Trajectories of P2Y12 inhibitor adherence in patients with acute coronary syndromes.

PURPOSE: P2Y12 inhibitors (P2Y12i) reduce cardiac events after acute coronary syndromes (ACS). However, suboptimal P2Y12i adherence persists. We aimed to examine P2Y12i non-adherence using group-based trajectory methods and to identify adherence predictors. METHODS: We conducted a population-based, retrospective cohort study using administrative data in Ontario, Canada of patients ≥65 years admitted for ACS between April 2014 and March 2018 with a P2Y12i dispensed within 7 days of discharge. We used group-based trajectory models to characterize longitudinal 1-year adherence patterns. Predictors associated with each adherence trajectory were identified by multinomial logistic regression. RESULTS: We included 11 917 patients using clopidogrel and 9763 using ticagrelor, aged [mean ± SD]: 77.33 ± 8.31/73.59 ± 6.79 years; men: 56.2%/65.4%, respectively. We identified 3 longitudinal adherence trajectories, that differed by agent: 75% of clopidogrel and 68% of ticagrelor patients showed a consistently adherent trajectory, while 13%/17% were gradually, and 12%/15% were rapidly non-adherent, respectively (p < 0.001). Differing baseline characteristics in each cohort were associated with observed adherence trajectories. Concomitant atrial fibrillation and prior bleeding history were associated with non-adherence among clopidogrel users. Among ticagrelor users, women and older persons were more likely to be rapidly non-adherent, adherence declining steeply starting 1 month post-ACS. CONCLUSIONS: We identified distinct adherence trajectories for clopidogrel and ticagrelor post-ACS, with 3 out of 4 clopidogrel patients but only 2 out of 3 ticagrelor patients in the consistently adherent trajectory. Intensive interventions targeted to the period of steep adherence decline post-ACS, particularly for women and older persons initiating ticagrelor, and patients with atrial fibrillation on clopidogrel should be considered and investigated further.

The Association of Sodium-Glucose Cotransporter 2 Inhibitors With Cardiovascular Outcomes in Anthracycline-Treated Patients With Cancer.

Background: Sodium glucose cotransporter-2 inhibitors (SGLT2is) are hypothesized to reduce the risk of anthracycline-associated cardiotoxicity. Objectives: This study sought to determine the association between SGLT2is and cardiovascular disease (CVD) after anthracycline-containing chemotherapy. Methods: Using administrative data sets, we conducted a population-based cohort study of people >65 years of age with treated diabetes and no prior heart failure (HF) who received anthracyclines between January 1, 2016, and December 31, 2019. After estimating propensity scores for SGLT2i use, the average treatment effects for the treated weights were used to reduce baseline differences between SGLT2i-exposed and -unexposed controls. The outcomes were hospitalization for HF, incident HF diagnoses (in- or out-of-hospital), and documentation of any CVD in future hospitalizations. Death was treated as a competing risk. Cause-specific HRs for each outcome were determined for SGLT2i-treated people relative to unexposed controls. Results: We studied 933 patients (median age 71.0 years, 62.2% female), 99 of whom were SGLT2i treated. During a median follow-up of 1.6 years, there were 31 hospitalizations for HF (0 in the SGLT2i group), 93 new HF diagnoses, and 74 hospitalizations with documented CVD. Relative to controls, SGLT2i exposure was associated with HR of 0 for HF hospitalization (P < 0.001) but no significant difference in incident HF diagnosis (HR: 0.55; 95% CI: 0.23-1.31; P = 0.18) or CVD diagnosis (HR: 0.39; 95% CI: 0.12-1.28; P = 0.12). There was no significant difference in mortality (HR: 0.63; 95% CI: 0.36-1.11; P = 0.11). Conclusions: SGLT2is may reduce the rate of HF hospitalization after anthracycline-containing chemotherapy. This hypothesis warrants further testing in randomized controlled trials.

Real-World Examination of Revascularization Strategies for Left Main Coronary Disease in Ontario, Canada.

BACKGROUND: Randomized trials have compared percutaneous coronary intervention and coronary artery bypass grafting (CABG) in patients with left main coronary artery disease undergoing nonemergent revascularization. However, there is a paucity of real-world contemporary observational studies comparing percutaneous coronary intervention (PCI) and CABG. OBJECTIVES: The purpose of this study was to compare the long-term clinical outcomes of CABG versus PCI in patients with left main coronary disease. METHODS: Clinical and administrative databases for Ontario, Canada, were linked to obtain records of all patients with angiographic evidence of left main coronary artery disease (≥50% stenosis) treated with either isolated CABG or PCI from 2008 to 2020. Emergent, cardiogenic shock, and ST-segment elevation myocardial infarction patients were excluded. Baseline characteristics of patients were compared and 1:1 propensity score matching was performed. Late mortality and major adverse cardiac and cerebrovascular events were compared between the matched groups using a Cox proportional hazard model. RESULTS: After exclusions, 1,299 and 21,287 patients underwent PCI and CABG, respectively. Prior to matching, PCI patients were older (age 75.2 vs 68.0 years) and more likely to be women (34.6% vs 20.1%), although they had less CAD burden. Propensity score matching on 25 baseline covariates yielded 1,128 well-matched pairs. There was no difference in early mortality between PCI and CABG (5.5% vs 3.9%; P = 0.075). Over 7-year follow-up, all-cause mortality (53.6% vs 35.2%; HR: 1.63; 95% CI: 1.42-1.87; P < 0.001) and major adverse cardiac and cerebrovascular events (66.8% vs 48.6%; HR: 1.77; 95% CI: 1.57-2.00) were significantly higher with PCI than CABG. CONCLUSIONS: CABG was the most common revascularization strategy in this real-world registry. Patients undergoing PCI were much older and of higher risk at baseline. After matching, there was no difference in early mortality but improved late survival and freedom from major adverse cardiac and cerebrovascular events with CABG.

Multiple arterial coronary bypass grafting is associated with better survival compared with second-generation drug-eluting stents in patients with stable multivessel coronary artery disease.

OBJECTIVE: We sought to compare the long-term outcomes of multiarterial graft (MAG) coronary artery bypass grafting (CABG) versus percutaneous coronary intervention (PCI) with second-generation drug-eluting stents (DES) to treat stable multivessel coronary artery disease. METHODS: This study was a multicenter population-based retrospective analysis of all residents of Ontario, Canada, from January 1, 2011, to December 31, 2019. We identified 3600 cases of elective primary isolated CABG with MAG and 2187 cases of PCI with second-generation DES. RESULTS: After the application of propensity score-weighting using overlap weights, MAG was associated with better survival over 5 years compared with DES (96.8% vs 94.5%; hazard ratio [HR], 0.56; 95% CI, 0.37-0.85). MAG was also associated with better secondary outcomes including a composite of death, myocardial infarction, and stroke (94.3% vs 88.5%; HR, 0.49; 95% CI, 0.36-0.65). The rate of death, stroke, myocardial infarction, and repeat revascularization (91.2% vs 70.7%; HR, 0.24; 95% CI, 0.20-0.30), and the individual end points of myocardial infarction (1.4% vs 6.9%; HR, 0.22; 95% CI, 0.13-0.35), and repeat revascularization (4.1% vs 24.2%; HR, 0.14; 95% CI, 0.10-0.18) were lower with MAG. PCI with second-generation DES was associated with a lower rate of stroke up to 5 years (0.6% vs 1.8%; HR, 3.97; 95% CI, 1.45-10.88). CONCLUSIONS: CABG with MAG was associated with better survival and fewer major cardiac adverse events compared with second-generation DES and might be considered the treatment of choice for patients with stable multivessel coronary artery disease. Further randomized controlled trials are needed to confirm this hypothesis.

Derivation and validation of predictive indices for cardiac readmission after coronary and valvular surgery - A multicenter study.

Objective: To derive and validate models to predict the risk of a cardiac readmission within one year after specific cardiac surgeries using information that is commonly available from hospital electronic medical records. Methods: In this retrospective cohort study, we derived and externally validated clinical models to predict the likelihood of cardiac readmissions within one-year of isolated CABG, AVR, and combined CABG+AVR in Ontario, Canada, using multiple clinical registries and routinely collected administrative databases. For all adult patients who underwent these procedures, multiple Fine and Gray subdistribution hazard models were derived within a competing-risk framework using the cohort from April 2015 to March 2018 and validated in an independent cohort (April 2018 to March 2020). Results: For the model that predicted post-CABG cardiac readmission, the c-statistic was 0.73 in the derivation cohort and 0.70 in the validation cohort at one-year. For the model that predicted post-AVR cardiac readmission, the c-statistic was 0.74 in the derivation and 0.73 in the validation cohort at one-year. For the model that predicted cardiac readmission following CABG+AVR, the c-statistic was 0.70 in the derivation and 0.66 in the validation cohort at one-year. Conclusions: Prediction of one-year cardiac readmission for isolated CABG, AVR, and combined CABG+AVR can be achieved parsimoniously using multidimensional data sources. Model discrimination was better than existing models derived from single and multicenter registries.

Comparison of Multidimensional Frailty Instruments for Estimation of Long-term Patient-Centered Outcomes After Cardiac Surgery.

Importance: Little is known about the performance of available frailty instruments in estimating patient-relevant outcomes after cardiac surgery. Objective: To examine how well the Johns Hopkins Adjusted Clinical Groups (ACG) frailty indicator, the Hospital Frailty Risk Score (HFRS), and the Preoperative Frailty Index (PFI) estimate long-term patient-centered outcomes after cardiac surgery. Design, Setting, and Participants: This retrospective cohort study was conducted in Ontario, Canada, among residents 18 years and older who underwent coronary artery bypass grafting or aortic, mitral or tricuspid valve, or thoracic aorta surgery between October 2008 and March 2017. Long-term care residents, those with discordant surgical encounters, and those receiving dialysis or dependent on a ventilator within 90 days were excluded. Statistical analysis was conducted from July 2021 to January 2022. Main Outcomes and Measures: The primary outcome was patient-defined adverse cardiovascular and noncardiovascular events (PACE), defined as the composite of severe stroke, heart failure, long-term care admission, new-onset dialysis, and ventilator dependence. Secondary outcomes included mortality and individual PACE events. The association between frailty and PACE was examined using cause-specific hazard models with death as a competing risk, and the association between frailty and death was examined using Cox models. Areas under the receiver operating characteristic curve (AUROC) were determined over 10 years of follow-up for each frailty instrument. Results: Of 88 456 patients (22 924 [25.9%] female; mean [SD] age, 66.3 [11.1] years), 14 935 (16.9%) were frail according to ACG criteria, 63 095 (71.3%) according to HFRS, and 76 754 (86.8%) according to PFI. Patients with frailty were more likely to be older, female, and rural residents; to have lower income and multimorbidity; and to undergo urgent surgery. Patients meeting ACG criteria (hazard ratio [HR], 1.66; 95% CI, 1.60-1.71) and those with higher HFRS scores (HR per 1.0-point increment, 1.10; 95% CI, 1.09-1.10) and PFI scores (HR per 0.1-point increment, 1.75; 95% CI, 1.73-1.78) had higher rates of PACE. Similar magnitudes of association were observed for each frailty instrument with death and individual PACE components. The HFRS had the highest AUROC for estimating PACE during the first 2 years and death during the first 4 years, after which the PFI had the highest AUROC. Conclusions and Relevance: These findings could help to tailor the use of frailty instruments by outcome and follow-up duration, thus optimizing preoperative risk stratification, patient-centered decision-making, candidate selection for prehabilitation, and personalized monitoring and health resource planning in patients undergoing cardiac surgery.

Derivation and validation of predictive indices for 30-day mortality after coronary and valvular surgery in Ontario, Canada.

BACKGROUND: Coronary artery bypass grafting (CABG) and surgical aortic valve replacement (AVR) are the 2 most common cardiac surgery procedures in North America. We derived and externally validated clinical models to estimate the likelihood of death within 30 days of CABG, AVR or combined CABG + AVR. METHODS: We obtained data from the CorHealth Ontario Cardiac Registry and several linked population health administrative databases from Ontario, Canada. We derived multiple logistic regression models from all adult patients who underwent CABG, AVR or combined CABG + AVR from April 2017 to March 2019, and validated them in 2 temporally distinct cohorts (April 2015 to March 2017 and April 2019 to March 2020). RESULTS: The derivation cohorts included 13 435 patients who underwent CABG (30-d mortality 1.73%), 1970 patients who underwent AVR (30-d mortality 1.68%) and 1510 patients who underwent combined CABG + AVR (30-d mortality 3.05%). The final models for predicting 30-day mortality included 15 variables for patients undergoing CABG, 5 variables for patients undergoing AVR and 5 variables for patients undergoing combined CABG + AVR. Model discrimination was excellent for the CABG (c-statistic 0.888, optimism-corrected 0.866) AVR (c-statistic 0.850, optimism-corrected 0.762) and CABG + AVR (c-statistic 0.844, optimism-corrected 0.776) models, with similar results in the validation cohorts. INTERPRETATION: Our models, leveraging readily available, multidimensional data sources, computed accurate risk-adjusted 30-day mortality rates for CABG, AVR and combined CABG + AVR, with discrimination comparable to more complex American and European models. The ability to accurately predict perioperative mortality rates for these procedures will be valuable for quality improvement initiatives across institutions.

Importance of accounting for loss to follow-up when comparing mortality between immigrants and long-term residents: a population-based retrospective cohort.

OBJECTIVES: To evaluate the association between immigration status and all-cause mortality in different disease cohorts, and the impact of loss to follow-up on the observed associations. DESIGN: Population-based retrospective cohort study using linked administrative health data in Ontario, Canada. SETTING: We followed adults with a first-ever diagnosis of ischaemic stroke, cancer or schizophrenia between 2002 and 2013 from index event to death, loss to follow-up, or end of follow-up in 2018. PRIMARY AND SECONDARY OUTCOME MEASURES: Our outcomes of interest were all-cause mortality and loss to follow-up. For each disease cohort, we calculated adjusted HRs of death in immigrants compared with long-term residents, adjusting for demographic characteristics and comorbidities, with and without censoring for those who were lost to follow-up. We calculated the ratio of two the HRs and the respective CL using bootstrapping methods. RESULTS: Immigrants were more likely to be lost to follow-up than long-term residents in all disease cohorts. Not accounting for this loss to follow-up overestimated the magnitude of the association between immigration status and mortality in those with ischaemic stroke (HR of death before vs after accounting for censoring: 0.78 vs 0.83, ratio=0.95; 95% CL 0.93 to 0.97), cancer (0.74 vs 0.78, ratio=0.96; 0.95 to 0.96), and schizophrenia (0.54 vs 0.56, ratio=0.97; 0.96 to 0.98). CONCLUSIONS: Immigrants to Canada have a survival advantage that varies by the disease studied. The magnitude of this advantage is modestly overestimated by not accounting for the higher loss to follow-up in immigrants.

Multiple arterial coronary bypass grafting is associated with greater survival in women.

OBJECTIVE: Multiple arterial grafting (MAG) in coronary artery bypass grafting (CABG) is associated with higher survival and freedom from major adverse cardiac and cerebrovascular events (MACCEs) in observational studies of mostly men. It is not known whether MAG is beneficial in women. Our objectives were to compare the long-term clinical outcomes of MAG versus single arterial grafting (SAG) in women undergoing CABG for multivessel disease. METHODS: Clinical and administrative databases for Ontario, Canada, were linked to obtain all women with angiographic evidence of left main, triple or double vessel disease undergoing isolated non-emergent primary CABG from 2008 to 2019. 1:1 propensity score matching was performed. Late mortality and MACCE (composite of stroke, myocardial infarction, repeat revascularisation and death) were compared between the matched groups with a stratified log-rank test and Cox proportional-hazards model. RESULTS: 2961 and 7954 women underwent CABG with MAG and SAG, respectively, for multivessel disease. Prior to propensity-score matching, compared with SAG, those who underwent MAG were younger (66.0 vs 68.9 years) and had less comorbidities. After propensity-score matching, in 2446 well-matched pairs, there was no significant difference in 30-day mortality (1.6% vs 1.8%, p=0.43) between MAG and SAG. Over a median and maximum follow-up of 5.0 and 11.0 years, respectively, MAG was associated with greater survival (HR 0.85, 95% CI 0.75 to 0.98) and freedom from MACCE (HR 0.85, 95% CI 0.76 to 0.95). CONCLUSIONS: MAG was associated with greater survival and freedom from MACCE and should be considered for women with good life expectancy requiring CABG.

Development and Validation of a Prognostic Tool for Direct Enteral Tube Insertion After Acute Stroke.

Background and Purpose- We aimed to create a novel prognostic risk score to estimate outcomes after direct enteral tube placement in acute stroke. Methods- We used the Ontario Stroke Registry and linked databases to obtain clinical information on all patients with direct enteral tube insertion after ischemic stroke or intracerebral hemorrhage from July 1, 2003 to June 30, 2010 (derivation cohort) and July 1, 2010 to March 31, 2013 (validation cohort). We used multivariable regression to assign scores to predictor variables for 3 outcomes after tube placement: favorable outcome (discharge modified Rankin Scale score 0-3 and alive at 90 days), poor outcome (discharge modified Rankin Scale score 5 or death at 90 days), and 30-day mortality. Results- Variables associated with a favorable outcome were younger age, preadmission independence, ischemic stroke rather than intracerebral hemorrhage, lower stroke severity, and a shorter time between stroke and tube placement. Variables associated with a poor outcome were older age, preadmission dependence, atrial fibrillation, greater stroke severity, and tracheostomy. Age, preadmission dependence, atrial fibrillation, cancer, chronic obstructive pulmonary disease, and shorter time to tube placement were associated with increased 30-day mortality. Using these variables, we created an online calculator to facilitate estimation of individual patient risk of favorable and poor outcomes. C-statistic in the validation cohort was 0.82 for favorable outcome, 0.65 for poor outcome, and 0.62 for 30-day mortality, and calibration was adequate. Conclusions- We developed risk scores to estimate outcomes after direct enteral tube insertion for acute dysphagic stroke. This information may be useful in discussions with patients and families when there is prognostic uncertainty surrounding outcomes with direct enteral tube placement after stroke.

Association Between Immigration Status and Acute Stroke Care: A Retrospective Study.

Background and Purpose- Immigrants to high-income countries have a lower incidence of stroke compared with long-term residents; however, little is known about the care and outcomes of stroke in immigrants. Methods- We used linked clinical and administrative data to conduct a retrospective cohort study of adults seen in the emergency department or hospitalized with ischemic stroke or transient ischemic attack between July 1, 2003, and April 1, 2013, and included in the provincial stroke registry. We ascertained immigration status using immigration records and compared processes of stroke care delivery between immigrants (defined as those immigrating after 1985) and long-term residents. In the subgroup with ischemic stroke, we calculated inverse probability treatment weight (IPTW)-adjusted risk ratios for disability on discharge (modified Rankin Scale score of 3 to 5), accounting for demographic characteristics and comorbid conditions to compare outcomes between immigrants and long-term residents. Results- We included 34 987 patients with ischemic stroke or transient ischemic attack, of whom 2649 (7.6%) were immigrants. Immigrants were younger than long-term residents at the time of stroke/transient ischemic attack (median age 67 years versus 76 years; P<0.001). In the subgroup with ischemic stroke, there were no differences in stroke care delivery, except that a higher proportion of immigrants received thrombolysis than long-term residents (21.2% versus 15.5%; P<0.001). Immigrants with ischemic stroke had a higher adjusted risk of being disabled on discharge (adjusted risk ratio, 1.18; 95% CI, 1.13-1.22) compared to long-term residents. Conclusions- Stroke care is similar in Canadian immigrants and long-term residents. Future research is needed to confirm the observed association between immigration status and disability after stroke and to identify factors underlying the association.

Off-pump versus on-pump coronary artery bypass grafting in moderate renal failure.

OBJECTIVES: Off-pump coronary artery bypass (OPCAB) may benefit select high-risk patients. We sought to analyze the long-term outcomes of OPCAB versus on-pump coronary artery bypass (ONCAB) in patients with moderate renal failure. METHODS: A retrospective cohort analysis of primary isolated CAB surgery performed in Ontario, Canada, from October 2008 to March 2016 in the CorHealth Ontario Cardiac Registry identified 50,115 cases. Of these, 7782 (15.5%) had estimated glomerular filtration rate (eGFR) of 30 to 59 mL/min/1.73 m2. OPCAB was compared to ONCAB after propensity score matching. RESULTS: Following propensity score matching, 1578 patient pairs were formed. Total number of bypass grafts was higher in ONCAB (3.31 ± 1.01 vs 3.12 ± 1.14; P < .01) and more arterial grafts were used in OPCAB (1.55 ± 0.71 vs 1.14 ± 0.58; P < .01). OPCAB was associated with lower rate of in-hospital stroke (0.7% vs 2.2%; P < .01), renal failure requiring dialysis (1.2% vs 2.9%; P < .01), and blood transfusion (52.4% vs 69.3%; P < .01). There was no difference in perioperative mortality (2.4% vs 3.0%; P = .36) between OPCAB and ONCAB, respectively. At 8-year follow-up, survival probability was not different when comparing OPCAB versus ONCAB: 62% versus 65%, respectively (hazard ratio, 0.98; 95% confidence interval, 0.84-1.13; P = .38). Cumulative incidence of permanent dialysis did not differ at 8-year follow-up: 7% versus 7%, respectively (hazard ratio, 1.01; 95% confidence interval, 0.72-1.43; P = .74. CONCLUSIONS: OPCAB is associated with improved in-hospital renal outcomes, but is not associated with changes in short- or long-term mortality, or with the long-term cumulative incidence of end-stage renal failure requiring permanent dialysis in patients with moderate renal failure.

The Risk of Cardiovascular Events on Cannabis' Highest Day.

Knowledge of the acute cardiovascular effects of cannabis consumption remains largely unknown and is important given the changing landscape of legalization of recreational cannabis use. "4/20" is an annual event where many individuals gather to consume cannabis. An increased risk of adverse health events such as motor vehicle accidents has previously been reported to occur on "4/20." In this study, population-based administrative databases in Ontario, Canada, were used to evaluate the association between "4/20" and cardiovascular events. An increased risk of cardiovascular events on a population level was not observed on "4/20." Additional research into the changes in the prevalence of the use of cannabis with recreational legalization and acute and chronic risk with cannabis use is suggested.

Same-Day Discharge After Elective Percutaneous Coronary Interventions in Ontario, Canada.

Background To manage overcrowding and bed shortages in Canadian hospitals, same-day discharge (SDD) after percutaneous coronary intervention (PCI) has emerged as a solution to improve resource utilization. However, limited information exists regarding current trends, hospital variation, and safety of SDD PCI in Canada. Methods and Results We evaluated outpatients undergoing elective PCI in Ontario, Canada, from October 2008 to March 2016. SDD was defined when patients were discharged on the day of PCI, and non-SDD was defined as those patients who had 1 overnight stay. The primary outcome was 30-day all-cause death or hospitalization for acute coronary syndrome. Inverse probability of treatment weighting with propensity score was used to account for differences in baseline and clinical characteristics between SDD and non-SDD groups. Among 35 972 patients who underwent elective PCI at 17 PCI centers in Ontario, 10 801 patients (30%) had SDD PCI and 25 121 patients (70%) had non-SDD PCI. Substantial hospital variation for SDD PCI was observed, ranging from 0% to 87% during the study period. In the propensity-weighted cohort, SDD patients had no significant difference in 30-day rates of death or hospitalization for acute coronary syndrome (1.3% versus 1.6%; hazard ratio: 0.84 [95% CI, 0.65-1.08]; P=0.17) compared with non-SDD patients. SDD and non-SDD patients also had no significant difference in 30-day rates of mortality or coronary revascularization. Conclusions In this large population-based cohort of elective PCI patients, we demonstrated the safety of SDD PCI. Increased adoption of this strategy could lead to improved bed-flow efficiency and substantial savings for the Canadian healthcare system without comprising outcomes.

A Clinical Risk Scoring Tool to Predict Readmission After Cardiac Surgery: An Ontario Administrative and Clinical Population Database Study.

BACKGROUND: Reducing readmission after cardiac surgery remains a quality improvement priority yet most readmission risk models examine only coronary artery bypass grafting (CABG). Our objective was to develop a predictive risk score for readmission after discharge in cardiac surgery. METHODS: All adults > 18 years undergoing isolated CABG, isolated/multiple valve, or combined CABG/valve surgery from 2008 to 2016 in Ontario were eligible. Risk factors for 30-day readmission after discharge were obtained through linkages of the CorHealth Ontario Cardiac Registry to other administrative health databases. Hazard ratios (HR) for risk factors were calculated using Cox proportional hazards regression with 95% confidence intervals (95% CI). We developed a clinical risk scoring tool weighted by beta coefficients from the final model. Discrimination and calibration was performed using c-statistics and comparing the predicted with observed probabilities across deciles of predicted risk. RESULTS: A total of 63,336 patients underwent CABG and/or valve surgery from 2008 to 2016. The 30-day readmission rate was 11.5% overall. Patients who were readmitted were older with higher incidences of cardiac comorbidities compared with nonreadmitted patients. Significant risk factors for readmission from the final model were prolonged length of stay (HR: 1.45; 95% CI: 1.57, 1.86; P < 0.0001), isolated valve surgery (HR: 1.35; 95% CI: 1.26, 1.44; P < 0.0001), in-hospital complications of sepsis (HR: 1.47; 95% CI: 1.05, 2.07; P = 0.024), and acute myocardial infarction (HR: 1.36; 95% CI: 1.09, 1.71; P = 0.007). A clinical risk scoring tool with 22 variables was derived that delineated patients into 1 of 5 risk quintiles. The c-statistic for the overall model was 0.63. CONCLUSIONS: Readmission after cardiac surgery is common and moderately predictable in this contemporary cohort.

Multiple Arterial Grafting Is Associated With Better Outcomes for Coronary Artery Bypass Grafting Patients.

BACKGROUND: Observational studies have shown better survival in patients undergoing coronary artery bypass grafting (CABG) with 2 arterial grafts compared with 1. However, whether a third arterial graft is associated with incremental benefit remains uncertain. We sought to analyze the outcomes of 3 versus 2 arterial grafts during CABG. As a secondary objective, we compared CABG with 2 or 3 arterial grafts (multiple arterial grafts [MAG]) with CABG using a single arterial graft (SAG). METHODS: Retrospective cohort analyses of all patients undergoing primary isolated CABG in Ontario, Canada, from October 2008 to March 2016. Propensity score matching was performed between patients with 3 arterial grafts (3Art group) versus 2 (2Art group). The primary outcome was time to first event of a composite of death, myocardial infarction, stroke, and repeat revascularization (major adverse cardiac and cerebrovascular events). Additional analyses were performed to evaluate the association between MAG versus SAG and long-term outcomes using propensity score matching. RESULTS: Fifty thousand, two hundred thirty patients underwent isolated CABG during our study period; 3044 (6.1%) and 8253 (16.4%) patients had 3 and 2 arterial grafts, respectively, resulting in 2789 propensity score matching pairs for the primary analyses. Mean and maximum follow-up was 4.2 and 8.5 years, respectively. Radial artery grafting was more common in the 3Art versus 2Art group (79.3% versus 65.6%, P<0.01). In-hospital outcomes were not significantly different, including death (3Art 0.8% versus 2Art 0.5%, P=0.26). Up to 8 years, there were no differences in major adverse cardiac and cerebrovascular events (3Art 27%, 95% confidence interval [CI], 24% to 30% versus 2Art 25%, 95% CI, 22% to 28%; hazard ratio [HR], 1.08, 95% CI, 0.94-1.25), death (HR, 1.08; 95% CI, 0.90-1.29), myocardial infarction (HR, 1.15; 95% CI, 0.87-1.51), stroke (HR, 1.39; 95% CI, 0.95-2.06), or repeat revascularization (HR, 1.04; 95% CI, 0.82-1.32). When evaluating MAG versus SAG, 8629 patient pairs were formed using propensity score matching. At 8 years, cumulative incidences of major adverse cardiac and cerebrovascular events (HR, 0.82, 95% CI, 0.77-0.88), survival (HR, 0.80; 95% CI, 0.73-0.88), repeat revascularization (HR, 0.79; 95% CI, 0.69-0.90), and myocardial infarction (HR, 0.83; 95% CI, 0.72-0.97) were superior in the MAG group. CONCLUSIONS: CABG with 3 arterial grafts was not associated with increased in-hospital death nor with better clinical outcomes at 8-year follow-up, compared with CABG with 2 arterial grafts. MAG was associated with superior outcomes compared with SAG.

Importance of Considering Competing Risks in Time-to-Event Analyses: Application to Stroke Risk in a Retrospective Cohort Study of Elderly Patients With Atrial Fibrillation.

BACKGROUND: Ignoring competing risks in time-to-event analyses can lead to biased risk estimates, particularly for elderly patients with multimorbidity. We aimed to demonstrate the impact of considering competing risks when estimating the cumulative incidence and risk of stroke among elderly atrial fibrillation patients. METHODS AND RESULTS: Using linked administrative databases, we identified patients with atrial fibrillation aged ≥66 years discharged from hospital in ON, Canada between January 1, 2007, and March 31, 2011. We estimated the cumulative incidence of stroke hospitalization using the complement of the Kaplan-Meier function and the cumulative incidence function. This was repeated after stratifying the cohort by presence of prespecified comorbidities: chronic kidney disease, chronic obstructive pulmonary disease, cancer, or dementia. The full cohort was used to regress components of the CHA2DS2VASc (congestive heart failure, hypertension, age, diabetes mellitus, stroke, vascular disease, sex) score on the hazard of stroke hospitalization using the Fine-Gray and Cox methods. These models were subsequently used to predict the 5-year risk of stroke hospitalization. Among 136 156 patients, the median CHA2DS2VASc score was 4 and 84 728 patients (62.2%) had ≥1 prespecified comorbidity. The 5-year cumulative incidence of stroke was 5.4% (95% confidence interval, 5.3%-5.5%), whereas that of death without stroke was 48.8% (95% confidence interval, 48.5%-49.1%). The incidence of both events was overestimated by the Kaplan-Meier method; stroke incidence was overestimated by a relative factor of 39%. The degree of overestimation was larger among patients with non-CHA2DS2VASc comorbidity because of higher incidence of death without stroke. The Fine-Gray model demonstrated better calibration than the Cox model, which consistently overpredicted stroke incidence. CONCLUSIONS: The incidence of death without stroke was 9-fold higher than that of stroke, leading to biased estimates of stroke risk with traditional time-to-event methods. Statistical methods that appropriately account for competing risks should be used to mitigate this bias.

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.

Association of Atrial Fibrillation and Oral Anticoagulant Use With Perioperative Outcomes After Major Noncardiac Surgery.

BACKGROUND: We examined the association of atrial fibrillation (AF) and oral anticoagulant use with perioperative death and bleeding among patients undergoing major noncardiac surgery. METHODS AND RESULTS: A population-based study of patients aged 66 years and older who underwent elective (n=87 257) or urgent (n=35 930) noncardiac surgery in Ontario, Canada (April 2012 to March 2015) was performed. Outcomes were compared between AF groups using inverse probability of treatment weighting using the propensity score. Of 4612 urgent surgical patients with AF, treatments before surgery included warfarin (n=1619), a direct oral anticoagulant (DOAC) (n=729), and no anticoagulation (n=2264). After urgent surgery, the death rate within 30 days was significantly higher in patients with AF compared with patients with no AF (hazard ratio [HR], 1.28; 95% confidence interval [CI], 1.12-1.45). In contrast, among 4769 elective surgical patients with AF treated with warfarin (n=1453), a DOAC (n=1165), or no anticoagulation (n=2151), prior AF was not associated with higher mortality. Comparing patients with AF who were or were not anticoagulated, there was no difference in 30-day mortality after urgent (HR, 0.95; 95% CI, 0.79-1.14) or elective (HR, 0.65; 95% CI, 0.38-1.09) surgery. There was no difference in 30-day mortality between patients with AF treated with a DOAC or warfarin after urgent (HR, 0.91; 95% CI, 0.70-1.18) or elective (HR, 1.64; 95% CI, 0.77-3.53) surgery. Bleeding and thromboembolic rates did not differ significantly among patients with AF prescribed a DOAC or warfarin. CONCLUSIONS: Prior AF was associated with 30-day mortality among patients undergoing urgent surgery. In patients with AF, neither the preoperative use of oral anticoagulants, nor the type of agent (either a DOAC or warfarin) were associated with the rate of 30-day mortality.