Hospital volumes and the likelihood of stent implantation among patients undergoing catheterization of the left heart: more is more?

Background Percutaneous coronary intervention (PCI) is an established procedure, but recent studies analyzing the indication for stenting are going to change clinical practice. Previous studies suggested that hospital volume is inversely related to in-hospital mortality but its impact on likelihood of stent implantation and the number of stents remains unclear. Purpose There is a conflict of objectives between nationwide care including short transfer and intervention times and a few large centers with maximum technology and experience. We examine the effect of hospital volume on in-hospital mortality, likelihood of stent implantation, number of stents, length of hospital stay, and reimbursement in a recent nationwide cohort from Germany. Methods Using German national electronic health records, all patients who underwent coronary angiography with a documented coronary artery disease were identified by ICD and OPS codes. Risk-adjustment was applied using a predefined set of patient characteristics to account for differences in the risk factor composition of the patient populations between centers. Results In 2017, a total of 528,188 patients with a documented coronary artery disease underwent coronary angiography in Germany. Mean age was 69.8 years and 29.3% of patients were female. 55% of all patients received PCI, with a mean number of 1.01 stents implanted per patient. In-hospital mortality was 2.9%, length of hospital stay was 6.5 days and mean reimbursement was €5,531. Multivariable regression analyses showed a positive linear association between hospital volumes and the likelihood of stent implantation (p=0.003) as well as the number of implanted stents (p=0.020). No association was found between hospital volumes and in-hospital mortality (p=0.105), length of hospital stay (p=0.201) or reimbursement (p=0.108). Inspection of the non-linear impact of procedure volumes on stent implantation practices indicates a ceiling effect in the volume-outcome relationship: implantation likelihood and number of stents per patient are lowest in centers with less than 100 procedures per year (34.4% and 0.62, respectively). Then, implantation likelihood and number of stents constantly increase until the volume category of 500 procedures per year and center. For centers with >500 procedures per year, the likelihood of stent implantation and the number of implanted stents remained relatively constant (about 60% and 1.07, respectively). Conclusion Patients undergoing coronary angiography in low-volume centers are less frequently subject to PCI but at comparable risk for in-hospital mortality. Furthermore, the data suggest that more complex cases are treated in high volume centers with consistent mortality rates and thus constant safety is ensured in high volume hospitals. Thresholds are discussed. Impact of hospital volumes on PCI Funding Acknowledgement Type of funding source: None

P3716Increased two-year cerebrovascular event rate in patients with bilateral high carotid tempratures

Introduction The association of carotid plaque inflammation with cerebrovascular events is a matter of rigorous research. Microwave Radiometry (MWR) allows in vivo noninvasive measurement of the internal temperatures of tissues, reflecting inflammation. Purpose To investigate whether increased carotid temperatures in patients with documented coronary artery disease (CAD) are associated with cerebrovascular events. Methods Consecutive patients with significant CAD from three tertiary centers were included in the study. Maximum carotid plaque thickness was assessed in all carotids by ultrasound. ΔT by MWR was assigned as the temperature difference (maximal minus minimum) along the carotid artery. ΔT ≥0.90°C was assigned as high ΔT. All patients were followed-up clinically for two years and all strokes were adjudicated by an independent committee. Transient ischemic attacks were excluded. Results In total 300 patients were included in the study. High ΔT temperatures bilaterally were measured in 47 patients (15.7%). Three patients (1.0%) suffered a stroke, including one fatal. Stoke rate was 4.3% in the group with bilateral high ΔT and 0.4% in non-high ΔT group (p=0.02). In Kaplan-Meier plot patients with bilateral high ΔT showed higher stroke rate (log-rank p=0.004, figure) Conclusions Bilateral high carotid temperatures are associated with increased two-year stroke rate. The potential value of the present finding in risk stratification of intermediate carotid stenosis mandates further investigation.