Ventricular Arrhythmias After Primary Percutaneous Coronary Intervention for STEMI.

Importance: Currently, mortality risk for patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) with an uncomplicated postprocedure course is low. Less is known regarding the risk of in-hospital ventricular tachycardia (VT) and ventricular fibrillation (VF). Objective: To evaluate the risk of late VT and VF after primary PCI for STEMI. Design, Setting, and Participants: This cohort study included adults aged 18 years or older with STEMI treated with primary PCI between January 1, 2015, and December 31, 2018, identified in the US National Cardiovascular Data Registry Chest Pain-MI Registry. Data were analyzed from April to December 2020. Main Outcomes and Measures: Multivariable logistic regression was used to evaluate the risk of late VT (≥7 beat run of VT during STEMI hospitalization ≥1 day after PCI) or VF (any episode of VF≥1 day after PCI) associated with cardiac arrest and associations between late VT or VF and in-hospital mortality in the overall cohort and a cohort with uncomplicated STEMI without prior myocardial infarction or heart failure, systolic blood pressure less than 90 mm Hg, cardiogenic shock, cardiac arrest, reinfarction, or left ventricular ejection fraction (LVEF) less than 40%. Results: A total of 174 126 eligible patients with STEMI were treated with primary PCI at 814 sites in the study; 15 460 (8.9%) had VT or VF after primary PCI, and 4156 (2.4%) had late VT or VF. Among the eligible patients, 99 905 (57.4%) at 807 sites had uncomplicated STEMI. The median age for patients with late VT or VF overall was 63 years (IQR, 55-73 years), and 75.5% were men; the median age for patients with late VT or VF with uncomplicated STEMI was 60 years (IQR, 53-69 years), and 77.7% were men. The median length of stay was 3 days (IQR, 2-7 days) for the overall cohort with late VT or VF and 3 days (IQR, 2-4 days) for the cohort with uncomplicated STEMI with late VT or VF. The risk of late VT or VF was 2.4% (overall) and 1.7% (uncomplicated STEMI). Late VT or VF with cardiac arrest occurred in 674 patients overall (0.4%) and in 117 with uncomplicated STEMI (0.1%). LVEF was the most significant factor associated with late VT or VF with cardiac arrest (adjusted odds ratio [AOR] for every 5-unit decrease ≤40%: 1.67; 95% CI, 1.54-1.85). Late VT or VF events were associated with increased odds of in-hospital mortality in the overall cohort (AOR, 6.40; 95% CI, 5.63-7.29) and the cohort with uncomplicated STEMI (AOR, 8.74; 95% CI, 6.53-11.70). Conclusions and Relevance: In this study, a small proportion of patients with STEMI treated with primary PCI had late VT or VF. However, late VT or VF with cardiac arrest was rare, particularly in the cohort with uncomplicated STEMI. This information may be useful when determining the optimal timing for hospital discharge after STEMI.

Contemporary Methods for Predicting Acute Kidney Injury After Coronary Intervention.

BACKGROUND: Acute kidney injury (AKI) is the most common complication after percutaneous coronary intervention (PCI). Accurately estimating patients' risks not only creates a means of benchmarking performance but can also be used prospectively to inform practice. OBJECTIVES: The authors sought to update the 2014 National Cardiovascular Data Registry (NCDR) AKI risk model to provide contemporary estimates of AKI risk after PCI to further improve care. METHODS: Using the NCDR CathPCI Registry, we identified all 2020 PCIs, excluding those on dialysis or lacking postprocedural creatinine. The cohort was randomly split into a 70% derivation cohort and a 30% validation cohort, and logistic regression models were built to predict AKI (an absolute increase of 0.3 mg/dL in creatinine or a 50% increase from preprocedure baseline) and AKI requiring dialysis. Bedside risk scores were created to facilitate prospective use in clinical care, along with threshold contrast doses to reduce AKI. We tested model calibration and discrimination in the validation cohort. RESULTS: Among 455,806 PCI procedures, the median age was 67 years (IQR: 58.0-75.0 years), 68.8% were men, and 86.8% were White. The incidence of AKI and new dialysis was 7.2% and 0.7%, respectively. Baseline renal function and variables associated with clinical instability were the strongest predictors of AKI. The final AKI model included 13 variables, with a C-statistic of 0.798 and excellent calibration (intercept = -0.03 and slope = 0.97) in the validation cohort. CONCLUSIONS: The updated NCDR AKI risk model further refines AKI prediction after PCI, facilitating enhanced clinical care, benchmarking, and quality improvement.

Implications of a Race Term in GFR Estimates Used to Predict AKI After Coronary Intervention.

BACKGROUND: The prediction of mortality, bleeding, and acute kidney injury (AKI) after percutaneous coronary intervention (PCI) traditionally relied on race-based estimates of the glomerular filtration rate (GFR). Recently, race agnostic equations were developed to advance equity. OBJECTIVES: The authors aimed to compare the accuracy and implications of various GFR equations when used to predict AKI after PCI. METHODS: Using the National Cardiovascular Data Registry (NCDR) CathPCI data set, we identified patients undergoing PCI in 2020 and calculated their AKI risk using the 2014 NCDR AKI risk model. We created 4 AKI models per patient for each estimate of baseline renal function: the traditional GFR equation with a race term, 2 GFR equations without a race term, and serum creatinine alone. We then compared each model's performance predicting AKI. RESULTS: Among 455,806 PCI encounters, the median age was 67 years, 32.2% were women, and 8.5% were Black. In Black patients, risk models without a race term were better calibrated than models incorporating an equation with a race term (intercept: -0.01 vs 0.15). Race-agnostic models reclassified 6% of Black patients into higher-risk categories, potentially prompting appropriate mitigation efforts. However, even with a race-agnostic model, AKI occurred in Black patients 18% more often than expected, which was not explained by captured patient or procedural characteristics. CONCLUSIONS: Incorporating a GFR estimate without a Black race term into the NCDR AKI risk prediction model yielded more accurate prediction of AKI risk for Black patients, which has important implications for reducing disparities and benchmarking.

A Geriatric Approach to Percutaneous Coronary Interventions in Older Adults, Part II: A JACC: Advances Expert Panel.

We review a comprehensive risk assessment approach for percutaneous coronary interventions in older adults and highlight the relevance of geriatric syndromes within that broader perspective to optimize patient-centered outcomes in interventional cardiology practice. Reflecting the influence of geriatric principles in older adults undergoing percutaneous coronary interventions, we propose a "geriatric" heart team to incorporate the expertise of geriatric specialists in addition to the traditional heart team members, facilitate uptake of the geriatric risk assessment into the preprocedural risk assessment, and address ways to mitigate these geriatric risks. We also address goals of care in older adults, highlighting common priorities that can impact shared decision making among older patients, as well as frequently encountered pharmacotherapeutic considerations in the older adult population. Finally, we clarify gaps in current knowledge and describe crucial areas for future investigation.

Assessment and Management of Older Adults Undergoing PCI, Part 1: A JACC: Advances Expert Panel.

As the population ages, older adults represent an increasing proportion of patients referred to the cardiac catheterization laboratory. Older adults are the highest-risk group for morbidity and mortality, particularly after complex, high-risk percutaneous coronary interventions. Structured risk assessment plays a key role in differentiating patients who are likely to derive net benefit vs those who have disproportionate risks for harm. Conventional risk assessment tools from national cardiovascular societies typically rely on 3 pillars: 1) cardiovascular risk; 2) physiologic and hemodynamic risk; and 3) anatomic and procedural risks. We propose adding a fourth pillar: geriatric syndromes, as geriatric domains can supersede all other aspects of risk.

Initial Management Strategy and Long-Term Outcomes in 186 Cases of Spontaneous Coronary Artery Dissection.

Spontaneous coronary artery dissection (SCAD) is a rare but important nonatherosclerotic cause of acute coronary syndrome. Indications for revascularization and long-term outcomes of SCAD remain areas of active investigation. We report our experience with initial management strategy and long-term outcomes in SCAD. We reviewed all patients treated at our institution from 1996-2021 with a SCAD diagnosis. Demographics, comorbidities, clinical presentations, angiography findings, and management strategies were obtained by chart review. The primary outcome was a composite of cardiac death, recurrent/progressive SCAD, subsequent diagnosis of congestive heart failure, or subsequent/repeat revascularization after the initial management. Unadjusted Kaplan-Meier survival analysis was performed. Of 186 patients with a SCAD diagnosis treated at our institution, 149 (80%) were female. Medical management was the initial treatment in 134 (72.0%) patients, percutaneous coronary intervention (PCI) in 43 (23.1%), and coronary artery bypass grafting in 9 (4.8%). Surgery/PCI intervention was associated with younger age (38.8 vs 47.7 years, P = 0.01), ST elevation myocardial infarction on presentation (67.0% vs 34.0%, P < 0.001), lower ejection fraction (45.0% vs 55.0%, P = 0.002), and left anterior descending coronary artery dissection (75.0% vs 51.0%, P = 0.006). Ten-year freedom from our composite outcome was similar between revascularized patients and those managed with medical therapy (P = 0.36). Median follow-up time was 4.5 years. SCAD in the setting of ST elevation myocardial infarction, left anterior descending coronary artery involvement, or decreased cardiac function suggests greater ischemic insult and was associated with initial percutaneous or surgical revascularization. Despite worse disease on initial presentation, long-term outcomes of patients undergoing revascularization are similar to medically managed patients with SCAD.

Analysis of Oral Anticoagulant Dosing and Adherence to Therapy Among Patients With Nonvalvular Atrial Fibrillation.

Importance: Although reduced doses of direct oral anticoagulants (DOACs) are approved for patients with nonvalvular atrial fibrillation (NVAF) at high risk of bleeding, little is known about dosing accuracy, particularly in patients with renal dysfunction. Objective: To determine whether underdosing of DOACs is associated with longitudinal adherence to anticoagulation. Design, Setting, and Participants: This retrospective cohort analysis used data from the Symphony Health claims data set. This national medical and prescription data set comprises 280 million patients and 1.8 million prescribers in the US. Patients included had at least 2 claims for NVAF between January 2015 and December 2017. The dates of analysis for this article were from February 2021 to July 2022. Exposures: This study included patients with CHA2DS2-VASc scores of 2 or higher who were treated with a dose of DOACs who did and did not meet label-specified criteria for dose reduction. Main Outcomes and Measures: Logistic regression models examined factors associated with off-label dosing (ie, dosing not recommended by US Food and Drug Administration [FDA] labeling), the association of creatinine clearance with recommended DOAC dosing, and the association of DOAC underdosing and excess dosing with 1-year adherence. Results: Among the 86 919 patients included (median [IQR] age, 74 [67-80] years; 43 724 men [50.3%]; 82 389 White patients [94.8%]), 7335 (8.4%) received an appropriately reduced dose, and 10 964 (12.6%) received an underdose not consistent with FDA recommendations, meaning that 59.9% (10 964 of 18 299) of those who received a reduced dose received an inappropriate dose. Patients who received off-label doses of DOACs were older (median [IQR] age, 79 [73-85] vs 73 [66-79] years) and had higher CHA2DS2-VASc scores (median [IQR], 5 [4-6] vs 4 [3-6]) compared with patients who received appropriate doses (as recommended by FDA labeling). Renal dysfunction, age, heart failure, and the prescribing clinician being in a surgical specialty were associated with dosing not recommended by FDA labeling. Almost one-third of patients (9792 patients [31.9%]) with creatinine clearance less than 60 mL per minute taking DOACs were either underdosed or excess-dosed not consistent with FDA recommendations. For every 10-unit decrease in creatinine clearance, the odds of the patient receiving an appropriately dosed DOAC was lower by 21%. Treatment with underdosed DOACs was associated with a lower likelihood of adherence (adjusted odds ratio, 0.88; 95% CI, 0.83-0.94) and higher risk of anticoagulation discontinuation (adjusted odds ratio, 1.20; 95% CI, 1.13-1.28) by 1 year. Conclusions and Relevance: In this study of oral anticoagulant dosing, DOAC dosing that did not follow FDA label recommendations was observed in a substantial number of patients with NVAF, occurred more frequently in patients with worse renal function, and was associated with less-consistent long-term anticoagulation. These results suggest a need for efforts to improve the quality of DOAC use and dosing.

Challenge in Predicting Persistence to P2Y12 Inhibitors: A Perspective From the ARTEMIS Trial.

Background Premature discontinuation of P2Y12 inhibitor therapy has been associated with adverse cardiac events, which might be preventable by improving medication persistence. Current risk models have limited ability to predict patients at risk of P2Y12 inhibitor nonpersistence. Methods and Results ARTEMIS (Affordability and Real-World Antiplatelet Treatment Effectiveness after Myocardial Infarction Study) was a randomized, controlled trial testing the impact of a copayment assistance intervention on P2Y12 inhibitor persistence and outcomes. Among 6212 patients post myocardial infarction with a planned 1-year course of P2Y12 inhibitor therapy, nonpersistence was defined as a gap in P2Y12 inhibitor filled >30 days by pharmacy fill data. We developed a predictive model for 1-year P2Y12 inhibitor nonpersistence among patients randomized to usual care. P2Y12 inhibitor nonpersistence rates were 23.8% (95% CI, 22.7%-24.8%) at 30 days and 47.9% (46.6%-49.1%) at 1 year; the majority of these patients had in-hospital percutaneous coronary intervention. Patients who received the copayment assistance intervention had nonpersistence rates of 22.0% (20.7%-23.3%) at 30 days and 45.3% (43.8%-46.9%) at 1 year. A 53-variable multivariable model predicting 1-year persistence had a C-index of 0.63 (optimism-corrected C-index 0.58). Model discrimination did not improve with inclusion of patient-reported perceptions about disease, medication-taking beliefs, and prior medication-filling behavior in addition to demographic and medical history data (C-index 0.62). Conclusions Despite addition of patient-reported variables, models predicting persistence with P2Y12 inhibitor therapy performed poorly, thereby suggesting the need for continued patient and clinician education on the importance of P2Y12 inhibitor therapy after acute myocardial infarction. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02406677.

Influence of Obesity on Coronary Artery Disease and Clinical Outcomes in the ADVANCE Registry.

BACKGROUND: The relationship between body size and cardiovascular events is complex. This study utilized the ADVANCE (Assessing Diagnostic Value of Noninvasive FFRCT in Coronary Care) Registry to investigate the association between body mass index (BMI), coronary artery disease (CAD), and clinical outcomes. METHODS: The ADVANCE registry enrolled patients undergoing evaluation for clinically suspected CAD who had >30% stenosis on cardiac computed tomography angiography. Patients were stratified by BMI: normal <25 kg/m2, overweight 25-29.9 kg/m2, and obese ≥30 kg/m2. Baseline characteristics, cardiac computed tomography angiography and computed tomography fractional flow reserve (FFRCT), were compared across BMI groups. Adjusted Cox proportional hazards models assessed the association between BMI and outcomes. RESULTS: Among 5014 patients, 2166 (43.2%) had a normal BMI, 1883 (37.6%) were overweight, and 965 (19.2%) were obese. Patients with obesity were younger and more likely to have comorbidities, including diabetes and hypertension (all P<0.001), but were less likely to have obstructive coronary stenosis (65.2% obese, 72.2% overweight, and 73.2% normal BMI; P<0.001). However, the rate of hemodynamic significance, as indicated by a positive FFRCT, was similar across BMI categories (63.4% obese, 66.1% overweight, and 67.8% normal BMI; P=0.07). Additionally, patients with obesity had a lower coronary volume-to-myocardial mass ratio compared with patients who were overweight or had normal BMI (obese BMI, 23.7; overweight BMI, 24.8; and normal BMI, 26.3; P<0.001). After adjustment, the risk of major adverse cardiovascular events was similar regardless of BMI (all P>0.05). CONCLUSIONS: Patients with obesity in the ADVANCE registry were less likely to have anatomically obstructive CAD by cardiac computed tomography angiography but had a similar degree of physiologically significant CAD by FFRCT and similar rates of adverse events. An exclusively anatomic assessment of CAD in patients with obesity may underestimate the burden of physiologically significant disease that is potentially due to a significantly lower volume-to-myocardial mass ratio.

Variation in resource utilization and mortality among patients with varying MR type and severity.

BACKGROUND: Limited data exists regarding the relationships between resource use and outcomes in patients with mitral regurgitation (MR). We examined resource utilization and outcomes across MR type and severity. METHODS: Using the Duke Echocardiography Laboratory Database, we identified patients with an index echo demonstrating moderate or severe MR (2000-2016) and examined 5-year cumulative rates of resources (ie, TTE, TEE, cardiac catheterization, cardiology/CTS referral, MV surgery/TEER, hospitalizations) by severity and type. We performed a multivariable landmark analysis of resource use during a 6 to 12 month period and 5-year mortality; and a multivariable analysis of the association between MR type and 5-year hospitalization costs. RESULTS: Among 4,511 patients with moderate or severe MR, 84.7% had moderate MR and 42.2% had secondary ischemic MR. The median age was 70 years-moderate, 66 years-severe. The mean 5-year cumulative resource utilization rate was 11.1 encounters/patients. Among patients with moderate or severe MR, there was significant variation in utilization of each resource by MR type (all P < .05). For severe MR, the performance of cardiac catheterization or MV surgery during the landmark period was associated with significantly lower mortality; for moderate MR, CTS referral during the landmark was associated with significantly lower mortality (P < .05). Patients with secondary ischemic and non-ischemic MR had significantly higher 5-year hospitalization costs compared with primary myxomatous MR (P < .05). CONCLUSIONS: Resource utilization and outcomes vary by MR type and severity. Utilization of resources, such as TTE, during guideline-recommended surveillance periods was not associated with a reduction in mortality while other care (catheterization or surgery) was associated with improved survival.

Apixaban for Patients With Atrial Fibrillation on Hemodialysis: A Multicenter Randomized Controlled Trial.

BACKGROUND: There are no randomized data evaluating the safety or efficacy of apixaban for stroke prevention in patients with end-stage kidney disease on hemodialysis and with atrial fibrillation (AF). METHODS: The RENAL-AF trial (Renal Hemodialysis Patients Allocated Apixaban Versus Warfarin in Atrial Fibrillation) was a prospective, randomized, open-label, blinded-outcome evaluation (PROBE) of apixaban versus warfarin in patients receiving hemodialysis with AF and a CHA2DS2-VASc score ≥2. Patients were randomly assigned 1:1 to 5 mg of apixaban twice daily (2.5 mg twice daily for patients ≥80 years of age, weight ≤60 kg, or both) or dose-adjusted warfarin. The primary outcome was time to major or clinically relevant nonmajor bleeding. Secondary outcomes included stroke, mortality, and apixaban pharmacokinetics. Pharmacokinetic sampling was day 1, day 3, and month 1. RESULTS: From January 2017 through January 2019, 154 patients were randomly assigned to apixaban (n=82) or warfarin (n=72). The trial stopped prematurely because of enrollment challenges. Time in therapeutic range (international normalized ratio, 2.0-3.0) for warfarin-treated patients was 44% (interquartile range, 23%-59%). The 1-year rates for major or clinically relevant nonmajor bleeding were 32% and 26% in apixaban and warfarin groups, respectively (hazard ratio, 1.20 [95% CI, 0.63-2.30]), whereas 1-year rates for stroke or systemic embolism were 3.0% and 3.3% in apixaban and warfarin groups, respectively. Death was the most common major event in the apixaban (21 patients [26%]) and warfarin (13 patients [18%]) arms. The pharmacokinetic substudy enrolled the target 50 patients. Median steady-state 12-hour area under the curve was 2475 ng/mL×h (10th to 90th percentiles, 1342-3285) for 5 mg of apixaban twice daily and 1269 ng/mL×h (10th to 90th percentiles, 615-1946) for 2.5 mg of apixaban twice daily. There was substantial overlap between minimum apixaban blood concentration, 12-hour area under the curve, and maximum apixaban blood concentration for patients with and without a major or clinically relevant nonmajor bleeding event. CONCLUSIONS: There was inadequate power to draw any conclusion regarding rates of major or clinically relevant nonmajor bleeding comparing apixaban and warfarin in patients with AF and end-stage kidney disease on hemodialysis. Clinically relevant bleeding events were ≈10-fold more frequent than stroke or systemic embolism among this population on anticoagulation, highlighting the need for future randomized studies evaluating the risks versus benefits of anticoagulation among patients with AF and end-stage kidney disease on hemodialysis. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02942407.

Does the Effectiveness of a Medicine Copay Voucher Vary by Baseline Medication Out-Of-Pocket Expenses? Insights From ARTEMIS.

Background Persistence to P2Y12 inhibitors after myocardial infarction (MI) remains low. Out-of-pocket cost is cited as a factor affecting medication compliance. We examined whether a copayment intervention affected 1-year persistence to P2Y12 inhibitors and clinical outcomes. Methods and Results In an analysis of ARTEMIS (Affordability and Real-World Antiplatelet Treatment Effectiveness After Myocardial Infarction Study), patients with MI discharged on a P2Y12 inhibitor were stratified by baseline out-of-pocket medication burden: low ($0-$49 per month), intermediate ($50-$149 per month), and high (≥$150 per month). The impact of the voucher intervention on 1-year P2Y12 inhibitor persistence was examined using a logistic regression model with generalized estimating equations. We assessed the rates of major adverse cardiovascular events among the groups using a Kaplan-Meier estimator. Among 7351 MI-treated patients at 282 hospitals, 54.2% patients were in the low copay group, 32.0% in the middle copay group, and 13.8% in the high copay group. Patients in higher copay groups were more likely to have a history of prior MI, heart failure, and diabetes compared with the low copay group (all P<0.0001). Voucher use was associated with a significantly higher likelihood of 1-year P2Y12 inhibitor persistence regardless of copayment tier (low copay with versus without voucher: adjusted odds ratio [OR], 1.44 [95% CI, 1.25-1.66]; middle copay: adjusted OR, 1.63 [95% CI, 1.37-1.95]; high copay group: adjusted OR, 1.41 [95% CI, 1.05-1.87]; P interaction=0.42). Patients in the high copay group without a voucher had similar risk of 1-year major adverse cardiovascular events compared with patients in the high copay group with a voucher (adjusted hazard ratio, 0.89 [95% CI, 0.66-1.21]). Conclusions Medication copayment vouchers were associated with higher medication persistence at 1 year following an MI, regardless of out-of-pocket medication burden. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02406677.

One-Year Follow-Up of Vascular Intervention Trials Disrupted by the COVID-19 Pandemic: A Use-Case landscape.

INTRODUCTION: The COVID-19 pandemic had an unprecedented impact on cardiovascular clinical research. The decision-making and state of study operations in cardiovascular trials 1-year after interruption has not been previously described. METHODS: In the spring of 2020, we created a pandemic impact task force to develop a landscape of use case scenarios from 17 device trials of peripheral artery disease (PAD) and coronary artery disease (CAD) interventions. In conjunction with publicly available (clinictrials.gov) study inclusion criteria, primary endpoints and study design, information was shared for this use-case landscape by trial leadership and data owners. RESULTS: A total of 17 actively enrolling trials (9 CAD and 8 PAD) volunteered to populate the use case landscape. All 17 were multicenter studies (12 in North America and 5 international). Fifteen studies were industry-sponsored, of which 13 were FDA approved IDEs, one was PCORI-sponsored and two were sponsored by the NIH. Enrollment targets ranged from 150 to 9000 pts. At the time of interruption, 5 trials were <20 % enrolled, 9 trials were 50-80 % enrolled and 3 trials were >80 % enrolled. At 1 year, the majority of studies were continuing to enroll in the context of more sporadic but ongoing pandemic activity. CONCLUSIONS: At 1 year from the first surge interruptions, most trials had resumed enrollment. Trials most heavily interrupted were trials early in enrollment and those trials not able to pivot to virtual patient and site visits. Further work is needed to determine the overall impact on vascular intervention trials disrupted during the COVID-19 pandemic.

Cangrelor Use Patterns and Transition to Oral P2Y12 Inhibitors Among Patients With Myocardial Infarction: Initial Results From the CAMEO Registry.

Background In clinical trials, cangrelor has been shown to reduce percutaneous coronary intervention-related ischemic complications without increasing major bleeding. This study was performed to examine cangrelor use and transition to oral P2Y12 inhibitors in routine clinical practice. Methods and Results The CAMEO (Cangrelor in Acute Myocardial Infarction: Effectiveness and Outcomes) registry is a multicenter, retrospective observational study of platelet inhibition strategies for patients with myocardial infarction undergoing percutaneous coronary intervention. In phase 1, data were collected on consecutive patients with myocardial infarction (n=482) treated with any P2Y12 inhibitor to understand cangrelor use by hospital. In phase 2, data were collected in a 2:1 (cangrelor-: non-cangrelor-treated) ratio of patients with myocardial infarction (n=873). In phase 1, cangrelor use varied across hospitals (overall, 50.4% [range, 6.0%-100%]). Of patients receiving cangrelor in both phases (n=819), 3.3% received either the bolus or infusion only. Cangrelor was infused for a median of 121 (76-196) minutes; and 38.3% received an infusion for <2 hours. Most patients transitioned from cangrelor to ticagrelor (ticagrelor, 85.3%; clopidogrel, 9.5%; prasugrel, 5.2%). Many patients (16.4%) had a >1-hour gap between cangrelor cessation and oral P2Y12 inhibitor initiation; this was highest among those transitioned to clopidogrel (56.6% versus 34.5% prasugrel versus 10.8% ticagrelor; P<0.001). Only 27.3% were dosed with cangrelor and transitioned to an oral P2Y12 inhibitor in a fashion consistent with the pivotal trials and US Food and Drug Administration label. Conclusions This multicenter registry demonstrated interhospital variability in how cangrelor was administered and transitioned to an oral P2Y12 inhibitor. These findings highlight opportunities for optimization of cangrelor dosing, infusion duration, and transition of care from the catheterization laboratory to the ward setting.