Kaul, Padma

Abstract Aims The incidence of respiratory failure and use of invasive or non-invasive mechanical ventilation (MV) in the cardiac intensive care units (CICUs) is increasing. While institutional MV volumes are associated with reduced mortality in medical and surgical ICUs, this volume–mortality relationship has not been characterized in the CICU. Methods and results National population-based data were used to identify patients admitted to CICUs (2005–2015) requiring MV in Canada. CICUs were categorized into low (≤100), intermediate (101–300), and high (>300) volume centres based on spline knots identified in the association between annual MV volume and mortality. Outcomes of interest included all-cause in-hospital mortality, the proportion of patients requiring prolonged MV (>96 h) and CICU length of stay (LOS). Among 47 173 CICU admissions requiring MV, 89.5% (42 200) required invasive MV. The median annual CICU MV volume was 43 (inter-hospital range 1–490). Compared to low-volume centres (35.9%), in-hospital mortality was lower in intermediate [29.2%, adjusted odds ratio (aOR) 0.84, 95% confidence interval (CI) 0.72–0.97, P = 0.019] and high-volume (18.2%; aOR 0.82, 95% CI 0.66–1.02, P = 0.076) centres. Prolonged MV was higher in low-volume (29.2%) compared to high-volume (14.8%, aOR 0.70, 95% CI 0.55–0.89, P = 0.003) and intermediate-volume (23.0%, aOR 0.85, 95% CI 0.68–1.06, P = 0.14] centres. Mortality and prolonged MV were lower in percutaneous coronary intervention (PCI)-capable and academic centres, but a shorter CICU LOS was observed only in subgroup of PCI-capable intermediate- and high-volume hospitals. Conclusions In a national dataset, we observed that higher CICU MV volumes were associated with lower incidence of in-hospital mortality, prolonged MV, and CICU LOS. Our data highlight the need for minimum MV volume benchmarks for CICUs caring for patients with respiratory failure.

Abstract Funding Acknowledgements Type of funding sources: None. Background The incidence of respiratory failure and the provision of invasive and non-invasive mechanical ventilation (MV) in patients admitted to cardiac intensive care units (CICU) are increasing. While institutional MV volumes are associated with reduced mortality in medical and surgical ICUs, this relationship has not been characterized in the CICU population. Purpose By describing the relationship between institutional MV volume and outcomes in the CICUs, we hope to shed light on minimum volume benchmarks for providing MV. Methods National Canadian population-based data from 2005 to 2015 was used to identify patients admitted to CICUs requiring MV. CICUs were categorized into low (≤100), intermediate (101-300), and high (>300) volume centers based on spline knots identified in the association between annual MV volume and mortality (Figure). Outcomes of interests included all-cause in-hospital mortality, the proportion of patients requiring prolonged MV (>96 hours) and CICU length of stay (LOS). Results Among the 47,173 CICU admissions that required MV, 89.5% (42,200) required invasive mechanical ventilation. The median annual CICU MV volume was 127 (range 1-490). In-hospital mortality was lower in intermediate (29.2%, adjusted odds ratio [aOR] 0.84, 95% CI 0.72-0.97, p = 0.019) and high-volume (18.2%; aOR 0.82, 95% CI 0.66-1.02, p = 0.076) centers, compared to low volume centers (35.9%). The proportion of patients requiring prolonged MV was higher in low-volume (29.2%) compared to high-volume (14.8%, OR 0.70, 95% 0.55-0.89, p = 0.003) centers. Point estimates for mortality and prolonged MV were lower in PCI-capable and academic centers (Table). Significantly (p <0.01) lower CICU LOS was observed only in the subgroup of PCI-capable intermediate- and high-volume hospitals. Conclusions In a national dataset, we observed that higher CICU MV hospital volumes were associated with lower in-hospital mortality, CICU LOS, and fewer episodes of prolonged MV. Pending further validation, these data suggest minimum MV volume benchmarks for CICUs caring for patients with respiratory failure. Further research is warranted to explore these associations in more detail. Unadjusted volume-outcome relationshipsOutcomesGroup 1 Annual Volume ≤100Group 2 Annual Volume 101-300Group 3 Annual Volume >300Totalp-valueTotal N1770224351512047173In-hospital mortality6357 (35.0%)7122 (29.2%)933 (18.2%)14412 (30.6%)p < 0.0001Median CICU LOS(hours)85796679p < 0.0001Episodes of prolonged MV5161 (29.2%)5608 (23.0%)758 (14.8%)11527 (24.4%)p < 0.0001Abbreviations OR (odds ratio), RD (risk difference), CI (confidence interval), PCI (percutaneous coronary intervention), LOS (length of stay)Abstract Figure. Annual CICU MV volume and mortality

Background: Emerging evidence suggests that coronary intensive care units are evolving into intensive care environments with an increasing burden of non-cardiovascular illness, but previous studies have been limited to older populations or single center experiences. Methods: Canadian national health-care data was used to identify all patients ≥18 years admitted to dedicated coronary intensive care units (2005–2015) and admissions were categorized as primary cardiac or non-cardiac. The outcomes of interest included longitudinal trends in admission diagnoses, critical care therapies, and all-cause in-hospital mortality. Results: Among the 373,992 patients admitted to a coronary intensive care unit, minimal changes in the proportion of patients admitted with a primary cardiac (88.2% to 86.9%; p<0.001) and non-cardiac diagnoses (11.8% to 13.1%; p<0.001) were observed. Among cardiac admissions, a temporal increase in the proportion of ST-segment elevation myocardial infarction (19.4% to 24.1%, p<0.001), non-ST-segment elevation myocardial infarction (14.6% to 16.2%, p<0.001), heart failure (7.3% to 8.4%, p<0.001), shock (4.9% to 5.7%, p<0.001), and decline in unstable angina (4.9% to 4.0%, p<0.001) and stable coronary diseases (21.3% to 12.4%, p<0.001) was observed. The proportion of patients requiring critical care therapies (57.8% to 63.5%, p<0.001) including mechanical ventilation (9.6% to 13.1%, p<0.001) increased. In-hospital mortality rates for patients with primary cardiac (4.9% to 4.4%; adjusted odds ratio 0.71, 95% confidence interval 0.63–0.79) and non-cardiac (17.8% to 16.1%; adjusted odds ratio 0.84, 0.73–0.97) declined; results were consistent when stratified by academic vs community hospital, and by the presence of on-site percutaneous coronary intervention. Conclusion: In a national dataset we observed a changing case-mix among patients admitted to a coronary intensive care unit, though the proportion of patients with a primary cardiac diagnosis remained stable. There was an increase in clinical acuity highlighted by critical care therapies, but in-hospital mortality rates for both primary cardiac and non-cardiac conditions declined across all hospitals. Our findings confirm the changing coronary intensive care unit case-mix and have implications for future coronary intensive care unit training and staffing.

Aims: Registries have reported large inter-hospital differences in intensive care unit admission rates for patients with acute heart failure, but little is known about the potential economic impact of over-admission of low-risk patients with heart failure to higher cost intensive care units. We described the variability in intensive care unit admission practices, the provision of critical care therapies, and estimated the potential national cost savings if all hospitals adopted low intensive care unit admission practices for patients admitted with heart failure. Methods: Using a national population health dataset, we identified 349,693 heart failure admission hospitalisations with a primary diagnosis of heart failure between 2007 and 2016. Hospitals were categorised as low (first quartile), medium (second and third quartile) and high (fourth quartiles) intensive care unit utilisation. Results: The mean intensive care unit admission rate was 16.4% (inter-hospital range 0.3–51%) including 5.4% in low, 14.5% in medium and 30% in high utilisation hospitals. Intensive care unit therapies in low, medium and high intensive care unit utilisation hospitals were 54.5%, 45.1% and 24.1% ( P<0.001), respectively and the inhospital mortality rate was not significantly different. The proportion of hospital costs incurred by intensive care unit care was 7.8% in low, 19.8% in medium and 28.2% in high ( P<0.001) admission hospitals. The potential cost savings of altering intensive care unit utilisation practices for patients with heart failure was CAN$234.8m over the study period. Conclusions: In a national cohort of patients hospitalised with heart failure, we observed that low intensive care unit utilisation centres had lower hospital costs with no differences in mortality rates. The development of standardised admission criteria for high-cost and high acuity intensive care unit beds could reduce costs to the healthcare system.