Antiplatelet and anticoagulation therapy during percutaneous coronary interventions: A review for the interventionalist.

Pharmacotherapy for percutaneous coronary interventions is essential to optimize the balance between thrombosis and bleeding. Currently, choices abound for the selection of antiplatelet and anticoagulation therapies during percutaneous intervention (PCI). This review article discusses the mechanisms, pharmacokinetics/dynamics, and clinical data behind the various pharmacotherapies including; aspirin, thienopyridines, glycoprotein IIb/IIIa inhibitors, vorapaxar, heparin, direct thrombin inhibitors, and factor Xa inhibitors.

Timing of Percutaneous Coronary Intervention and Therapeutic Hypothermia in Patients With ST-Elevation Myocardial Infarction and Out-of-hospital Cardiac Arrest.

The American College of Cardiology/American Heart Association guidelines include a Class 1 recommendation to initiate therapeutic hypothermia (TH) in comatose patients with out-of-hospital cardiac arrest (OHCA) with an initial shockable rhythm who have achieved return of spontaneous circulation. There is also a Class 1 recommendation for immediate angiography in these patients whose initial electrocardiography shows ST-elevation myocardial infarction (STEMI). However, due to a lack of clinical trials evaluating these patients who have received both percutaneous coronary intervention (PCI) and TH, controversy remains regarding whether the two can be safely combined. Furthermore, in patients who receive TH and PCI, another question to address is which therapy to initiate first. This article focuses on how best to manage comatose OHCA survivors who have an initial shockable rhythm and STEMI.

Fractured inferior vena cava filter strut presenting with ST-segment elevation and cardiac tamponade.

The fracture of an inferior vena cava filter strut and its migration to the heart is a rare sequela of implanted inferior vena cava filters. Perforation through the right ventricle into the pericardium with resultant cardiopulmonary compromise is even less frequent. We report the case of a 53-year-old man who presented with chest pain and hypotension consequent to cardiac tamponade. A fractured inferior vena cava filter strut had migrated and perforated his right ventricle. The fractured strut was successfully removed by means of cardiac surgery. Inferior vena cava filters should be placed when necessary to minimize the risk of pulmonary embolism, and regular radiologic monitoring should be performed; however, the eventual extraction of retrievable filters should be considered. In addition to discussing the patient's case, we briefly review the relevant medical literature.

Takotsubo cardiomyopathy as a sequela of elective direct-current cardioversion for atrial fibrillation.

In takotsubo cardiomyopathy, the clinical appearance is that of an acute myocardial infarction in the absence of obstructive coronary artery disease, with apical ballooning of the left ventricle. The condition is usually precipitated by a stressful physical or psychological experience. The mechanism is unknown but is thought to be related to catecholamine excess. We present the case of a 67-year-old woman who experienced cardiogenic shock caused by takotsubo cardiomyopathy, immediately after undergoing elective direct-current cardio-version for atrial fibrillation. After a course complicated by left ventricular failure, cardiogenic shock, and ventricular tachycardia, she made a complete clinical and echocardiographic recovery. In addition to this case, we discuss the possible direct effect of cardioversion in takotsubo cardiomyopathy.

Noninvasive risk stratification for sudden death in asymptomatic patients with Wolff-Parkinson-White syndrome.

Sudden cardiac death (SCD) as the first clinical manifestation of Wolff-Parkinson-White (WPW) syndrome is a well-documented, although rare occurrence. The incidence of SCD in patients with WPW ranges from 0% to 0.39% annually. Controversy exists regarding risk stratification for patients with preexcitation on surface electrocardiogram (ECG), particularly in those who are asymptomatic. This article focuses on the role of risk stratification using exercise and pharmacologic testing in patients with WPW pattern on ECG.

Aldosterone receptor antagonists in cardiovascular disease: a review of the recent literature and insight into potential future indications.

Randomized controlled trials demonstrate the efficacy of aldosterone receptor antagonists (spironolactone and eplerenone) as a useful pharmacologic intervention specifically in patients with New York Heart Association (NYHA) class III and IV heart failure, in patients with an ejection fraction <40% after myocardial infarction, and most recently in patients with mildly symptomatic heart failure. However, aldosterone receptor antagonists may be beneficial in a broader patient population. Aldosterone receptor antagonists can potentially serve as an antiarrhythmic pharmacologic agent for atrial and ventricular arrhythmias, an anti-ischemic medication in coronary artery disease through prevention of myocardial fibrosis and vascular damage, and as an agent in people with asymptomatic and mild heart failure (NYHA classes I and II) and diastolic heart failure. However, many clinicians remain reluctant to prescribe this highly efficacious pharmacologic therapy for a variety of reasons, including concerns about polypharmacy and hyperkalemia. Recent observational analysis demonstrates that less than one-third of eligible patients hospitalized with heart failure actually received aldosterone antagonist therapy. This article will review the current and potential future uses of aldosterone receptor antagonists across the entire spectrum of cardiovascular disease. The authors have no funding, financial relationships, or conflicts of interest to disclose.

Apical ballooning syndrome associated with isolated severe hyponatremia: case report and suggested pathophysiology.

An 82-year-old woman who presented to her primary care physician for preoperative evaluation was incidentally found to have severe hyponatremia (sodium = 118 mmol/L). The patient was then admitted for workup and treatment of hyponatremia. On day 2 of the admission, the patient was found to have new T-wave inversions on a telemetry monitor. Further workup, including an electrocardiogram, cardiac markers, echocardiogram, and a cardiac catheterization were consistent with the diagnosis of apical ballooning syndrome (ABS). Mechanisms of how severe hyponatremia may lead to ABS are discussed as well as a possible approach to the management of severe hyponatremia in postmenopausal women.

Embolic risk in atrial fibrillation that arises from hyperthyroidism: review of the medical literature.

Atrial fibrillation, the most common cardiac complication of hyperthyroidism, occurs in an estimated 10% to 25% of overtly hyperthyroid patients. The prevalence of atrial fibrillation increases with age in the general population and in thyrotoxic patients. Other risk factors for atrial fibrillation in thyrotoxic patients include male sex, ischemic or valvular heart disease, and congestive heart failure. The incidence of arterial embolism or stroke in thyrotoxic atrial fibrillation is less clear. There are many reports of arterial thromboembolism associated with hyperthyroidism, including cases of young adults without coexisting risk factors other than thyrotoxic atrial fibrillation. The use of anticoagulative agents to prevent thromboembolic sequelae of thyrotoxic atrial fibrillation is controversial: National organizations provide conflicting recommendations in their practice guidelines. Herein, we review the medical literature and examine the evidence behind the recommendations in order to determine the best approach to thromboembolic prophylaxis in patients who have atrial fibrillation that is associated with hyperthyroidism.

Statin therapy in the perioperative period.

Statins are frequently used as chronic therapy for reducing cardiovascular mortality and morbidity, but there has been less emphasis on the role of statins in the perioperative period. This review evaluates data regarding statin use in vascular and noncardiac surgery, the use of statins in combination with ß-blockers in the perioperative period, perioperative statin use in patients already treated with statins, and the safety of statin therapy in the perioperative period. Current recommendations state that patients who are prescribed statins as chronic therapy should continue treatment in the perioperative period, but data suggest that there may be benefit from the use of perioperative statins in a wider population.

The problem of stent thrombosis associated with drug-eluting stents and the optimal duration of dual antiplatelet therapy.

Drug-eluting stents have significantly reduced the problem of restenosis, but there is an association between drug-eluting stents and stent thrombosis that can be a significant clinical problem resulting in myocardial infarction or death. The risk for stent thrombosis increases in certain clinical situations and has been reduced through the use of dual antiplatelet therapy for prolonged periods. Until new therapies are developed, it is essential that patients who have had drug-eluting stents implanted continue with dual-antiplatelet therapy for at least 1 year and possibly for an indefinite period.

Mortality and atrial fibrillation: is there a causal relationship?

Almost all studies show that atrial fibrillation (AF) is associated with increased mortality. What is less certain is whether this association is a straightforward cause-and-effect relationship, or if AF is merely a marker of severity of cardiovascular disease(s) or the aging process. AF can lead to the worsening of left ventricular filling, contribute to loss of atrioventricular synchrony, affect cardiac remodeling, and even cause a tachycardia-induced cardiomyopathy. AF could be a marker for underlying atherosclerotic disease that itself determines mortality, or the increased oxygen consumption associated with an increasing ventricular rate may lead to ischemia secondary to increased myocardial consumption and precipitate acute coronary syndromes. Although it is generally accepted that the stasis of atrial blood in AF promotes clot formation, studies have shown increases in specific coagulation factors-all of which have the ability to increase morbidity and/or mortality through their elevations. Another possibility is that AF is not the cause of the hypercoagulable state, but is instead a marker of such a state.

Is there a need to continue anticoagulation following "successful" atrial fibrillation ablation?

Atrial fibrillation (AF) is the most common clinically significant arrhythmia worldwide, and its incidence is increasing. There has been increasing interest in ablation therapy to treat atrial fibrillation. One reason some patients undergo AF ablation might be to obviate the need for warfarin therapy, although current guidelines do not support this rationale. The current review shows that it is difficult to define a true "cure" postablation, as many of these patients will go on to experience future paroxysms of AF (either symptomatic or silent). The mechanism underlying embolism in patients with AF is not completely understood, and no long-term evidence exists that "successfully ablated" patients return to a baseline risk of stroke comparable to an AF-naive population. The authors recommend continued long-term anticoagulation post-AF ablation in patients satisfying CHADS criteria for elevated stroke risk.

The atherosclerotic aortic arch: considerations in diagnostic imaging.

The atheromatous aortic arch poses a diagnostic and therapeutic challenge to the clinician. The association between aortic atheroma and clinical events such as stroke and distal embolization have been well described in the literature, but the best approach to assessment of risk is controversial and evolving. This review seeks to highlight the significance of factors such as aortic plaque morphology, distribution, and severity. The different imaging modalities currently available for evaluating aortic plaque (including transesophageal echocardiography, non-contrast- and contrast-enhanced computed tomography, positron emission computed tomography, magnetic resonance imaging, and intraoperative epiaortic ultrasonography are compared and contrasted.

Assessment of myocardial viability: review of the clinical significance.

The identification of myocardial viability in patients with coronary artery disease and left ventricular dysfunction (LVD) has important clinical and prognostic implications. Two terms commonly used to define clinical conditions of potentially reversible contractile dysfunction are stunned myocardium and hibernating myocardium. Stunned myocardium refers to transient depression of contractile function secondary to an acute ischemic insult. Hibernating myocardium is a form of contractile dysfunction of living myocytes in the setting of chronic ischemia or chronically reduced flow reserve. Numerous observational studies have shown improved clinical outcomes after revascularization of patients with LVD and evidence of myocardial viability, although patients with nonviable myocardium have not been shown to have the same benefits. The use of noninvasive techniques to determine myocardial viability provides important information to guide clinicians in deciding which patients with LVD are likely to receive benefit from a revascularization procedure. Positron emission tomography, single-photon emission computed tomography, dobutamine echocardiography, and cardiac magnetic resonance imaging each have advantages and limitations.

Angiotensin-converting enzyme inhibitors in acute myocardial infarction: a clinical approach.

Angiotensin-converting enzyme inhibitor therapy has been shown to be effective in treating patients across the spectrum of cardiac disease. Utility has been demonstrated for both prevention and treatment. This article reviews the data regarding angiotensin-converting enzyme inhibitor therapy in acute myocardial infarction, with emphasis on determining what is known regarding the mode of administration, optimal timing for initiation of treatment, and whether patients can be identified who are most likely to benefit from treatment.

High-density lipoprotein cholesterol: a potential therapeutic target for prevention of coronary artery disease.

High-density lipoprotein cholesterol has an important role in the pathophysiology of coronary artery disease. High-density lipoprotein cholesterol is becoming an increasingly important prognostic and therapeutic target. The purpose of this paper is to review the biochemical pathways involved in reverse cholesterol transport and to discuss potential, clinically based high-density lipoprotein therapies that may contribute to reduction in risk of atherosclerosis.

Methemoglobinemia and transesophageal echo.

Methemoglobin (MHb) is the oxidized form of Hemoglobin (Hb) containing iron in its ferric (Fe3+) rather than ferrous (Fe2+) state. Under physiologic conditions, diaphorase II accounts for only a small percentage of the red blood cell reducing capacity but can be pharmacologically activated by exogenous cofactors. Methemoglobinemia is an abnormal elevation of MHb levels resulting in impaired oxygen delivery to tissues as well as a left shift of the oxygen-Hb dissociation curve. We present the case of a 56-year-old female patient who underwent transesophageal echocardiography (TEE) prior to elective cardioversion. Prep for TEE included use of Hurricane spray. Twenty min after receipt, the patient's O2 saturation by pulse oximetry dropped from 100% to 86%; heart rate and blood pressure were unchanged. Physical exam revealed pallor, perioralcyanosis and acrocyanosis without tachypnea, respiratory distress, or jugular venous distension. A 100% non-rebreather mask provided no improvement. MHb was suspected and arterial blood gasses were drawn which was dark chocolate in appearance. Methylene Blue at 1 mg/kg over 5 minutes was administered empirically. ABG results were: pH 7.44/ CO2 40/ O2 315/ HCO2 26/ O2 sat 69%; MHb levels were 30.1% confirming the diagnosis of methemoglobinemia. This condition resolved within minutes. Though uncommon, MHb is the most Sported adverse event associated with topical benzocaine use. Untreated, it can lead to significant cardiopulmonary compromise, neurologic sequelae, and even death. Prompt recognition of this potentially life-threatening side-effect is essential in order to provide opportune treatment.