Preoperative Treatment of Obstructive Sleep Apnea With Positive Airway Pressure is Associated With Decreased Incidence of Atrial Fibrillation After Cardiac Surgery.

OBJECTIVE: Based on clinical studies in the nonsurgical population that positive airway pressure (PAP) therapy for patients with obstructive sleep apnea (OSA) provides benefits for those with atrial fibrillation, the authors tested the hypothesis that PAP in patients with OSA reduces the incidence of postoperative atrial fibrillation (POAF) after cardiac surgery. DESIGN: Retrospective analysis. SETTING: Single-center university hospital. PARTICIPANTS: The study comprised 192 patients in sinus rhythm preoperatively who were undergoing nontransplantation or ventricular assist device implantation cardiac surgery requiring cardiopulmonary bypass but not requiring systemic circulatory arrest, with documented PAP adherence from January 2008 to October 2015. INTERVENTIONS: Retrospective review of medical records. MEASUREMENTS AND MAIN RESULTS: POAF was defined as atrial fibrillation requiring therapeutic intervention. Of the 192 patients with OSA, 104 (54%) were documented to be PAP-adherent and 88 (46%) were reported to be PAP-nonadherent. Among PAP users, 49 (47%) developed POAF; among PAP nonusers, 59 (66%) developed POAF. The adjusted hazard ratio was 0.59 (95% confidence interval 0.40-0.86, p<0.01). No differences were observed in intensive care unit length of stay (4.0±3.4 days for PAP-adherent group v 5.0±6.2 days for PAP-nonadherent group; p = 0.22) or hospital length of stay (10.7±6.6 days for PAP-adherent group v 10.9±7.3 days for PAP nonadherent group; p = 0.56). A lower median postoperative creatinine rise was observed in PAP-adherent patients (18.2% [8.3%-37.5%) v 31.3% [13.3%-50%]; p< 0.01). CONCLUSION: Preoperative PAP use in patients with OSA was associated with a decreased rate of POAF after cardiac surgery.

Obstructive Sleep Apnea Is an Independent Predictor of Postoperative Atrial Fibrillation in Cardiac Surgery.

OBJECTIVE: To test the hypothesis that obstructive sleep apnea (OSA) is a risk factor for development of postoperative atrial fibrillation (POAF) after cardiac surgery. DESIGN: Retrospective analysis. SETTING: Single-center university hospital. PARTICIPANTS: Five hundred forty-five patients in sinus rhythm preoperatively undergoing coronary artery bypass grafting (CABG), aortic valve replacement, mitral valve replacement/repair, or combined valve/CABG surgery from January 2008 to April 2011. INTERVENTIONS: Retrospective review of medical records. MEASUREMENTS AND MAIN RESULTS: Postoperative atrial fibrillation was defined as atrial fibrillation requiring therapeutic intervention. Of 545 cardiac surgical patients, 226 (41%) patients developed POAF. The risk was higher in 72 OSA patients than 473 patients without OSA (67% v 38%, adjusted hazard ratio 1.83 [95% CI: 1.30-2.58], p<0.001). Of the 32 OSA patients who used home positive airway pressure (PAP) therapy, 18 (56%) developed POAF compared with 29 of 38 (76%) patients who did not use PAP at home (unadjusted hazard ratio 0.63 [95% CI: 0.35-1.15], p = 0.13). CONCLUSION: OSA is significantly associated with POAF in cardiac surgery patients. Further investigation is needed to determine whether or not use of positive airway pressure in OSA patients reduces the risk of POAF.

Factors contributing to adverse perioperative events in adults with congenital heart disease: a structured analysis of cases from the closed claims project.

OBJECTIVE: Prior investigations have suggested that the rapidly growing population of adults with congenital heart disease is at increased risk of perioperative morbidity and mortality, but information is limited on the nature of those perioperative factors that may relate to adverse outcomes. We sought to use a national claims database to describe the contribution of perioperative factors to adverse outcomes and compare contributing factors in cardiac vs. noncardiac operations. DESIGN: The study is a retrospective in-depth structured analysis of cases from the Anesthesia Closed Claims Project database. SETTING: We examined the largest national anesthesia malpractice claims database. PATIENTS: We included all claims cases involving adult patients with congenital heart disease (CHD). INTERVENTIONS: Patients in this retrospective analysis were classified by type of surgery (cardiac or noncardiac). OUTCOME MEASURES: Perioperative factors contributing to an adverse event were assessed by an expert panel of cardiac anesthesiologists. RESULTS: Of 21 confirmed cases, 11 (52%) involved cardiac procedures and 10 (48%) noncardiac procedures. The most common factors contributing to the adverse event in cardiac cases were surgical technique (73% of cases) and intraoperative anesthetic care (55%), whereas in noncardiac cases, postoperative monitoring/care (50%), CHD (50%) and preoperative assessment or optimization (40%) were most common. The factors contributing to the patient injury differed similarly: in cardiac cases, the most common factors were intraoperative anesthetic care (55%) and surgical technique (45%) compared with postoperative monitoring/care (50%) and CHD (50%) in noncardiac cases. CONCLUSIONS: Within the limitations of a small number of events in a claims-based database, this study offers advantages of being a national, structured analysis of real cases to provide detailed information on phenomena that are otherwise abstract and hypothesized by expert opinion. These results should help affirm the role of anesthesiologists in acquiring and executing expertise as consultants in perioperative medicine for adults with congenital heart disease patients.

P-wave characteristics on routine preoperative electrocardiogram improve prediction of new-onset postoperative atrial fibrillation in cardiac surgery.

OBJECTIVE: To test the hypothesis that including preoperative electrocardiogram (ECG) characteristics with clinical variables significantly improves the new-onset postoperative atrial fibrillation prediction model. DESIGN: Retrospective analysis. SETTING: Single-center university hospital. PARTICIPANTS: Five hundred twenty-six patients, ≥ 18 years of age, who underwent coronary artery bypass grafting, aortic valve replacement, mitral valve replacement/repair, or a combination of valve surgery and coronary artery bypass grafting requiring cardiopulmonary bypass. INTERVENTIONS: Retrospective review of medical records. MEASUREMENTS AND MAIN RESULTS: Baseline characteristics and cardiopulmonary bypass times were collected. Digitally-measured timing and voltages from preoperative electrocardiograms were extracted. Postoperative atrial fibrillation was defined as atrial fibrillation requiring therapeutic intervention. Two hundred eight (39.5%) patients developed postoperative atrial fibrillation. Clinical predictors were age, ejection fraction<55%, history of atrial fibrillation, history of cerebral vascular event, and valvular surgery. Three ECG parameters associated with postoperative atrial fibrillation were observed: Premature atrial contraction, p-wave index, and p-frontal axis. Adding electrocardiogram variables to the prediction model with only clinical predictors significantly improved the area under the receiver operating characteristic curve, from 0.71 to 0.78 (p<0.01). Overall net reclassification improvement was 0.059 (p = 0.09). Among those who developed postoperative atrial fibrillation, the net reclassification improvement was 0.063 (p = 0.03). CONCLUSION: Several p-wave characteristics are independently associated with postoperative atrial fibrillation. Addition of these parameters improves the postoperative atrial fibrillation prediction model.

Decentralization of care for adults with congenital heart disease in the United States: a geographic analysis of outpatient surgery.

BACKGROUND: Guidelines recommend that adults with congenital heart disease (CHD) undergo noncardiac surgery in regionalized centers of expertise, but no studies have assessed whether this occurs in the United States. We hypothesized that adults with CHD are less likely than children to receive care at specialized CHD centers. METHODS: Using a comprehensive state ambulatory surgical registry (California Ambulatory Surgery Database, 2005-2011), we calculated the proportion of adult and pediatric patients with CHD who had surgery at a CHD center, distance to the nearest CHD center, and distance to the facility where surgery was performed. RESULTS: Patients with CHD accounted for a larger proportion of the pediatric population (n = 11,254, 1.0%) than the adult population (n = 10,547, 0.07%). Only 2,741 (26.0%) adults with CHD had surgery in a CHD center compared to 6,403 (56.9%) children (p<0.0001). Adult CHD patients who had surgery at a non-specialty center (11.9 ± 15.4 miles away) lived farther from the nearest CHD center (37.9 ± 43.0 miles) than adult CHD patients who had surgery at a CHD center (23.2 ± 28.4 miles; p<0.0001). Pediatric CHD patients who had surgery at a non-specialty center (18.0 ± 20.7 miles away) lived farther from the nearest CHD center (35.7 ± 45.2 miles) than pediatric CHD patients who had surgery at a CHD center (22.4 ± 26.0 miles; p<0.0001). CONCLUSIONS: Unlike children with CHD, most adults with CHD (74%) do not have outpatient surgery at a CHD center. For both adults and children with CHD, greater distance from a CHD center is associated with having surgery at a non-specialty center. These results have significant public health implications in that they suggest a failing to achieve adequate regional access to specialized ACHD care. Further studies will be required to evaluate potential strategies to more reliably direct this vulnerable population to centers of expertise.

Perioperative morbidity and mortality after noncardiac surgery in young adults with congenital or early acquired heart disease: a retrospective cohort analysis of the National Surgical Quality Improvement Program database.

An increasing number of patients with congenital heart disease survive to adulthood. Expert opinion suggests that noncardiac surgery is a high-risk event, but few data describe perioperative outcomes in this population. Using the National Surgical Quality Improvement Program database, we identified a cohort of patients aged 18 to 39 years with prior heart surgery who underwent noncardiac surgery between 2005 and 2010. A comparison cohort with no prior cardiovascular surgery was matched on age, sex, race/ethnicity, operation year, American Society of Anesthesiologists physical status, and Current Procedural Terminology code. A study cohort consisting of 1191 patients was compared with a cohort of 5127 patients. Baseline dyspnea, inpatient status at the time of surgery, and a prior operation within 30 days were more common in the study cohort. Postoperative outcomes were less favorable in the study cohort. Observed rates of death, perioperative cardiac arrest, myocardial infarction, stroke, respiratory complications, renal failure, sepsis, venous thromboembolism, perioperative transfusion, and reoperation were significantly higher in the study cohort (P < 0.01 for all). Mean postoperative length of stay was greater in the study cohort (5.8 vs 3.6 days, P < 0.01). Compared with a matched control cohort, young adult patients with a history of prior cardiac surgery experienced significantly greater perioperative morbidity and mortality after noncardiac surgery. A history of prior cardiac surgery represents a marker of substantial perioperative risk in this young population that is not accounted for by the matched variables. These results suggest that adult patients with congenital heart disease are at risk for adverse outcomes and support the need for further registry-based investigations.

Temporal changes in survival after cardiac surgery are associated with the thirty-day mortality benchmark.

OBJECTIVE: To assess the hypothesis that postoperative survival exhibits heterogeneity associated with the timing of quality metrics. DATA SOURCES: Retrospective observational study using the Nationwide Inpatient Sample from 2005 through 2009. STUDY DESIGN: Survival analysis was performed on all admission records with a procedure code for major cardiac surgery (n = 595,089). The day-by-day hazard function for all-cause in-hospital mortality at 1-day intervals was analyzed using joinpoint regression (a data-driven method of testing for changes in hazard). DATA EXTRACTION METHODS: A comprehensive analysis of a publicly available national administrative database was performed. PRINCIPAL FINDINGS: Statistically significant shifts in the pattern of postoperative mortality occurred at day 6 (95 percent CI = day 5-8) and day 30 (95 percent CI = day 20-35). CONCLUSIONS: While the shift at day 6 plausibly can be attributed to the separation between routine recovery and a complicated postoperative course, the abrupt increase in mortality at day 30 has no clear organic etiology. This analysis raises the possibility that this observed shift may be related to clinician behavior because of the use of 30-day mortality as a quality metric, but further studies will be required to establish causality.

Perioperative morbidity and mortality of cardiothoracic surgery in patients with a do-not-resuscitate order.

Background. Do-not-resuscitate (DNR) orders are often active in patients with multiple comorbidities and a short natural life expectancy, but limited information exists as to how often these patients undergo high-risk operations and of the perioperative outcomes in this population. Methods. Using comprehensive inpatient administrative data from the Public Discharge Data file (years 2005 through 2010) of the California Office of Statewide Health Planning and Development, which includes a dedicated variable recording DNR status, we identified cohorts of DNR patients who underwent major cardiac or thoracic operations and compared themto age- and procedure-matched comparison cohorts. The primary study outcome was in-hospital mortality. Results. DNR status was not uncommon in cardiac (n = 2,678, 1.1% of all admissions for cardiac surgery, age 71.6 ± 15.9 years) and thoracic (n = 3,129, 3.7% of all admissions for thoracic surgery, age 73.8 ± 13.6 years) surgical patient populations. Relative to controls, patients who were DNR experienced significantly greater inhospital mortality after cardiac (37.5% vs. 11.2%, p < 0.0001 and thoracic (25.4% vs. 6.4%) operations. DNR status remained an independent predictor of in-hospital mortality onmultivariate analysis after adjustment for baseline and comorbid conditions in both the cardiac (OR 4.78, 95% confidence interval 4.21-5.41, p < 0.0001) and thoracic (OR 6.11, 95% confidence interval 5.37-6.94, p < 0.0001) cohorts. Conclusions. DNR status is associated with worse outcomes of cardiothoracic surgery even when controlling for age, race, insurance status, and serious comorbid disease. DNR status appears to be a marker of substantial perioperative risk, and may warrant substantial consideration when framing discussions of surgical risk and benefit, resource utilization, and biomedical ethics surrounding end-of-life care.

Heart transplantation with or without prior mechanical circulatory support in adults with congenital heart disease.

OBJECTIVES: Recent analyses establish that heart transplantation is increasing among adults with congenital heart disease (ACHD), but the effects of pretransplant mechanical circulatory support (MCS) on perioperative and post-transplant outcomes have not been examined in the ACHD population. METHODS: Scientific Registry of Transplant Recipients data on all adult heart transplants from September 1987 to September 2012 (n = 47 160) were classified based on primary diagnosis codes as CHD or non-CHD and MCS or non-MCS. Demographic, procedural, outcome and survival variables were compared between MCS and non-MCS ACHD patient groups. RESULTS: MCS was used in 83 (6.8%) ACHD patients compared with 8625 (18.8%) patients without CHD (P < 0.001). MCS as a fraction of ACHD transplants increased over time (P = 0.002). MCS patients spent more time on the wait list, had a higher baseline serum creatinine and were more likely to be male, status 1A, hospitalized, in the ICU and/or on a ventilator prior to transplant. However, MCS patients experienced equivalent short-term survival (30-day mortality = 10.8% in MCS vs 13.5% in non-MCS, P = 0.62) and overall survival by Kaplan-Meier analysis (P = 0.57). MCS patients had a longer post-transplant length of stay and were more likely to be transfused, but otherwise had no significant differences in adverse outcomes. CONCLUSIONS: MCS is less commonly used in adult CHD patients compared with all patients undergoing heart transplant, but has been increasing over time. Within the ACHD population, patients with MCS have a higher risk profile, but except for increased transfusion rate and longer length of stay, do not experience less favourable post-transplant outcomes.

Resource use trends in extracorporeal membrane oxygenation in adults: an analysis of the Nationwide Inpatient Sample 1998-2009.

OBJECTIVE: The study objective was to determine whether significant trends over time have occurred in resource use associated with the use of extracorporeal membrane oxygenation in critically ill adults. METHODS: All adult admissions involving extracorporeal membrane oxygenation were examined by using the Nationwide Inpatient Sample database (years 1998-2009). Trends in volume, outcome, and resource use (including hospital charges, length of stay, and charges per day) were analyzed. RESULTS: An estimated total of 8753 admissions involved extracorporeal membrane oxygenation over the study period. Overall length of stay was 18.3 ± 1.3 days. Total hospital charges averaged $344,009 ± $30,707 per admission, with average charges per day of $40,588 ± $3099. Cumulative national charges for extracorporeal membrane oxygenation admissions increased significantly from $109.0 million in 1998 to $764.7 million in 2009 (P = .0016). Charges per patient and length of stay also increased significantly (P = .0032 and .0321, respectively). The increasing trend in the number of extracorporeal membrane oxygenation admissions during the study period was not statistically significant (P = .19). The post-cardiotomy group had more favorable outcomes and lower resource use. A shift was observed in the relative case-mix of extracorporeal membrane oxygenation admissions over the study period, with a relative decrease in the post-cardiotomy group and increases in the cardiogenic shock, respiratory failure, and lung transplant groups. CONCLUSIONS: These results suggest that dramatic increases in resource use associated with extracorporeal membrane oxygenation are not solely the result of increased volume, but in part are due to a shift toward extracorporeal membrane oxygenation use in patient groups (other than in the post-cardiotomy setting) with greater resource use and worse outcomes.

Perioperative outcomes of major noncardiac surgery in adults with congenital heart disease.

BACKGROUND: An increasing number of patients with congenital heart disease are surviving to adulthood. Consensus guidelines and expert opinion suggest that noncardiac surgery is a high-risk event, but few data describe perioperative outcomes in this population. METHODS: By using the Nationwide Inpatient Sample database (years 2002 through 2009), the authors compared patients with adult congenital heart disease (ACHD) who underwent noncardiac surgery with a non-ACHD comparison cohort matched on age, sex, race, year, elective or urgent or emergency procedure, van Walraven comborbidity score, and primary procedure code. Mortality and morbidity were compared between the two cohorts. RESULTS: A study cohort consisting of 10,004 ACHD patients was compared with a matched comparison cohort of 37,581 patients. Inpatient mortality was greater in the ACHD cohort (407 of 10,004 [4.1%] vs. 1,355 of 37,581 [3.6%]; unadjusted odds ratio, 1.13; P = 0.031; adjusted odds ratio, 1.29; P < 0.001). The composite endpoint of perioperative morbidity was also more commonly observed in the ACHD cohort (2,145 of 10.004 [21.4%] vs. 6,003 of 37,581 [16.0%]; odds ratio, 1.44; P < 0.001). ACHD patients comprised an increasing proportion of all noncardiac surgical admissions over the study period (P value for trend is <0.001), and noncardiac surgery represented an increasing proportion of all ACHD admissions (P value for trend is <0.001). CONCLUSIONS: Compared with a matched control cohort, ACHD patients undergoing noncardiac surgery experienced increased perioperative morbidity and mortality. Within the limitations of a retrospective analysis of a large administrative dataset, this finding demonstrates that this is a vulnerable population and suggests that better efforts are needed to understand and improve the perioperative care they receive.

Case report: a thrombus in the venous reservoir while using bivalirudin in a patient with heparin-induced thrombocytopenia undergoing heart transplantation.

Direct thrombin inhibitors are heparin alternatives for anticoagulation during cardiopulmonary bypass in patients with heparin-induced thrombocytopenia. We report a case of a large thrombus forming in the venous reservoir while using bivalirudin. We suggest that blood stasis associated with the full venous reservoir maintained in this case led to formation of a large thrombus at the top of the venous canister. Furthermore, activated clotting times may not accurately reflect the magnitude of anticoagulation when using direct thrombin inhibitors.