No abstract

Implantable cardiac devices such as implantable cardioverterdefibrillators (ICDs) and cardiac resynchronisation therapy (CRT) devices lead to improved survival and better clinical outcomes in appropriately selected patients with heart failure (HF) with a reduced ejection fraction (EF). Although there are significant sex differences in the aetiology, pathophysiology and clinical course of HF, clinical practice guidelines for cardiac device therapy are not sex-specific and are based on clinical trials where the majority of patients enrolled were men. In this review, we explore sex differences in clinical outcomes and utilisation of ICDs and CRT and explore the reasons for these disparities. Implantable Cardioverter-DefibrillatorsThe annual incidence of sudden cardiac death (SCD) in the US is estimated to be 300,000 to 450,000.1 A major risk factor for SCD is HF with reduced EF. There have been several large randomised controlled studies that have demonstrated a mortality benefit from ICDs in eligible patients for both primary and secondary prevention of SCD. However, under-representation of women in these trials has made it somewhat difficult to determine the sex-specific survival benefit of ICD therapy. Evidence for the Use of ICD Therapy for Primary and Secondary Prevention of SCD Sex Differences in Outcomes with ICD Therapy Sex Differences in ICD Therapy for Secondary Prevention of SCDCurtis et al. 6 analysed a 5 % national sample of patients from the US Centers for Medicare & Medicaid Services eligible for ICD therapy and found that, in the secondary prevention ICD cohort, there was a statistically significant mortality benefit for both sexes even after adjustment for other factors. Sex Differences in Primary Prevention ICDsIn the MUSTT trial, 3 a total of 301 women were enrolled, and they constituted 10 % (68) of the randomised patients and 16 % (233) of those followed in the registry. Overall, there was no statistically significant difference in mortality between men and women in the electrophysiology (EP)-guided therapy group (21 % versus 32 %; p=0.13) or in the registry (20 % versus 27 %; p=0.15). However, there was a trend towards increased mortality in women, although the trial did not have sufficient power to detect gender differences due to the small number of women enrolled.In MADIT-II, 1,232 patients with ischaemic cardiomyopathy were enrolled of which 192 (16 %) were women. 4 Patients received ICDs versus standard medical therapy, with a total of 119 women receiving ICD therapy. Women were noted to have more advanced HF, as well as AbstractMultiple studies have demonstrated that implantable cardioverter-defibrillators (ICDs) and cardiac resynchronisation therapy (CRT) provide significant mortality and morbidity benefits to eligible patients irrespective of gender. However, female patients are less likely to receive this life-saving therapy and are significantly under-represented in cardiac device trials. Various performance improvement programmes have proved that this gender disparity can be reduce...

KM is noninferior to an ELR for detecting arrhythmias in the outpatient setting. The ease of use and portability of this device make it an attractive option for the detection of symptomatic arrhythmias.

There are important gender differences in cardiac electrophysiology that affect the epidemiology, presentation, and prognosis of various arrhythmias. Women have been noted to have higher resting heart rates compared to men. They also have a longer QT interval, which puts them at an increased risk for drug-induced torsades de pointes. Women with atrial fibrillation are at a higher risk of stroke, and they are less likely to receive anticoagulation and ablation procedures compared to men. Women have a lower risk of sudden cardiac death and are less likely to have known coronary artery disease at the time of an event compared to men. Both men and women have been shown to derive an equal survival benefit from implantable cardioverter defibrillators and cardiac resynchronization therapy, although these devices are significantly underutilized in women. Women also appear to have a better response to cardiac resynchronization therapy in terms of reduced numbers of hospitalizations and more robust reverse ventricular remodeling. Further studies are required to elucidate the underlying pathophysiology of these sex differences in cardiac arrhythmias. IntroductionSex differences in cardiac electrophysiology affect the epidemiology, presentation, and prognosis of various arrhythmias. These sex differences can have important clinical and therapeutic implications. Although the exact reason for these differences is not known, the potential mechanisms include differences in cardiac size, structure, and the different ways in which hormones, drugs, and electrolytes affect cardiac ion channels in men and women. The purpose of this review is to provide a synopsis of the important gender differences with respect to arrhythmias and to summarize updates from recent studies.

No abstract

P atients with atrial fibrillation (AF) may require electric cardioversion, either because of intolerable symptoms related to AF or as part of a rhythm control strategy. See Editorial by KotechaElectric cardioversion using a biphasic waveform has a procedural success rate of 86% to 94%, sometimes requiring multiple shocks.1-3 The success of electric cardioversion depends on the duration of AF, transthoracic impedance, delivered energy, and the type of electric shock used.1 Pharmacological cardioversion using antiarrhythmic drugs (AADs) has a lower success rate and may take a few hours to days to achieve sinus rhythm.Magnesium (Mg) is an abundant mineral in the body, present in bone, the heart, and the central nervous system. In the heart, Mg modulates potassium (slow-activating delayed rectifier K channel, I Ks ) and calcium channels (L-type) in both the atria and the ventricles. 4,5 Mg has been shown to have membrane-stabilizing properties within the atrium. 4 This membrane-stabilizing property may be particularly helpful in rhythm control of AF. Data from the Framingham offspring and Atherosclerosis Risk in Communities (ARIC) prospective cohorts have linked low serum Mg levels to AF. 6,7 Studies on pharmacological cardioversion have shown increased success of cardioversion when Mg is used along with an AAD. 8,9 A recent study on electric cardioversion showed that the infusion of a K-Mg electrolyte solution was successful in facilitating electric cardioversion of AF.3 On the basis of data suggesting an association of low Mg levels with the incidence of AF and the membrane-stabilizing property of Mg in the atrium with the modulation of I K+ and I Ca2+ currents, we postulated that administration of Mg alone would be useful in increasing the success of cardioversion. The purpose of this study was to investigate the benefit of intravenous © 2016 American Heart Association, Inc. Circ Arrhythm Electrophysiol

Coronary subclavian steal syndrome is a rare complication of coronary artery bypass grafting surgery (CABG) when a left internal mammary artery (LIMA) graft is utilized. This syndrome is characterized by retrograde flow from the LIMA to the left subclavian artery (SA) when a proximal left SA stenosis is present. We describe a unique case of an elderly male who underwent CABG 6 years ago who presented with prolonged chest pain, mildly elevated troponins, and unequal pulses in his arms. A CTA of the chest demonstrated a severely calcified occluded proximal left SA jeopardizing his LIMA graft. Subclavian angiography was performed with an attempt to revascularize the patient's occluded left SA which was unsuccessful. We referred the patient for nuclear stress testing which demonstrated a moderate size area of anterior ischemia on imaging; the patient exercised to a fair exercise capacity of 7 METS with no chest pain and no ECG changes. Subsequent coronary angiography showed severe native three-vessel coronary artery disease with intermittent retrograde blood flow from the LIMA to the left SA distal to the occlusion, jeopardizing perfusion to the left anterior descending (LAD) coronary artery distribution. He declined further options for revascularization and was discharged with medical management.

Introduction Decitabine (Dec) is not approved in the United States (US) for acute myeloid leukemia (AML) because it did not improve overall survival compared with standard conventional induction treatment. We asked what would be the cost effectiveness of Dec versus conventional induction therapy in AML patients (pts) older than 60 years of age. Methods The standard conventional induction including cytarabine, and daunorubicin, (AD) (N Engl J Med. 2009 361:1235-48) was compared with Dec (Haematologica. 2012 97:393-401) using a semi-Markov model compiling survival and cost data. Survival probabilities were retrieved from the literature. Data accounted for re-induction therapy with IDA-FLAG (idarubicin, fludarabine, cytarabine and granulocyte colony-stimulating factor) and consolidation therapy with high-dose cytarabine (HiDAC) but not for stem cell transplantation. The assumption-based model considered a maximum of 4 cycles of HiDAC and continuing Dec until loss of benefit. Drug costs were derived from the 2012 US market. Hospital costs accrued were evaluated in a diagnosis-related group (DRG) system. Drug dosage was estimated based on a body surface area of 1.85 m2. The quality of life (QoL) was assumed as 1 for healthy individuals; 0 for death; 0.524 for active disease; 0.91 for AML in remission on AD; 0.71 and 0.524 for AML being actively treated with Dec or AD, and 0.81 for AML in remission treated with Dec or HIDAC. QoL data were based on the literature except for pts on consolidation therapy. The latter was the mean of QoL of AML in remission and AML actively being treated. Results Assuming 1,000 pts for each treatment arm in a semi-Markov model over 1 year time horizon, the quality-adjusted life year (QALY) for AD vs. Dec was 0.1754 and 0.5982. The percentage survival for AD and Dec was 45.2% and 50.5%. Their costs were $127,867 and $55,777. The incremental cost-effectiveness ratio (ICER) was -$72,090/0.4228 = -$170,506/year. By sensitivity analysis, Dec was superior to AD to all parameters (Table 1). Conclusion Dec is a more cost-effective therapy for pts older than 60 years of age than conventional induction therapy. Given the economic pressures in the US Health System, one should consider approving Dec for newly diagnosed AML pts older than 60 years of age. Disclosures: No relevant conflicts of interest to declare.