warfarin and Heart-Arrest

There is a modest risk of myocardial infarction (MI) and myocardial ischemic events in patients with atrial fibrillation.. Data from the RE-LY study (Randomized Evaluation of Long-Term Anticoagulation Therapy) were used to report rates of MI, unstable angina, cardiac arrest, and cardiac death and the prespecified net clinical benefit and treatment effects of dabigatran versus warfarin. MI occurred at annual rates of 0.82% and 0.81% with dabigatran 110 or 150 mg BID compared with 0.64% with warfarin (hazard ratio [HR] 1.29, 95% confidence interval [CI] 0.96-1.75, P=0.09 for dabigatran 110 mg; HR 1.27, 95% CI 0.94-1.71, P=0.12 for dabigatran 150 mg). Annual rates of a composite of MI, unstable angina, cardiac arrest, and cardiac death were 3.16% per year with dabigatran 110 mg, 3.33% per year with dabigatran 150 mg, and 3.41% per year with warfarin (HR versus warfarin 0.93, 95% CI 0.80-1.06, P=0.28 for dabigatran 110 mg and HR 0.98, 95% CI 0.85-1.12, P=0.77 for dabigatran 150 mg). Events prespecified as "net clinical benefit" (all strokes, systemic embolism, MI, pulmonary embolism, major bleeding, and all-cause death) occurred at a rate of 7.34% per year with dabigatran 110 mg, 7.11% per year with dabigatran 150 mg, and 7.91% per year with warfarin (HR 0.92, 95% CI 0.84-1.01, P=0.09 for dabigatran 110 mg and HR 0.90, 95% CI 0.82-0.99, P=0.02 for dabigatran 150 mg). The relative effects of dabigatran versus warfarin on myocardial ischemic events were consistent in patients with or without a baseline history of MI or coronary artery disease.. There was a nonsignificant increase in MI with dabigatran compared with warfarin, but other myocardial ischemic events were not increased. Treatment effects of dabigatran were consistent in patients at higher and lower risk of myocardial ischemic events.

Topics: Aged; Aged, 80 and over; Angina, Unstable; Anticoagulants; Antithrombins; Atrial Fibrillation; Benzimidazoles; beta-Alanine; Dabigatran; Death, Sudden, Cardiac; Dose-Response Relationship, Drug; Female; Heart Arrest; Humans; Incidence; Male; Middle Aged; Myocardial Ischemia; Risk Factors; Single-Blind Method; Warfarin

IgG-specific and polyspecific PF4-dependent enzyme-immunoassays (EIAs) have exceptionally high sensitivity (≥99%) for diagnosis of heparin-induced thrombocytopenia (HIT), a drug reaction caused by platelet-activating antibodies detectable by serotonin-release assay (SRA). The IgG-specific EIAs are recommended for screening, as their high sensitivity is accompanied by relatively high specificity vis-à-vis polyspecific EIAs. We investigated the frequency of SRA-positive/EIA-negative (SRA+/EIA-) HIT, prompted by referral to our reference HIT laboratory of serial blood samples from a patient ("index case") with false-negative IgG-specific EIAs. Despite initial clinical suspicion for HIT, repeat negative IgG-specific EIAs prompted heparin resumption, which triggered recurrent thrombocytopenia and near-fatal cardiac arrest, indicating likely post-heparin HIT-associated anaphylactoid reaction. Further investigations revealed a strong-positive SRA, whether performed with heparin alone, PF4 alone, or PF4/heparin, with inhibition by Fc receptor-blocking monoclonal antibody (indicating IgG-mediated platelet activation); however, five different IgG-specific immunoassays yielded primarily negative (or weak-positive) results. To investigate the frequency of SRA+/EIA- HIT, we reviewed the laboratory and clinical features of patients with this serological profile during a 6-year period in which our reference laboratory investigated for HIT using both SRA and IgG-specific EIA. Although ~0.2% of 8546 patients had an SRA+/EIA- profile, further review of 15 such cases indicated clerical/laboratory misclassification or false-positive SRA in all, with no SRA+/EIA- HIT case identified. We conclude that while SRA+/EIA- HIT is possible-as shown by our index case-this clinical picture is exceptionally uncommon. Moreover, the requirement for a positive EIA is a useful quality control maneuver that reduces risk of reporting a false-positive SRA result.

Topics: Adult; Anaphylaxis; Anticoagulants; Autoantibodies; Autoantigens; Blood Platelets; Drug Therapy, Combination; False Negative Reactions; Female; Heart Arrest; Heparin; Humans; Immunoenzyme Techniques; Immunoglobulin G; Immunoglobulin M; Medical Errors; Obesity; Platelet Activation; Platelet Factor 4; Pulmonary Embolism; Recurrence; Sensitivity and Specificity; Serotonin; Thrombocytopenia; Venous Thrombosis; Warfarin

Topics: Animals; Anti-Bacterial Agents; Anticoagulants; Ants; Bartonella Infections; Brain Diseases; Diagnosis, Differential; Doxycycline; Heart Arrest; Humans; Insect Bites and Stings; Male; Middle Aged; Pulmonary Embolism; Tomography, X-Ray Computed; Vancomycin; Warfarin

The optimum international normalized ratio (INR) monitoring frequency for hospitalized patients receiving warfarin is unknown.. Assess relationship between daily versus less frequent INR monitoring and overanticoagulation and warfarin-related adverse events.. Retrospective cohort study using Medicare Patient Safety Monitoring System data.. Randomly selected acute care hospitals across the United States.. Patients hospitalized from 2009 to 2013 for pneumonia, acute cardiac disease, or surgery who received warfarin.. None.. (1) Association between frequency of INR monitoring and an INR ≥6.0 or warfarin-related adverse event. (2) Association between the rate of change of the INR and a subsequent INR ≥5.0 and ≥6.0.. Among 8529 patients who received warfarin for ≥3 days, for 1549 (18.2%) the INR was not measured on 2 or more days. These patients had higher propensity-adjusted odds ratios (ORs) of having a warfarin-associated adverse event (OR: 1.48, 95% confidence interval [CI]: 1.02-2.17) for cardiac patients and surgical patients (OR: 1.73, 95% CI: 1.20-2.48), with no significant association for pneumonia patients. Cardiac and pneumonia patients with 1 day or more without an INR measurement had higher propensity-adjusted ORs of having an INR ≥6.0 (OR: 1.61, 95% CI: 1.07-2.41 and OR: 1.92, 95% CI: 1.36-2.71, respectively). A 1-day increase in the INR of ≥0.9 occurred in 621 patients (12.5%) and predicted a subsequent INR of ≥6.0 (positive likelihood ratio of 4.2).. Daily INR measurement and recognition of a rapidly rising INR might decrease the frequency of warfarin-associated adverse events in hospitalized patients.

Topics: Aged; Aged, 80 and over; Anticoagulants; Cohort Studies; Drug Monitoring; Forecasting; Heart Arrest; Hospitalization; Humans; International Normalized Ratio; Intracranial Hemorrhages; Medicare; Middle Aged; Patient Harm; Random Allocation; United States; Warfarin

To identify risk factors for lower limb loss after arterial embolectomy a cohort of 1189 patients was studied. Detailed data were obtained for 165 patients who underwent a major amputation within 30 days of embolectomy and for 165 matched controls. The amputation risk was increased in patients with two or more myocardial infarctions (odds ratio (OR) 3.1, 95 per cent confidence interval (CI) 0.8-11.2), chronic ischaemia (OR 2.1, CI 0.9-4.9), long duration of symptoms (OR 4.3, CI 1.9-9.6, for greater than or equal to 25 h versus less than or equal to 6 h) or postoperative heart failure (OR 3.4, CI 1.8-6.5). Reduced risks were found in association with acute myocardial infarction (OR 0.3, CI 0.1-0.9) and postoperative anticoagulation treatment with warfarin (OR 0.3, CI 0.1-0.9). The independent prognostic value of chronic ischaemia and symptom duration, and the beneficial effect of postoperative anticoagulation gained additional support in multivariate analysis. We conclude that the risk of early amputation after arterial embolectomy or thrombectomy can be predicted by several clinical characteristics.

Topics: Acute Disease; Adult; Aged; Aged, 80 and over; Amputation, Surgical; Arterial Occlusive Diseases; Case-Control Studies; Cohort Studies; Female; Heart Arrest; Humans; Ischemia; Leg; Male; Middle Aged; Myocardial Infarction; Postoperative Complications; Risk Factors; Warfarin

Topics: Aged; Drug Synergism; Drug Therapy, Combination; Heart Arrest; Humans; Male; Myocardial Infarction; Phenytoin; Warfarin

There are a number of important drug interactions with amiodarone. This agent appears to have a marked effect on the kinetics of some commonly used cardiovascular drugs, such as warfarin, digoxin, quinidine, and procainamide, and has dynamic interactions with others, such as the beta blockers and some calcium antagonists. Bleeding has been reported, apparently caused by a potentiation of the anticoagulant effect of warfarin by amiodarone. Torsades de pointes has been observed when quinidine, propafenone, or mexiletine is given together with amiodarone. Furthermore, amiodarone may interact with beta-blocking agents and some of the calcium antagonists to produce symptomatic sinus bradycardia and sinus arrest, especially in a latent or overt sick sinus syndrome. During surgery, amiodarone may induce hypotension and an atropine-resistant bradycardia, possibly by interacting with anesthetic agents. A knowledge of the time of onset, extent, duration, and possible mechanisms of the interactions of amiodarone with other cardioactive drugs is still incomplete, but further studies are of great therapeutic importance.

Topics: Adrenergic beta-Antagonists; Amiodarone; Anti-Arrhythmia Agents; Arrhythmia, Sinus; Benzofurans; Blood Coagulation Disorders; Calcium; Digoxin; Drug Interactions; Drug Synergism; Heart Arrest; Humans; Kinetics; Quinidine; Tachycardia; Warfarin

Topics: Adult; Aged; Anesthesia, Inhalation; Blood Pressure; Blood Transfusion; Female; Gastrointestinal Hemorrhage; Halothane; Heart Arrest; Hip; Humans; Hypotension, Controlled; Joint Prosthesis; Male; Methylmethacrylates; Middle Aged; Myocardial Infarction; Osteotomy; Pentolinium Tartrate; Postoperative Complications; Pulmonary Embolism; Respiratory Insufficiency; Sodium; Thromboembolism; Thrombophlebitis; Warfarin

Topics: Angina Pectoris; Coronary Disease; Heart Arrest; Heart Block; Heparin; Humans; Meperidine; Morphine; Myocardial Infarction; Nitroglycerin; Oxygen Inhalation Therapy; Rest; Warfarin