Faculty Bibliography

Background: Hyperoxia produces reactive oxygen species, apoptosis, and vasoconstriction, and is associated with adverse outcomes in patients with heart failure and cardiac arrest. Our aim was to evaluate the association between hyperoxia and mortality in patients (pts) receiving positive pressure ventilation (PPV) in the cardiac intensive care unit (CICU).
Method(s): Patients admitted to our medical center CICU who received any PPV (invasive or non-invasive) from 2001 through 2012 were included. Hyperoxia was defined as time-weighted mean of PaO2 >120mmHg and non-hyperoxia as PaO2 <=120mmHg during CICU admission. Primary outcome was in-hospital mortality. Multivariable logistic regression was used to assess the association between hyperoxia and in-hospital mortality adjusted for age, female sex, Oxford Acute Severity of Illness Score, creatinine, lactate, pH, PaO2/FiO2 ratio, PCO2, PEEP, and estimated time spent on PEEP.
Result(s): Among 1493 patients, hyperoxia (median PaO2 147mmHg) during the CICU admission was observed in 702 (47.0%) pts. In-hospital mortality was 29.7% in the non-hyperoxia group and 33.9% in the hyperoxia group ((log rank test, p=0.0282, see figure). Using multivariable logistic regression, hyperoxia was independently associated with in-hospital mortality (OR 1.507, 95% CI 1.311-2.001, p=0.00508). Post-hoc analysis with PaO2 as a continuous variable was consistent with the primary analysis (OR 1.053 per 10mmHg increase in PaO2, 95% CI 1.024-1.082, p=0.0002).
Conclusion(s): In a large CICU cohort, hyperoxia was associated with increased mortality. Trials of titration of supplemental oxygen across the full spectrum of critically ill cardiac patients are warranted

BACKGROUND:Vascular injury and inflammation during percutaneous coronary intervention (PCI) are associated with increased risk of post-PCI adverse outcomes. Colchicine decreases neutrophil recruitment to sites of vascular injury. The anti-inflammatory effects of acute colchicine administration before PCI on subsequent myocardial injury are unknown. METHODS:In a prospective, single-site trial, subjects referred for possible PCI (n=714) were randomized to acute preprocedural oral administration of colchicine 1.8 mg or placebo. RESULTS:=0.001). CONCLUSIONS:Acute preprocedural administration of colchicine attenuated the increase in interleukin-6 and high-sensitivity C-reactive protein concentrations after PCI when compared with placebo but did not lower the risk of PCI-related myocardial injury. Registration: URL: https://www.clinicaltrials.gov; Unique Identifiers: NCT02594111, NCT01709981.

Background Positive end-expiratory pressure (PEEP) may have differential hemodynamic effects according to right ventricular (RV), left ventricular (LV) function and filling pressures. We assessed the association between PEEP and outcomes in patients (pts) admitted to the cardiac intensive care unit (CICU) undergoing mechanical ventilation (MV). Methods Patients undergoing MV in the first 48 hours of CICU admission at Beth Israel Deaconess Medical Center (MIMIC III database) were included. Pts were stratified into preload dependent (hypovolemia, RV dysfunction, tamponade, hypertrophic obstructive cardiomyopathy) and high afterload (LV dysfunction). Pts with a pulmonary artery catheter (PAC) were classified by their pulmonary artery diastolic pressure (PADP) as high (>20mmHg) and normal (<20mmHg). Mortality, lactate clearance and inotropic vasopressor score were compared in pts with PEEP levels above and below the median. Multivariable regression analysis was performed adjusting for age, sex, OASIS score, PaO2, pH, lactate and cardiac arrest on admission. Results We included 321 CICU pts (age 68, IQR 57-78) who had a median PEEP levels of 5.38 (IQR 5.00-6.78) cmH2O in the preload dependent group and 5.00 (IQR 5.00-8.00) cmH2O in the afterload dependent group. Unadjusted hospital mortality was higher in pts receiving PEEP above the median in the preload dependent group (66.7% vs. 36.4%, p=0.04, adjusted OR 1.74 95%CI 0.85-3.57, p=0.12), but not in the afterload dependent group (31.1% vs. 26% p=0.51, adjusted OR 1.002 95%CI 0.81-1.24, p=0.98). In patients with PAC (n=80), multivariate analysis demonstrated no differences in mortality by PEEP in low PADP (OR 0.93, 95%CI 0.38-2.75, p=0.87) or high PADP (OR 1.17, 95%CI 0.72-1.91p=0.51). There were no differences in lactate clearance or inotropic/vasopressor score by PEEP in preload/afterload dependent status and with normal/high PADP. Conclusion In CICU pts undergoing MV, the use of low-moderate levels of PEEP was not associated with differences in outcomes. Further research is warranted to better characterize the impact of PEEP, particularly at higher levels, on hemodynamics and clinical outcomes.
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BACKGROUND:Temporary mechanical circulatory support (MCS) devices provide hemodynamic assistance for shock refractory to pharmacological treatment. Most registries have focused on single devices or specific etiologies of shock, limiting data regarding overall practice patterns with temporary MCS in cardiac intensive care units. METHODS:The CCCTN (Critical Care Cardiology Trials Network) is a multicenter network of tertiary CICUs in North America. Between September 2017 and September 2018, each center (n=16) contributed a 2-month snapshot of consecutive medical CICU admissions. RESULTS:Of the 270 admissions using temporary MCS, 33% had acute myocardial infarction-related cardiogenic shock (CS), 31% had CS not related to acute myocardial infarction, 11% had mixed shock, and 22% had an indication other than shock. Among all 585 admissions with CS or mixed shock, 34% used temporary MCS during the CICU stay with substantial variation between centers (range: 17%-50%). The most common temporary MCS devices were intraaortic balloon pumps (72%), Impella (17%), and veno-arterial extracorporeal membrane oxygenation (11%), although intraaortic balloon pump use also varied between centers (range: 40%-100%). Patients managed with intraaortic balloon pump versus other forms of MCS (advanced MCS) had lower Sequential Organ Failure Assessment scores and less severe metabolic derangements. Illness severity was similar at high- versus low-MCS utilizing centers and at centers with more advanced MCS use. CONCLUSIONS:There is wide variation in the use of temporary MCS among patients with shock in tertiary CICUs. While hospital-level variation in temporary MCS device selection is not explained by differences in illness severity, patient-level variation appears to be related, at least in part, to illness severity.

Importance/UNASSIGNED: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/UNASSIGNED:To characterize patients admitted to contemporary, advanced CICUs. Design, Setting, and Participants/UNASSIGNED: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/UNASSIGNED:Demographics, diagnoses, management, and outcomes. Results/UNASSIGNED: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/UNASSIGNED: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.

Therapeutic hypothermia, the standard for post-resuscitation care of out-of-hospital sudden cardiac arrest (SCA), is an area that the most recent resuscitation guidelines note "has not been studied adequately." We conducted a two-phase study examining the role of intra-arrest hypothermia for out-of-hospital SCA, first standardizing the resuscitation and transport of patients to resuscitation centers where post-resuscitation hypothermia was required and then initiating hypothermia during out-of-hospital resuscitation efforts. The primary end points were return of spontaneous circulation (ROSC), sustained ROSC, survival to hospital admission, and survival to discharge. Comparing the cohort of standard hospital-initiated hypothermia (Phase I) with the prehospital-initiated hypothermia via large-volume ice-cold saline (LVICS) infusion (Phase II), no difference was noted for any end point: ROSC (56.4% vs. 53.4%, p = 0.51; 95% confidence interval [CI]: -5.7 to 11.4), sustained ROSC (46.9% vs. 42.8%, p = 0.38; 95% CI: -4.7 to 12.4), hospital admission (44.7% vs. 37.7%, p = 0.13; 95% CI: -1.9 to 15.4), hospital discharge among those surviving to admission (40.0% vs. 28.0%, p = 0.08; 95% CI: -1.5 to 27.8), or neurological outcome among those surviving to discharge (76.0% vs. 71.4%, p = 0.73; 95% CI: -26.9 to 38.7). Patients presenting in ventricular fibrillation were more likely to survive to hospital discharge in both phases, although a trend toward worsened early outcomes (ROSC, sustained ROSC, and survival to admission) with intra-arrest hypothermia was noted in this subgroup. Multivariable regression analyses failed to demonstrate any survival benefit associated with the intra-arrest initiation of hypothermia via LVICS. Our study, the largest study of intra-arrest initiation of hypothermia published to date, failed to demonstrate any effect on survival for out-of-hospital SCA patients, confirming findings of previously published smaller studies. We therefore do not recommend the use of intra-arrest cooling via LVICS infusion as part of routine out-of-hospital SCA resuscitative efforts.