Current Cardiology Reviews - Volume 14, Issue 2, 2018

Out of hospital cardiac arrest affects 350,000 Americans yearly and is associated with a high mortality rate. Improving survival rates in this population rests on the prompt and effective implementation of four key principles. These include 1) early recognition of cardiac arrest 2) early use of chest compressions 3) early defibrillation, which in turn emphasizes the importance of public access defibrillation programs and potential for drone technology to allow for early defibrillation in private or rural settings 4) early and aggressive post-arrest care including the consideration of therapeutic hypothermia, early coronary angiography +/- percutaneous coronary intervention and a hyper-invasive approach to out-of-hospital refractory cardiac arrest.

Background: Cardiac arrest remains a common and lethal condition associated with high morbidity and mortality. Even with improving survival rates, the successfully resuscitated post cardiac arrest patient is also at risk for poor neurological outcomes, functional status and long- term survival if not managed appropriately. Given that acute coronary occlusion has been found to be the leading cause of cardiac arrest, long-term prognosis is good in selected patients after successful outof- hospital resuscitation and ST elevation myocardial infarction who are taken for immediate coronary angiography, treated with primary percutaneous coronary intervention and hypothermia when indicated. Conclusion: A priority should therefore be placed in diagnosing as quickly as possible patients who have an acute coronary occlusion (i.e. ST elevation myocardial infarction) and implementing the appropriate and timely therapeutic strategy, which will require close chain of survival co- ordination and the services of the cardiac catheterization lab. Here we review previous and current guidelines as well as associated evidence.

Background: Out of hospital cardiac arrest management of patients with non-ST myocardial infarction per current American Heart Association and European Resuscitation Council guidelines leave the decision in regard to early angiography up to the physician operators. Guidelines are clear on the positive impact of early intervention on survival and improvement on left ventricular function in patients presenting with cardiac arrest and ST elevation myocardial infarction on electrocardiogram. This review aims to analyze the data that current guidelines are based upon in regards to out of hospital cardiac arrest with electrocardiogram findings of non-ST elevation myocardial infarction as well as review of other clinical trials that support early angiography and reperfusion strategies. Conclusion: Analysis of current literature shows that early coronary evaluation in patients with no finding of ST elevation on ECG can help improve survival in patients suffering out of hospital cardiac arrest.

Background: Out of Hospital Cardiac Arrest (OHCA) remains not an uncommon occurrence in USA and the rest of the world. However, the survival to discharge following an episode of OHCA in adults is still very disappointing at around 10%. Several areas of improvement including education of general public in early Cardio Pulmonary Resuscitation (CPR) by bystander, chest compression first, and improvement of Emergency Medical response time have had a positive effect on the outcomes and survival but still much needs to be done. Recently, new data has emerged with regards to post resuscitation care and mild induced hypothermia (now preferably called; Targeted Temperature Management {TTM}) and several advances have been made. Conclusion: The purpose of this review is to summarize and compare the most recent guidelines and also provide a practical approach to TTM especially with regards to the field of cardiology.

Background: Sudden Cardiac Death (SCD) remains a major public health concern, accounting for more than 50% of cardiac deaths. The majority of these deaths are related to ischemic heart disease, however increasingly recognized are non-ischemic causes such as cardiac channelopathies. Bradyarrhythmias and pulseless electrical activity comprise a larger proportion of out-ofhospital arrests than previously realized, particularly in patients with more advanced heart failure or noncardiac triggers such as pulmonary embolism. Patients surviving Sudden Cardiac Arrest (SCA) have a substantial risk of recurrence, particularly within 18 months post event. The timing of tachyarrhythmias complicating acute infarction has important implications regarding the likelihood of recurrence, with those occurring within 48 hours having a more favorable long-term outcome. In the absence of a clear reversible cause, implantable cardioverter defibrillators remain the mainstay in the secondary prevention of SCD. Post defibrillation electromechanical dissociation is common in patients with cardiomyopathy and can lead to SCD despite successful defibrillation of the primary tachyarrhythmia. Antiarrhythmic agents are highly effective in preventing recurrent arrhythmias in specific diseases such as the congenital long QT syndrome. Conclusion: Catheter ablation is used most commonly to prevent recurrent ICD therapies in patients with structural heart disease-related ventricular arrhythmias, however recent publications have shown substantial benefit in other entities such as idiopathic ventricular fibrillation.

Refractory out of hospital cardiac arrest is a common problem that is associated with poor overall survival rates and neurological outcomes. There are various definitions that have been used but the most accepted one is cardiac arrest that requires more than 10 minutes of Cardiopulmonary Resuscitation (CPR) efforts or more than 3 defibrillation attempts. There have been different pharmacologic and non-pharmacologic therapies that were studied in these patients. None of the antiarrhythmic or vasopressor medications have been consistently shown to improve survival or neurological outcomes in this subset of patients. This has led to the introduction of various devices aimed at improving outcomes such as mechanical CPR devices, Extracorporeal Cardiopulmonary Resuscitation (ECPR), targeted temperature management and early invasive approach. There is accumulating evidence that there seems to be an improvement in outcomes when these devices are used in refractory cardiac arrest patients. But none of these devices have been shown to improve outcomes when used in isolation. This underscores the importance of systematic approach to these complex patients and using these therapies in combination. There has been a paradigm shift in the approach to these patients. Instead of repeated and prolonged CPR attempts in the field, it is suggested that these patients need to be moved to cardiac arrest centers with a mechanical CPR device in place, so a percutaneous Extracorporeal Membrane Oxygenator (ECMO) can be placed to “buy” time for other therapies such as therapeutic hypothermia and early coronary angiography followed by intervention as indicated. Careful selection of patients who might potentially benefit from this approach is critical to the success of these programs.

Background: Cardiac arrest in the Catheterization Lab is a rare and unique scenario that is often logistically challenging. It often has dire prognosis especially in patients suffering from severe pre-existing illnesses (high risk patient) such as acute myocardial infarction with cardiogenic shock, or patients undergoing high risk procedures. As the number of complex interventional procedures increases, cardiac arrest in the cath lab will become more common and optimal management of this scenario is critical for both the patient and operator. Conclusion: In this review, we will discuss the special challenges during the resuscitation efforts in cath lab, especially with tradition chest compression. We will discuss the alternative options including mechanical compression devices and Invasive Percutaneous Mechanical Circulatory Support Devices. Finally, we will offer management suggestions on selecting the appropriate circulatory support device based on clinical and anatomic risks.

Background: To develop an understanding of current practices in the management of transient secondary hypothyroidism in pediatric postoperative cardiopulmonary bypass (CPB) patients. Methods: Electronic survey comprising a 10-item questionnaire was sent to sixty-four high volume pediatric heart centers in the United States and United Kingdom. Survey participants included cardiologists, intensivists, cardiothoracic surgeons, and advanced practice providers. A retrospective chart review was also performed at a large regional referral center in the Midwest on subjects 0-18 years old who underwent CPB from 2005-2015. Information obtained included a unique identifier, date of birth, age, procedure performed, CPB time, date of surgery and date and type of Thyroid Function Test (TFT) ordered. Results: 1,153 individuals from 64 congenital heart centers were contacted via email to participate in the electronic survey. In the 3-month response window, 129 completed surveys were received from cardiologists (55%), intensivists (17%), surgeons (15%), “other” (8%), and advanced practice providers (5%). This yielded a response rate of 11.2%. Of the 129 respondents, only 10 providers routinely order TFTs prior to (n=7) and after (n=1) CPB or when clinically indicated (n=2). All 10 providers order thyroid stimulating hormone test, 7 order thyroxine, and 3 order triiodothyronine. Only 1 provider routinely treats children with prophylactic thyroid hormone replacement therapy after CPB. Our retrospective review included 502 CPB events with 442 unique patients. Of the events, 20 patients received preoperative TFT testing while 11 received postoperative testing. Conclusions: There is a general lack of uniformity in the evaluation, diagnosis, and treatment of transient secondary hypothyroidism in pediatric postoperative CPB patients.

Background: Congestive heart failure is an increasingly prevalent terminal illness in a globally aging population. Prognosis for this disease remains poor despite optimal therapy. Evidence suggests that a palliative care approach may be beneficial – and is currently recommended – in advanced congestive heart failure but these services remain underutilized. Objectives: To identify the main challenges to the access and delivery of palliative care in patients with advanced congestive heart failure, and to summarize recommendations for clinical practice based on the available literature. Methods: MEDLINE and EMBASE were searched for articles published from 1995-2017 pertaining to end of life care in individuals suffering from CHF. Only four randomized controlled trials were found. Results: We identified ten key challenges to access and delivery of palliative care services in this patient population: (1) Prognostic uncertainty, (2) Provider education/training, (3) Ambiguity surrounding coordination of care, (4) Timing of palliative care referral, (5) Inadequate community supports, (6) Difficulty communicating uncertainty, (7) Fear of taking away hope, (8) Insufficient advance care planning, (9) Inadequate understanding of illness, and (10) Discrepant patient/family care goals. Provider and patient education, early discussion about prognosis, and a multidisciplinary team-based approach are recommended as we move towards a model where symptom palliation exists concurrently with active disease-modifying therapies. Conclusion: Despite evidence that palliative care may improve symptom control and quality of life in patients with advanced congestive heart failure, a multitude of current challenges hinder access to these services. Education, early discussion of prognosis and advance care planning, and multidisciplinary team-based care may be a helpful initial approach as further targeted work addresses these challenges.