Sex Differences in Characteristics, Resource Utilization, and Outcomes of Cardiogenic Shock: Data From the Critical Care Cardiology Trials Network (CCCTN) Registry.

BACKGROUND: Sex disparities exist in the management and outcomes of various cardiovascular diseases. However, little is known about sex differences in cardiogenic shock (CS). We sought to assess sex-related differences in the characteristics, resource utilization, and outcomes of patients with CS. METHODS: The Critical Care Cardiology Trials Network is a multicenter registry of advanced cardiac intensive care units (CICUs) in North America. Between 2018 and 2022, each center (N=35) contributed annual 2-month snapshots of consecutive CICU admissions. Patients with CS were stratified as either CS after acute myocardial infarction or heart failure-related CS (HF-CS). Multivariable logistic regression was used for analyses. RESULTS: Of the 22 869 admissions in the overall population, 4505 (20%) had CS. Among 3923 patients with CS due to ventricular failure (32% female), 1235 (31%) had CS after acute myocardial infarction and 2688 (69%) had HF-CS. Median sequential organ failure assessment scores did not differ by sex. Women with HF-CS had shorter CICU lengths of stay (4.5 versus 5.4 days; P<0.0001) and shorter overall lengths of hospital stay (10.9 versus 12.8 days; P<0.0001) than men. Women with HF-CS were less likely to receive pulmonary artery catheters (50% versus 55%; P<0.01) and mechanical circulatory support (26% versus 34%; P<0.0001) compared with men. Women with HF-CS had higher in-hospital mortality than men, even after adjusting for age, illness severity, and comorbidities (34% versus 23%; odds ratio, 1.76 [95% CI, 1.42-2.17]). In contrast, there were no significant sex differences in utilization of advanced CICU monitoring and interventions, or mortality, among patients with CS after acute myocardial infarction. CONCLUSIONS: Women with HF-CS had lower use of pulmonary artery catheters and mechanical circulatory support, shorter CICU lengths of stay, and higher in-hospital mortality than men, even after accounting for age, illness severity, and comorbidities. These data highlight the need to identify underlying reasons driving the differences in treatment decisions, so outcomes gaps in HF-CS can be understood and eliminated.

Patients With Acute Coronary Syndromes Admitted to Contemporary Cardiac Intensive Care Units: Insights From the CCCTN Registry.

BACKGROUND: With the improvement in outcomes for acute coronary syndrome (ACS), the practice of routine admission to cardiac intensive care units (CICUs) is evolving. We aimed to describe the epidemiology of patients with ACS admitted to contemporary CICUs. METHODS: Using the CCCTN (Critical Care Cardiology Trials Network) Registry for consecutive medical CICU admissions across 26 advanced CICUs in North America between 2017 and 2020, we identified patients with a primary diagnosis of ACS at CICU admission and compared patient characteristics, resource utilization, and outcomes to patients admitted with a non-ACS diagnosis and across sub-populations of patients with ACS, including by indication for CICU admission. RESULTS: Of 10 118 CICU admissions, 29.4% (n=2978) were for a primary diagnosis of ACS, with significant interhospital variability (range, 13.4%-56.6%). Compared with patients admitted with a diagnosis other than ACS, patients with ACS had fewer comorbidities, lower acute severity of illness with less utilization of advanced CICU therapies (41.3% versus 66.1%, P<0.0001), and lower CICU mortality (5.4% versus 9.9%, P<0.0001). Monitoring alone, without another CICU indication at the time of admission, was the most frequent admission indication in patients with ACS (53.8%); less common indications in patients with ACS included respiratory insufficiency, shock, or the need for vasoactive therapy. Of patients with ACS admitted for monitoring alone, 94.8% did not subsequently require advanced intensive care unit therapies and had a low CICU length of stay (1.5 days [0.9-2.4] versus 2.6 [1.4-5.1], P<0.0001) and CICU mortality (0.6% versus 11.0%, P<0.0001), compared with patients with ACS with an admission indication beyond monitoring. CONCLUSIONS: In a registry of tertiary care CICUs, ACS represent ≈1/3 of all admissions with significant variability across hospitals. More than half of the ACS admissions to the CICU were for routine monitoring alone, with a low rate of complications and mortality. This observation highlights an opportunity for prospective studies to refine triage strategies for lower risk patients with ACS.

Epidemiology of Acute Heart Failure in Critically Ill Patients With COVID-19: An Analysis From the Critical Care Cardiology Trials Network.

BACKGROUND: Acute heart failure (HF) is an important complication of coronavirus disease 2019 (COVID-19) and has been hypothesized to relate to inflammatory activation. METHODS: We evaluated consecutive intensive care unit (ICU) admissions for COVID-19 across 6 centers in the Critical Care Cardiology Trials Network, identifying patients with vs without acute HF. Acute HF was subclassified as de novo vs acute-on-chronic, based on the absence or presence of prior HF. Clinical features, biomarker profiles and outcomes were compared. RESULTS: Of 901 admissions to an ICU due to COVID-19, 80 (8.9%) had acute HF, including 18 (2.0%) with classic cardiogenic shock (CS) and 37 (4.1%) with vasodilatory CS. The majority (n = 45) were de novo HF presentations. Compared to patients without acute HF, those with acute HF had higher cardiac troponin and natriuretic peptide levels and similar inflammatory biomarkers; patients with de novo HF had the highest cardiac troponin levels. Notably, among patients critically ill with COVID-19, illness severity (median Sequential Organ Failure Assessment, 8 [IQR, 5-10] vs 6 [4-9]; P = 0.025) and mortality rates (43.8% vs 32.4%; P = 0.040) were modestly higher in patients with vs those without acute HF. CONCLUSIONS: Among patients critically ill with COVID-19, acute HF is distinguished more by biomarkers of myocardial injury and hemodynamic stress than by biomarkers of inflammation.

De Novo vs Acute-on-Chronic Presentations of Heart Failure-Related Cardiogenic Shock: Insights from the Critical Care Cardiology Trials Network Registry.

BACKGROUND: Heart failure-related cardiogenic shock (HF-CS) accounts for an increasing proportion of cases of CS in contemporary cardiac intensive care units. Whether the chronicity of HF identifies distinct clinical profiles of HF-CS is unknown. METHODS AND RESULTS: We evaluated admissions to cardiac intensive care units for HF-CS in 28 centers using data from the Critical Care Cardiology Trials Network registry (2017-2020). HF-CS was defined as CS due to ventricular failure in the absence of acute myocardial infarction and was classified as de novo vs acute-on-chronic based on the absence or presence of a prior diagnosis of HF, respectively. Clinical features, resource use, and outcomes were compared among groups. Of 1405 admissions with HF-CS, 370 had de novo HF-CS (26.3%), and 1035 had acute-on-chronic HF-CS (73.7%). Patients with de novo HF-CS had a lower prevalence of hypertension, diabetes, coronary artery disease, atrial fibrillation, and chronic kidney disease (all P < 0.01). Median Sequential Organ Failure Assessment (SOFA) scores were higher in those with de novo HF-CS (8; 25th-75th: 5-11) vs acute-on-chronic HF-CS (6; 25th-75th: 4-9, P < 0.01), as was the proportion of Society of Cardiovascular Angiography and Intervention (SCAI) shock stage E (46.1% vs 26.1%, P < 0.01). After adjustment for clinical covariates and preceding cardiac arrest, the risk of in-hospital mortality was higher in patients with de novo HF-CS than in those with acute-on-chronic HF-CS (adjusted hazard ratio 1.36, 95% confidence interval 1.05-1.75, P = 0.02). CONCLUSIONS: Despite having fewer comorbidities, patients with de novo HF-CS had more severe shock presentations and worse in-hospital outcomes. Whether HF disease chronicity is associated with time-dependent compensatory adaptations, unique pathobiological features and responses to treatment in patients presenting with HF-CS warrants further investigation.

A case report of cardiogenic shock from takotsubo cardiomyopathy with left ventricular outflow tract obstruction: fundamental lessons in cardiac pathophysiology.

BACKGROUND: A subset of patients with takotsubo cardiomyopathy will develop significant dynamic left ventricular outflow tract (LVOT) obstruction leading to cardiogenic shock. However, traditional therapies for cardiogenic shock that focus on increased inotropy and afterload reduction can be detrimental in this situation. CASE SUMMARY: We describe a 71-year-old woman who presented to the emergency department with typical, substernal chest pain found to be hypotensive with ST-elevations in the lateral leads. Coronary angiography showed no significant coronary artery disease, but a left ventriculogram demonstrated takotsubo cardiomyopathy. Right heart catheterization revealed cardiogenic shock and elevated filling pressures. Haemodynamics and symptoms worsened with the initiation of dopamine and placement of intra-aortic balloon pump but improved with the initiation of phenylephrine. Follow-up echocardiogram demonstrated dynamic LVOT obstruction with concomitant severe mitral regurgitation (MR). The patient recovered in the intensive care unit for 5 days after successful weaning of phenylephrine and initiation of low-dose beta-blocker. Repeat echocardiogram 3 weeks later showed complete resolution of apical akinesis, LVOT obstruction, and MR. DISCUSSION: Elucidating whether dynamic LVOT obstruction is contributing to cardiogenic shock physiology is paramount since the management radically differs depending on the presence or absence of obstruction. Corrective therapy focuses on reducing the LVOT gradient and includes fluid administration to improve preload, beta-blocker therapy to increase diastolic filling time, and vasopressors to raise afterload.

The Range of Cardiogenic Shock Survival by Clinical Stage: Data From the Critical Care Cardiology Trials Network Registry.

OBJECTIVES: Cardiogenic shock presents with variable severity. Categorizing cardiogenic shock into clinical stages may improve risk stratification and patient selection for therapies. We sought to determine whether a structured implementation of the 2019 Society for Cardiovascular Angiography and Interventions clinical cardiogenic shock staging criteria that is ascertainable in clinical registries discriminates mortality in a contemporary population with or at-risk for cardiogenic shock. DESIGN: We developed a pragmatic application of the Society for Cardiovascular Angiography and Interventions cardiogenic shock staging criteria-A (at-risk), B (beginning), C (classic cardiogenic shock), D (deteriorating), or E (extremis)-and examined outcomes by stage. SETTING: The Critical Care Cardiology Trials Network is an investigator-initiated multicenter research collaboration coordinated by the TIMI Study Group (Boston, MA). Consecutive admissions with or at-risk for cardiogenic shock during two annual 2-month collection periods (2017-2019) were analyzed. PATIENTS: Patients with or at-risk for cardiogenic shock. MEASUREMENTS AND MAIN RESULTS: Of 8,240 CICU admissions reviewed, 1,991 (24%) had or were at-risk for cardiogenic shock. Distributions across the five stages were as follows: A: 33%; B: 7%; C: 16%; D: 23%; and E: 21%. Overall in-hospital mortality among patients with established cardiogenic shock was 39%; however, mortality varied from only 15.8% to 32.1% to 62.5% across stages C, D, and E (Cochran-Armitage ptrend < 0.0001). The Society for Cardiovascular Angiography and Interventions stages improved mortality prediction beyond the Sequential Organ Failure Assessment and Intra-Aortic Balloon Pumpin Cardiogenic Shock II scores. CONCLUSIONS: Although overall mortality in cardiogenic shock remains high, it varies considerably based on clinical stage, identifying stage C as relatively lower risk. We demonstrate a pragmatic adaptation of the Society for Cardiovascular Angiography and Interventions cardiogenic shock stages that effectively stratifies mortality risk and could be leveraged for future clinical research.

Incidence, underlying conditions, and outcomes of patients receiving acute renal replacement therapies in tertiary cardiac intensive care units: An analysis from the Critical Care Cardiology Trials Network Registry.

BACKGROUND: The prevalence of renal disease in cardiac intensive care units (CICUs) is increasing, but little is known about the utilization, concurrent therapies, and outcomes of patients requiring acute renal replacement therapy (RRT) in this specialized environment. METHODS: In the Critical Care Cardiology Trials Network, 16 centers submitted data on CICU admissions including acute RRT (defined as continuous renal replacement therapy and/or acute intermittent dialysis). RESULTS: Among 2,985 admissions, 178 (6.0%; interhospital range 1.0%-16.0%) received acute RRT. Patients receiving RRT, versus not, were more commonly admitted for cardiogenic shock (15.7% vs 4.2%, P < .01), cardiac arrest (9.6% vs 3.7%, P < .01), and acute general medical diagnoses (10.7% vs 5.8%, P < .01), whereas acute coronary syndromes (16.9% vs 32.1%, P < .01) were less frequent. Variables independently associated with acute RRT included diabetes, heart failure, liver disease, severe valvular disease, shock, cardiac arrest, hypertension, and younger age. In patients receiving acute RRT, versus not, advanced therapies including mechanical ventilation (55.6% vs 18.0%), vasoactive support (73.0% vs 35.2%), invasive hemodynamic monitoring (59.6% vs 29.2%), and mechanical circulatory support (27.5% vs 8.4%) were more common. Acute RRT was associated with higher in-hospital mortality (42.1% vs 9.3%, adjusted odds ratio 3.74, 95% CI, 2.52-5.53) and longer median length of stay (10.0 vs 5.3 days, P < .01). In conclusion, acute RRT in contemporary CICUs was associated with the provision of other advanced therapies and lower survival. CONCLUSIONS: These data underscore the risks associated with the provision of renal support in patients with primary cardiovascular problems and the need to develop standardized indications and potential futility measures in this specialized population.

Clinical Practice Patterns in Temporary Mechanical Circulatory Support for Shock in the Critical Care Cardiology Trials Network (CCCTN) Registry.

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.

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.

Epidemiology of Shock in Contemporary Cardiac Intensive Care Units.

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.

Effect of catheter movement and contact during application of radiofrequency energy on ablation lesion characteristics.

BACKGROUND: The efficient delivery of radiofrequency (RF) energy through an endocardial ablation catheter is affected by variable tissue contact due to cardiac motion with myocardial contraction and respiration. In addition, many operators intentionally move an ablation catheter during the delivery of radiofrequency energy when targeting specific arrhythmias that require lines of conduction block such as atrial flutter and atrial fibrillation. We sought to characterize and quantify any effects of catheter movement and intermittent ablation catheter contact on lesion characteristics. METHODS: An ex vivo model consisting of recently excised viable bovine myocardium, a circulating saline bath at 37 °C, a submersible load cell, and a deflectable sheath with an ablation catheter was assembled. A stepper motor attached to an ablation catheter apparatus was programmed to simulate linear drag lesions and series of point lesions with variable contact using constant force. Lesion volumes were analyzed using a digital micrometer by measuring depth, max width, depth at max width, and surface width and compared. RESULTS: The drag lesion was significantly larger than a pointby-point linear lesion using a constant force of 15 g (2,088± 122 mm3 vs. 1,595±121.6; p =0.01) when controlling for RF time and power. For single point lesion assessment, constant contact lesions were significantly larger than lesions created with intermittent contact using the same duration of RF (194± 68 mm3 vs. 112.5±53; p =0.03). There was no significant difference in lesion size between the constant contact at 60 s and 90-s intermittent contact lesions (194±68 mm3 vs.186±69). CONCLUSIONS: In our ex vivo model, externally irrigated radiofrequency catheters produced drag lesion volumes equal to or larger than those created by a point-by-point method.We also found decreased lesion size due to intermittent contact can be overcome by increasing duration of ablation time.