Kashani, Kianoush

Abstract Funding Acknowledgements None. Background Hyperoxemia (a high PaO2, i.e. >200-300 mmHg) has been associated with adverse outcomes in general critical care settings as well as in acute cardiovascular care conditions. The association between hyperoxemia and mortality has not been characterized in the heterogeneous population admitted to the cardiac intensive care unit (CICU). We aimed to examine the association between hyperoxemia on CICU admission with in-hospital mortality. Methods We retrospectively analyzed Mayo Clinic CICU patients from January 2007 to April 2018. PaO2 closest on admission was analyzed as a continuous variable (per 100 mmHg) and categorized as: 60-100 mmHg (51.9%), 101-150 mmHg (28.6%), 151-200 mmHg (10.6%), 201-300 mmHg (6.4%), and >300 mmHg (2.5%). Those without PaO2 on admission and those with hypoxemia were excluded. The primary outcome was all-cause in-hospital mortality evaluated using logistic regression, after adjusting for age, Charlson Comorbidity Index, M-CARS, and use of IMV and NIPPV. Results A total of 3,368 patients were included (median 70.3 years, 39.4% women). Admission diagnoses included ACS (37.0%, with 19.8% STEMI), HF (67.8%), shock (33.0%) and cardiac arrest (25.3%). Median admission PaO2 was 99 (IQR 78, 136) mmHg, with no difference in median PaO2 between hospital survivors and inpatient deaths (99 versus 98, p = 0.38). A J-shaped relationship was observed between admission PaO2 and in-hospital mortality (Figure A), with slightly higher mortality below 100 mmHg and incrementally higher mortality above this threshold (esp. at >200 mmHg). The incremental association between higher PaO2 and mortality (adjusted OR 1.17 per 100 mmHg higher, 95% CI 1.01-1.34, P = 0.03) was focused in the highest PaO2 group (i.e., >300 mmHg; Figure B). Conclusion Hyperoxia (esp. PaO2 >300 mmHg) on CICU admission is associated with increased in-hospital mortality, demonstrating a J-shaped association with an inflection point of lowest mortality around 100 mmHg. Further studies are warranted to assess if specific oxygen targets influence outcomes in critically ill cardiac patients.

Introduction: Studies have demonstrated an association between hyperkalemia and increased mortality in patients with myocardial infarction, but limited data exist regarding hyperkalemia and associated death among unselected cardiac intensive care unit (CICU) patients. Hypothesis: Hyperkalemia is associated with mortality in CICU patients. Methods: Historical cohort of 9,681 CICU patients admitted from January 2007 to December 2015 with serum potassium measured on admission. Hyperkalemia was defined as admission potassium >=5.0 mEq/L, normokalemia as admission potassium 3.5-4.9 mEq/L, and hypokalemia as admission potassium <3.5 mEq/L. Multivariate logistic regression was used to determine predictors of hospital mortality. Post-discharge survival was assessed using Kaplan-Meier analysis and Cox proportional hazards models. Results: Mean age was 67±15 years with 3,629 (36%) females and hospital mortality of 9%. Hyperkalemia occurred in 1,187 (12.3%), and hypokalemia occurred in 719 (7.4%). Compared to normokalemic patients, both hyperkalemic patients (unadjusted OR 2.85, 95% CI 2.40-3.39; P<.001) and hypokalemic patients (unadjusted OR 2.31, 95% CI 1.85-2.88; P<.001) were at increased risk of hospital mortality. After adjustment for illness severity and renal function, only hyperkalemic patients were at increased risk of hospital death (adjusted OR 1.35, 95% CI 1.07-1.69; p = 0.01), while hypokalemic patients were not (P = NS). Among hospital survivors, hyperkalemic patients had lower post-discharge survival by Kaplan-Meier analysis (P <0.001), while hypokalemic patients had similar survival compared to normokalemic patients (p = NS). After adjustment for illness severity and renal function, hospital survivors with hyperkalemia were at increased risk for post-discharge mortality compared with normokalemic patients (adjusted HR 1.16, 95% CI 1.05-1.28; p=.003). Conclusions: Hyperkalemia on CICU admission is associated with higher hospital and post-discharge mortality, independent of renal function and illness severity. This emphasizes the importance of potassium abnormalities as a risk predictor in patients admitted to the CICU.

Background: Troponin-T (TnT) elevation is common in severe sepsis and septic shock, but the impact on mortality and other clinical outcomes remains uncertain. Methods: This was a retrospective review of adult patients with severe sepsis and septic shock admitted to all the intensive care units (ICU) at Mayo Clinic, Rochester from January 2012 to December 2014. Patients with congenital heart disease or pre-existing moderate or greater valvular disease were excluded. TnT elevation was defined as initial TnT ≥0.1 ng/mL or rise in 3- and 6-hour TnT ≥0.03 ng/mL. Primary outcomes included ICU, hospital, 28-day and 1-year mortality and secondary outcomes were need for and duration of non-invasive ventilation or invasive mechanical ventilation, ICU readmission, and ICU and hospital length of stay. Two-tailed p <0.05 was considered statistically significant. Results: During this three-year period, TnT was measured in 372/765 patients (49%) with septic shock with TnT elevation noted in 329/372 (88%) patients. In patients with and without TnT elevation, initial TnT was 0.14±0.26 vs. 0.14±0.02 ng/mL, p =0.57 and peak TnT was 0.20±0.36 vs. 0.08±0.11 ng/mL, p <0.001. Severity of illness scores, laboratory values, vasopressor use, clinical parameters and medications were similar between patients with and without TnT elevation, except that patients with TnT elevation were older and had more frequent history of coronary atherosclerosis, chronic kidney disease, heart failure and atrial fibrillation (all p <0.05). There was no significant difference in ICU mortality [43 (13%) vs. 8 (19%), p =0.34] and hospital mortality [75 (23%) vs. 12 (28%), p =0.45] between patients with and without TnT elevation. Long-term follow-up of 220/329 (67%) patients showed no significant difference in 28-day mortality [97/216 (45%) vs. 1/4 (25%); p =0.63] or 1-year mortality [163/216 (75%) vs. 4/4 (100%); p =0.58]. There was no significant difference in any of the secondary outcomes between patients with and without elevated TnT (all p >0.05). There was no difference in mortality with increasing quartiles of peak TnT. Conclusions: Troponin elevation is associated with older age and higher comorbidity burden, but does not predict mortality in patients with severe sepsis and septic shock.