Rivaroxaban versus placebo in patients with acute coronary syndromes (ATLAS ACS-TIMI 46): a randomised, double-blind, phase II trial

BACKGROUND

Rivaroxaban is an oral direct factor Xa inhibitor that has been effective in prevention of venous thromboembolism in patients undergoing elective orthopaedic surgery. However, its use after acute coronary syndromes has not been investigated. In this setting, we assessed the safety and efficacy of rivaroxaban and aimed to select the most favourable dose and dosing regimen.

METHODS

In this double-blind, dose-escalation, phase II study, undertaken at 297 sites in 27 countries, 3491 patients stabilised after an acute coronary syndrome were stratified on the basis of investigator decision to use aspirin only (stratum 1, n=761) or aspirin plus a thienopyridine (stratum 2, n=2730). Participants were randomised within each strata and dose tier with a block randomisation method at 1:1:1 to receive either placebo or rivaroxaban (at doses 5-20 mg) given once daily or the same total daily dose given twice daily. The primary safety endpoint was clinically significant bleeding (TIMI major, TIMI minor, or requiring medical attention); the primary efficacy endpoint was death, myocardial infarction, stroke, or severe recurrent ischaemia requiring revascularisation during 6 months. Safety analyses included all participants who received at least one dose of study drug; efficacy analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00402597.

FINDINGS

Three patients in stratum 1 and 26 in stratum 2 never received the study drug. The risk of clinically significant bleeding with rivaroxaban versus placebo increased in a dose-dependent manner (hazard ratios [HRs] 2.21 [95% CI 1.25-3.91] for 5 mg, 3.35 [2.31-4.87] for 10 mg, 3.60 [2.32-5.58] for 15 mg, and 5.06 [3.45-7.42] for 20 mg doses; p<0.0001). Rates of the primary efficacy endpoint were 5.6% (126/2331) for rivaroxaban versus 7.0% (79/1160) for placebo (HR 0.79 [0.60-1.05], p=0.10). Rivaroxaban reduced the main secondary efficacy endpoint of death, myocardial infarction, or stroke compared with placebo (87/2331 [3.9%] vs 62/1160 [5.5%]; HR 0.69, [95% CI 0.50-0.96], p=0.0270). The most common adverse event in both groups was chest pain (248/2309 [10.7%] vs 118/1153 [10.2%]).

INTERPRETATION

The use of an oral factor Xa inhibitor in patients stabilised after an acute coronary syndrome increases bleeding in a dose-dependent manner and might reduce major ischaemic outcomes. On the basis of these observations, a phase III study of low-dose rivaroxaban as adjunctive therapy in these patients is underway.

FUNDING

Johnson & Johnson Pharmaceutical Research & Development and Bayer Healthcare AG.

Consensus Statement: Cardiovascular Safety Profile of Triptans (5-HT1B/1D Agonists) in the Acute Treatment of Migraine

BACKGROUND

Health care providers frequently cite concerns about cardiovascular safety of the triptans as a barrier to their use. In 2002, the American Headache Society convened the Triptan Cardiovascular Safety Expert Panel to evaluate the evidence on triptan-associated cardiovascular risk and to formulate consensus recommendations for making informed decisions for their use in patients with migraine.

OBJECTIVE

To summarize the evidence reviewed by the Triptan Cardiovascular Safety Expert Panel and their recommendations for the use of triptans in clinical practice.

PARTICIPANTS

The Triptan Cardiovascular Safety Expert Panel was composed of a multidisciplinary group of experts in neurology, primary care, cardiology, pharmacology, women's health, and epidemiology.

EVIDENCE AND CONSENSUS PROCESS

An exhaustive search of the relevant published literature was reviewed by each panel member in preparation for an open roundtable meeting. Pertinent issues (eg, cardiovascular pharmacology of triptans, epidemiology of cardiovascular disease, cardiovascular risk assessment, migraine) were presented as a prelude to group discussion and formulation of consensus conclusions and recommendations. Follow-up meetings were held by telephone.

CONCLUSIONS

(1) Most of the data on triptans are derived from patients without known coronary artery disease. (2) Chest symptoms occurring during use of triptans are generally nonserious and are not explained by ischemia. (3) The incidence of serious cardiovascular events with triptans in both clinical trials and clinical practice appears to be extremely low. (4) The cardiovascular risk-benefit profile of triptans favors their use in the absence of contraindications.

The safety of intravenous dipyridamole thallium myocardial perfusion imaging. Intravenous Dipyridamole Thallium Imaging Study Group

Clinical data on 3,911 patients were collected from 64 individual investigators to evaluate the safety of intravenous dipyridamole-thallium imaging as an alternative to exercise thallium imaging for the evaluation of coronary artery disease. There were two deaths because of myocardial infarctions, two nonfatal myocardial infarctions, and six cases of acute bronchospasm. Chest pain occurred in 770 patients (19.7%). Headache and dizziness were reported by 476 patients (12.2%) and 460 patients (11.8%), respectively. ST-T changes on the electrocardiogram were seen in 292 patients (7.5%). Use of parenteral aminophylline to treat adverse events associated with intravenous dipyridamole brought complete relief of symptoms in 439 of 454 patients (96.7%). There is a potential for increased risk for serious ischemic events in patients with a history of unstable angina who are administered intravenous dipyridamole. In patients with acutely unstable angina (i.e., continuing chest pain) or in the acute phase of myocardial infarction, use of intravenous dipyridamole in thallium scintigraphy should be avoided. There is also an increased risk for bronchospasm in patients with a history of asthma; acute bronchospasm can be relieved immediately by administration of aminophylline. These results demonstrate that intravenous dipyridamole-thallium scintigraphy is a relatively safe, noninvasive technique for the evaluation of coronary artery disease.

Prospective multicenter evaluation of cocaine-associated chest pain. Cocaine Associated Chest Pain (COCHPA) Study Group

OBJECTIVE

To describe a large cohort of patients who had chest pain following cocaine use, and to determine the incidence of and clinical characteristics predictive for myocardial infarction in this group of patients.

METHODS

A prospective observational cohort study of consecutive patients with cocaine-associated chest pain was conducted in six municipal hospital emergency departments (EDs). Demographic variables, drug abuse patterns, medical histories, chest pain characteristics, ECG results, and laboratory data were recorded. Myocardial infarction was the primary endpoint.

RESULTS

Fourteen of 246 patients (5.7%; 95% confidence interval [CI], 2.7-8.7%) had myocardial infarction, as diagnosed by elevated CK-MB isoenzyme levels. There were two deaths (0.8%). The patients had a median age of 33 years. The majority were male (71.5%), non-white (83.3%), cigarette smokers (83.3%) who used cocaine regularly. Chest pain began a median of 60 minutes after cocaine use and persisted for a median of 120 minutes. Chest pain was most frequently described as substernal (71.3%) and pressure-like (46.7%). Shortness of breath (59.3%) and diaphoresis (38.6%) were common. There was no clinical difference between patients who had myocardial infarctions and those who did not. Twelve patients had arrhythmias and four had congestive heart failure. All cases requiring intervention were evident upon presentation. An ECG revealing ischemia or infarction had a sensitivity of 35.7% for predicting a myocardial infarction. The specificity, positive predictive value, and negative predictive value of the ECGs were 89.9%, 17.9%, and 95.8%, respectively.

CONCLUSIONS

Myocardial infarction in patients who have cocaine-associated chest pain is not uncommon. No clinical parameter available to the physician can adequately identify patients at very low risk for myocardial infarction. Therefore, all patients with cocaine-associated chest pain should be evaluated for myocardial infarction.

Impairment of myocardial protection in type 2 diabetic patients

Diabetic patients are more prone to develop postinfarction complications. It remained unclear whether diabetes mellitus- or sulfonylureas-associated changes of ATP-sensitive potassium (K(ATP)) channels, an integral player in ischemic preconditioning, are responsible for the increased mortality. The purpose of this study was to determine the impact of diabetes mellitus per se and different sulfonylurea administration on cardioprotective effects in diabetic patients undergoing coronary angioplasty. Myocardial ischemia after coronary angioplasty was evaluated in 20 nondiabetic and 23 diabetic patients chronically taking either glibenclamide or glimepiride. Nondiabetic patients treated with glimepiride significantly lowered the ischemic burden assessed by an ST-segment shift, chest pain score, and myocardial lactate extraction ratios compared with the glibenclamide-treated patients, implying that acute administration of glimepiride did not abolish cardioprotection. In the diabetic glibenclamide-treated group, the reduction in the ST-segment shift afforded by nicorandil in the first inflation (-58% vs. the first inflation in the glibenclamide group alone) was similar to that afforded by preconditioning (-59% during the second vs. the first inflation). In glimepiride-treated groups, the magnitude of attenuated lactate production was less in diabetes than that in nondiabetes at the second inflation, suggesting that diabetes mellitus per se plays a role in determining lactate production. Our results show that both diabetes mellitus and sulfonylureas can act in synergism to inhibit activation of K(ATP) channels in patients undergoing coronary angioplasty. The degree of inhibition assessed by metabolic and electrocardiographic parameters is less severe during treatment with glimepiride than with glibenclamide. Restitution of a preconditioning response in glimepiride-treated patients may be the potential beneficial mechanism.

Lung abnormalities after dasatinib treatment for chronic myeloid leukemia: a case series

Tyrosine kinase inhibitors have revolutionized the treatment of chronic myeloid leukemia and are increasingly used for other indications. Fluid retention, however, including pleural effusions, are a significant side effect of imatinib, the first-line treatment for chronic myeloid leukemia. We investigated pleural and pulmonary complications in patients treated with dasatinib, a novel multitargeted tyrosine kinase inhibitor, as part of clinical trial protocols. Of 40 patients who received dasatinib (70 mg twice daily) for imatinib resistance or intolerance, 9 (22.5%) developed dyspnea, cough, and chest pain. Of these nine patients, six had pleural effusions (all were exudates) and seven had lung parenchyma changes with either ground-glass or alveolar opacities and septal thickening (four patients had both pleural effusions and lung parenchyma changes). Lymphocytic accumulations were detected in pleural and bronchoalveolar lavage fluids in all patients except for one who presented with neutrophilic alveolitis. Pleural biopsies revealed lymphocytic infiltration in one patient and myeloid infiltration in another. After dasatinib interruption, lung manifestations resolved in all cases and did not recur in three of four patients when dasatinib was reintroduced at a lower dose (40 mg twice daily). Thus, lung physicians should be aware that lung manifestations, presumably related to an immune-mediated mechanism rather than fluid retention, may occur with dasatinib treatment.

Validation of a brief observation period for patients with cocaine-associated chest pain

BACKGROUND

Retrospective studies of patients with cocaine-associated chest pain suggest that a strategy of discharging patients from the emergency department after a 12-hour observation period if they do not have evidence of ischemia should be associated with a very low rate of complications.

METHODS

We prospectively evaluated the safety of a 9-to-12-hour observation period in patients with cocaine-associated chest pain who were at low-to-intermediate risk of cardiovascular events. Consecutive patients who reported or tested positive for cocaine use and who received protocol-driven care in a chest-pain observation unit were included. Patients who had normal levels of troponin I, without new ischemic changes on electrocardiography, and who had no cardiovascular complications (dysrhythmias, acute myocardial infarction, or recurrent symptoms) during the 9-to-12-hour observation period were discharged from the unit. The main outcome was death from cardiovascular causes at 30 days.

RESULTS

Three hundred forty-four patients with cocaine-associated chest pain were evaluated. Forty-two of these patients (12 percent) were directly admitted to the hospital. The study cohort comprised the remaining 302 patients. During the 30-day follow-up period, none of the patients died of a cardiovascular event (0 percent; 95 percent confidence interval, 0 to 0.99), and only 4 of the 256 patients for whom detailed follow-up data were available had a nonfatal myocardial infarction (1.6 percent; 95 percent confidence interval, 0.1 to 3.1). All four nonfatal myocardial infarctions occurred in patients who continued to use cocaine.

CONCLUSIONS

Patients with cocaine-associated chest pain who do not have evidence of ischemia or cardiovascular complications over a 9-to-12-hour period in a chest-pain observation unit have a very low risk of death or myocardial infarction during the 30 days after discharge.

Frequency of acute coronary syndrome in patients presenting to the emergency department with chest pain after methamphetamine use

We reviewed the frequency of acute coronary syndrome (ACS) in patients presenting to our emergency department (ED) with chest pain after methamphetamine (MAP) use during a 2-year interval. Thirty-three patients (25 males, 8 females; average age 40.4 +/- 8.0 years) with a total of 36 visits met study inclusion criteria: 1) non-traumatic chest pain, 2) positive MAP urine toxicology screen, 3) admission to "rule-out" myocardial infarction, 4) chest radiograph demonstrating no infiltrates. An ACS was diagnosed in 9 patients (25%). Three patients (8%) (2 ACS and 1 non-ACS) suffered cardiac complications (ventricular fibrillation, ventricular tachycardia, supraventricular tachycardia, respectively). Age, gender, cardiac risk factors, prior coronary artery disease, initial systolic blood pressure and heart rate did not differ significantly in the ACS and non-ACS groups. The initial and subsequent electrocardiograms (EKG) were normal in 1/9 (11%) patients with ACS and 16/27 (59%) without ACS (p < 0.05). Our findings suggest that: 1) ACS is common in patients hospitalized for chest pain after MAP use, and 2) the frequency of other potentially life-threatening cardiac complications is not negligible. A normal EKG lowers the likelihood of ACS, but an abnormal EKG is not helpful in distinguishing patients with or without ACS.

Acute myocardial infarction and chest pain syndromes after cocaine use

Seventy patients hospitalized with chest pain after cocaine use were retrospectively evaluated to define the risk and clinical course of acute myocardial infarction (AMI). AMI developed in 22 patients (31%) and transient myocardial ischemia was seen in an additional 9 patients (13%). Coronary risk factors did not distinguish those who developed AMI from those who did not. The presenting electrocardiogram was abnormal in 20 of 22 patients who evolved AMI and in 19 of 48 of those who did not. Creatine kinase levels were elevated in 75% of the patients, including 65% of those who did not develop AMI, but creatine kinase-MB elevations were only observed in the AMI group. The route of cocaine administration did not predict AMI and there was no predilection for a particular coronary vascular bed. The length of time between drug use and onset of AMI pain was often quite prolonged (median interval, 18 vs 1 hour in the non-AMI group). Eight of the patients with AMI underwent cardiac catheterization and 4 had significant coronary narrowing.

Safety of intravenous dipyridamole for stress testing with thallium imaging

Cardiac and noncardiac side effects were studied in 293 consecutive patients referred for nonexercise stress thallium imaging with intravenous dipyridamole. Six minutes after the initiation of infusion, there was a mean 9-beat/min increase in heart rate and a mean 12-mm Hg decrease in systolic blood pressure. The largest increase in heart rate exceeded 20 beats/min in only 13% of patients and the largest decrease in systolic blood pressure exceeded 20 mm Hg in 31%. Noncardiac side effects were headache (11%), lightheadedness or dizziness (5%) and nausea (4%). Only 9 patients required intravenous aminophylline for relief of noncardiac side effects: severe headache in 7 and nausea in 2. Cardiac side effects included chest pain in 76 patients (26%), of whom 70% were given aminophylline for relief of symptoms. Sixty patients (20%) had ischemic ST-segment depression and 56 (19%) had arrhythmias (ventricular in 50 and atrial in 6). There were no deaths, myocardial infarctions or sustained arrhythmias due to dipyridamole administration. Among 62 patients also undergoing cardiac catheterization, side effects except for arrhythmias were unrelated to the number of vessels with coronary artery disease. Intravenous dipyridamole is safe for nonexercise stress testing and has few serious side effects. However, the possibility of ischemia requires careful selection of patients and monitoring of vital signs and the electrocardiogram during the test.

Fluorouracil cardiotoxicity

OBJECTIVE

To review the clinical manifestations, postulated mechanisms, and therapeutic implications of fluorouracil-induced cardiac toxicity.

DATA SOURCE

A MEDLINE search was used to identify pertinent literature.

STUDY SELECTION

Studies and case reports on fluorouracil cardiotoxicity were identified through a MEDLINE search. A manual review of bibliographies of identified articles was performed to ensure that all pertinent articles were included.

DATA EXTRACTION

Data pertaining to all aspects of fluorouracil cardiac toxicity, including pathogenesis, predisposing factors, clinical manifestations, and therapeutic implications, were evaluated.

DATA SYNTHESIS

Estimates from large series suggest a 1.6-2.3 percent incidence of clinically demonstrated cardiotoxicity. Predisposing factors include the presence of coronary artery disease and concurrent radiotherapy. Postulated mechanisms include direct myocardial ischemia, coronary spasm, or cardiotoxic impurities in fluorouracil formulation. Clinical manifestations include chest pain, nausea, diaphoresis with typical ischemic electrocardiographic (ECG) changes, relieved to normal after stopping the drug therapy. Nitrates and calcium-channel blockers do not protect against cardiotoxicity.

CONCLUSIONS

Fluorouracil cardiotoxicity may be much more common and clinically significant than previously thought. A high index of suspicion for cardiotoxicity must be maintained when the drug is administered, especially in the presence of heart disease and concomitant radiation therapy. In the presence of chest pain, it is mandatory to stop the infusion and, if possible, to replace fluorouracil with another chemotherapeutic agent.

Reactive airways dysfunction syndrome due to chlorine: sequential bronchial biopsies and functional assessment

Very little information is available on the acute histopathological bronchial alterations caused by reactive airways dysfunction syndrome (RADS). We had the opportunity to carry out sequential bronchial biopsies in a subject with RADS due to chlorine (60 h, 15 days, 2 and 5 months after the acute exposure), and also to assess spirometry and bronchial responsiveness to methacholine. A 36 year old worker in a water-filtration plant (nonsmoker) abruptly inhaled high concentrations of chlorine on September 12, 1994. He experienced immediate nasal and throat burning, retrosternal burning and wheezing, and these symptoms persisted during and after the workshift. Two days later, he complained of retrosternal burning, dyspnoea and wheezing. Inspiratory wheezing was documented. His forced expiratory volume in one second (FEV1) was 66% of predicted and the provocative concentration of methacholine causing a 20% fall in FEV1 (PC20) was slightly abnormal (2.5 mg.mL-1). On the following day, the patient underwent bronchial biopsies, which showed almost complete replacement of the epithelium by a fibrinohaemorhagic exsudate. The subject was prescribed inhaled steroids. Fifteen days after the accident, the PC20 was improved to 6 mg.mL-1. Bronchial biopsies showed considerable epithelial desquamation with an inflammatory exudate and swelling of the subepithelial space. Five weeks after the accident, the PC20 was normal (57 mg.mL-1). Inhaled steroids were stopped. Two months after the accident, the PC20 deteriorated to 4 mg.mL-1. Biopsies then showed regeneration of the epithelium by basal cells and there was still a pronounced inflammatory infiltrate. Inhaled steroids were restarted. Three and five months later, the PC20 was normal (24 mg.mL-1). Bronchial biopsies showed a greatly improved epithelium and reduction of the inflammatory infiltrate. This case report shows that reactive airways dysfunction syndrome can cause acute, marked, though partially reversible, histological abnormalities. Inhaled steroids may modulate changes in bronchial responsiveness in this condition.

Ketamine abusers presenting to the emergency department: a case series

Ketamine hydrochloride, familiar to emergency physicians as a dissociative anesthetic, has been abused as a hallucinogen for almost 30 years. The drug produces effects similar to those of phencyclidine but with a much shorter duration of effect. Since 1996, an increasing number of patients have presented to Connecticut Emergency Departments (EDs) after the intentional abuse of ketamine. Because the medical literature contains almost no information on the consequences of ketamine abuse, we have compiled a series of ketamine abusers presenting to the ED. Among the 20 patients in this series, common presenting complaints included anxiety, chest pain, and palpitations. Tachycardia was the most common physical examination finding. Nystagmus, a common finding after phencyclidine use, was seen in only three cases. The most frequent complications after ketamine abuse were severe agitation and rhabdomyolysis. The symptoms of ketamine intoxication appear to be short-lived, with 18 of the 20 patients discharged from the ED within 5 h of presentation. Emergency physicians should include ketamine in the differential diagnosis of drug- or toxin-induced hallucinations. Methods for detecting this drug in biologic fluids are reviewed as are treatment recommendations for managing the patient who presents to the ED after abusing ketamine.

Cardiovascular tolerability and safety of triptans: a review of clinical data

Triptans are not widely used in clinical practice despite their well-established efficacy, endorsement by the US Headache Consortium, and the demonstrable need to employ effective intervention to reduce migraine-associated disability. Although the relatively restricted use of triptans may be attributed to several factors, research suggests that prescribers' concerns about cardiovascular safety prominently figure in limiting their use. This article reviews clinical data--including results of clinical trials, postmarketing studies and surveillance, and pharmacodynamic studies--relevant to assessing the cardiovascular safety profile of the triptans. These data demonstrate that triptans are generally well tolerated. Chest symptoms occurring during use of triptans are usually nonserious and usually not attributed to ischemia. Incidence of triptan-associated serious cardiovascular adverse events in both clinical trials and clinical practice appears to be extremely low. When they do occur, serious cardiovascular events have most often been reported in patients at significant cardiovascular risk or in those with overt cardiovascular disease. Adverse cardiovascular events also have occurred, however, in patients without evidence of cardiovascular disease. Several lines of evidence suggest that nonischemic mechanisms are responsible for sumatriptan-associated chest symptoms, although the mechanism of chest symptoms has not been determined to date. Importantly, most of the clinical trials and clinical practice data on triptans are derived from patients without known cardiovascular disease. Therefore, the conclusions of this review cannot be extended to patients with cardiovascular disease. The cardiovascular safety profile of triptans favors their use in the absence of contraindications.

Chest pain associated with cocaine: an assessment of prevalence in suburban and urban emergency departments

STUDY OBJECTIVE

Chest pain and myocardial infarction following the use of cocaine have been well documented. We assessed the prevalence of cocaine use in patients who presented to the emergency department with chest pain of possibly ischemic origin.

DESIGN

During times of research assistant availability, consecutive adults with the chief complaint of chest pain unexplained by trauma or radiographic abnormality were questioned about cocaine use in the preceding week. Urine was tested for the presence of cocaine or cocaine metabolites with a highly accurate bedside urine test kit (specificity, 100%; sensitivity 98%). Anonymous unlinked data-collection methods were used. Therefore we could not determine whether the patients who used cocaine had sustained myocardial infarctions.

SETTING

One suburban and three urban EDs.

RESULTS

We enrolled 359 patients with a mean age of 51 years, 8% of whom sustained myocardial infarctions. Sixty patients (17%) had cocaine or cocaine metabolites in urine. The likelihood of testing positive for cocaine varied by age group: 18 to 30 years, 29%; 31 to 40 years, 48%; 41 to 50 years, 18%; 51 to 60 years, 3%; 61 years or older, 0% (P < .0001). Of the 60 patients who tested positive for cocaine, only 43 (72%) admitted recent use.

CONCLUSION

Many ED patients with chest pain have recently used cocaine. Because the recent use of cocaine is not uncommon in patients with chest pain up to 60 years old, such patients should be questioned about cocaine use. When treatment or disposition may be altered, consideration should be given to objective assessment of cocaine use because patient self-report does not appear reliable.

Tolerance and safety of pharmacologic coronary vasodilation with adenosine in association with thallium-201 scintigraphy in patients with suspected coronary artery disease

Adenosine thallium-201 myocardial scintigraphy is a promising test for coronary artery disease detection, but its safety has not been reported in large patient cohorts. Accordingly, the tolerance and safety profile of adenosine infusion were analyzed in 607 patients (351 men, 256 women, mean age 63 +/- 11 years) undergoing this test either because of suspected coronary artery disease (Group I, n = 482) or for risk stratification early (5.2 +/- 2.8 days) after myocardial infarction (Group II, n = 125). Adenosine increased the heart rate from 74.5 +/- 14.0 to 91.8 +/- 15.9 beats/min (p less than 0.001) and decreased systolic blood pressure from 137.8 +/- 26.8 to 120.7 +/- 26.1 mm Hg (p less than 0.001). Side effects were frequent and similar in both groups. Flushing occurred in 35%, chest pain in 34%, headache in 21% and dyspnea in 19% of patients. Only 35.6% of Group I patients with chest pain during adenosine infusion had concomitant transient perfusion abnormalities, compared with 60.7% of Group II patients (p less than 0.05). First- and second-degree AV block occurred in 9.6% and 3.6% of patients, respectively, and ischemic ST changes in 12.5% of cases. Concomitance of chest pain and ischemic ST depression was uncommon (6%) but, when present, predicted perfusion abnormalities in 73% of patients. Most side effects ceased rapidly after stopping the adenosine infusion. The side effects were severe in only 1.6% of patients and in only six patients (1%) was it necessary to discontinue the infusion. No serious adverse reactions such as acute myocardial infarction or death occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

An evaluation of cocaine-induced chest pain

STUDY OBJECTIVE

To determine if enzymatic evidence of acute myocardial injury is present in patients complaining of chest pain after cocaine use when the ECG is normal or nondiagnostic.

DESIGN

Serial ECG and creatinine kinase (CK) and CK isoenzymes (CK-ISO) determinations were performed at time of emergency department presentation and every six hours over 12 hours on individuals complaining of chest pain within six hours of last cocaine use.

SETTING

ED of an urban tertiary care center.

TYPE OF PARTICIPANTS

Forty-two individuals with a mean age of 28.5 years.

INTERVENTIONS

Patients with positive CK-ISOs were admitted immediately to formally rule out myocardial infarction. Patients developing ECG changes during observation period also were admitted even if CK-ISOs were normal. Patients with unchanged ECGs and normal CK-ISOs were discharged after 12 hours of observation.

RESULTS

Eight patients (19%) had elevated CK and CK-ISO values at presentation. Two of these patients had elevated values on three sequential determinations and were believed to have sustained acute myocardial infarction. Six patients had elevated CK and CK-ISOs at presentation only. ECGs remained normal or nondiagnostic in all patients.

CONCLUSIONS

Enzymatic evidence of acute myocardial injury may occur in patients who develop chest pain after cocaine use and have normal or nondiagnostic ECGs. This injury may reflect acute infarction or transient ischemia. Single or serial normal or nondiagnostic ECGs do not rule out ischemia or injury in this group of patients.

Feasibility and safety of high-dose adenosine perfusion cardiovascular magnetic resonance

INTRODUCTION

Adenosine is the most widely used vasodilator stress agent for cardiovascular magnetic resonance (CMR) perfusion studies. With the standard dose of 140 mcg/kg/min some patients fail to demonstrate characteristic haemodynamic changes: a significant increase in heart rate (HR) and mild decrease in systolic blood pressure (SBP). Whether an increase in the rate of adenosine infusion would improve peripheral and, likely, coronary vasodilatation in those patients is unknown. The aim of the present study was to assess the tolerance and safety of a high-dose adenosine protocol in patients with inadequate haemodynamic response to the standard adenosine protocol when undergoing CMR perfusion imaging.

METHODS

98 consecutive patients with known or suspected coronary artery disease (CAD) underwent CMR perfusion imaging at 1.5 Tesla. Subjects were screened for contraindications to adenosine, and an electrocardiogram was performed prior to the scan. All patients initially received the standard adenosine protocol (140 mcg/kg/min for at least 3 minutes). If the haemodynamic response was inadequate (HR increase < 10 bpm or SBP decrease < 10 mmHg) then the infusion rate was increased up to a maximum of 210 mcg/kg/min (maximal infusion duration 7 minutes).

RESULTS

All patients successfully completed the CMR scan. Of a total of 98 patients, 18 (18%) did not demonstrate evidence of a significant increase in HR or decrease in SBP under the standard adenosine infusion rate. Following the increase in the rate of infusion, 16 out of those 18 patients showed an adequate haemodynamic response. One patient of the standard infusion group and two patients of the high-dose group developed transient advanced AV block. Significantly more patients complained of chest pain in the high-dose group (61% vs. 29%, p = 0.009). On multivariate analysis, age > 65 years and ejection fraction < 57% were the only independent predictors of blunted haemodynamic responsiveness to adenosine.

CONCLUSIONS

A substantial number of patients do not show adequate peripheral haemodynamic response to standard-dose adenosine stress during perfusion CMR imaging. Age and reduced ejection fraction are predictors of inadequate response to standard dose adenosine. A high-dose adenosine protocol (up to 210 mcg/kg/min) is well tolerated and results in adequate haemodynamic response in nearly all patients.

Failure of preventing 5-fluorouracil cardiotoxicity by prophylactic treatment with verapamil

The most common cardiotoxic effects of 5-fluorouracil (5-FU) are chest pain and ischemic ECG abnormalities. Coronary vasospasm may be the underlying mechanism. If so, prophylactic treatment with calcium channel blockers might have a beneficial effect. In the present study, prophylaxis with verapamil (120 mg three times daily) was given to 58 patients with esophageal or advanced head and neck carcinoma during induction chemotherapy with cisplatin and continuous infusion with 5-FU. Signs of ischemia appeared in 12% of the patients as compared to 13% in a previously studied compatible group of patients not receiving prophylaxis. The study does not support the hypothesis that prophylactic treatment with verapamil reduces the incidence of ischemia in patients undergoing 5-FU treatment. Verapamil might, however, modify the adverse cardiac effects of 5-FU by preventing supraventricular tachyarrhythmia.

Respiratory symptoms, sensitization, and exposure response relationships in spray painters exposed to isocyanates

RATIONALE

Associations between oligomeric isocyanate exposure, sensitization, and respiratory disease have received little attention, despite the extensive use of isocyanate oligomers.

OBJECTIVES

To investigate exposure-response relationships of respiratory symptoms and sensitization in a large population occupationally exposed to isocyanate oligomers during spray painting.

METHODS

The prevalence of respiratory symptoms and sensitization was assessed in 581 workers in the spray-painting industry. Personal exposure was estimated by combining personal task-based inhalatory exposure measurements and time activity information. Specific IgE and IgG to hexamethylene diisocyanate (HDI) were assessed in serum by ImmunoCAP assay and enzyme immunoassays using vapor and liquid phase HDI-human serum albumin (HDI-HSA) and HSA conjugates prepared with oligomeric HDI.

MEASUREMENTS AND MAIN RESULTS

Respiratory symptoms were more prevalent in exposed workers than among comparison office workers. Log-linear exposure-response associations were found for asthmalike symptoms, chronic obstructive pulmonary disease-like symptoms, and work-related chest tightness (prevalence ratios for an interquartile range increase in exposure of 1.2, 1.3 and 2.0, respectively; P </= 0.05). The prevalence of specific IgE sensitization was low (up to 4.2% in spray painters). Nevertheless, IgE to N100 (oligomeric HDI)-HSA was associated with exposure and work-related chest tightness. The prevalence of specific IgG was higher (2-50.4%) and strongly associated with exposure.

CONCLUSIONS

The results provide evidence of exposure-response relationships for both work-related and non-work-related respiratory symptoms and specific sensitization in a population exposed to oligomers of HDI. Specific IgE was found in only a minority of symptomatic individuals. Specific IgG seems to be merely an indicator of exposure.

Dihydro-5-azacytidine in malignant mesothelioma. A phase II trial demonstrating activity accompanied by cardiac toxicity. Cancer and Leukemia Group B

BACKGROUND

Malignant mesothelioma is a disease that is refractory to chemotherapy. Therefore, the objective of this multi-institutional, cooperative group Phase II trial was to determine the efficacy of dihydro-5-azacytidine (DHAC), a pyrimidine analogue, in the treatment of malignant mesothelioma.

METHODS

Forty-one patients with histologically confirmed malignant mesothelioma received 120-hour continuous infusions of DHAC (1,500 mg/m2/day every 21 days) until maximal response, intolerable toxicity, or disease progression.

RESULTS

One patient had a complete response, two had objective partial responses, and four had regression of evaluable disease. The overall response rate was 17%. The one complete responder remains without disease progression at 6 years. Chest pain and nausea were the most common toxicities. Supraventricular tachycardia and pericardial effusion occurred in 20% and 15% of patients, respectively. In most patients, gastrointestinal effects were manageable. There was no significant hematologic toxicity.

CONCLUSIONS

In malignant mesothelioma, a disease that is refractory to chemotherapy, dihydro-5-azacytidine has definite antitumor activity. Its modest hematologic toxicity profile favors its use in combination with other agents. Caution regarding cardiac arrhythmias and pericardial effusion is necessary.

Chest symptoms after sumatriptan: a two-year clinical practice review in 735 consecutive migraine patients

OBJECTIVES

To assess, in clinical practice, the (i) incidence, (ii) within-patient consistency, and (iii) clinical spectrum of chest symptoms (chest symptoms) after subcutaneous (sc) and oral sumatriptan, and (iv) to identify risk factors for chest symptoms.

DESIGN

Two-year retrospective survey with mailed self-administered questionnaire.

SETTING

Neurology outpatient clinic of university hospital.

SUBJECTS

Migraine patients with or without aura (n = 869).

MAIN OUTCOME MEASURES

Incidence, within-patient consistency and characteristics of chest symptoms; demographic and clinical characteristics of patients.

RESULTS

There were 735 (85%) respondents. Sumatriptan was used by 453 patients, during 25 months (median), for 28000 attacks (median: 33 attacks/patient). Of sumatriptan users, 41% (sc) and 24% (oral) had chest symptoms in all attacks, 39% (sc) and 58% (oral) in none, and the remaining in some attacks. Because of chest symptoms, 10% discontinued sumatriptan. Chest symptoms mostly consisted of heavy arms and chest pressure, started within 5 (sc) to 30 (oral) min, and lasted 30 (sc) to 60 (oral) min. Compared with patients without chest symptoms, patients with chest symptoms more often were females and younger, and went to rest immediately after sumatriptan administration (all p < 0.001); they also tended to have lower body mass indices, more severe attacks and less efficacy of sumatriptan (all 0.001 < p < 0.05). Patients with chest symptoms had no higher incidence of cardiovascular symptoms or risk factors.

CONCLUSIONS

Chest symptoms are frequent, within-patients consistent, but rarely important, adverse events of (notably sc) sumatriptan. The risk of chest symptoms is patient-dependent and not related, even opposite, to cardiovascular disease. This contradicts the hypothesis that chest symptoms after sumatriptan are caused by cardiac ischemia. Patient acceptance of chest symptoms is improved by pre-advising on the risk and nature of chest symptoms.