Schulman, Steven P.

Objectives: The medical complexity and critical care needs of patients admitted to cardiac ICUs are increasing, and prospective studies examining the underlying cardiac and noncardiac diagnoses, the management strategies, and the prognosis of cardiac ICU patients with respiratory failure are needed. Design: Prospective cohort study. Setting: The Critical Care Cardiology Trials Network is a research collaborative of cardiac ICUs across the United States and Canada. Patients: We included all medical cardiac ICU admissions at 25 cardiac ICUs during two consecutive months annually at each center from 2017 to 2019. Measurements: We evaluated the use of advanced respiratory therapies including invasive mechanical ventilation, noninvasive ventilation, and high-flow nasal cannula versus no advanced respiratory support across admission diagnoses and the association with in-hospital mortality. Main Results: Of 8,240 cardiac ICU admissions, 1,935 (23.5%) were treated with invasive mechanical ventilation, 573 (7.0%) with noninvasive ventilation, and 281 (3.4%) with high-flow nasal cannula. Admitting diagnoses among those with advanced respiratory support were diverse including general medical problems in patients with heart disease as well as primary cardiac problems. In-hospital mortality was higher in patients who received invasive mechanical ventilation (38.1%; adjusted odds ratio, 2.53; 2.02–3.16) and noninvasive ventilation or high-flow nasal cannula (8.8%; adjusted odds ratio, 2.25; 1.73–2.93) compared with patients without advanced respiratory support (4.6%). Reintubation rate was 7.6%. The most common variables associated with respiratory insufficiency included heart failure, infection, chronic obstructive pulmonary disease, and pulmonary vascular disease. Conclusions: One-third of cardiac ICU admissions receive respiratory support with associated increased mortality. These data provide benchmarks for quality improvement ventures in the cardiac ICU, inform cardiac critical care training and staffing patterns, and serve as foundation for future studies aimed at improving outcomes.

Abstract Background The incidences of invasive mechanical ventilation and non-invasive ventilation among patients with non-ST segment elevation myocardial infarction and associated prognosis are not well characterized. Methods We conducted a retrospective cohort study of patients with admission diagnosis of non-ST segment elevation myocardial infarction using the US National Inpatient Sample database between 2002–2014. The exposure variable was invasive mechanical ventilation or non-invasive ventilation within 24 h of admission, compared to no respiratory support. The primary outcome was in-hospital mortality. We determined the association between respiratory support and mortality using Cox proportional hazard models. Results A total of 4,152,421 non-ST segment elevation myocardial infarction hospitalizations were identified, among whom 1.3% required non-invasive ventilation and 1.9% required invasive mechanical ventilation. Non-invasive ventilation use increased over time (0.4% in 2002 to 2.4% in 2014, p<0.001) while there was no definite trend in invasive mechanical ventilation use. Revascularization was lower for non-ST segment elevation myocardial infarction hospitalizations including invasive mechanical ventilation (23.9%) and non-invasive ventilation (14.5%) compared to 36.5% of those without respiratory support (p<0.001). In-hospital mortality was 3.1% for non-ST segment elevation myocardial infarction without respiratory support compared to 9.2% with non-invasive ventilation (adjusted hazard ratio 1.86, 95% confidence interval 1.74–1.98) and 37.2% with invasive mechanical ventilation (adjusted hazard ratio 3.03, 95% confidence interval 2.88–3.19). Mortality for non-ST segment elevation myocardial infarction-non-invasive ventilation is improving over time while mortality for non-ST segment elevation myocardial infarction-invasive mechanical ventilation is increasing over time. Conclusion Mechanical respiratory support in non-ST segment elevation myocardial infarction is used in an important minority of cases, is increasing and is independently associated with mortality. Studies of the optimal management of acute coronary syndrome complicated by respiratory failure are needed to improve outcomes.

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.

Background Clinical investigations of shock in cardiac intensive care units (CICUs) have primarily focused on acute myocardial infarction (AMI) complicated by cardiogenic shock (AMICS). Few studies have evaluated the full spectrum of shock in contemporary CICUs. Methods and Results The Critical Care Cardiology Trials Network is a multicenter network of advanced CICUs in North America. Anytime between September 2017 and September 2018, each center (n=16) contributed a 2-month snap-shot of all consecutive medical admissions to the CICU. Data were submitted to the central coordinating center (TIMI Study Group, Boston, MA). Shock was defined as sustained systolic blood pressure <90 mm Hg with end-organ dysfunction ascribed to the hypotension. Shock type was classified by site investigators as cardiogenic, distributive, hypovolemic, or mixed. Among 3049 CICU admissions, 677 (22%) met clinical criteria for shock. Shock type was varied, with 66% assessed as cardiogenic shock (CS), 7% as distributive, 3% as hypovolemic, 20% as mixed, and 4% as unknown. Among patients with CS (n=450), 30% had AMICS, 18% had ischemic cardiomyopathy without AMI, 28% had nonischemic cardiomyopathy, and 17% had a cardiac cause other than primary myocardial dysfunction. Patients with mixed shock had cardiovascular comorbidities similar to patients with CS. The median CICU stay was 4.0 days (interquartile range [IQR], 2.5–8.1 days) for AMICS, 4.3 days (IQR, 2.1–8.5 days) for CS not related to AMI, and 5.8 days (IQR, 2.9–10.0 days) for mixed shock versus 1.9 days (IQR, 1.0–3.6) for patients without shock ( P <0.01 for each). Median Sequential Organ Failure Assessment scores were higher in patients with mixed shock (10; IQR, 6–13) versus AMICS (8; IQR, 5–11) or CS without AMI (7; IQR, 5–11; each P <0.01). In-hospital mortality rates were 36% (95% CI, 28%–45%), 31% (95% CI, 26%–36%), and 39% (95% CI, 31%–48%) in AMICS, CS without AMI, and mixed shock, respectively. Conclusions The epidemiology of shock in contemporary advanced CICUs is varied, and AMICS now represents less than one-third of all CS. Despite advanced therapies, mortality in CS and mixed shock remains high. Investigation of management strategies and new therapies to treat shock in the CICU should take this epidemiology into account.

AbstractObjectivesWith clinical use of high‐sensitivity troponin I (hsTnI), more frequent troponin elevations will occur. However, the burden and implications of these elevations are not well understood. The authors quantified the prevalence of elevated hsTnI in patients presenting with possible acute coronary syndrome (ACS) who do not have elevated troponin with a current generation assay (cardiac troponin I [cTnI]) and determined the association of these newly detected elevations with a composite of all‐cause mortality and subsequent cardiac hospitalization.MethodsThis was a prospective observational study of 808 subjects evaluated for possible ACS and followed for up to 1 year. Troponin values were measured with hsTnI (Abbott Laboratories) and cTnI (Abbott and Beckman Coulter). Cardiac hospitalization was defined as hospitalization for ACS, revascularization, acute heart failure (AHF), or tachy/brady arrhythmia that occurred after the index emergency department (ED) visit or hospital discharge.ResultsForty subjects (5%) were diagnosed with ACS (26 myocardial infarction and 14 unstable angina). On the initial sample, the prevalence of elevated hsTnI among subjects with nonelevated cTnI was 9.2% using a gender‐neutral cutoff (95% confidence interval [CI] = 7.1% to 11.4%) and 11.1% using a gender‐specific cutoff (95% CI = 8.8% to 13.4%). Adjudicated diagnoses for subjects whose initial samples had elevated hsTnI but nonelevated cTnI (gender‐neutral cutoff) were as follows: three (4.6%) ACS, 15 (23.1%) AHF, three (4.6%) volume overload etiology unclear/noncardiac, three (4.6%) cardiac (non‐ACS), and 41 (63.1%) other. Of the 65 patients whose initial samples had hsTnI but nonelevated cTnI, eight developed cTnI elevation on subsequent serial sampling. After traditional cardiovascular risk factors and renal function were adjusted for, subjects with elevated initial hsTnI but nonelevated cTnI (initial and serial sampling) had a higher risk of all‐cause mortality and subsequent cardiac hospitalization than subjects with both nonelevated hsTnI and nonelevated cTnI (hazard ratio [HR] = 1.91, 95% CI = 1.14 to 3.19).ConclusionsOn the initial sample, 9% to 11% of subjects without cTnI elevation had hsTnI elevation. Although the majority of the patients with these newly detected hsTnI elevations did not have ACS, they had a higher risk for all‐cause mortality and subsequent cardiac hospitalization.