Strategies for mitigating an influenza pandemic

Development of strategies for mitigating the severity of a new influenza pandemic is now a top global public health priority. Influenza prevention and containment strategies can be considered under the broad categories of antiviral, vaccine and non-pharmaceutical (case isolation, household quarantine, school or workplace closure, restrictions on travel) measures. Mathematical models are powerful tools for exploring this complex landscape of intervention strategies and quantifying the potential costs and benefits of different options. Here we use a large-scale epidemic simulation to examine intervention options should initial containment of a novel influenza outbreak fail, using Great Britain and the United States as examples. We find that border restrictions and/or internal travel restrictions are unlikely to delay spread by more than 2-3 weeks unless more than 99% effective. School closure during the peak of a pandemic can reduce peak attack rates by up to 40%, but has little impact on overall attack rates, whereas case isolation or household quarantine could have a significant impact, if feasible. Treatment of clinical cases can reduce transmission, but only if antivirals are given within a day of symptoms starting. Given enough drugs for 50% of the population, household-based prophylaxis coupled with reactive school closure could reduce clinical attack rates by 40-50%. More widespread prophylaxis would be even more logistically challenging but might reduce attack rates by over 75%. Vaccine stockpiled in advance of a pandemic could significantly reduce attack rates even if of low efficacy. Estimates of policy effectiveness will change if the characteristics of a future pandemic strain differ substantially from those seen in past pandemics.

Effect of atenolol on mortality and cardiovascular morbidity after noncardiac surgery. Multicenter Study of Perioperative Ischemia Research Group

BACKGROUND

Perioperative myocardial ischemia is the single most important potentially reversible risk factor for mortality and cardiovascular complications after noncardiac surgery. Although more than 1 million patients have such complications annually, there is no effective preventive therapy.

METHODS

We performed a randomized, double-blind, placebo-controlled trial to compare the effect of atenolol with that of a placebo on overall survival and cardiovascular morbidity in patients with or at risk for coronary artery disease who were undergoing noncardiac surgery. Atenolol was given intravenously before and immediately after surgery and orally thereafter for the duration of hospitalization. Patients were followed over the subsequent two years.

RESULTS

A total of 200 patients were enrolled. Ninety-nine were assigned to the atenolol group, and 101 to the placebo group. One hundred ninety-four patients survived to be discharged from the hospital, and 192 of these were followed for two years. Overall mortality after discharge from the hospital was significantly lower among the atenolol-treated patients than among those who were given placebo over the six months following hospital discharge (0 vs. 8 percent, P<0.001), over the first year (3 percent vs. 14 percent, P=0.005), and over two years (10 percent vs. 21 percent, P=0.019). The principal effect was a reduction in deaths from cardiac causes during the first six to eight months. Combined cardiovascular outcomes were similarly reduced among the atenolol-treated patients; event-free survival throughout the two-year study period was 68 percent in the placebo group and 83 percent in the atenolol group (P=0.008).

CONCLUSIONS

In patients who have or are at risk for coronary artery disease who must undergo noncardiac surgery, treatment with atenolol during hospitalization can reduce mortality and the incidence of cardiovascular complications for as long as two years after surgery.

Effect of cyclosporine on reperfusion injury in acute myocardial infarction

BACKGROUND

Experimental evidence suggests that cyclosporine, which inhibits the opening of mitochondrial permeability-transition pores, attenuates lethal myocardial injury that occurs at the time of reperfusion. In this pilot trial, we sought to determine whether the administration of cyclosporine at the time of percutaneous coronary intervention (PCI) would limit the size of the infarct during acute myocardial infarction.

METHODS

We randomly assigned 58 patients who presented with acute ST-elevation myocardial infarction to receive either an intravenous bolus of 2.5 mg of cyclosporine per kilogram of body weight (cyclosporine group) or normal saline (control group) immediately before undergoing PCI. Infarct size was assessed in all patients by measuring the release of creatine kinase and troponin I and in a subgroup of 27 patients by performing magnetic resonance imaging (MRI) on day 5 after infarction.

RESULTS

The cyclosporine and control groups were similar with respect to ischemia time, the size of the area at risk, and the ejection fraction before PCI. The release of creatine kinase was significantly reduced in the cyclosporine group as compared with the control group (P=0.04). The release of troponin I was not significantly reduced (P=0.15). On day 5, the absolute mass of the area of hyperenhancement (i.e., infarcted tissue) on MRI was significantly reduced in the cyclosporine group as compared with the control group, with a median of 37 g (interquartile range, 21 to 51) versus 46 g (interquartile range, 20 to 65; P=0.04). No adverse effects of cyclosporine administration were detected.

CONCLUSIONS

In our small, pilot trial, administration of cyclosporine at the time of reperfusion was associated with a smaller infarct by some measures than that seen with placebo. These data are preliminary and require confirmation in a larger clinical trial.

A factorial trial of six interventions for the prevention of postoperative nausea and vomiting

BACKGROUND

Untreated, one third of patients who undergo surgery will have postoperative nausea and vomiting. Although many trials have been conducted, the relative benefits of prophylactic antiemetic interventions given alone or in combination remain unknown.

METHODS

We enrolled 5199 patients at high risk for postoperative nausea and vomiting in a randomized, controlled trial of factorial design that was powered to evaluate interactions among as many as three antiemetic interventions. Of these patients, 4123 were randomly assigned to 1 of 64 possible combinations of six prophylactic interventions: 4 mg of ondansetron or no ondansetron; 4 mg of dexamethasone or no dexamethasone; 1.25 mg of droperidol or no droperidol; propofol or a volatile anesthetic; nitrogen or nitrous oxide; and remifentanil or fentanyl. The remaining patients were randomly assigned with respect to the first four interventions. The primary outcome was nausea and vomiting within 24 hours after surgery, which was evaluated blindly.

RESULTS

Ondansetron, dexamethasone, and droperidol each reduced the risk of postoperative nausea and vomiting by about 26 percent. Propofol reduced the risk by 19 percent, and nitrogen by 12 percent; the risk reduction with both of these agents (i.e., total intravenous anesthesia) was thus similar to that observed with each of the antiemetics. All the interventions acted independently of one another and independently of the patients' baseline risk. Consequently, the relative risks associated with the combined interventions could be estimated by multiplying the relative risks associated with each intervention. Absolute risk reduction, though, was a critical function of patients' baseline risk.

CONCLUSIONS

Because antiemetic interventions are similarly effective and act independently, the safest or least expensive should be used first. Prophylaxis is rarely warranted in low-risk patients, moderate-risk patients may benefit from a single intervention, and multiple interventions should be reserved for high-risk patients.

Hypersensitivity reactions from taxol

Taxol is an antitumor agent in clinical trial that has been shown to have activity against advanced ovarian carcinoma and melanoma. Hypersensitivity reactions (HSRs) have been one of the toxicities observed with administration of this drug. Of 301 patients treated, 32 patients have had definite (27 patients) or possible (five patients) hypersensitivity reactions to taxol. All but one patient had the reaction from the first or second exposure to this agent. Reactions occurred at a variety of doses and were characterized most frequently by dyspnea, hypotension, bronchospasm, urticaria, and erythematous rashes. Thirteen (41%) patients had received premedication designed to prevent such toxicity; nevertheless, they sustained HSRs. Prolonging the drug infusion appears to have somewhat reduced, but not obviated, the risk of HSRs. The cause (taxol itself or its excipient Cremophor EL; Badische Anilin und Soda-Fabrik AG [BASF], Ludwigshafen, Federal Republic of Germany) and the mechanism of these reactions to taxol are unknown. We provide guidelines to prevent or minimize such toxicity and treat reactions if they still occur.

A controlled trial of long-term inhaled hypertonic saline in patients with cystic fibrosis

BACKGROUND

Inhaled hypertonic saline acutely increases mucociliary clearance and, in short-term trials, improves lung function in people with cystic fibrosis. We tested the safety and efficacy of inhaled hypertonic saline in a long-term trial.

METHODS

In this double-blind, parallel-group trial, 164 patients with stable cystic fibrosis who were at least six years old were randomly assigned to inhale 4 ml of either 7 percent hypertonic saline or 0.9 percent (control) saline twice daily for 48 weeks, with quinine sulfate (0.25 mg per milliliter) added to each solution to mask the taste. A bronchodilator was given before each dose, and other standard therapies were continued during the trial.

RESULTS

The primary outcome measure, the rate of change (slope) in lung function (reflected by the forced vital capacity [FVC], forced expiratory volume in one second [FEV1], and forced expiratory flow at 25 to 75 percent of FVC [FEF25-75]) during the 48 weeks of treatment, did not differ significantly between groups (P=0.79). However, the absolute difference in lung function between groups was significant (P=0.03) when averaged across all post-randomization visits in the 48-week treatment period. As compared with the control group, the hypertonic-saline group had significantly higher FVC (by 82 ml; 95 percent confidence interval, 12 to 153) and FEV1 (by 68 ml; 95 percent confidence interval, 3 to 132) values, but similar FEF25-75 values. The hypertonic-saline group also had significantly fewer pulmonary exacerbations (relative reduction, 56 percent; P=0.02) and a significantly higher percentage of patients without exacerbations (76 percent, as compared with 62 percent in the control group; P=0.03). Hypertonic saline was not associated with worsening bacterial infection or inflammation.

CONCLUSIONS

Hypertonic saline preceded by a bronchodilator is an inexpensive, safe, and effective additional therapy for patients with cystic fibrosis. (ClinicalTrials.gov number, NCT00271310.)

Mucus clearance and lung function in cystic fibrosis with hypertonic saline

BACKGROUND

Abnormal homeostasis of the volume of airway surface liquid in patients with cystic fibrosis is thought to produce defects in mucus clearance and airway defense. Through osmotic forces, hypertonic saline may increase the volume of airway surface liquid, restore mucus clearance, and improve lung function.

METHODS

A total of 24 patients with cystic fibrosis were randomly assigned to receive treatment with inhaled hypertonic saline (5 ml of 7 percent sodium chloride) four times daily with or without pretreatment with amiloride. Mucus clearance and lung function were measured during 14-day baseline and treatment periods.

RESULTS

Long-term inhalation of hypertonic saline without pretreatment with amiloride (i.e., with placebo pretreatment) resulted in a sustained (> or =8 hours) increase in 1-hour rates of mucus clearance, as compared with those with amiloride pretreatment (14.0+/-2.0 vs. 7.0+/-1.5 percent, respectively; P=0.02) and increased 24-hour rates of mucus clearance over baseline. Furthermore, inhalation of hypertonic saline with placebo improved the forced expiratory volume in one second (FEV1) between the baseline period and the treatment period (mean difference, 6.62 percent; 95 percent confidence interval, 1.6 to 11.7; P=0.02), whereas hypertonic saline with amiloride did not improve FEV1 (mean difference, 2.9 percent; 95 percent confidence interval, -2.2 to 8.0; P=0.23). Forced vital capacity (FVC), the forced expiratory flow between 25 and 75 percent of FVC (FEF25-75), and respiratory symptoms also significantly improved in patients treated with hypertonic saline and placebo, whereas the residual volume as a proportion of total lung capacity (RV:TLC) did not change in either group. A comparison of the changes in lung function in the two groups showed no significant difference. In vitro data suggested that sustained hydration of airway surfaces was responsible for the sustained improvement in mucus clearance, whereas inhibition of osmotically driven water transport by amiloride accounted for the observed loss of clinical benefit.

CONCLUSIONS

In patients with cystic fibrosis, inhalation of hypertonic saline produced a sustained acceleration of mucus clearance and improved lung function. This treatment may protect the lung from insults that reduce mucus clearance and produce lung disease.

Incidence of venous thrombosis in a large cohort of 66,329 cancer patients: results of a record linkage study

BACKGROUND

The incidence of venous thrombosis (VT) for cancer patients is increased compared with patients without cancer, but estimations of the incidence for different types of cancer have rarely been made because of the low incidence of various types of cancer. Large registries offer an opportunity to study the risk of VT in large cohorts of cancer patients, which is essential in decisions on prophylactic anti-coagulant treatment.

METHODS

This cohort study estimates the incidence of VT in cancer patients by using record linkage of a Cancer Registry and an Anticoagulation Clinic database in the Netherlands. Cumulative incidences in patients with different types of malignancies were estimated. We calculated relative risks (RRs) in relation to the presence of distant metastases and treatment.

RESULTS

Tumors of the bone, ovary, brain, and pancreas are associated with the highest incidence of VT (37.7, 32.6, 32.1, and 22.7/1000/0.5 year). Patients with distant metastases had a 1.9-fold increased risk [RRadj: 1.9; 95% confidence interval (CI): 1.6-2.3]. Chemotherapy leads to a 2.2-fold increased risk (RR(adj): 2.2; 95% CI: 1.8-2.7) and hormonal therapy leads to a 1.6-fold increased risk (RRadj: 1.6; 95% CI: 1.3-2.1) compared with patients not using these treatment modalities. Patients with radiotherapy or surgery did not have an increased risk.

CONCLUSIONS

We compared the overall incidences of VT in the first half year in our study to the risk of major bleeding as described in the literature. For patients with distant metastases, for several types of cancer, prophylactic anti-thrombotic treatment could be beneficial.

Randomized Trial of High Loading Dose of Clopidogrel for Reduction of Periprocedural Myocardial Infarction in Patients Undergoing Coronary Intervention

Background— Aggressive platelet inhibition is crucial to reduce myocardial injury and early cardiac events after coronary intervention. Although observational data have suggested that pretreatment with a high loading dose of clopidogrel may be more effective than a conventional dose, this hypothesis has never been tested in a randomized trial.

Methods and Results— A total of 255 patients scheduled to undergo percutaneous coronary intervention were randomized to a 600-mg (n=126) or 300-mg (n=129) loading regimen of clopidogrel given 4 to 8 hours before the procedure. Creatine kinase MB, troponin I, and myoglobin levels were measured at baseline and at 8 and 24 hours after intervention. The primary end point was the 30-day occurrence of death, myocardial infarction (MI), or target vessel revascularization. The primary end point occurred in 4% of patients in the high loading dose versus 12% of those in the conventional loading dose group ( P =0.041) and was due entirely to periprocedural MI. Peak values of all markers were significantly lower in patients treated with the 600-mg regimen ( P ≤0.038). Safety end points were similar in the 2 arms. At multivariable analysis, the high loading regimen was associated with a 50% risk reduction of MI (OR 0.48, 95% CI 0.15 to 0.97, P =0.044). An incremental benefit was observed in patients randomized to the 600-mg dose who were receiving statins, with an 80% risk reduction.

Conclusions— Pretreatment with a 600-mg loading dose of clopidogrel 4 to 8 hours before the procedure is safe and, as compared with the conventional 300-mg dose, significantly reduced periprocedural MI in patients undergoing percutaneous coronary intervention. These results may influence practice patterns with regard to antiplatelet therapy before percutaneous revascularization.

Pretreatment with prasugrel in non-ST-segment elevation acute coronary syndromes

BACKGROUND

Although P2Y12 antagonists are effective in patients with non-ST-segment elevation (NSTE) acute coronary syndromes, the effect of the timing of administration--before or after coronary angiography--is not known. We evaluated the effect of administering the P2Y12 antagonist prasugrel at the time of diagnosis versus administering it after the coronary angiography if percutaneous coronary intervention (PCI) was indicated.

METHODS

We enrolled 4033 patients with NSTE acute coronary syndromes and a positive troponin level who were scheduled to undergo coronary angiography within 2 to 48 hours after randomization. Patients were randomly assigned to receive prasugrel (a 30-mg loading dose) before the angiography (pretreatment group) or placebo (control group). When PCI was indicated, an additional 30 mg of prasugrel was given in the pretreatment group at the time of PCI and 60 mg of prasugrel was given in the control group.

RESULTS

The rate of the primary efficacy end point, a composite of death from cardiovascular causes, myocardial infarction, stroke, urgent revascularization, or glycoprotein IIb/IIIa inhibitor rescue therapy (glycoprotein IIb/IIIa bailout) through day 7, did not differ significantly between the two groups (hazard ratio with pretreatment, 1.02; 95% confidence interval [CI], 0.84 to 1.25; P=0.81). The rate of the key safety end point of all Thrombolysis in Myocardial Infarction (TIMI) major bleeding episodes, whether related or not related to coronary-artery bypass grafting (CABG), through day 7 was increased with pretreatment (hazard ratio, 1.90; 95% CI, 1.19 to 3.02; P=0.006). The rates of TIMI major bleeding and life-threatening bleeding not related to CABG were increased by a factor of 3 and 6, respectively. Pretreatment did not reduce the rate of the primary outcome among patients undergoing PCI (69% of the patients) but increased the rate of TIMI major bleeding at 7 days. All the results were confirmed at 30 days and in prespecified subgroups.

CONCLUSIONS

Among patients with NSTE acute coronary syndromes who were scheduled to undergo catheterization, pretreatment with prasugrel did not reduce the rate of major ischemic events up to 30 days but increased the rate of major bleeding complications. (Funded by Daiichi Sankyo and Eli Lilly; ACCOAST ClinicalTrials.gov number, NCT01015287.).

European-Canadian randomized trial of paclitaxel in relapsed ovarian cancer: high-dose versus low-dose and long versus short infusion

PURPOSE

Taxol (paclitaxel; Bristol-Myers Squibb, Wallingford, CT) is a new anticancer agent with activity in a number of human tumors, including epithelial ovarian cancer. In nonrandomized trials, doses studied have ranged from 135 mg/m2 to 250 mg/m2 administered over 24 hours with premedication to avoid hypersensitivity reactions (HSRs). This study addressed two questions: the dose-response relationship of Taxol in relapsed ovarian cancer and the safety of a short infusion given with premedication.

METHODS

Women with platinum-pretreated epithelial ovarian cancer and measurable recurrent disease were randomized in a bifactorial design to receive either 175 or 135 mg/m2 of Taxol over either 24 or 3 hours. Major end points were the frequency of significant HSRs and objective response rate. Secondary end points were progression-free and overall survival.

RESULTS

Of 407 patients randomized, 391 were eligible and 382 assessable for response. Analysis was performed according to the bifactorial design. Severe HSRs were rare (1.5% patients) and were not affected by either dose or schedule. Response was slightly higher at the 175-mg/m2 dose (20%) than at 135 mg/m2 (15%), but this was not statistically significant (P = .2). However, progression-free survival was significantly longer in the high-dose group (19 v 14 weeks; P = .02). Significantly more neutropenia was seen when Taxol was administered as a 24-hour infusion. Response rates were similar in the 24- and 3-hour groups (19% and 16%, respectively; P = .6). No survival differences were noted.

CONCLUSION

The 3-hour infusion of Taxol is safe when given with premedication and is associated with less neutropenia. There is a modest dose effect with longer time to progression at 175 mg/m2. The observation that longer infusion produces more myelosuppression but does not yield higher response rates should lead to further studies to determine the optimal dose and schedule of this interesting new agent.

In vivo visualization of embryonic stem cell survival, proliferation, and migration after cardiac delivery

BACKGROUND

Recent studies have shown that stem cell therapy can promote tissue regeneration; however, monitoring stem cells in vivo remains problematic owing to limitations of conventional histological assays and imaging modalities.

METHODS AND RESULTS

Murine embryonic stem (ES) cells were stably transduced with a lentiviral vector carrying a novel triple-fusion (TF) reporter gene that consists of firefly luciferase, monomeric red fluorescence protein, and truncated thymidine kinase (fluc-mrfp-ttk). ES cell viability, proliferation, and differentiation ability were not adversely affected by either reporter genes or reporter probes compared with nontransduced control cells (P=NS). Afterward, 1x10(7) of ES cells carrying the TF reporter gene (ES-TF) were injected into the myocardium of adult nude rats (n=20). Control animals received nontransduced ES cells (n=6). At day 4, the bioluminescence and positron emission tomography signals in study animals were 3.7x10(7)+/-5.8x10(6) photons.s(-1).cm(-2) per steradian (sr) and 0.08+/-0.03% injected dose/g, respectively (P<0.05 versus control). Both signals increased progressively from week 1 to week 4, which indicated ES cell survival and proliferation in the host. Histological analysis demonstrated the formation of intracardiac and extracardiac teratomas. Finally, animals (n=4) that were treated with intraperitoneal injection of ganciclovir (50 mg/kg) did not develop teratomas when compared with control animals (n=4) treated with saline (1 mL/kg).

CONCLUSIONS

This is the first study to characterize ES cells that stably express fluorescence, bioluminescence, and positron emission tomography reporter genes and monitor the kinetics of ES cell survival, proliferation, and migration. This versatile imaging platform should have broad applications for basic research and clinical studies on stem cell therapy.

Randomized Trial of Atorvastatin for Reduction of Myocardial Damage During Coronary Intervention

Background— Small myocardial infarctions after percutaneous coronary intervention have been associated with higher risk of cardiac events during follow-up. Observational studies have suggested that statins may lower the risk of procedural myocardial injury. The aim of our study was to confirm this hypothesis in a randomized study.

Methods and Results— One hundred fifty-three patients with chronic stable angina without previous statin treatment were enrolled in the study. Patients scheduled for elective coronary intervention were randomized to atorvastatin (40 mg/d, n=76) or placebo (n=77) 7 days before the procedure. Creatine kinase-MB, troponin I, and myoglobin levels were measured at baseline and at 8 and 24 hours after the procedure. Detection of markers of myocardial injury above the upper normal limit was significantly lower in the statin group versus the placebo group: 12% versus 35% for creatine kinase-MB ( P =0.001), 20% versus 48% for troponin I ( P =0.0004), and 22% versus 51% for myoglobin ( P =0.0005). Myocardial infarction by creatine kinase-MB determination was detected after coronary intervention in 5% of patients in the statin group and in 18% of those in the placebo group ( P =0.025). Postprocedural peak levels of creatine kinase-MB (2.9±3 versus 7.5±18 ng/mL, P =0.007), troponin I (0.09±0.2 versus 0.47±1.3 ng/mL, P =0.0008), and myoglobin (58±36 versus 81±49 ng/mL, P =0.0002) were also significantly lower in the statin than in the placebo group.

Conclusions— Pretreatment with atorvastatin 40 mg/d for 7 days significantly reduces procedural myocardial injury in elective coronary intervention. These results may influence practice patterns with regard to adjuvant pharmacological therapy before percutaneous revascularization.

N-3 Fatty acids for the prevention of atrial fibrillation after coronary artery bypass surgery: a randomized, controlled trial

OBJECTIVES

The aim of this study was to assess the efficacy of preoperative and postoperative treatment with n-3 polyunsaturated fatty acids (PUFAs) in preventing the occurrence of atrial fibrillation (AF) after coronary artery bypass graft surgery (CABG).

BACKGROUND

Postoperative AF is a common complication of CABG. There is growing clinical evidence that PUFAs have cardiac antiarrhythmic effects.

METHODS

A total of 160 patients were prospectively randomized to a control group (81 patients, 13 female, 64.9 +/- 9.1 years) or PUFAs 2 g/day (79 patients, 11 female, 66.2 +/- 8.0 years) for at least 5 days before elective CABG and until the day of discharge from the hospital. The primary end point was the development of AF in the postoperative period. The secondary end point was the hospital length of stay after surgery. All end points were independently adjudicated by two cardiologists blinded to treatment assignment.

RESULTS

The clinical and surgical characteristics of the patients in the two groups were similar. Postoperative AF developed in 27 patients of the control group (33.3%) and in 12 patients of the PUFA group (15.2%) (p = 0.013). There was no significant difference in the incidence of nonfatal postoperative complications, and postoperative mortality was similar in the PUFA-treated patients (1.3%) versus controls (2.5%). After CABG, the PUFA patients were hospitalized for significantly fewer days than controls (7.3 +/- 2.1 days vs. 8.2 +/- 2.6 days, p = 0.017).

CONCLUSIONS

This study first demonstrates that PUFA administration during hospitalization in patients undergoing CABG substantially reduced the incidence of postoperative AF (54.4%) and was associated with a shorter hospital stay.

Preoperative amiodarone as prophylaxis against atrial fibrillation after heart surgery

BACKGROUND

Atrial fibrillation occurs commonly after open-heart surgery and may delay hospital discharge. The purpose of this study was to assess the use of preoperative amiodarone as prophylaxis against atrial fibrillation after cardiac surgery.

METHODS

In this double-blind, randomized study, 124 patients were given either oral amiodarone (64 patients) or placebo (60 patients) for a minimum of seven days before elective cardiac surgery. Therapy consisted of 600 mg of amiodarone per day for seven days, then 200 mg per day until the day of discharge from the hospital. The mean (+/-SD) preoperative total dose of amiodarone was 4.8+/-0.96 g over a period of 13+/-7 days.

RESULTS

Postoperative atrial fibrillation occurred in 16 of the 64 patients in the amiodarone group (25 percent) and 32 of the 60 patients in the placebo group (53 percent) (P=0.003). Patients in the amiodarone group were hospitalized for significantly fewer days than were patients in the placebo group (6.5+/-2.6 vs. 7.9+/-4.3 days, P=0.04). Nonfatal postoperative complications occurred in eight amiodarone-treated patients (12 percent) and in six patients receiving placebo (10 percent, P=0.78). Fatal postoperative complications occurred in three patients who received amiodarone (5 percent) and in two who received placebo (3 percent, P= 1.00). Total hospitalization costs were significantly less for the amiodarone group than for the placebo group ($18,375+/-$13,863 vs. $26,491+/-$23,837, P=0.03).

CONCLUSIONS

Preoperative oral amiodarone in patients undergoing complex cardiac surgery is well tolerated and significantly reduces the incidence of postoperative atrial fibrillation and the duration and cost of hospitalization.

Behavioral and physiological studies of non-narcotic analgesia in the rat elicited by certain environmental stimuli

These experiments characterized the analgesia resulting from exposure to certain noxious and/or stressful manipulations. Rats exposed either to electric grid shock (0.35-2.0 mA for 10-30 sec) or to 5 min of presumably non-painful centrifugal rotation (about 7.0 transverse g's) were analgesic as measured by tail-flick, hot plate and responses to applications of a calibrated paw pinch or alligator clip. Analgesia produced by shock (SA) or centrifugal rotation (RA) persisted after termination of these manipulations. Neither SA nor RA were attended by generalized sensory, attentional or motoric deficits. Intraperitoneal injection of hypertonic saline also increased tail-flick latencies. Exposure to brief ether anesthesia or horizontal oscillation, both of which have been reported to increase ACTH secretion (a commonly used indicator of stress), did not produce analgesia as measured by the tail-flick test. The use of classical conditioning procedures to pair shock with environmental stimuli resulted in increased tail-flick latencies. The narcotic antagonist naloxone (1 mg/kg, i.p.) did not reduce the tail-flick inhibition produced by shock, rotation, hypertonic saline or classical conditioning. Chlordiazepoxide (5 mg/kg, i.p.) also failed to antagonize the increased tail-flick latencies produced by shock or conditioning. Tail-flick inhibition produced by shock or rotation was markedly reduced by complete spinal cord transection at thoracic levels. These results suggest that: (1) the selective modulation of nociceptive input at the level of the spinal cord can be mediated by a supraspinal system or systems physiologically distinct from those involved in analgesia produced by the administration of opiates; (2) non-narcotic modulation of nociceptive input occurring within the spinal cord can be learned by exposure to classical conditioning procedures; and (3) noxious stimuli are sufficient but not necessary to produce a non-narcotic analgesia; stress alone, however, is not always sufficient to produce this analgesia.

Risk of and prophylaxis for venous thromboembolism in hospital patients. Thromboembolic Risk Factors (THRIFT) Consensus Group

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NG-methylarginine, an inhibitor of endothelium-derived nitric oxide synthesis, is a potent pressor agent in the guinea pig: does nitric oxide regulate blood pressure in vivo?

Nitric oxide is a major endothelium-derived vascular smooth muscle relaxing factor; its synthesis from L-arginine is selectively inhibited by L-NG-methylarginine. To assess whether basal nitric oxide release contributes to blood pressure regulation in vivo, we have investigated the cardiovascular effects of L-NG-methylarginine in the anesthetized guinea pig. L-NG-methylarginine (0.1-10 mg/kg, i.v. bolus) elicited a sustained, dose-dependent, increase in arterial pressure and a moderate bradycardia. L-arginine (30 mg/kg i.v.) prevented or reversed the pressor effect of L-NG-methylarginine, while atropine (2 mg/kg) abolished the associated bradycardia. In contrast, L-arginine did not attenuate the pressor effect of norepinephrine or angiotensin. Our findings suggest that basal nitric oxide production is sufficient to modulate peripheral vascular resistance; hence nitric oxide may play a role in arterial pressure homeostasis.

Trabeculectomy with simultaneous topical application of mitomycin-C in refractory glaucoma

From May 1981 to Feb. 1989 trabeculectomy with per-operative topical application of mitomycin C was performed on eyes with refractory glaucoma. All eyes had undergone prior one, two or more than two antiglaucoma surgeries without success for IOP control. Other risk factors in the present series of eyes included young age, aphakia, rubeosis and glaucoma secondary to trauma or associated with anterior uveitis. 59 eyes underwent trabeculectomy with mitomycin application. 14 eyes were lost. 45 eyes of 42 cases, 33 eyes of 31 males and 12 eyes of 11 females were followed for a period of 1 to 8 years, an average 3.0 +/- 1.9 years. The success for IOP control less than 21 mmHg was 77.8%, 35/45 eyes. The success rates were 92%, 11/12 eyes in females and 73%, 24/33 eyes in males. Complications reported in 5-fluorouracil studies such as corneal epithelial toxicity and delayed healing of conjunctival wound were not encountered. The histo-pathological changes of wound healing after trabeculectomy with topical mitomycin application was discussed. In the healing process success to achieve filtration is more likely by pharmacolocally interferring with earlier steps in the process. We recommend the use of per-operative topical application of mitomycin C during trabeculectomy in eyes with uncontrolled glaucoma and poor prognosis, specifically after previous cataract extraction or unsuccessful antiglaucoma surgery.

Resistance to thienopyridines: clinical detection of coronary stent thrombosis by monitoring of vasodilator-stimulated phosphoprotein phosphorylation

We carried out a prospective evaluation of a new vasodilator-stimulated phosphoprotein (VASP) phosphorylation assay in order to detect patients with high-risk coronary subacute stent thrombosis (SAT) despite thienopyridine regimen. Twenty healthy donors (group 1) without any medication were compared to 16 stented patients (group 2) treated by ticlopidin or clopidogrel initiated 2 days before stenting and aspirin (250 mg/day). No difference in platelet reactivity was noted between group 1 and group 2 treated only with aspirin (72.00% +/- 4.17% vs. 69.73% +/- 5.62%, respectively; P = NS). Significant differences were found between patients of group 2 treated with aspirin alone (69.73% +/- 5.62%), after 2.0 days (60.14% +/- 9.60%; P < 0.05), and after 4.8 +/- 1.3 days (48.37% +/- 11.19%; P < 0.05) with thienopyridine-aspirin. Among 1,684 consecutive stented patients, 16 patients who presented an SAT (group 3) were compared with 30 other stented patients free of SAT (group 4). We found a significant difference between group 3 (63.28% +/- 9.56%) and group 4 (39.80% +/- 10.9%; P < 0.0001). VASP phosphorylation analysis may be useful for the detection of coronary SAT.

Treatment of intracranial aneurysms using the pipeline flow-diverter embolization device: a single-center experience with long-term follow-up results

BACKGROUND AND PURPOSE

Flow-diverting devices now offer a new treatment alternative for cerebral aneurysms. We present the results of a large single-center series of patients treated with the PED, including long-term follow-up.

MATERIALS AND METHODS

Between November 2008 and September 2011, sidewall aneurysms with a wide neck (≥4 mm) or unfavorable dome-neck ratio (≤1.5); large/giant, fusiform, dissecting, blister-like, and recurrent sidewall aneurysms; aneurysms at difficult angles; and aneurysms in which a branch was originating directly from the sac were treated with the PED. Patients were premedicated with dual antiplatelet medications. Data, including demographics, aneurysm features, clinical presentation, complications, results, and follow-up information, for up to 2 years are presented.

RESULTS

Two hundred fifty-one aneurysms in 191 patients were treated. Of these, 96 (38.3%) were large or giant (≥10 mm). In 34/251 (13.5%), PEDs were used for retreatment. Adjunctive coiling was performed in 11 aneurysms (2.1%). The mean number of devices per aneurysm was 1.3. One aneurysm ruptured in the fourth month posttreatment (0.5%), and symptomatic in-construct stenosis was detected in 1 patient (0.5%) treated with percutaneous transarterial angioplasty. Any event rate was 27/191 (14.1%), with a permanent morbidity of 1% and mortality of 0.5%. Control angiography was available in 182 (95.3%) patients with 239 (95.2%) aneurysms. In 121 aneurysms (48.2%), 1- to 2-year control angiography was available. The aneurysm occlusion rate was 91.2% in 6 months, increasing to 94.6%.

CONCLUSIONS

Use of the PED is safe, efficacious, and durable in cerebral aneurysm treatment, with low morbidity-mortality and high occlusion rates as confirmed with mid- to long-term control angiography.

Phase II study of taxol in patients with untreated advanced non-small-cell lung cancer

BACKGROUND

Taxol, a complex plant product (a diterpene) extracted from the bark of Taxus brevifolia, has demonstrated substantial anticancer activity in ovarian and breast cancers, malignant melanoma, and acute myelogenous leukemia. Due to allergic reactions in phase I and early phase II studies, use of a 24-hour infusion of taxol with prophylactic dexamethasone, diphenhydramine, and cimetidine has been recommended.

PURPOSE

In this phase II study, we attempted to determine the efficacy and toxicity of taxol in patients with advanced (stage IIIB or IV) non-small-cell lung cancer who had never received chemotherapy.

METHODS

Patients were not excluded because of prior surgery or because of radiotherapy administered more than 4 weeks before study entry. Taxol was administered in the hospital at a dose of 200 mg/m2 as an intravenous infusion over 24 hours and repeated every 3 weeks, provided that patients had recovered from any toxic effects. Dexamethasone, cimetidine, and diphenhydramine were given before chemotherapy to prevent hypersensitivity reactions. Therapy was continued for at least two courses unless there was rapid disease progression and for at least three courses if no change was observed and no grade 3 or 4 toxic effects occurred. Treatment was continued for six more courses after maximum response or for two more courses after complete remission but was discontinued if disease progressed.

RESULTS

Of the 27 patients entered in the study, 25 were assessable for toxic effects and response. One patient had an allergic reaction that was not life threatening. The overall response rate was 24% (one complete response and five partial responses). An additional seven patients (28%) had minor response. Granulocytopenia was the dose-limiting toxic effect, and neutropenic fever occurred in eight of 118 courses. One additional patient developed neutropenic sepsis with hypotension but recovered with intensive treatment.

CONCLUSIONS

Taxol appears to have activity against non-small-cell carcinoma of the lung.

IMPLICATIONS

A phase II study combining taxol, etoposide, and cisplatin and using hematopoietic stimulating factors is now proposed. The optimal dose for combination chemotherapy has yet to be determined. An important consideration is potential cardiac effects of taxol with other drugs.

Towards safer colonoscopy: a report on the complications of 5000 diagnostic or therapeutic colonoscopies

The diagnostic and therapeutic benefits of colonoscopy are well known but most large-scale surveys, especially those involving multiple centres, may underestimate the range and incidence of complications. The detailed records of 5000 colonoscopies in a specialist unit have been analysed and conclusions drawn which may help to make the procedure safer. The incidence of haemorrhage was 1% and bowel perforation 0.1%. All the major haemorrhages occurred during polypectomies over 2 cm in size. Secondary haemorrhage was an unpredictable occurrence, one to 14 days later. Three deaths followed colonoscopy: one cardiorespiratory death was related to oversedation; a second was due to mismanaged ischaemic colitis developing two days after traumatic instrumentation, and the third was due to peritonitis. Minor complications included thrombophlebitis, abdominal distension, and vasovagal episodes. Because of experience during the first half of the series and also due to improvements in instrumentation, the complication rate of the later part of the series was halved. Recommendations include the avoidance of oversedation, review of previous barium enema films so as to be aware of large polyps which are more likely to bleed, and the recognition of situations where perforation or septicaemia is likely to occur.