There is significant hospital-level variation in patient survival after cardiac arrests occurring in the cardiac catheterization laboratory (CCL) in the United States, an analysis of registry data shows. The findings, published online Monday and in the Dec. 26 issue of JACC: Cardiovascular Interventions, analyzed data from the GWTG (Get With The Guidelines)–Resuscitation registry provided by the American Heart Association (AHA), to identify the factors associated with higher survival rates after an index cardiac arrest in the CCL. Led by Avnish Tripathi, MD, PhD, MPH, from the University of Kentucky College of Medicine, Bowling Green, the team analyzed data from 4,787 patients from 231 hospitals – finding that risk-adjusted survival rates (RASRs) varied from a median of 20% to 52% among hospitals in the lowest and highest tertiles, respectively. “In a large national registry, we found that there was significant variation in hospital rates of survival for IHCA in the CCL,” they said, warning that in-hospital cardiac arrest (IHCA) in the CCL creates a unique challenge to provide adequate chest compressions and treat the underlying cause of cardiac arrest. “Our findings suggest an opportunity to improve survival rates for IHCA in the CCL at some hospitals,” they said. “Despite a significant improvement in IHCA survival over time, survival rates vary across hospitals and regions in the United States.” Study details The team analyzed data from 4,787 patients aged 18 or over who had an index IHCA in the CCL at 231 hospitals between January 1, 2003, and December 31, 2017. Hierarchical models were used to adjust for demographics, comorbidities, and cardiac arrest characteristics to generate RASRs to discharge for each hospital with ≥5 cases during the study period. Median odds ratio (OR) was then used to quantify the extent of hospital-level variation in RASR. Tripathi and colleagues found the median RASR was 36% (interquartile range [IQR]: 21%). They reported wide variation in hospital rates of survival for IHCA in the CCL, noting that the median RASRs for hospitals in the lowest, middle, and highest tertiles were 20% (IQR: 14%-24%), 36% (IQR: 33%-39%), and 52% (IQR: 46%-60%), respectively. Higher hospital volume of cardiac arrests in the CCL and presence of an initial shockable cardiac arrest rhythm of pulseless ventricular tachycardia (VT) or ventricular fibrillation (VF) were associated with higher survival rate, they said. “We additionally examined the differences in RASR by initial rhythm type,” the authors wrote “The overall median hospital RASR was 55% (IQR: 40%-73%) for IHCA with an initial shockable cardiac arrest rhythm of pulseless ventricular tachycardia (VT) or ventricular fibrillation (VF) and 28% (IQR: 17%-39%) for IHCA with an initial non-shockable cardiac arrest rhythm of asystole and pulseless electric activity (PEA).” The median OR was 1.71 (95% confidence interval [CI]: 1.52-1.87), they noted, adding that this suggests the odds of survival for patients with identical characteristics with IHCA in the CCL from two randomly chosen different hospitals varied by 71%. “Even in controlled settings such as the CCL, there is significant hospital-level variation in survival after in-hospital cardiac arrest, which suggests an important opportunity to improve resuscitation outcomes in procedural areas,” said Tripathi and colleagues. A distinct event that deserves further study Writing in an accompanying editorial, Matthew I. Tomey, MD, from the Icahn School of Medicine at Mount Sinai, New York, said the findings of the study are to be applauded for calling attention to variability in outcomes of in-laboratory cardiac arrest (ILCA) – which he notes to be a “distinct entity,” differing in substantive ways from out-of-hospital cardiac arrest and IHCA – that warrants its own categorization, dedicated study, new evidence and specific guidance. “Notably, significant variation in survival was observed not only at discharge, but also immediately and 24-hours postarrest, suggesting that the discrepancy in outcomes derived not merely from differences in postresuscitation hospital care, but also from differences in resuscitation itself,” he said, noting that hospitals in the lowest tertile of risk-adjusted survival rate tended to have a lower proportion of white patients, higher burden of respiratory and renal comorbidity, higher prevalence of an initial non-shockable rhythm and a lower volume of ILCA. However, the editorialist noted that certain variables that may be important to the type of ILCA were missing from the data source and the analysis. This included details of the type of interventional procedure performed, details of procedural performance, availability, and utilization of specific mechanical circulatory support devices including mechanical chest compression devices, and the leadership and execution of resuscitation, he said. “Furthermore, it is presumed, but unknown, that participating hospitals consistently ascertained all ILCA events,” he said, noting that variability in inclusion of cases – and, in particular, brief, aborted cardiac arrests – could “substantially” affect measured rates of survival. Given these limitations, Tomey noted that caution is required both in interpreting the magnitude of variation suggested by the calculated median OR and in inferring actionable steps to improve survival. “In order to rigorously study ILCA in service of understanding drivers of outcomes, explaining disparities, and informing quality improvement, there is a need for our reporting instruments and registries to capture variables particular to ILCA and the performance of resuscitation in the cardiac catheterization laboratory,” he said, adding that a “necessary first step” is the development of consensus data elements for supplemental reporting in cases of ILCA. “Once defined, these elements will be vital to harmonize data collection efforts in the context of institutional quality improvement, observational studies, and pragmatic trials of resuscitation care in the cardiac catheterization laboratory,” he said. Sources: Tripathi A, Chan PS, Albagdadi MS, et al. Variation in Survival After Cardiopulmonary Arrest in Cardiac Catheterization Laboratories in the United States. JACC Cardiovasc Interv 2022;15:2463-2471. Tomey MI. In-Laboratory Cardiac Arrest: A Distinct Event Deserving Dedicated Study JACC Cardiovasc Interv 2022;15:2472-2474. Image Credit: Akarawut – stock.adobe.com