Elizabeth M. Volz

Bio: Elizabeth M. Volz is an academic researcher from Duke University. The author has contributed to research in topics: Medicine & Heart failure. The author has an hindex of 2, co-authored 2 publications receiving 140 citations.

Evolution of the coronary care unit: Clinical characteristics and temporal trends in healthcare delivery and outcomes*

Abstract: Objective:To describe long-term temporal trends in patient characteristics, processes of care, and in-hospital outcomes among unselected admissions within the contemporary coronary care unit.Design:Hospital administrative database that records both payment and operation data.Setting:Coronary care un

How to use diuretics in heart failure

Abstract: Systemic and pulmonary congestion is a central aspect of both acute and chronic heart failure and directly leads to many of the clinical manifestations of these syndromes. Therefore, diuretic therapy to treat congestion plays a fundamental role in heart failure management. However, although diuretics are the most common drugs prescribed for heart failure, there is limited quality evidence to guide their use. Unlike other components of the heart failure armamentarium, such as β-blockers and angiotensin-converting enzyme inhibitors, diuretics (with the exception of aldosterone antagonists) have not been shown to decrease heart failure progression or improve mortality. Additionally, some observational data suggest that diuretics may actually be harmful in heart failure, contributing to neurohormonal activation, renal dysfunction, and potentially mortality. Despite these concerns, diuretics remain ubiquitous in heart failure management because of the need to address symptoms of congestion and the lack of alternative strategies. Recently, the development of a variety of potential adjuncts or alternatives to diuretic therapy has suggested the need for an active reappraisal of diuretic therapy for heart failure. The main classes of diuretics are the loop diuretics, potassium-sparing diuretics, and thiazides. Loop diuretics, the mainstay of acute and chronic therapy for heart failure, are “threshold drugs”; therefore, an adequate dose to achieve a pharmacodynamic effect (ie, to increase urine output) must be prescribed for effective therapy. The minimum dose to achieve diuresis and manage congestion should be used to minimize adverse effects. For patients refractory to initial dosing of intravenous diuretics, options include dose escalation, use of continuous infusion rather than intermittent boluses, or combination therapy with the addition of a thiazide or thiazide-like diuretic (eg, metolazone). Management of chronic heart failure often includes patient-directed titration of diuretics based on changes in symptoms or body weight in an attempt to decrease hospitalizations, although the efficacy of this strategy has not been tested in well-designed trials. Aldosterone antagonists, which are used primarily as neurohormonal agents rather than for their diuretic effects, are indicated for patients with systolic failure and moderate to severe symptoms, as long as renal function and serum potassium are stable and monitored closely. All diuretic therapy requires careful monitoring of electrolytes and renal function. Whether newer modalities for managing congestion (vasopressin antagonists, adenosine A1 antagonists, and ultrafiltration therapy) will be an improvement over diuretic therapy will be determined by the results of multiple ongoing clinical trials.

Evolution of Critical Care Cardiology: Transformation of the Cardiovascular Intensive Care Unit and the Emerging Need for New Medical Staffing and Training Models A Scientific Statement From the American Heart Association

Abstract: Critical care, defined as the diagnosis and management of life-threatening conditions that require close or constant attention by a group of specially trained health professionals, is inherent to the practice of cardiovascular medicine. The demand for cardiovascular critical care is increasing with the aging of the population and is reflected by trends in the use of critical care in general.1 Between 2000 and 2005, although the total number of hospital beds in the United States declined by 4.2%, the number of critical care beds increased by 6.5% and the annual costs attributed to critical care increased by 44%, representing 13.4% of hospital costs.2 Projections for the next 15 years suggest that the need for critical care will increase markedly in the United States and globally.1,3–5 For example, in Canada, a 57% increase in the need for critical care beds is anticipated during that period.5 Concurrent with increases in demand, the medical demographics of general and cardiac critical care have evolved toward a patient population with an increasing number of comorbid medical conditions who require more prolonged and more technologically sophisticated invasive support. As a result, the delivery of critical care is advancing substantially in its complexity. Moreover, accumulating evidence has indicated that outcomes are better when critical care is provided by specially trained providers in a dedicated intensive care unit (ICU).6–9 In the context of this evolution, provision of optimal care in the contemporary cardiac ICU (CICU) presents a different set of challenges and requires an expanded set of skills compared with 10 years ago. Cardiovascular medicine has lagged behind other medical disciplines that have met the “critical care crisis”4 with ICU-focused innovations in organization, training, and quality improvement. Therefore, the American Heart Association Council on Cardiopulmonary, Critical …

Requiem for the 'vulnerable plaque'.

Abstract: The concept of the so-called ‘vulnerable plaque’ has proved highly useful to guide research and thinking regarding the pathophysiology of the acute coronary syndromes (ACS). Yet, the time may have come to reconsider this construct, as knowledge has accumulated, the risk profile of the populace has shifted, and our current therapies have reshaped the disease. Over the last several decades, the quest to identify and treat the ‘vulnerable plaque’ has generated much interest.1 Loaded with lipid, macrophage rich, covered by a thin fibrous cap, and considered perilously poised to rupture, the thin-capped fibroatheroma (TCFA) has become a target for imaging, possible intervention, model attempts in animals, and much discussion.2 Many equate type 1 myocardial infarction with ‘plaque rupture’. Yet, the ‘vulnerable plaque’ concept, as useful as it has proved heuristically, may not represent the contemporary challenge, an unmet clinical need, or a fertile field for future research. The notion of the ‘vulnerable plaque’ arose from autopsy studies that disclosed some two-thirds to three-fourths of fatal acute myocardial infarctions resulted from a fracture of the plaque's fibrous cap that engendered thrombosis ( Table 1 ; Figure 1 ). The elegant post-mortem studies of pathologist pioneers redirected the cardiology community from confusion about the causality of thrombosis in ACS and a focus on vasospasm towards plaque rupture.3,4 However compelling, the number of ruptured plaques resulting in luminal occlusion in these autopsy studies lacked a ‘denominator’. While such studies could interrogate the culprit of a fatal myocardial infarction, they did not determine how many plaques with morphologic characteristics associated with vulnerability did not cause a fatal rupture. View this table: Table 1 Challenges to the ‘vulnerable plaque’ concept Figure 1 Contrasts between …

Delirium in the cardiovascular ICU: exploring modifiable risk factors.

Abstract: Objective Delirium, an acute organ dysfunction, is common among critically ill patients leading to significant morbidity and mortality; its epidemiology in a mixed cardiology and cardiac surgery intensive care unit (CVICU) is not well established. We sought to determine the prevalence and risk factors for delirium among CVICU patients.

The association between ICU readmission rate and patient outcomes.

Abstract: Objective:To examine the association between ICU readmission rates and case-mix–adjusted outcomes.Design:Retrospective cohort study of ICU admissions from 2002 to 2010.Setting:One hundred five ICUs at 46 United States hospitals.Patients:Of 369,129 admissions, 263,082 were first admissions that were

Demographics, Care Patterns, and Outcomes of Patients Admitted to Cardiac Intensive Care Units: The Critical Care Cardiology Trials Network Prospective North American Multicenter Registry of Cardiac Critical Illness.

Abstract: Importance Single-center and claims-based studies have described substantial changes in the landscape of care in the cardiac intensive care unit (CICU). Professional societies have recommended research to guide evidence-based CICU redesigns. Objective To characterize patients admitted to contemporary, advanced CICUs. Design, Setting, and Participants This study established the Critical Care Cardiology Trials Network (CCCTN), an investigator-initiated multicenter network of 16 advanced, tertiary CICUs in the United States and Canada. For 2 months in each CICU, data for consecutive admissions were submitted to the central data coordinating center (TIMI Study Group). The data were collected and analyzed between September 2017 and 2018. Main Outcomes and Measures Demographics, diagnoses, management, and outcomes. Results Of 3049 participants, 1132 (37.1%) were women, 797 (31.4%) were individuals of color, and the median age was 65 years (25th and 75th percentiles, 55-75 years). Between September 2017 and September 2018, 3310 admissions were included, among which 2557 (77.3%) were for primary cardiac problems, 337 (10.2%) for postprocedural care, 253 (7.7%) for mixed general and cardiac problems, and 163 (4.9%) for overflow from general medical ICUs. When restricted to the initial 2 months of medical CICU admissions for each site, the primary analysis population included 3049 admissions with a high burden of noncardiovascular comorbidities. The top 2 CICU admission diagnoses were acute coronary syndrome (969 [31.8%]) and heart failure (567 [18.6%]); however, the proportion of acute coronary syndrome was highly variable across centers (15%-57%). The primary indications for CICU care included respiratory insufficiency (814 [26.7%]), shock (643 [21.1%]), unstable arrhythmia (521 [17.1%]), and cardiac arrest (265 [8.7%]). Advanced CICU therapies or monitoring were required for 1776 patients (58.2%), including intravenous vasoactive medications (1105 [36.2%]), invasive hemodynamic monitoring (938 [30.8%]), and mechanical ventilation (652 [21.4%]). The overall CICU mortality rate was 8.3% (95% CI, 7.3%-9.3%). The CICU indications that were associated with the highest mortality rates were cardiac arrest (101 [38.1%]), cardiogenic shock (140 [30.6%]), and the need for renal replacement therapy (51 [34.5%]). Notably, patients admitted solely for postprocedural observation or frequent monitoring had a mortality rate of 0.2% to 0.4%. Conclusions and Relevance In a contemporary network of tertiary care CICUs, respiratory failure and shock predominated indications for admission and carried a poor prognosis. While patterns of practice varied considerably between centers, a substantial, low-risk population was identified. Multicenter collaborative networks, such as the CCCTN, could be used to help redesign cardiac critical care and to test new therapeutic strategies.