Ambulatory Cardiology or General Internal Medicine Assessment Prior to Scheduled Major Vascular Surgery is Associated with Improved Outcomes.

OBJECTIVE: To characterize the association between ambulatory cardiology or general internal medicine (GIM) assessment prior to surgery and outcomes following scheduled major vascular surgery. BACKGROUND: Cardiovascular risk assessment and management prior to high-risk surgery remains an evolving area of care. METHODS: This is population-based retrospective cohort study of all adults who underwent scheduled major vascular surgery in Ontario, Canada, April 1, 2004-March 31, 2019. Patients who had an ambulatory cardiology and/or GIM assessment within 6 months prior to surgery were compared to those who did not. The primary outcome was 30-day mortality. Secondary outcomes included: composite of 30-day mortality, myocardial infarction or stroke; 30-day cardiovascular death; 1-year mortality; composite of 1-year mortality, myocardial infarction or stroke; and 1-year cardiovascular death. Cox proportional hazard regression using inverse probability of treatment weighting (IPTW) was used to mitigate confounding by indication. RESULTS: Among 50,228 patients, 20,484 (40.8%) underwent an ambulatory assessment prior to surgery: 11,074 (54.1%) with cardiology, 8,071 (39.4%) with GIM and 1,339 (6.5%) with both. Compared to patients who did not, those who underwent an assessment had a higher Revised Cardiac Risk Index (N with Index over 2= 4,989[24.4%] vs. 4,587[15.4%], P<0.001) and more frequent pre-operative cardiac testing (N=7,772[37.9%] vs. 6,113[20.6%], P<0.001) but, lower 30-day mortality (N=551[2.7%] vs. 970[3.3%], P<0.001). After application of IPTW, cardiology or GIM assessment prior to surgery remained associated with a lower 30-day mortality (weighted Hazard Ratio [95%CI] = 0.73 [0.65-0.82]) and a lower rate of all secondary outcomes. CONCLUSIONS: Major vascular surgery patients assessed by a cardiology or GIM physician prior to surgery have better outcomes than those who are not. Further research is needed to better understand potential mechanisms of benefit.

Validating emergency department cardioversion procedures in provincial administrative data in Ontario, Canada.

BACKGROUND: Cardioversion of acute-onset atrial fibrillation (AF) via electrical or pharmacological means is a common procedure performed in many emergency departments. While these procedures appear to be very safe, the rarity of subsequent adverse outcomes such as stroke would require huge sample sizes to confirm that conclusion. Big data can supply such sample sizes. OBJECTIVE: We aimed to validate several potential codes for successful emergency department cardioversion of AF patients. METHODS: This study combined 3 observational datasets of emergency department AF visits seen at one of 26 hospitals in Ontario, Canada, between 2008 and 2012. We linked patients who were eligible for emergency department cardioversion to several province-wide health administrative datasets to search for the associated cardioversion billing and procedural codes. Using the observational data as the gold standard for successful cardioversion, we calculated the test characteristics of a billing code (Z437) and of procedural codes 1.HZ.09JAFS and 1.HZ.09JAJS. Both include pharmacological and electrical cardioversions, as well as unsuccessful attempts; the latter is <10% using electricity (in Canada, standard practice is to proceed to electrical cardioversion if pharmacological cardioversion is unsuccessful). RESULTS: Of 4557 unique patients in the three datasets, 2055 (45.1%) were eligible for cardioversion. Nine hundred thirty-three (45.4%) of these were successfully cardioverted to normal sinus rhythm. The billing code had slightly better test characteristics overall than the procedural codes. Positive predictive value (PPV) of a billing was 89.8% (95% CI, 87.0-92.2), negative predictive value (NPV) 70.5% (95% CI, 68.1-72.8), sensitivity 52.1% (95% CI, 48.8-55.3), and specificity 95.1% (95% CI, 93.7-96.3). CONCLUSIONS: AF patients who have been successfully cardioverted in an emergency department can be identified with high PPV and specificity using a billing code. Studies that require high sensitivity for cardioversion should consider other methods to identify cardioverted patients.

A clinical decision instrument to predict 30-day death and cardiovascular hospitalizations after an emergency department visit for atrial fibrillation: The Atrial Fibrillation in the Emergency Room, Part 2 (AFTER2) study.

BACKGROUND: In previous work, we derived and validated a tool that predicts 30-day mortality in emergency department atrial fibrillation (AF) patients. The objective of this study was to derive and validate a tool that predicts a composite of 30-day mortality and return cardiovascular hospitalizations. METHODS: This retrospective cohort study at 24 emergency departments in Ontario, Canada, included patients with a primary diagnosis of AF who were seen between April 2008 and March 2009. We assessed a composite outcome of 30-day mortality and subsequent hospitalizations for a cardiovascular reason, including stroke. RESULTS: Of 3,510 patients, 2,343 were randomly selected for the derivation cohort, leaving 1,167 in the validation cohort. The composite outcome occurred in 227 (9.7%) and 125 (10.7%) patients in the derivation and validation cohorts, respectively. Eleven variables were independently associated with the outcome: older age, not taking anticoagulation, HAS-BLED score of ≥3, 3 laboratory results (positive troponin, supratherapeutic international normalized ratio, and elevated creatinine), emergency department administration of furosemide, and 4 patient comorbidities (heart failure, chronic obstructive lung disease, cancer, dementia). In the validation cohort, the observed 30-day outcomes in the 5 risk strata that were defined using the derivation cohort were 2.0%, 6.6%, 10.7%, 12.5%, and 20.0%. The c statistic was 0.73 and 0.69 in the derivation and validation cohort, respectively. CONCLUSIONS: Using a population-based sample, we derived and validated a tool that predicts the risk of early death and rehospitalization for a cardiovascular reason in emergency department AF patients. The tool can offer information to managing physicians about the risk of death and rehospitalization for AF patients seen in the in emergency department, as well as identify patient groups for future targeted interventions aimed at preventing these outcomes.

A Clinical Decision Instrument for 30-Day Death After an Emergency Department Visit for Atrial Fibrillation: The Atrial Fibrillation in the Emergency Room (AFTER) Study.

STUDY OBJECTIVE: The high volume of patients treated in an emergency department (ED) for atrial fibrillation is predicted to increase significantly in the next few decades. Currently, 11% of these patients die within a year. We sought to derive and validate a complex model and a simplified model that predicts mortality in ED patients with atrial fibrillation. METHODS: This population-based, retrospective cohort study included 3,510 adult patients with a primary diagnosis of atrial fibrillation who were treated at 24 hospital EDs in Ontario, Canada, between April 2008 and March 2009. The main outcome was 30-day all-cause mortality. RESULTS: In the derivation cohort (n=2,343; mean age 68.8 years), 2.6% of patients died within 30 days of the ED visit versus 2.7% in the validation cohort (n=1,167; mean age 68.3 years). Variables associated with mortality in the complex model included age, presenting pulse rate and systolic blood pressure, presence of chest pain, 2 laboratory results (positive troponin result and creatinine level greater than 200 µmol [2.26 mg/dL]), 4 comorbidities (smoking, chronic obstructive pulmonary disease, cancer, and dementia), an increased bleeding risk, and a second acute ED diagnosis (in addition to atrial fibrillation). Observed 30-day mortality in the 5 risk strata that were defined by the predicted probability of death were 0.44%, 0.41%, 0.23%, 1.61%, and 10.3%. The c statistics were 0.88 and 0.87 in the derivation and validation cohorts, respectively. The a priori-selected 6-variable model, TrOPs-BAC, included a positive Troponin result, Other acute ED diagnosis, Pulmonary disease (chronic obstructive pulmonary disease), Bleeding risk, Aged 75 years or older, and Congestive heart failure. The c statistic for the simplified model was 0.81 in both the derivation and validation cohorts. CONCLUSION: Using a population-based sample, we derived and validated both a complex and a simplified instrument that predicts mortality after an emergency visit for atrial fibrillation. These may aid clinicians in identifying high-risk patients for hospitalization while safely discharging more patients home.

The Long-Term Use of Warfarin Among Atrial Fibrillation Patients Discharged From an Emergency Department With a Warfarin Prescription.

STUDY OBJECTIVE: The optimal timing to begin stroke prevention therapy in patients being discharged from an emergency department (ED) with atrial fibrillation is not known. We determined whether eligible patients who were provided with an ED prescription for oral anticoagulation had better rates of long-term anticoagulation use than eligible patients who were referred to their primary care provider for further care. METHODS: As part of a historical cohort study, in this planned substudy we abstracted data from patient charts with a primary diagnosis of atrial fibrillation from 24 EDs between April 1, 2008, and March 31, 2009. In the current study, discharged patients aged 65 years and older who had a CHADS2 score greater than or equal to 2 and a HAS-BLED score less than 3, with no history of falls and who were not receiving oral anticoagulation when they presented to the ED, were included. We compared the frequency of warfarin use at 6 months and 1 year after ED discharge for patients who were given a prescription for warfarin before they left the ED to those who were not. RESULTS: Among 137 qualifying patients, 33 (24.1%) were provided with a warfarin prescription before discharge from the ED. At 6 months, 25 of the 33 were still receiving warfarin, compared with 34 of 104 among the patients who were not given an ED prescription (absolute difference, 43.1%; 95% confidence interval [CI] 23.8 to 57.2). At 1 year, 75.8% versus 35.6% (absolute difference, 40.2%; 95% CI 20.9 to 54.4) were receiving warfarin, respectively. Among the patients who filled a prescription for warfarin, the mean number of days from ED discharge until a warfarin prescription was filled was 6.0 (SD 21.3) for patients who were provided with an ED prescription compared with 205 (SD 377) for those who were not. CONCLUSION: Among ED patients who met criteria for guideline-recommended use of stroke prevention therapy, those who received an initial prescription in the ED had a higher frequency of long-term warfarin use than those for whom the decision to initiate therapy was referred to another care provider.

A population-based description of atrial fibrillation in the emergency department, 2002 to 2010.

STUDY OBJECTIVE: We aimed to describe the demographics, care, and outcomes of patients with atrial fibrillation in the emergency department (ED), as well as temporal changes over time. METHODS: In this retrospective cohort study, we used a province-wide database to identify all adult patients who were treated in a nonpediatric ED in the province of Ontario with a primary diagnosis of atrial fibrillation, April 2002 to March 2010. We determined the frequency and rate of ED visits and assessed patient demographics, ED care, and outcomes, both overall and by year. RESULTS: During the 8-year study period, 113,786 patients made 143,003 ED visits for atrial fibrillation, accounting for 0.5% of all ED visits. The annual number of ED visits increased from 15,931 to 20,168 (29.4%; 95% confidence interval [CI] 28.7% to 30.1%) between 2002 and 2010, whereas the crude rate increased from 172 per 100,000 to 195 per 100,000 persons. Median age was 72.0 years (Interquartile range 61.0 to 80.0 years) and 50.8% were women, which did not change significantly during the study period. The percentage of index ED visits with a physician billing for cardioversion increased from 6.3% (95% CI 5.9% to 6.7%) to 11.8% (95% CI 11.3% to 12.3%). Although the percentage of patients with a CHADS2 score greater than or equal to 2 increased from 49.3% (95% CI 48.4% to 50.2%) to 53.6% (95% CI 52.9% to 54.4%) and high-acuity ED triage scores increased from 41.1% (95% CI 40.2% to 42.0%) to 62.5% (95% CI 61.7% to 63.2%), hospital admissions decreased from 48.1% (95% CI 47.3% to 49.0%) to 38.4% (95% CI 37.6% to 39.2%). Thirty-day mortality was 3.3% (95% CI 3.2% to 3.4%) and showed a slight downward trend during the study period (P=.05), whereas subsequent hospitalizations within 30 days for atrial fibrillation or stroke (2.8%; 95% CI 2.7% to 2.9%) and repeated ED visits (7.3%; 95% CI 7.1% to 7.4%) remained unchanged. CONCLUSION: The number of ED visits for atrial fibrillation increased markedly during an 8-year period. Although it appears that slightly higher-risk patients are being treated in the province's EDs, fewer patients are being admitted to the hospital, and mortality rates have not increased.

Evaluating early repeat emergency department use in patients with atrial fibrillation: a population-based analysis.

BACKGROUND: Emergency department (ED) use by patients with atrial fibrillation is high and will accelerate with the aging of the population. In patients with atrial fibrillation who are discharged from the ED, we aimed to describe their subsequent outpatient care, return ED visits, and management strategies associated with early return. METHODS: We conducted a retrospective cohort analysis of patients 65 years or older with a primary ED diagnosis of atrial fibrillation who were discharged home from an ED in the province of Ontario, Canada, between April 2007 and March 2010. We describe subsequent outpatient care and repeat ED visits within 14 days of the index visit. We assessed factors associated with a repeat visit, overall, as well as by repeat visit outcome (discharged or admitted). RESULTS: Among 12,772 index ED visits, the mean (SD) age was 77 (7.4) years, and 14-day mortality was 0.7% (95% CI 0.5%-0.8%). Within 14 days, 67.8% had no follow-up care, 19.4% saw solely a family physician, and 12.8% saw a specialist (internist or cardiologist). There were 1,310 (10.3%) repeat ED visits made by 1,146 (9.0%) patients. Management strategies associated with a lower hazard of a repeat visit included follow-up care with a specialist (hazard ratio 0.61; P = .003) and a digoxin prescription (vs a ß-blocker; hazard ratio 0.69, P = .001). CONCLUSIONS: Among older patients with atrial fibrillation discharged from an ED in the province of Ontario, 9% make 1 or more repeat visits within 14 days. Reductions in repeat emergency visits by low-risk patients are associated with timely specialist follow-up care.

Factors associated with 90-day death after emergency department discharge for atrial fibrillation.

STUDY OBJECTIVE: More than 10% of patients treated in the emergency department (ED) for atrial fibrillation die within a year of the visit. We sought to describe the post-ED care of an older population of atrial fibrillation patients who were discharged home from the ED and to assess patient characteristics and processes of care associated with risk of death within 90 days of discharge. METHODS: This retrospective cohort analysis included patients aged 65 years or older with a primary ED diagnosis of atrial fibrillation who were treated at all nonpediatric EDs in the province of Ontario, Canada, between April 2007 and March 2010. Only the index emergency visit for each patient was included, and patients admitted to the hospital were excluded. We evaluated the association of postdischarge outpatient care and medications, ED cardioversion, and site volumes of atrial fibrillation patients with adjusted hazard of 90-day death. RESULTS: Among 12,772 qualifying index ED visits, there were 417 (3.3%; 95% confidence interval [CI] 3.0% to 3.6%) deaths within 90 days of the visit. Patients with no follow-up care had a significantly increased hazard of death (hazard ratio [HR] 2.27; 95% CI 1.50 to 3.43) relative to those who consulted a family physician, as did patients prescribed a calcium-channel blocker (HR 1.55; 95% CI 1.15 to 2.09) relative to a ß-blocker. A filled warfarin prescription was associated with a lower hazard of death (HR 0.70; 95% CI 0.51 to 0.95). Higher site volumes (HR 0.66; 95% CI 0.41 to 1.08), cardioversion (HR 0.69; 95% CI 0.42 to 1.15), and follow-up care by a specialist only (HR 0.75; 95% CI 0.51 to 1.12) were not associated with 90-day mortality. CONCLUSION: Among older atrial fibrillation patients discharged from the ED in the province of Ontario, lack of follow-up care had the strongest association with subsequent mortality. If validated, these results suggest that as proportionately more of these patients are discharged from EDs in future, the focus should go beyond ED care itself to the care subsequent to the emergency visit.