Faculty Bibliography

PURPOSE/OBJECTIVE:Patients with acute myocardial infarction (AMI) and respiratory impairment may be treated with either invasive or non-invasive mechanical ventilation (MV). However, there has been little testing of non-invasive MV in the setting of AMI. Our objective was to evaluate the incidence and associated clinical outcomes of patients with AMI who were treated with non-invasive or invasive MV. METHODS:This was a retrospective observational study in which consecutive patients with AMI (n = 1610) were enrolled. The association between exclusively non-invasive MV, invasive MV and outcomes was assessed by multivariable models. RESULTS:Mechanical ventilation was used in 293 patients (54% invasive and 46% exclusively non-invasive). In-hospital mortality rates for patients without MV, with exclusively non-invasive MV, and with invasive MV were 4.0%, 8.8%, and 39.5%, respectively (P<0.001). The median lengths of hospital stay were 6 (5.8-6.2), 13 (11.2-4.7), and 28 (18.0-37.9) days, respectively (P<0.001). Exclusively non-invasive MV was not associated with in-hospital death (adjusted HR = 0.90, 95% CI 0.40-1.99, P = 0.79). Invasive MV was strongly associated with a higher risk of in-hospital death (adjusted HR = 3.07, 95% CI 1.79-5.26, P<0.001). CONCLUSIONS:In AMI setting, 18% of the patients required MV. Almost half of these patients were treated with exclusively non-invasive strategies with a favorable prognosis, while patients who needed to be treated invasively had a three-fold increase in the risk of death. Future prospective randomized trials are needed to compare the effectiveness of invasive and non-invasive MV for the initial approach of respiratory failure in AMI patients.

BACKGROUND:Clinical practice guidelines recommend admitting patients with stable non-ST-segment elevation acute coronary syndrome (NSTE ACS) to telemetry units, yet up to two-thirds of patients are admitted to higher-acuity critical care units (CCUs). The outcomes of patients with stable NSTE ACS initially admitted to a CCU vs a cardiology ward with telemetry have not been described. METHODS:We used population-based data of 7,869 patients hospitalized with NSTE ACS admitted to hospitals in Alberta, Canada, between April 1, 2007, and March 31, 2013. We compared outcomes among patients initially admitted to a CCU (n=5,141) with those admitted to cardiology telemetry wards (n=2,728). RESULTS:Patients admitted to cardiology telemetry wards were older (median 69 vs 65years, P<.001) and more likely to be female (37.2% vs 32.1%, P<.001) and have a prior myocardial infarction (14.3% vs 11.5%, P<.001) compared with patients admitted to a CCU. Patients admitted directly to cardiology telemetry wards had similar hospital stays (6.2 vs 5.7days, P=.29) and fewer cardiac procedures (40.3% vs 48.5%, P<.001) compared with patients initially admitted to CCUs. There were no differences in the frequency of in-hospital mortality (1.3% vs 1.2%, adjusted odds ratio [aOR] 1.57, 95% CI 0.98-2.52), cardiac arrest (0.7% vs 0.9%, aOR 1.37, 95% CI 0.94-2.00), 30-day all-cause mortality (1.6% vs 1.5%, aOR 1.50, 95% CI 0.82-2.75), or 30-day all-cause postdischarge readmission (10.6% vs 10.8%, aOR 1.07, 95% CI 0.90-1.28) between cardiology telemetry ward and CCU patients. Results were similar across low-, intermediate-, and high-risk Duke Jeopardy Scores, and in patients with non-ST-segment myocardial infarction or unstable angina. CONCLUSIONS:There were no differences in clinical outcomes observed between patients with NSTE ACS initially admitted to a ward or a CCU. These findings suggest that stable NSTE ACS may be managed appropriately on telemetry wards and presents an opportunity to reduce hospital costs and critical care capacity strain.

The cardiac intensive care unit (CICU) has changed considerably over time and now serves a unique patient population with a high burden of cardiovascular and noncardiovascular critical illness. Patient complexity and technological evolutions in the CICU have catalyzed the development of critical care cardiology, a fledgling discipline that combines specialization in cardiovascular diseases with knowledge and experience in critical care medicine. Numerous uncertainties and challenges threaten to stymie the growth of this field. A multidisciplinary dialogue focused on the best care design for the CICU patient is needed as we consider alternative approaches to clinical training, staffing, and investigation in this rapidly evolving arena.

There is insufficient data on patients with small body size to determine if this should be considered a risk factor for continuous-flow left ventricular assist device (CF-LVAD) support. We sought to evaluate survival outcomes, adverse events, and functional status of CF-LVAD patients with body surface area (BSA) <1.5 m in a large national registry. Adults with BSA < 1.5 m (n = 128) implanted with a HeartMate II (HMII)-LVAD from the Interagency Registry for Mechanically Assisted Circulatory Support registry from April 2008 to December 2012 formed this cohort. Outcomes were compared with HMII bridge to transplant (BTT) and destination therapy (DT) post approval studies. The majority of patients were female (n = 106, 83%). A total of 64% (n = 82) were implanted for BTT and 36% (n = 46) for DT. The median BSA (range) was 1.44 (1.19-1.49) and 1.45 (1.25-1.49) m for BTT and DT, respectively. Overall survival 1 year post implant was 81% +/- 5% for BTT and 84% +/- 6% for DT. The most common adverse events for BTT and DT patients were bleeding (0.91, 0.88 events/patient year) and driveline infection (16%, 0.28 events/patient year). Six months post implantation, 87% of BTT and 77% of DT patients were New York Heart Association functional class I or II. Post implant survival, functional status improvement, and adverse event profile for adult BTT and DT HMII patients with BSA < 1.5 m are favorable and comparable with outcomes published in the overall patient population.

Management of the advanced heart failure patient can be complex. Therapies include cardiac transplantation and mechanical circulatory support, as well inotropic agents for the short-term. Despite a growing armamentarium of resources, the clinician must carefully weigh the risks and benefits of each therapy to develop an optimal treatment strategy. While cardiac transplantation remains the only true "cure" for end-stage disease, this resource is limited and the demand continues to far outpace the supply. For patients who are transplant-ineligible or likely to succumb to their illness prior to transplant, ventricular assist device therapy has now become a viable option for improving morbidity and mortality. Particularly for the non-operative patient, intravenous inotropes can be utilized for symptom control. Regardless of the treatments considered, care of the heart failure patient requires thoughtful dialogue, multidisciplinary collaboration, and individualized care. While survival is important, most patients covet quality of life above all outcomes. An often overlooked component is the patient's control over the dying process. It is vital that clinicians make goals-of-care discussions a priority when seeing patients with advanced heart failure. The use of palliative care consultation is well-validated and facilitates these difficult conversations to ensure that all patient needs are ultimately met.

BACKGROUND:Despite the beneficial effects of mechanical circulatory support (MCS), the majority of patients ultimately will have an adverse event. Although hemolysis is common among temporary devices, the incidence and clinical significance of hemolysis in patients managed with long-term, durable left ventricular assist device (LVAD) therapy is largely unknown. METHODS:Data were obtained from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS). All adults who received a continuous-flow LVAD (CF-LVAD) between June 2006 and March 2012 were included. A hemolytic event was defined as a plasma-free hemoglobin >40 mg/dl in association with clinical signs of hemolysis occurring at least 72 hours after LVAD implant. Descriptive statistics, time-dependent analyses and multivariable modeling were employed for statistical purposes. RESULTS:A total of 4,850 patients followed for a mean of 11.1 months comprised the final study population. There were 340 hemolytic events in 260 patients. Freedom from hemolysis was 97% at 3 months, 94% at 1 year and 91% at 2 years. Mean time from implant to first hemolysis event was 7.4 months. Younger age (<60 years) was independently associated with greater hemolysis (p < 0.001). Thrombotic device malfunction, device exchange and mortality were all significantly higher after hemolysis, with the greatest risk for each occurring within 6 months. CONCLUSIONS:Hemolysis is not a rare event after CF-LVAD implantation and is associated with an early increase in morbidity and death. Future study should focus on other device and implant characteristics that may lead to hemolytic events, as well as appropriate strategies for managing affected patients.

BACKGROUND:Delirium is common in the medical and surgical intensive care unit (ICU), and its association with morbidity and mortality is well described. Despite emerging data, which have highlighted a growing critical care burden in the contemporary cardiac ICU (CICU), much less is known about delirium in this specialized setting. METHODS AND RESULTS/RESULTS:Records for consecutive CICU patients aged ≥18 years who were admitted to our academic, tertiary care institution from December 2012 to March 2014 for a primary cardiovascular diagnosis were reviewed. Only those with a documented Confusion Assessment Method for ICU score were included in the final analysis. Baseline characteristics, resource use, and outcomes were collected. Disease severity was assessed using the modified Acute Physiology and Chronic Health Evaluation II score and the Simplified Acute Physiology ScoreII. Multivariable logistic and linear regression models were constructed to evaluate the association between CICU delirium, length of stay, and death. Among 590 patients included, the prevalence of CICU delirium was 20.3%. Delirious patients were older, had greater disease severity, required longer ICU stays (5 vs 2 days; P < .001), and had higher mortality (27% vs 3%; P < .001). In the adjusted setting, delirium remained strongly associated with both increased mortality (P < .001) and length of stay (P = .001). CONCLUSIONS:In those with cardiac critical illness, delirium is common and associated with worse survival and greater resource consumption. Future study is needed to validate these findings and to develop effective strategies for the early identification and treatment of the delirious CICU patient.

OBJECTIVE:Patients with primary cardiovascular disorders and comorbidities are commonly admitted to ICUs; however, little is known about the current state of cardiac research being conducted in these adult ICU patients. DESIGN/METHODS:Retrospective analysis. PATIENTS OR SUBJECTS/METHODS:None. SETTING/METHODS:In separate searches of ongoing phase II-IV clinical trials registered with ClinicalTrials.gov and funding grants available in the Canadian Institutes for Health Research funding decision database between 1999 and 2012, we identified all research initiatives focused on adult ICU patients. INTERVENTIONS/METHODS:None. MEASUREMENTS AND MAIN RESULTS/RESULTS:The primary outcome of interest was the proportion of cardiac-specific ICU studies, defined as any involving a cardiac population with a cardiac intervention (or observation for observational analyses) and/or a cardiac outcome. A total of 192 unique studies including adult ICU patients were identified from the ClinicalTrials.gov database. These were most commonly classified as respiratory or ventilation (19%), infectious (14.1%), or neurologic (12.0%) in focus. A total of 105 grants were identified in the Canadian Institutes for Health Research database. Funded studies most commonly addressed respiratory or ventilator questions (18.1%), infectious disease issues (12.4%), or hematological/thrombosis questions (9.5%). Only 4.6% of all ICU studies in ClinicalTrials.gov and 1.9% of all Canadian Institutes for Health Research grants could be considered cardiac. CONCLUSIONS:These findings highlight the relative paucity of cardiac-specific research in the intensive care setting relative to the high prevalence of acute cardiac diseases and comorbidities. This observed disparity warrants timely attention and should lead to meaningful research opportunities aimed at improving the outcomes of critically ill cardiac patients.