Alina Nicoara

Utility of a Simple Algorithm to Grade Diastolic Dysfunction and Predict Outcome After Coronary Artery Bypass Graft Surgery

BACKGROUND Inclusion of a measure of left ventricular diastolic dysfunction (LVDD) may improve risk prediction after cardiac surgery. Current LVDD grading guidelines rely on echocardiographic variables that are not always available or aligned to allow grading. We hypothesized that a simplified algorithm involving fewer variables would enable more patients to be assigned a LVDD grade compared with a comprehensive algorithm, and also be valid in identifying patients at risk of long-term major adverse cardiac events (MACE). METHODS Intraoperative transesophageal echocardiography data were gathered on 905 patients undergoing coronary artery bypass graft surgery, including flow and tissue Doppler-based measurements. Two algorithms were constructed to categorize LVDD: a comprehensive four-variable algorithm, A, was compared with a simplified version, B, with only two variables-transmitral early flow velocity and early mitral annular tissue velocity-for ease of grading and association with MACE. RESULTS Using algorithm A, only 563 patients (62%) could be graded, whereas 895 patients (99%) received a grade with algorithm B. Over the median follow-up period of 1,468 days, Cox modeling showed that LVDD was significantly associated with MACE when graded with algorithm B (p=0.013), but not algorithm A (p=0.79). Patients with the highest incidence of MACE could not be graded with algorithm A. CONCLUSIONS We found that an LVDD algorithm with fewer variables enabled grading of a significantly greater number of coronary artery bypass graft patients, and was valid, as evidenced by worsening grades being associated with MACE. This simplified algorithm could be extended to similar populations as a valid method of characterizing LVDD.

Mortality trends associated with acute renal failure requiring dialysis after CABG surgery in the United States.

Background/Aims: Acute renal failure is associated with a high risk of mortality when it complicates coronary artery bypass graft (CABG) surgery. We examined a large nationwide database from 1988 to 2003 and hypothesized that mortality in CABG-associated acute renal failure needing dialysis (ARF-D) had declined during this period. Methods: The Nationwide Inpatient Sample containing data on inpatient stays across 20% of US hospitals was used for our study. Multivariate logistic regression was used to determine an association between year and ARF-D mortality with standardized risk adjustment. Results: Incidence of ARF-D increased from 0.2 to 0.6% while mortality simultaneously decreased from 47.4% in 1988 to 29.7% in 2003. In the multivariable model, year was significantly associated with declining ARF-D mortality. Conclusions: The incidence of post-CABG ARF-D more than doubled from 1988 to 2003, while mortality simultaneously decreased by over one-third. Improved survival after ARF-D following CABG may be counterbalanced by increased morbidity and resource utilization.

Perioperative Diastolic Dysfunction A Comprehensive Approach to Assessment by Transesophageal Echocardiography

Left ventricular diastolic dysfunction (LVDD) has only recently been recognized as an important determinant of perioperative morbidity. Intraoperative echocardiographers have been slow to adopt assessment of LVDD into clinical practice. This has been partly attributable to the complex measurements required to characterize LVDD, which are in turn related to how our understanding of diastole has evolved. Additionally, the lack of effective therapeutic options has left many wondering whether it is worthwhile to characterize this pathology in the first place. However, therapies are developed more rapidly once a problem can be identified reliably. The assessment of LVDD is centered on how effectively the left ventricle can fill. Diastolic dysfunction affects intraventricular pressures and stiffness, which in turn affect the pressure relationship between the left atrium and the left ventricle thereby affecting transmitral flow. Since echocardiography can enable the measurement of flow velocities, transmitral diastolic filling flow patterns provide robust information on diastolic function. The impact of abnormal diastolic function on left atrial pressure has consequences for pulmonary venous flow, which can also be measured with echocardiography. However, given the limitations of flow velocity, direct measurement of tissue velocity can significantly improve the characterization of diastolic dysfunction. The evolution of Doppler and speckle-based methods of assessing tissue motion have vastly improved our understanding of diastolic function. With the development of simpler algorithms for categorization, and their gradual adoption by perioperative echocardiographers, LVDD should be better diagnosed and treated to improve postoperative outcomes.

Multinational Institutional Survey on Patterns of Intraoperative Transesophageal Echocardiography Use in Adult Cardiac Surgery

OBJECTIVES To assess institutional patterns of perioperative transesophageal echocardiography (TEE) usage. DESIGN The authors hypothesized that TEE is performed more frequently and comprehensively in academic centers, mainly by anesthesiologists, and barriers to performing TEE are due to inadequate resources. A survey was deployed to selected participants. Collated responses were assessed for demographic patterns in TEE practice, and 2-category comparisons were made with Chi-squared association tests. SETTING Web-based survey. PARTICIPANTS Practitioners in cardiovascular anesthesia/surgery in 200 institutions. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Surveys were completed by respondents representing 200 centers in 27 countries and 1,727 anesthesiologists with a mean annual institutional volume of 924 cases. Most centers were in the USA (53%) and were defined as academic (83%). Anesthesiologists performed (85%) and also read/reported TEEs (78%) in most centers. Three-dimensional TEE is performed routinely at 40% of centers. TEE is used routinely for valve surgery in 95% of institutions compared to 68% for coronary artery bypass graft surgery. Academic institutions assessed diastolic function more often than nonacademic centers (46% v 19%; p = 0.006). The most important reason cited for not using TEE in all cases was insufficient resource availability (47%). CONCLUSIONS These results suggest that TEE is performed more comprehensively in academic centers, mainly by anesthesiologists, and that lack of resources is a significant barrier to routine TEE usage. TEE is used more often for valve surgery than for coronary artery bypass graft surgery, and many centers use 3D TEE. This survey describes international TEE practice patterns and identifies limitations to universal adoption of TEE in cardiac surgery.

New developments in the treatment of acute pain after thoracic surgery.

Purpose of review This review examines recent advances and findings in the field of pain management in patients undergoing thoracic surgery. Recent findings Acute and chronic postoperative pain continues to remain a major problem and a primary concern for patients. Although thoracic epidural analgesia is still considered a ‘gold standard’, more evidence exists that paravertebral blockade has similar efficacy with a better side-effect and safety profile. The cornerstone of pain management remains a multimodal therapeutic strategy that provides both a central and a peripheral block by combining regional techniques with opioid and nonopioid analgesics. Summary Pain after thoracic surgery has a profound impact on perioperative outcome. Beyond the immediate perioperative period, acute pain contributes to the development of the debilitating chronic pain syndrome. Going forward, both procedural and pharmacologic interventions for acute and chronic pain should be studied in definitive multicenter, well designed randomized clinical trials.

Diastolic heart failure: diagnosis and therapy.

Purpose of review This article focuses on the recent findings in the diagnosis and treatment of diastolic heart failure (DHF) or heart failure with preserved ejection fraction. Recent findings DHF has become the most common form of heart failure in the population. Although diastolic dysfunction still plays a central role, it is now understood that DHF is a very complex clinical entity with heterogeneous pathophysiology and significant contribution from extracardiac comorbidities. Alterations in ventricular-arterial coupling play a significant role in the impaired hemodynamic response to exercise seen in these patients. The absence of diastolic dysfunction at rest does not exclude the diagnosis of DHF. There has been little to no progress made in identifying evidence-based, effective, and specific treatments for patients with DHF. This may be because of the pathophysiological heterogeneity, incomplete understanding of DHF, and heterogeneity of patients included in clinical trials with variable inclusion criteria. Summary The understanding of the phenotypic heterogeneity and multifactorial pathophysiology of DHF may lead to novel therapeutic targets in the future. Currently, the key to the treatment of DHF is aggressive management of contributing factors.

Primary graft dysfunction after heart transplantation: Incidence, trends, and associated risk factors

Changes in heart transplantation (HT) donor and recipient demographics may influence the incidence of primary graft dysfunction (PGD). We conducted a retrospective study to evaluate PGD incidence, trends, and associated risk factors by analyzing consecutive adult patients who underwent HT between January 2009 and December 2014 at our institution. Patients were categorized as having PGD using the International Society for Heart & Lung Transplantation (ISHLT)–defined criteria. Variables, including clinical and demographic characteristics of donors and recipients, were selected to assess their independent association with PGD. A time‐trend analysis was performed over the study period. Three‐hundred seventeen patients met inclusion criteria. Left ventricular PGD, right ventricular PGD, or both, were observed in 99 patients (31%). Risk factors independently associated with PGD included ischemic time, recipient African American race, and recipient amiodarone treatment. Over the study period, there was no change in the PGD incidence; however, there was an increase in the recipient pretransplantation use of amiodarone. The rate of 30‐day mortality was significantly elevated in those with PGD versus those without PGD (6.06% vs 0.92%, P = .01). Despite recent advancements, incidence of PGD remains high. Understanding associated risk factors may allow for implementation of targeted therapeutic interventions.

Neurophysiological Intraoperative Monitoring During Aortic Arch Surgery

Circulatory management during replacement of the aortic arch is complex and involves a period of circulatory arrest to provide a bloodless field during arch vessel anastomosis. To guard against ischemic brain injury, tissue metabolic demand is reduced by systemically cooling the patient prior to circulatory arrest. Neurophysiological intraoperative monitoring (NIOM) is often used during the course of these procedures to provide contemporaneous assessment of brain status to help direct circulatory management decisions and detect brain ischemia. In this review, we discuss the characteristics of electrocerebral activity through the process of cooling, circulatory arrest, and rewarming as depicted through commonly used NIOM modalities, including electroencephalography and peripheral nerve somatosensory-evoked potentials. Attention is directed toward the role NIOM has traditionally played during deep hypothermic circulatory arrest, where it is used to define the point of electrocerebral inactivity or maximal cerebral metabolic suppression prior to initiating circulatory arrest while also discussing the evolving utility of NIOM when systemic circulatory arrest is initiated at more moderate degrees of hypothermia in conjunction with regional brain perfusion. The use of cerebral tissue oximetry by near-infrared spectroscopy as an alternative NIOM modality during surgery of the aortic arch is addressed as well. Finally, special considerations for NIOM and the detection of spinal cord ischemia during hybrid aortic arch repair and emerging operative techniques are also discussed.

Delayed Postmyectomy Ventricular Septal Defect

From the *Division of Cardiothoracic Anesthesiology and Critical Care Medicine, Department of Anesthesiology, Duke University Med ical Center, Durham, NC; and yDivision of Cardiac Surgery, Department of Surgery, Duke University Medical Center, Durham, NC. Address reprint requests to Karsten Bartels, MD, Division of Car diothoracic Anesthesiology and Critical Care Medicine, Department of Anesthesiology, Duke University Medical Center, Box 3094, 2301 Erwin Road, Rm. 5688 HAFS, Durham, NC 27710. E mail: karsten.bartels@duke.edu K.B. was a cardiac anesthesia fellow. & 2013 Published by Elsevier Inc. 1053 0770/2602 0033

Unexpected intraoperative diagnosis of pulmonary embolism by transesophageal echocardiography.

36.00/0 http://dx.doi.org/10.1053/j.jvca.2012.10.009