The unmet need for addressing cardiac issues in intensive care research

Impact of cardiovascular risk factors and cardiac diseases on mortality in patients with moderate to severe ARDS: A retrospective cohort study

Background

History of coronary artery disease (CAD) and/or atrial fibrillation (AF) and/or valvular replacement (VR) are prevalent among patients admitted to intensive care units (ICUs). The impact of these conditions on outcomes in patients with acute respiratory distress syndrome (ARDS) remains insufficiently explored.

Methods

We performed a retrospective study on prospectively collected data from patients with ARDS and a PaO2/FiO2 ratio ≤150 mmHg. Patients were admitted between January 2006 and March 2022. We used multivariable logistic regression analysis. The primary outcome was 1-year mortality from admission to the ICU; secondary outcomes included mortality at 28 days and 90 days.

Results

Among 1.033 patients, 181 (17.5 %) had a history of CAD and/or AF and/or VR. History of CAD and/or AF and/or VR was independently associated with 1-year mortality (Odds-Ratio (OR) = 2.59, 95 % confidence interval (CI) 1.76-3.82, p < 0.001), with mortality at 90 days (OR = 1.87, 95 % CI 1.27-2.76, p = 0.001), but not with mortality at 28 days (OR = 1.40, 95 % CI 0.93-2.11, p = 0.10). In sensitivity analyses, history of CAD and/or AF and/or VR remained independently associated with 1-year mortality in ICU survivors (OR = 3.58, 95 % CI = 2.41-7.82, p < 0.001).

Conclusions

History of CAD and/or AF and/or VR was associated with mortality in ARDS. Prompt referral to cardiologists for comprehensive management post-ICU discharge may be warranted to optimize outcomes in this vulnerable population.

Research Priorities in Critical Care Cardiology: JACC Expert Panel

Over the last several decades, the cardiac intensive care unit (CICU) has seen a substantial evolution in the patient population, comorbidities, and diagnoses. However, the generation of high-quality evidence to manage these complex and critically ill patients has been slow. Given the scarcity of clinical trials focused on critical care cardiology (CCC), CICU clinicians are often left to extrapolate from studies that either exclude or poorly represent the patient population admitted to CICUs. The lack of high-quality evidence and limited guidance from society guidelines has led to significant variation in practice patterns for many of the most common CICU diagnoses. Several barriers, both common to critical care research and unique to CCC, have impeded progress. In this multinational perspective, we describe key areas of priority for CCC research, current challenges for investigation in the CICU, and essential elements of a path forward for the field.

Critical Care Cardiology Trials Network (CCCTN): a cohort profile

AIMS

The aims of the Critical Care Cardiology Trials Network (CCCTN) are to develop a registry to investigate the epidemiology of cardiac critical illness and to establish a multicentre research network to conduct randomised clinical trials (RCTs) in patients with cardiac critical illness.

METHODS AND RESULTS

The CCCTN was founded in 2017 with 16 centres and has grown to a research network of over 40 academic and clinical centres in the United States and Canada. Each centre enters data for consecutive cardiac intensive care unit (CICU) admissions for at least 2 months of each calendar year. More than 20 000 unique CICU admissions are now included in the CCCTN Registry. To date, scientific observations from the CCCTN Registry include description of variations in care, the epidemiology and outcomes of all CICU patients, as well as subsets of patients with specific disease states, such as shock, heart failure, renal dysfunction, and respiratory failure. The CCCTN has also characterised utilization patterns, including use of mechanical circulatory support in response to changes in the heart transplantation allocation system, and the use and impact of multidisciplinary shock teams. Over years of multicentre collaboration, the CCCTN has established a robust research network to facilitate multicentre registry-based randomised trials in patients with cardiac critical illness.

CONCLUSION

The CCCTN is a large, prospective registry dedicated to describing processes-of-care and expanding clinical knowledge in cardiac critical illness. The CCCTN will serve as an investigational platform from which to conduct randomised controlled trials in this important patient population.

ICU Versus High-Dependency Care Unit for Patients With Acute Myocardial Infarction: A Nationwide Propensity Score-Matched Cohort Study

OBJECTIVES

To compare the outcomes of patients with acute myocardial infarction who were treated in ICUs versus high-dependency care units (HDUs).

DESIGN

A nationwide, propensity score-matched, retrospective cohort study of a national administrative inpatient database in Japan from July 2010 to March 2018.

SETTING

Six hundred sixty-six acute-care hospitals with ICU and/or HDU beds covering about 75% of all ICU beds and 70% of all HDU beds in Japan.

PATIENTS

Adult patients who were hospitalized for acute myocardial infarction and admitted to the ICU or HDU on the day of hospital admission. Propensity score-matching analysis was performed to compare the inhospital mortality between patients treated in the ICU and HDU on the day of hospital admission.

INTERVENTIONS

ICU or HDU admission on the day of hospital admission.

MEASUREMENTS AND MAIN RESULTS

Of 135,142 eligible patients, 89,382 (66%) were admitted to the ICU and 45,760 (34%) were admitted to the HDU on the day of admission. After propensity score matching, there was no statistically significant difference in inhospital mortality between the ICU and HDU groups (5.0% vs 5.5%; difference, -0.5%; 95% CI, -1.0% to 0.1%). In the subgroup analyses, inhospital mortality was significantly lower in the ICU group than that in the HDU group among patients with Killip class IV (25.6% vs 28.4%; difference, -2.9%; 95% CI, -5.4% to -0.3%), patients who underwent intubation (40.0% vs 46.6%; difference, -6.6%; 95% CI, -10.6% to -2.7%), and patients who received mechanical circulatory support (21.8% vs 24.7%; difference, -2.8%; 95% CI, -5.5% to -0.2%).

CONCLUSIONS

Critical care in the ICU compared with that in the HDU was not associated with reduced inhospital mortality among the entire cohort of patients with acute myocardial infarction but was associated with reduced inhospital mortality among the subsets of patients with Killip class IV, intubation, or mechanical circulatory support.

Challenges in the conduct of randomised controlled trials in cardiogenic shock complicating acute myocardial infarction

Cardiogenic shock (CS) following acute myocardial infarction (AMI) is a major challenge in cardiovascular care. Mortality remains high with 40%-50% after thirty days. Randomised controlled trials (RCTs) play a key role to generate evidence on optimal care in this field. However, the number of completed or ongoing RCTs is still relatively low compared to the gaps in evidence. Challenges in the conduct of these trials are in particular the selection of patients and ethical issues in the informed consent process. When determining eligibility criteria, special attention should be paid to the severity of CS, to the inclusion of patients with cardiac arrest and to potential age limits. Median age of AMI-CS patients is increasing. Age limits are therefore controversial as it is important to include elderly patients in RCTs in order to make the results generalisable and to address the special needs of this group. As patients with AMI-CS are in most cases unable to provide informed consent themselves, a step-wise approach with acute consent by a legal representative or independent physicians and later informed consent by the patient if possible might be established depending on regularities of the respective ethical review board and country legislation. Multicenter studies should be sought to generate adequate power.

Intensive care unit versus high-dependency care unit for patients with acute heart failure: a nationwide propensity score-matched cohort study

Background

A structure and staffing model similar to that in general intensive care unit (ICUs) is applied to cardiac intensive care unit (CICUs) for patients with acute heart failure. However, there is limited evidence on the structure and staffing model of CICUs. The present study aimed to assess whether critical care for patients with acute heart failure in the ICUs is associated with improved outcomes than care in the high-dependency care units (HDUs), the hospital units in which patient care levels and costs are between the levels found in the ICU and general ward.

Methods

This nationwide, propensity score-matched, retrospective cohort study was performed using a national administrative inpatient database in Japan. We identified all patients who were hospitalized for acute heart failure and admitted to the ICU or HDU on the day of hospital admission from April 2014 to March 2019. Propensity score-matching analysis was performed to compare the in-hospital mortality between acute heart failure patients treated in the ICU and HDU on the day of hospital admission.

Results

Of 202,866 eligible patients, 78,646 (39%) and 124,220 (61%) were admitted to the ICU and HDU, respectively, on the day of admission. After propensity score matching, there was no statistically significant difference in in-hospital mortality between patients who were admitted to the ICU and HDU on the day of admission (10.7% vs. 11.4%; difference, − 0.6%; 95% confidence interval, − 1.5% to 0.2%). In the subgroup analyses, there was a statistically significant difference in in-hospital mortality between the ICU and HDU groups among patients receiving noninvasive ventilation (9.4% vs. 10.5%; difference, − 1.0%; 95% confidence interval, − 1.9% to − 0.1%) and patients receiving intubation (32.5% vs. 40.6%; difference, − 8.0%; 95% confidence interval, − 14.5% to − 1.5%). There were no statistically significant differences in other subgroup analyses.

Conclusions

Critical care in ICUs was not associated with lower in-hospital mortality than critical care in HDUs among patients with acute heart failure. However, critical care in ICUs was associated with lower in-hospital mortality than critical care in HDUs among patients receiving noninvasive ventilation and intubation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40560-021-00592-2.

Utilization and outcomes of early respiratory support in 6.5 million acute heart failure hospitalizations

AIMS

The incidence and outcomes of a requirement for non-invasive ventilation (NIV) or invasive mechanical ventilation (IMV) in acute heart failure (AHF) hospitalization are not clearly established. Thus, we aimed to characterize the incidence and trends in use of IMV and NIV in AHF and to estimate the magnitude of hazard for mortality associated with requiring IMV and NIV in AHF.

METHODS AND RESULTS

We used the National Inpatient Sample (NIS) to identify AHF hospitalizations between 2008 and 2014. The exposure variable of interest was IMV or NIV use within 24 h of hospital admission compared to no respiratory support. We analysed the association between ventilation strategies and in-hospital mortality using Cox proportional hazards models adjusting for demographics and comorbidities. We included 6 534 675 hospitalizations for AHF. Of these, 271 589 (4.16%) included NIV and 51 459 (0.79%) included IMV within the first 24 h of hospitalization and rates of NIV and IMV use increased over time. In-hospital mortality for AHF hospitalizations including NIV was 5.0% and 27% for IMV compared with 2.1% for neither (P < 0.001 for both). In an adjusted model, requirement for NIV was associated with over two-fold higher risk for in-hospital mortality [hazard ratio (HR) 2.10, 95% confidence interval (CI) 2.01-2.19; P < 0.001] and requirement for IMV was associated with over three-fold higher risk for in-hospital mortality (HR 3.39, 95% CI 3.14-3.66; P < 0.001).

CONCLUSION

Respiratory support is used in many AHF hospitalizations, and AHF patients who require respiratory support are at high risk for in-hospital mortality. Our work should inform prospective intervention trials and quality improvement ventures in this high-risk population.

Incidence, predictors and prognosis of respiratory support in non-ST segment elevation myocardial infarction

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.

Advanced Respiratory Support in the Contemporary Cardiac ICU

Supplemental Digital Content is available in the text.

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.

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

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.

The necessity of conversion from coronary care unit to the cardiovascular intensive care unit required for cardiologists

The in-hospital mortality rate of acute myocardial infarction (AMI) has dramatically decreased due to the treatment at the coronary care unit (CCU), especially with the progress of arrhythmia therapy and reperfusion therapy. On the other hand, severe heart failure and multiple organ failure are increasing due to aging populations and multiple organ diseases. As a result, patients with AMI without complications are less likely to be admitted to the CCU, and cardiologists staying in the CCU have also decreased. The mortality rate is high when complications such as cardiogenic shock, cardiac rupture, and in-hospital cardiac arrest occur in AMI, therefore careful intensive care even in low-risk AMI is necessary. For cardiologists, mechanical ventilation, renal replacement therapy, or infection control are necessary for cardiovascular intensive care, and integrated multidisciplinary care coordinated by skilled intensive care physicians, nurses, respiratory therapists, physiotherapists, pharmacists, nutritionists, social workers, and clinical engineers is important. Therefore, for the critical care of cardiovascular diseases, it is necessary to convert from CCU to the cardiovascular intensive care unit.

Editor’s Choice-Prospective registry of cardiac critical illness in a modern tertiary care Cardiac Intensive Care Unit

Background:

The changing landscape of care in the Cardiac Intensive Care Unit (CICU) has prompted efforts to redesign the structure and organization of advanced CICUs. Few studies have quantitatively characterized current demographics, diagnoses, and outcomes in the contemporary CICU.

Methods:

We evaluated patients in a prospective observational database, created to support quality improvement and clinical care redesign in an AHA Level 1 (advanced) CICU at Brigham and Women’s Hospital, Boston, MA, USA. All consecutive patients ( N=2193) admitted from 1 January 2015 to 31 December 2017 were included at the time of admission to the CICU.

Results:

The median age was 65 years (43% >70 years) and 44% of patients were women. Non-cardiovascular comorbidities were common, including chronic kidney disease (27%), pulmonary disease (22%), and active cancer (13%). Only 7% of CICU admissions were primarily for an acute coronary syndrome, which was the seventh most common individual diagnosis. The top three reasons for admission to the CICU were shock/hypotension (26%), cardiopulmonary arrest (11%), or primary arrhythmia without arrest (9%). Respiratory failure was a primary or major secondary reason for triage to the CICU in 17%. In-hospital mortality was 17.6%.

Conclusions:

In a tertiary, academic, advanced CICU, patients are elderly with a high burden of non-cardiovascular comorbid conditions. Care has shifted from ACS toward predominantly shock and cardiac arrest, as well as non-ischemic conditions, and the mortality of these conditions is high. These data may be useful to guide cardiac critical care redesign.

Incidence and Prognostic Impact of Respiratory Support in Patients With ST-Segment Elevation Myocardial Infarction

Data addressing the use of respiratory support in acute coronary syndromes are lacking. To address this evidence gap, we characterized prognostic impact and trends in utilization of invasive mechanical ventilation (IMV) and noninvasive ventilation (NIV) in patients hospitalized with ST-segment elevation myocardial infarction (STEMI) from 2002 through 2013 using the National Inpatient Sample. Multivariate logistic regression was performed to identify patient, hospital, and clinical characteristics associated with requiring IMV or NIV within 24 hours of hospitalization. Multivariate Cox proportional hazards regression was used to quantify the magnitude of in-hospital mortality associated with IMV and NIV use. From 2002 to 2013, we identified 1,867,114 patients with STEMI. Age, gender, higher co-morbidity burden, and chronic pulmonary disease were significantly associated with need for respiratory support. The use of IMV and NIV increased at average annual rates of 6.6% and 14.3%, respectively (p_trend <0.001). Age- and gender-adjusted mortality rates are high but declined for patients with STEMI requiring IMV (44.7% in 2002 to 37.6% in 2013, p_trend = 0.002) and NIV (11.6% in 2002 to 6.8% in 2013, p_trend <0.001). Compared to patients with STEMI with no ventilation need, a requirement for IMV or NIV was associated with increased adjusted in-hospital mortality (hazard ratio 2.5, p <0.001 and 1.7, p <0.001, respectively). In conclusion, approximately 1 in 23 patients hospitalized with STEMI will require respiratory support in the form of IMV or NIV. Patients with STEMI who require respiratory support have a high risk of death, although rates of in-hospital mortality have decreased over time.