Insights into hospital readmission patterns of atrial fibrillation patients.

INTRODUCTION: Patients admitted to the hospital with atrial fibrillation have associated morbidity and mortality and incur significant costs. Data characterizing atrial fibrillation patients at high risk for readmission are scarce. We sought to inform this area by characterizing and categorizing unplanned readmissions of atrial fibrillation patients. METHODS: Retrospective data were abstracted from the charts of patients discharged from 2008 to 2012 after an index hospitalization for atrial fibrillation and referred to the nurse practitioner-led transitional care program, Bridging the Discharge Gap Effectively. Unplanned readmissions were dichotomized as early (⩽30 days) or late (31-180 days) and further classified as either "atrial fibrillation/atrial fibrillation-related" (AF/AF-related), "Cardiac; not AF/AF-related," or "Not cardiac-related." Case classifications were adjudicated by a senior cardiologist. Patient demographics and readmission characteristics were then compared. RESULTS: Of 255 patients, 97 (38.0%) had unplanned readmissions within 180 days of discharge; 45 (46.4%) were early and 52 (53.6%) were late. Atrial fibrillation and cardiac causes accounted for 68.9% (n=31) of early readmissions and 65.4% (n=34) of late. Patients with late readmissions were more likely to have diabetes (32.7% vs. 17.7%, p=.022) and higher CHA2DS2VASc scores (3.63 vs. 2.98, p=0.026) than those not readmitted. No other differences in baseline characteristics were seen within or between groups. The 30-day all-cause readmission rate in this sample was 17.6% (n=45). CONCLUSION: Readmissions following hospital discharge for atrial fibrillation are common; approximately 50% of these readmissions are for reasons unrelated to atrial fibrillation. In order to reduce atrial fibrillation-related readmissions, further research is needed to characterize predictors of readmission and to develop effective transitional care interventions.

Endothelin limits insulin action in obese/insulin-resistant humans.

The normal action of insulin to vasodilate and redistribute blood flow in support of skeletal muscle metabolism is impaired in insulin-resistant states. Increased endogenous endothelin contributes to endothelial dysfunction in obesity and diabetes. Here, we test the hypothesis that increased endogenous endothelin action also contributes to skeletal muscle insulin resistance via impairments in insulin-stimulated vasodilation. We studied nine lean and seven obese humans, measuring the metabolic and hemodynamic effects of insulin (300 mU . m(-2) . min(-1)) alone and during femoral artery infusion of BQ123 (an antagonist of type A endothelin receptors, 1 micromol/min). Endothelin antagonism augmented skeletal muscle responses to insulin in obese subjects through changes in both leg blood flow (LBF) and glucose extraction. Insulin-stimulated LBF was significantly increased in obese subjects only. These changes, combined with differential effects on glucose extraction, resulted in augmented insulin-stimulated leg glucose uptake in obese subjects (54.7 +/- 5.7 vs. 107.4 +/- 18.9 mg/min with BQ123), with no change in lean subjects (103.7 +/- 11.4 vs. 88.9 +/- 16.3, P = 0.04 comparing BQ123 across groups). BQ123 allowed augmented leg glucose extraction in obese subjects even in the face of NOS antagonism. These findings suggest that increased endogenous endothelin action contributes to insulin resistance in skeletal muscle of obese humans, likely through both vascular and tissue effects.

Perioperative management of dual anti-platelet therapy.

Dual anti-platelet therapy denotes a regimen of aspirin plus a P2Y12 receptor inhibitor, clopidogrel, prasugrel, or ticagrelor. Such therapy is a cornerstone of medical management following acute coronary syndromes and is imperative following percutaneous coronary interventions. While there is uncertainty about the optimal duration of dual antiplatelet therapy following percutaneous coronary intervention, the new 2016 American College of Cardiology/American Heart Association Guidelines suggest that for patients with stable ischemic heart disease at least six months of such therapy following a drug eluting stent and one month following a bare metal stent should be implemented. In patients with acute coronary syndrome including non-ST elevation and ST elevation myocardial infarction it is recommended to extend dual antiplatelet therapy treatment to one year in both drug eluting stent and bare metal stent groups. There may be latitude for earlier discontinuation in appropriately selected patients; extended dual antiplatelet therapy beyond one year may be beneficial in others. Herein, we describe current guidelines and evidence supporting if and when dual antiplatelet therapy should be interrupted for surgery for patients who have undergone percutaneous coronary intervention.

Cardiac risk of noncardiac surgery.

Major perioperative cardiac events are estimated to complicate between 1.4% and 3.9% of surgeries. Because most surgeries are elective, there is the opportunity to implement strategies to reduce this risk. Accurate identification of patients at risk for such events will allow patients to be better informed about the benefit-to-risk ratio of procedures, and guide allotment of limited clinical resources, utilization of preventive interventions, and areas of future research. This review focuses on important features of the initial pre-operative clinical risk assessment, indications for diagnostic testing to quantify cardiac risk, and the methods and indications for pre-emptive therapies.

Quality improvement in acute coronary syndromes: translating evidence into practice.

Despite the substantial progress in elucidating the pathophysiology of acute coronary syndromes (ACS) and developing an array of therapeutic advances for the management of these conditions, several challenges still persist. The use of guideline recommendations for the care of patients with ACS by both healthcare providers and hospitals can improve short-term and long-term outcomes and potentially reduce healthcare costs. However, evidence suggests that adherence to guidelines is suboptimal. Several quality improvement programs, by both governmental and nongovernmental organizations, have been developed in an attempt to encourage maximal utilization of evidence-based interventions. In this review, we will examine the evidence for the importance of guideline adherence in the management of ACS, explore predictors of adherence to these guidelines, and provide evidence-based strategies for improving their implementation.

Perioperative cardiovascular care for patients undergoing noncardiac surgical intervention.

The field of perioperative medicine has garnered legitimacy during the past 3 decades. Adverse cardiovascular events in the perioperative period account for significant morbidity and mortality. Although testing patients preoperatively to detect ischemia and identify those who may benefit from modifications in care is a tempting strategy, risk assessment should account for posterior probability. Validated risk stratification tools, such as the Revised Cardiac Risk Index or the National Surgical Quality Improvement Program risk calculator, can assist in the identification of patients for whom preoperative noninvasive testing is justified and may change the plan of care. Furthermore, current guidelines emphasize that prophylactic coronary revascularization should not be performed exclusively for the purposes of reducing the risk of perioperative events. There has been enthusiasm for medical therapies that may reduce the risk of adverse cardiovascular events in the perioperative period. Current guidelines encourage the perioperative use of ß-blockade in patients already receiving such therapy and caution against initiating such therapy on the day of the surgical procedure. Reduction of morbidity and mortality in the perioperative period relies on an understanding of the myriad physiological perturbations in this period and thoughtful selection of patients for further testing and treatment.

Capsaicin sensitive-sensory nerves and blood pressure regulation.

Capsaicin (8-methyl-N-vannillyl-6-nonenamide), via binding to the vanilloid receptor subtype 1 (VR1), stimulates a subpopulation of primary afferent neurons that project to cardiovascular and renal tissues. These capsaicin-sensitive primary afferent neurons are not only involved in the perception of somatic and visceral pain, but also have a "sensory-effector" function. Regarding the latter, these neurons release stored neuropeptides through a calcium-dependent mechanism via the binding of capsaicin to the VR1. A subset of capsaicin-sensitive sensory nerves contains calcitonin gene-related peptide (CGRP) and substance P (SP). These sensory neuropeptides are potent vasodilators and natriuretic/diuretic factors. Neonatal degeneration of capsaicin-sensitive sensory nerves has revealed novel mechanisms that underlie increased salt sensitivity and several experimental models of hypertension. These mechanisms are reviewed, which include insufficient suppression of plasma renin activity and plasma aldosterone levels subsequent to salt loading, enhancement of sympathoexcitatory response in the face of a salt challenge, activation of the endothelin-1 receptor, and impaired natriuretic response to salt loading in capsaicin-pretreated rats. These data indicate that sensory nerves counterbalance the prohypertensive effects of several neuro-hormonal systems to maintain normal blood pressure when challenged with salt loading. Mechanisms underlying pneumotoxicity and pulmonary hypertension as revealed by degeneration of capsaicin-sensitive nerves are also discussed. Finally, the therapeutic utilities of capsaicin, endogenous anandamide, and CGRP agonists are assessed.

Surgery. ß-Blockers--still a trusted ally or time for retirement?

Uncertainty surrounds the benefit of ß-blocker treatment in various clinical settings. The researchers in a new retrospective analysis of preoperative ß-blocker use in CABG surgery now add to the debate, and suggest that these drugs might not improve perioperative outcomes.

Acute type B aortic dissection: insights from the International Registry of Acute Aortic Dissection.

Acute type B aortic dissection comprises approximately one-third of all aortic dissection cases. Although this catastrophic cardiovascular condition was first described in the medical literature over two centuries ago, data on the optimal diagnostic and treatment modalities for type B dissection was slow to evolve throughout the latter half of the twentieth century, even as newer diagnostic techniques and management strategies became commonplace. To further elucidate contemporary practice patterns and outcomes of aortic dissection, the International Registry of Acute Aortic Dissection (IRAD) was established in 1996. Over the past two decades, IRAD publications have steadily increased our knowledge and understanding about aortic dissection. Specifically in recent years, analyses of IRAD data have gone beyond simply characterizing the patient with acute type B aortic dissection and have attempted to identify the means by which the outcome of such a patient could be improved. Thus, we present herein three areas in which IRAD data has recently advanced our understanding of acute type B aortic dissection: temporal classification especially for the subacute time period, risk stratification for identifying complicated cases, and thoracic endovascular aortic repair (TEVAR).

Hypertensive and acute aortic syndromes.

Acute aortic syndromes are among the most lethal of the cardiovascular diseases. Delays in recognition, diagnosis, and treatment are associated with increases in mortality. Signs and symptoms are sometimes subtle and atypical, and a high index of suspicion is useful to guide the diagnostic evaluation. Uncontrolled hypertension remains the most significant treatable risk factor. Immediate management involves blood pressure reduction. ß-Blockers are the first drugs of choice. Although future directions should involve the evolution of operative and endovascular techniques and the development of sophisticated risk prediction tools, risk factor modification by addressing the burden of uncontrolled hypertension cannot be overlooked.

Radial artery perforation during transradial catheterization managed with a coronary polytetrafluoroethylene-covered stent graft.

A 69-year-old man underwent transradial catheterization (TRC) with successful percutaneous coronary intervention (PCI), but developed a radial artery perforation. Guiding catheter re-positioning and prolonged balloon inflation were unable to provide hemostasis. Successful reconstruction of the perforated vessel required the unconventional and novel use of a coronary polytetrafluoroethylene-covered stent graft.

Anticoagulation during pregnancy in patients with a prosthetic heart valve.

Effective anticoagulation is mandatory for pregnant women with mechanical heart valves. Oral anticoagulants offer the best maternal protection against thrombosis, but their use might be associated with an appreciable risk of fetal malformations and pregnancy loss. By contrast, heparin derivatives are associated with a reduced risk of fetal damage, but an increased risk of valve thrombosis in the mother, even with appropriate dose adjustment and monitoring of therapeutic efficacy. Given the varying risks of available anticoagulation strategies, and the paucity of data to inform the optimal approach, no single accepted treatment option exists for pregnant women with mechanical prosthetic valves. Although low-molecular-weight heparin is considered more efficacious than unfractionated heparin, treatment failures, even at therapeutic levels of factor Xa inhibition, have been reported. The risk of warfarin-related embryopathy might be overstated, particularly at doses ≤ 5 mg daily. We advocate an individualized anticoagulation strategy that takes into account the patient's preferences, calls for the use of vitamin K antagonists throughout pregnancy (substituted with a heparin derivative only close to term) for those patients at the greatest risk of thromboembolism, and relies on close multidisciplinary collaboration between the cardiac and obstetric care teams.