Mitral Annular Substrate and Ventricular Arrhythmias in Arrhythmogenic Mitral Valve Prolapse With Mitral Annular Disjunction.

BACKGROUND: In patients with bileaflet mitral valve prolapse (MVP), mitral annular disjunction (MAD) is associated with increased risk of sudden cardiac death via incompletely understood mechanisms. OBJECTIVES: This study assessed the substrate for ventricular arrhythmias in patients with bileaflet MVP and MAD as well as outcomes of catheter ablation with an emphasis on sustained, monomorphic ventricular tachycardia (VT). METHODS: A total of 18 consecutive patients (11 women, mean age 54 ± 15 years) with bileaflet MVP and MAD underwent catheter ablation for VT, and/or premature ventricular complexes (PVCs). Eight patients had a prior cardiac arrest. RESULTS: PVCs were targeted for ablation in all 18 patients (symptomatic PVCs n = 15, PVC-induced ventricular fibrillation n = 3). Sustained monomorphic VT was targeted in 7 of 18 patients. Electroanatomic mapping showed low voltage in the area of the mitral annulus corresponding to VT target sites in 6 of 7 patients with sustained VT. Four of 7 patients had low voltage in the areas of MAD. Six of 7 patients with VT were rendered noninducible post-ablation. The PVC burden was reduced from 11.0% ± 10.4% to 4.0% ± 5.5% (P = 0.004). Over a mean follow-up of 33.9 ± 43.4 months, no VTs recurred. There were no major complications. No repeat ablations for VT occurred. Five of 18 patients required repeat ablation for PVCs. CONCLUSIONS: In patients with bileaflet MVP and MAD undergoing catheter ablation, the mitral valve annulus often contains low-voltage areas harboring the substrate for monomorphic VT and PVCs. Ablation in these patients was safe and improved arrhythmia control.

Corrigendum to 'Association Between Hospital Resuscitation Team Leader Credentials and Survival Outcomes for In-Hospital Cardiac Arrest' [Mayo Clinic Proceedings Innovation Quality Outcomes, 2021, Vol 5, Issue 6, Pages 1021-1028, Article Number: doi: 10.1016/j.mayocpiqo.2021.06.002].

[This corrects the article DOI: 10.1016/j.mayocpiqo.2021.06.002.].

Arrhythmic Mitral Valve Prolapse and Mitral Annular Disjunction: Clinical Features, Pathophysiology, Risk Stratification, and Management.

Mitral valve prolapse (MVP) is a common cause of valvular heart disease. Although many patients with MVP have a benign course, there is increasing recognition of an arrhythmic phenotype associated with ventricular arrhythmias and sudden cardiac death (SCD). Pathophysiologic mechanisms associated with arrhythmias include cardiac fibrosis, mechanical stress induced changes in ventricular refractory periods, as well as electrophysiologic changes in Purkinje fibers. Clinically, a variety of risk factors including demographic, electrocardiographic, and imaging characteristics help to identify patients with MVP at the highest at risk of SCD and arrhythmias. Once identified, recent advances in treatment including device therapy, catheter ablation, and surgical interventions show promising outcomes. In this review, we will summarize the incidence of ventricular arrhythmias and SCD in patients with MVP, the association with mitral annular disjunction, mechanisms of arrhythmogenesis, methods for arrhythmic and SCD risk stratification including findings with multimodality imaging, and treatments for the primary and secondary prevention of SCD.

Association Between Hospital Resuscitation Team Leader Credentials and Survival Outcomes for In-hospital Cardiac Arrest.

OBJECTIVE: To assess whether survival rates for in-hospital cardiac arrest (IHCA) vary across hospitals depending on whether resuscitations are typically led by an attending physician, a physician trainee, or a nonphysician. PATIENTS AND METHODS: In 2018, we conducted a survey of hospitals participating in the national Get with the Guidelines - Resuscitation registry for IHCA. Using responses from the question "Who typically leads codes at your institution?" we categorized hospitals on the basis of who typically leads their resuscitations: attending physician, physician trainee, or nonphysician. We then compared risk-adjusted hospital rates of return of spontaneous circulation, survival to discharge, and favorable neurological survival from 2015 to 2017 between these 3 hospital groups by using multivariable hierarchical regression. RESULTS: Overall, 193 hospitals completed the study survey, representing a total of 44,477 IHCAs (mean age, 65.0±15.5 years; 40.8% were women). Most hospitals had resuscitations led by physicians, with 121 (62.7%) led by an attending physician, 58 (30.0%) by a physician trainee, and 14 (7.3%) by a nonphysician. The risk-standardized rates of survival to discharge were similar across hospitals, regardless of whether resuscitations were typically led by an attending physician, a physician trainee, or a nonphysician (25.6%±4.8%, 25.9%±4.7%, and 25.7%±3.6%, respectively; P=.88). Similarly, there were no differences between the 3 groups in risk-adjusted rates of return of spontaneous circulation (71.7%±6.3%, 73%±6.3%, and 73.4%±6.4%; P=.30) and favorable neurological survival (21.6%±7.1%, 22.7%±6.1%, and 20.9%±6.5%; P=.50). CONCLUSION: In hospitals in a national IHCA registry, IHCA resuscitations were usually led by physicians. However, there was no association between a hospital's typical resuscitation team leader credentials and IHCA survival outcomes.

Examining variation in Medicare payments and drivers of cost for carotid endarterectomy.

BACKGROUND: There is a growing interest in providing high quality and low-cost care to Americans. A pursuit exists to measure not only how well hospitals are performing but also at what cost. We examined the variation in costs associated with carotid endarterectomy (CEA), to determine which components contribute to the variation and what drives increased payments. MATERIALS AND METHODS: Patients undergoing CEA between 2009 and 2012 were identified in the Medicare provider and analysis review database. Hospital quintiles of cost were generated and variation examined. Multivariable logistic regression was performed to identify independent predictors of high-payment hospitals for both asymptomatic and symptomatic patients undergoing CEA. RESULTS: A total of 264,018 CEAs were performed between 2009 and 2012; 250,317 were performed in asymptomatic patients in 2302 hospitals and 13,701 in symptomatic patients in 1851 hospitals. Higher payment hospitals had a higher percentage of nonwhite patients and comorbidity burden. The largest contributors to variation in overall payments were diagnosis-related groups, postdischarge, and readmission payments. After accounting for clustering at the hospital level, independent predictors of high-payment hospitals for all patients were postoperative stroke, length of stay, and readmission ,whereas in the symptomatic group, additional drivers included yearly volume and serious complications. CONCLUSIONS: CEA Medicare payments vary nationwide with diagnosis-related group, readmission, and postdischarge payments being the largest contributors to overall payment variation. In addition, stroke, length of stay, and readmission were the only independent predictors of high payment for all patients undergoing CEA.

Hospital resource intensity and cirrhosis mortality in United States.

AIM: To determine whether hospital characteristics predict cirrhosis mortality and how much variation in mortality is attributable to hospital differences. METHODS: We used data from the 2005-2011 Nationwide Inpatient Sample and the American Hospital Association Annual survey to identify hospitalizations for decompensated cirrhosis and corresponding facility characteristics. We created hospital-specific risk and reliability-adjusted odds ratios for cirrhosis mortality, and evaluated patient and facility differences based on hospital performance quintiles. We used hierarchical regression models to determine the effect of these factors on mortality. RESULTS: Seventy-two thousand seven hundred and thirty-three cirrhosis admissions were evaluated in 805 hospitals. Hospital mean cirrhosis annual case volume was 90.4 (range 25-828). Overall hospital cirrhosis mortality rate was 8.00%. Hospital-adjusted odds ratios (aOR) for mortality ranged from 0.48 to 1.89. Patient characteristics varied significantly by hospital aOR for mortality. Length of stay averaged 6.0 ± 1.6 days, and varied significantly by hospital performance (P < 0.001). Facility level predictors of risk-adjusted mortality were higher Medicaid case-mix (OR = 1.00, P = 0.029) and LPN staffing (OR = 1.02, P = 0.015). Higher cirrhosis volume (OR = 0.99, P = 0.025) and liver transplant program status (OR = 0.83, P = 0.026) were significantly associated with survival. After adjusting for patient differences, era, and clustering effects, 15.3% of variation between hospitals was attributable to differences in facility characteristics. CONCLUSION: Hospital characteristics account for a significant proportion of variation in cirrhosis mortality. These findings have several implications for patients, providers, and health care delivery in liver disease care and inpatient health care design.

Understanding Inpatient Cost Variation in Kidney Transplantation: Implications for Payment Reforms.

OBJECTIVE: To examine the magnitude and sources of inpatient cost variation for kidney transplantation. METHODS: We used the 2005-2009 Nationwide Inpatient Sample to identify patients who underwent kidney transplantation. We first calculated the patient-level cost of each transplantation admission and then aggregated costs to the hospital level. We fit hierarchical linear regression models to identify sources of cost variation and to estimate how much unexplained variation remained after adjusting for case-mix variables commonly found in administrative datasets. RESULTS: We identified 8866 living donor (LDRT) and 5589 deceased donor (DDRT) renal transplantations. We found that higher costs were associated with the presence of complications (LDRT, 14%; P <.001; DDRT, 24%; P <.001), plasmapheresis (LDRT, 27%; P <.001; DDRT, 27%; P <.001), dialysis (LDRT, 4%; P <.001), and prolonged length of stay (LDRT, 84%; P <.001; DDRT, 82%; P <.001). Even after case-mix adjustment, a considerable amount of unexplained cost variation remained between transplant centers (DDRT, 52%; LDRT, 66%). CONCLUSION: Although significant inpatient cost variation is present across transplant centers, much of the cost variation for kidney transplantation is not explained by commonly used risk-adjustment variables in administrative datasets. These findings suggest that although there is an opportunity to achieve savings through payment reforms for kidney transplantation, policymakers should seek alternative sources of information (eg, clinical registry data) to delineate sources of warranted and unwarranted cost variation.