Faculty Bibliography

Targeted temperature management (TTM) after out-of-hospital cardiac arrest (OHCA) has been a focus of debate in an attempt to improve post-arrest outcomes. Contemporary trials examining the role of TTM after cardiac arrest suggest that targeting normothermia should be the standard of care for initially comatose survivors of cardiac arrest. Differences in patient populations have been demonstrated across trials, and important subgroups may be under-represented in clinical trials compared with real-world registries. In this review, we aimed to describe the populations represented in international OHCA registries and to propose a pathway to integrate clinical trial evidence into practice. The patient case mix among registries including survivors to hospital admission was similar to the pivotal trials (shockable rhythm, witnessed arrest), suggesting reasonable external validity. Therefore, for the majority of OHCA, targeted normothermia should be the strategy of choice. There remains conflicting evidence for patients with a nonshockable rhythm, with no clear evidence-based justification for mild hypothermia over targeted normothermia.

OBJECTIVE:To compare rates of clopidogrel response among patients receiving medication produced by 2 different manufacturers after acute coronary syndrome (ACS) and/or percutaneous coronary intervention. METHODS:This quality-improvement project included 515 adult patients receiving clopidogrel for ACS or ischemic heart disease and referred for coronary angiography/ percutaneous coronary intervention. The project was divided into 2 phases: (1) retrospective collection of baseline data (April 2019-October 2020); and (2) two 12-week, prospective phases in which all clopidogrel in the hospital was restricted to a single manufacturer at a time (November 2020-May 2021). The primary outcome was clopidogrel response measured by platelet function testing, defined as adenosine diphosphate (ADP) response <40% on light transmission aggregometry. RESULTS:Of 515 total patients included in both phases (mean age, 64.5 ± 11.4 years; 351 men [68.2%]; 450 with ACS [87.4%]), 52% were found to be clopidogrel responders based on results of platelet function testing. Among 135 patients in the prospective phase, there was a significantly lower proportion of patients who were clopidogrel responders in the Manufacturer 1 group compared with the Manufacturer 2 group (34.8% vs 55.1%, respectively; P=.03). After adjustment for age, sex, body mass index, aspirin response, therapeutic hypothermia, left heart catheterization indication, clopidogrel loading dose, time between loading dose and lab measurement, and manufacturer, aspirin response (odds ratio 0.96; 95% confidence interval, 0.95-0.97; P<.001) and manufacturer (odds ratio, 2.45; 95% confidence interval, 1.18-5.22; P=.02) were associated with clopidogrel response. CONCLUSIONS:In a large public hospital, we observed that pharmacodynamic response to clopidogrel varied by drug manufacturer. Further investigation and/or regulation is needed to minimize inter-manufacturer variability.

BACKGROUND:Cardiac arrest (CA) is a common reason for admission to the cardiac intensive care unit (CICU), though the relative burden of morbidity, mortality, and resource use between admissions with in-hospital (IH) and out-of-hospital (OH) CA is unknown. We compared characteristics, care patterns, and outcomes of admissions to contemporary CICUs after IHCA or OHCA. METHODS:The Critical Care Cardiology Trials Network is a multicenter network of tertiary CICUs in the US and Canada. Participating centers contributed data from consecutive admissions during 2-month annual snapshots from 2017 to 2021. We analyzed characteristics and outcomes of admissions by IHCA vs OHCA. RESULTS:We analyzed 2,075 admissions across 29 centers (50.3% IHCA, 49.7% OHCA). Admissions with IHCA were older (median 66 vs 62 years), more commonly had coronary disease (38.3% vs 29.7%), atrial fibrillation (26.7% vs 15.6%), and heart failure (36.3% vs 22.1%), and were less commonly comatose on CICU arrival (34.2% vs 71.7%), p<0.001 for all. IHCA admissions had lower lactate (median 4.3 vs 5.9) but greater utilization of invasive hemodynamics (34.3% vs 23.6%), mechanical circulatory support (28.4% vs 16.8%), and renal replacement therapy (15.5% vs 9.4%); p<0.001 for all. Comatose IHCA patients underwent targeted temperature management less frequently than OHCA patients (63.3% vs 84.9%, p<0.001). IHCA admissions had lower unadjusted CICU (30.8% vs 39.0%, p<0.001) and in-hospital mortality (36.1% vs 44.1%, p<0.001). CONCLUSION:Despite a greater burden of comorbidities, CICU admissions after IHCA have lower lactate, greater invasive therapy utilization, and lower crude mortality than admissions after OHCA.

BACKGROUND:Targeted temperature management (TTM) has been recommended after cardiac arrest (CA), however the specific temperature targets and cooling methods (intravascular cooling (IVC) versus surface cooling (SC)) remain uncertain. METHODS:PUBMED and EMBASE were searched until October 8, 2022 for randomized clinical trials (RCTs) investigating the efficacy of TTM after CA. The randomized treatment arms were categorized into the following 6 groups: 31..C to 33..C IVC, 31..C to 33..C SC, 34..C to 36..C IVC, 34..C to 36..C SC, strict normothermia or fever prevention (Strict NT or FP), and standard of care without TTM (No-TTM). The primary outcome was neurological recovery. P-score was used to rank the treatments, where a larger value indicates better performance. RESULTS:We identified 15 RCTs, involving 5,218 patients with CA. Compared to No-TTM as the reference, the other therapeutic options significantly improved neurological outcomes (vs No-TTM; 31..C to 33.. C IVC/UNASSIGNED:RR = 0.67, 95% CI 0.54 to 0.83; 31..C to 33..C SC RR = 0.73, 95% CI 0.61 to 0.87; 34..C to 36.. C IVC/UNASSIGNED:RR = 0.66, 95% CI 0.51 to 0.86; 34..C to 36..C SC: RR = 0.73, 0.59 to 0.90; Strict NT or FP: RR = 0.75, 95% CI 0.62 to 0.90). Overall, 31-33..C IVC had the highest probability to be the best therapeutic option to improve outcomes (the ranking P-score of 0.836). As a subgroup analysis, the ranking P-score showed that IVC might be a better cooling method compared to SC (IVC vs SC P-score: 0.960 vs 0.670). CONCLUSIONS:Hypothermia (31..C to 36..C IVC and SC) and active normothermia (Strict-NT and Strict-FP) were associated with better neurological outcomes compared to No-TTM, with IVC having a greater probability of being the better cooling method than SC.

The increase of intravenous drug use has led to an increase in right-sided infective endocarditis and its complications including septic pulmonary embolism. The objective of this study was to compare the outcomes of tricuspid valve (TV) operations in patients with drug-use infective endocarditis (DU-IE) complicated by septic pulmonary emboli (PE). Hospitalizations for DU-IE complicated by septic PE were identified from the National Inpatient Sample from 2002 to 2019. Outcomes of patients who underwent TV operations were compared with medical management. The primary outcome was the incidence of major adverse cardiovascular events (MACEs), defined as in-hospital mortality, myocardial infarction, stroke, cardiogenic shock, or cardiac arrest. An inverse probability of treatment weighted analysis was utilized to adjust for the differences between the cohorts. A total of 9,029 cases of DU-IE with septic PE were identified (mean age 33.6 years), of which 818 patients (9.1%) underwent TV operation. Surgery was associated with a higher rate of MACE (14.5% vs 10.8%, p <0.01), driven by a higher rate of cardiogenic shock (6.1% vs 1.2%, p <0.01) but a lower rate of mortality (2.7% vs 5.7%, p <0.01). Moreover, TV operation was associated with an increased need for permanent pacemakers, blood transfusions, and a higher risk of acute kidney injury. In the inverse probability treatment weighting analysis, TV operation was associated with an increased risk for MACE driven by a higher rate of cardiogenic shock and cardiac arrest, but a lower rate of mortality when compared with medical therapy alone. In conclusion, TV operations in patients with DU-IE complicated by septic PE are associated with an increased risk for MACE but a decreased risk of mortality. Although surgical management may be beneficial in some patients, alternative options such as percutaneous debulking should be considered given the higher risk.

Oxygen supplementation has been a mainstay in the management of patients with acute cardiac disease. While hypoxia is known to be detrimental, the adverse effects of artificially high oxygen levels (hyperoxia) have only recently been recognized. Hyperoxia may induce harmful hemodynamic effects, including peripheral and coronary vasoconstriction, and direct cellular toxicity through the production of reactive oxygen species. In addition, emerging evidence has shown that hyperoxia is associated with adverse clinical outcomes. Thus, it is essential for the cardiac intensive care unit (CICU) clinician to understand the available evidence and titrate oxygen therapies to specific goals. This review summarizes the pathophysiology of oxygen within the cardiovascular system and the association between supplemental oxygen and hyperoxia in patients with common CICU diagnoses, including acute myocardial infarction, heart failure, shock, cardiac arrest, pulmonary hypertension, and respiratory failure. Finally, we highlight lessons learned from available trials, gaps in knowledge, and future directions.