs, and < 1 μg/dL in 9/151 (6%) dogs. In 6/151 dogs HA was diagnosed based on ACTHST (stimulated serum cortisol concentration < 2 μg/dL), a prevalence of 4%. There was no difference in history, physical examination, and laboratory variables between dogs with HA and those with other causes of chronic SGD. In 4/6 dogs with HA, there was melena or hematochezia indicating gastrointestinal blood loss. Hyperkalemia, hyponatremia, or both was not observed in any dog.

Conclusion and Clinical Importance

The prevalence of HA among dogs with chronic SGD is higher than in the general population. Based on these results, testing adrenal function should be performed as a standard screening test in dogs with chronic SGD to differentiate between HA and chronic enteropathies.

Effect of aspirin and ifetroban on skeletal muscle blood flow in patients with congestive heart failure treated with Enalapril. Ifetroban Study Group

OBJECTIVES

The purpose of this study was to determine the acute and chronic effects of cyclooxygenase inhibition with aspirin and thromboxane A2 receptor blockade with ifetroban on the chronic vasodilating effects of enalapril in the skeletal muscle circulation of patients with heart failure.

BACKGROUND

Angiotensin-converting enzyme inhibition and antiplatelet therapy with aspirin independently reduce the risk for subsequent nonfatal coronary events in survivors of myocardial infarction. The safety of the combined administration of angiotensin-converting enzyme inhibitors and aspirin has been questioned due to their divergent effects on the vascular synthesis of vasodilating prostaglandins.

METHODS

Forearm blood flow (ml/min/100 ml) at rest and during rhythmic handgrip exercise and after transient arterial occlusion was determined by strain gauge plethysmography before and 4 h and six weeks after combined administration of enalapril with either aspirin, ifetroban or placebo in a multicenter, double-blind, randomized trial of 62 patients with mild to moderate heart failure.

RESULTS

Before randomization, forearm hemodynamics were similar in the three treatment groups except for increased resting forearm blood flow and decreased resting forearm vascular resistance in the aspirin group when compared with the placebo group. After combined administration of enalapril and study drug for 4 h and six weeks, changes from prerandomization values of mean arterial pressure, forearm blood flow and forearm vascular resistance at rest, during handgrip exercise and after transient arterial occlusion did not differ among the three treatment groups.

CONCLUSIONS

These findings demonstrate that the vasodilating effects of enalapril in the skeletal muscle circulation of patients with heart failure are not critically dependent on prostaglandin pathways.

Beliefs and opinions about hypnosis held by the general public: a systematic evaluation

A study was conducted to systematically evaluate the general public's beliefs and opinions about hypnosis as well as to ascertain the sources of their beliefs. The evaluation was based on four samples representing different ages, socio-economic backgrounds, interests, and geographical locations. A 27 item, two-page questionnaire was developed to evaluate the opinions on a wide variety of topics related to hypnosis and clinical applications of hypnosis. The results indicate that although the different sample groups obtain their information about hypnosis from different sources, their beliefs about hypnosis are remarkably consistent. While the results indicate an interesting mix of ideas about hypnosis, some results indicate that most people have a positive view of the therapeutic benefits, with a vast majority of respondents believing that it reduces the time that is usually required to uncover causes of a person's problems and that hypnotized persons can undergo dental and medical procedures without pain. Other findings indicate that an extremely large proportion of the general public views hypnosis as a powerful tool to recover accurate memories under a variety of conditions including accurate memories as far back as birth or even past lives. These findings may extend and dovetail with the findings that some professionals overestimate the influence of hypnosis on retrieving accurate memories.

Evaluation of a weight-adjusted single-bolus plasminogen activator in patients with myocardial infarction: a double-blind, randomized angiographic trial of lanoteplase versus alteplase

BACKGROUND

Lanoteplase (nPA) is a rationally designed variant of tissue plasminogen activator with greater fibrinolytic potency and slower plasma clearance than alteplase.

METHODS AND RESULTS

InTIME (Intravenous nPA for Treatment of Infarcting Myocardium Early), a multicenter, double-blind, randomized, double-placebo angiographic trial, evaluated the dose-response relationship and safety of single-bolus, weight-adjusted lanoteplase. Patients (n=602) presenting within 6 hours of acute myocardial infarction were randomized and treated with either a single-bolus injection of lanoteplase (15, 30, 60, or 120 kU/kg) or accelerated alteplase. The primary objective was to determine TIMI grade flow at 60 minutes. Angiographic assessments were also performed at 90 minutes and on days 3 to 5. Follow-up was continued for 30 days. Lanoteplase achieved its primary objective, demonstrating a dose-response in TIMI grade 3 flow at 60 minutes (23.6% to 47.1% of subjects, P<0. 001). Similar results were observed at 90 minutes (26.1% to 57.1%, P<0.001). At 90 minutes, coronary patency (TIMI 2 or 3) increased across the dose range up to 83% of subjects at 120 kU/kg lanoteplase compared with 71.4% with alteplase. Thus, at this dose, lanoteplase was superior to alteplase in restoring coronary patency (difference, 12%; 95% CI, 1% to 23%). The early safety experience in this study suggests that lanoteplase was well tolerated at all doses with safety comparable to that of alteplase.

CONCLUSIONS

Lanoteplase, a single-bolus, weight-adjusted agent, increased coronary patency at 60 and 90 minutes in a dose-dependent fashion. Coronary patency at 90 minutes was achieved more frequently with 120 kU/kg lanoteplase than alteplase. In this study, safety with lanoteplase and alteplase was comparable. InTIME-II, a worldwide mortality trial, will evaluate efficacy and safety with this promising new agent.

The multidrug resistance modulator valspodar (PSC 833) is metabolized by human cytochrome P450 3A. Implications for drug-drug interactions and pharmacological activity of the main metabolite

The metabolism of valspodar (PSC 833; PSC), which is developed as a multidrug resistance-reversing agent, was investigated to assess the potential for drug-drug interactions and the pharmacological activity of major metabolites. The primary metabolites of PSC produced by human liver microsomes were monohydroxylated, as revealed by LC/MS. The major site of hydroxylation was at amino acid 9, resulting in M9, as determined by cochromatography with synthetic M9. Dihydroxylated and N-demethylated metabolites were also detected. PSC metabolism in two human livers exhibited KM values of 1.3-2.8 microM. The intrinsic clearance was 9-36 ml/min/kg of body weight. PSC biotransformation was cytochrome P450 (CYP or P450) 3A dependent, based on chemical inhibition and on metabolism by Chinese hamster ovary cells expressing CYP3A. Ketoconazole was a competitive inhibitor (Ki = 0.01-0.04 microM). The inhibition by 27 compounds, including four antineoplastic agents, corresponded to the inhibitory potentials of these compounds toward CYP3A. For vinblastine, paclitaxel, doxorubicin, and etoposide, the IC50 values were 5, 12, 20, and 150 microM, respectively. M9 was also an inhibitor, with a lower apparent affinity for CYP3A (IC50 = 21 microM), compared with that of PSC. M9 was also less active as a multidrug resistance-reversing agent. M9 demonstrated low potency in sensitizing resistant cells to paclitaxel and was a poor inhibitor of rhodamine-123 efflux from paclitaxel-resistant cells. In addition, compared with PSC, a higher concentration of M9 was needed to compete with the photoaffinity labeling of P-glycoprotein. Conversely, PSC inhibited only reactions catalyzed by CYP3A, including cyclosporine A metabolism (IC50 = 6.5 microM) and p-hydroxyphenyl-C3'-paclitaxel formation (Ki = 1.2 microM). Thus, PSC behaves in a manner very similar to that of other cyclosporines, and a comparable drug-drug interaction profile is expected.

In vitro biotransformation of SDZ RAD: a new immunosuppressive macrolide in human liver microsomal preparations

In the present biotransformation study using human in vitro liver samples, metabolites of SDZ RAD were characterized by LC-MS. The major metabolites resulted from single hydroxylation and demethylation pathways and corresponded to the class of first-generation metabolites; 39-O-demethyl-RAD was identified as metabolite. The potential ring-opened degradation product resulting from ester hydrolysis and its dehydrated analogue (seco acid) was detected to comparable amounts in both the incubations and in controls without the presence of NADPH. The direct formation of rapamycin from SDZ RAD could not be detected in this study.

Acute and sublethal toxicity of seepage waters from garbage dumps to permanent cell lines and primary cultures of hepatocytes from rainbow trout (Oncorhynchus mykiss): a novel approach to environmental risk assessment for chemicals and chemical mixtures

In order to evaluate the suitability of cytopathological criteria in isolated fish hepatocytes as endpoints in (eco)toxicological research, liver cells isolated from rainbow trout (Oncorhynchus mykiss) by collagenase perfusion were exposed in vitro for up to 5 days to sublethal dilutions of two seepage water samples collected from garbage dumps. Hepatocytes were analysed with respect to acute (lactate dehydrogenase leakage) and sublethal toxicity (electron microscopy, stereology). In addition, acute toxicity (24 h) was tested in the piscine fibrocytic cell line R1 by means of crystal violet staining and neutral red retention. Acute toxicity in R1 cells and isolated hepatocytes could only be documented for sample I at dilutions of 1:2 and 1:4. This difference in toxicity could be corroborated by cytological alterations in isolated hepatocytes, which could be documented for dilutions of 1:100 and 1:8 in samples I and II, respectively. Ultrastructural changes were time- and dose-dependent and included reduction of hepatocellular volume, disturbance of intracellular compartmentation, modified heterochromatin distribution, transformation of rough endoplasmic reticulum into concentric membrane whorls, proliferation of lysosomes and cytoplasmic vacuoles, as well as reduction of hepatocellular glycogen. Although several hepatocellular reactions were found after exposure to either sample, the syndrome of ultrastructural alterations allowed clear differentiation between the two samples. Results illustrate that cytological effects far below macroscopically detectable damage can be discovered not only in intact fish, but also in fish cell culture systems. On the basis of the data presented, a multi-tiered test procedure for aquatic toxicity assessment exclusively based on tests with fish cell culture systems is proposed: (1) rapid screening for acute toxicity with permanent cell lines; (2) short-term tests with more complex, yet more sensitive systems such as primary hepatocytes with straightforward biochemical endpoints; (3) prolonged exposure of isolated hepatocytes in combination with ultrastructural and biochemical investigations as a sensitive tool to detect adverse effects at environmentally relevant toxicant concentrations.