Assessment of Days Alive Out of Hospital as a Possible End Point in Trials of Stroke Prevention for Atrial Fibrillation: A ROCKET AF Analysis

BACKGROUND

Days alive out of hospital (DAOH) is an objective and patient-centered net benefit end point. There are no assessments of DAOH in clinical trials of interventions for atrial fibrillation (AF), and it is not known whether this end point is of clinical utility in these populations.

METHODS AND RESULTS

ROCKET AF (Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation) was an international double-blind, double-dummy randomized clinical trial that compared rivaroxaban with warfarin in patients with atrial fibrillation at increased risk for stroke. We assessed DAOH using investigator-reported event data for up to 12 months after randomization in ROCKET AF. We assessed DAOH overall, by treatment group, and by subgroup, including age, sex, and comorbidities, using Poisson regression. The mean±SD number of days dead was 7.3±41.2, days hospitalized was 1.2±7.2, and mean DAOH was 350.7±56.2, with notable left skew. Patients with comorbidities had fewer DAOH overall. There were no differences in DAOH by treatment arm, with mean DAOH of 350.6±56.5 for those randomized to rivaroxaban and 350.7±55.8 for those randomized to warfarin (P=0.86). A sensitivity analysis found no difference in DAOH not disabled with rivaroxaban versus warfarin (DAOH not disabled, 349.2±59.5 days and 349.1 days±59.3 days, respectively, P=0.88).

CONCLUSIONS

DAOH did not identify a treatment difference between patients randomized to rivaroxaban versus warfarin. This may be driven in part by the low overall event rates in atrial fibrillation anticoagulation trials, which leads to substantial left skew in measures of DAOH.

Association Between Stable Coronary Artery Disease and Hospital Readmissions Following Catheter Ablation for Atrial Fibrillation

OBJECTIVE

To evaluate the association of stable coronary artery disease (CAD) with readmission following hospitalization for catheter ablation (CA) for atrial fibrillation (AF).

PATIENTS AND METHODS

Using the Nationwide Readmissions Database, we identified all hospitalizations from the last quarter of 2015 through 2019 with a Medicare Severity-Diagnosis Related Group designation for a percutaneous intracardiac procedure, a procedure code for CA, and a primary discharge diagnosis of AF. Cases of acute coronary syndrome (ACS) at index hospitalization were excluded to define stable CAD. The primary outcome was all-cause 90-day hospital readmission; secondary end points included readmissions for AF, repeated CA, ACS, and heart failure (HF).

RESULTS

Among 28,466 hospitalizations for CA for AF identified, 3171 (11.1%) involved patients with stable CAD. No hospitalizations included patients with HF diagnosis codes. The incidence of 90-day all-cause readmission was higher in patients with stable CAD (18.4% [400 of 2172] vs 14.4% [2549 of 17,667]; P=.006), as was the incidence of subsequent hospitalization with ACS (5.3% [21] vs 1.1% [28]; P<.001) or HF (17.0% [68] vs 10.2% [260]; P=.007). The incidence of readmission within 90 days with recurrent AF did not differ for those with or without stable CAD (21.9% [88] vs 26.5% [675]; P=.217). Pooled analysis of 90-day HF readmissions revealed a higher incidence among older patients, those with chronic kidney or pulmonary disease, and those with persistent and chronic AF subtypes.

CONCLUSION

Results of this large-scale analysis suggest that among patients hospitalized for CA for AF, stable CAD is associated with hospital readmissions within 90 days, including admissions for ACS and decompensated HF.

Predicting Malignant Ventricular Arrhythmias Using Real-Time Remote Monitoring

BACKGROUND

Although implantable cardioverter-defibrillator (ICD) therapies are associated with increased morbidity and mortality, the prediction of malignant ventricular arrhythmias has remained elusive.

OBJECTIVES

The purpose of this study was to evaluate whether daily remote-monitoring data may predict appropriate ICD therapies for ventricular tachycardia or ventricular fibrillation.

METHODS

This was a post hoc analysis of IMPACT (Randomized trial of atrial arrhythmia monitoring to guide anticoagulation in patients with implanted defibrillator and cardiac resynchronization devices), a multicenter, randomized, controlled trial of 2,718 patients evaluating atrial tachyarrhythmias and anticoagulation for patients with heart failure and ICD or cardiac resynchronization therapy with defibrillator devices. All device therapies were adjudicated as either appropriate (to treat ventricular tachycardia or ventricular fibrillation) or inappropriate (all others). Remote monitoring data in the 30 days before device therapy were utilized to develop separate multivariable logistic regression and neural network models to predict appropriate device therapies.

RESULTS

A total of 59,807 device transmissions were available for 2,413 patients (age 64 ± 11 years, 26% women, 64% ICD). Appropriate device therapies (141 shocks, 10 antitachycardia pacing) were delivered to 151 patients. Logistic regression identified shock lead impedance and ventricular ectopy as significantly associated with increased risk of appropriate device therapy (sensitivity 39%, specificity 91%, AUC: 0.72). Neural network modeling yielded significantly better (P < 0.01 for comparison) predictive performance (sensitivity 54%, specificity 96%, AUC: 0.90), and also identified patterns of change in atrial lead impedance, mean heart rate, and patient activity as predictors of appropriate therapies.

CONCLUSIONS

Daily remote monitoring data may be utilized to predict malignant ventricular arrhythmias in the 30 days before device therapies. Neural networks complement and enhance conventional approaches to risk stratification.

Pathophysiology, Echocardiographic Diagnosis, and Treatment of Atrial Functional Mitral Regurgitation: JACC State-of-the-Art Review

The conventional view holds that functional mitral regurgitation (MR) is caused by restriction of leaflet motion resulting from displacement of the papillary muscle-bearing segments of the left ventricle. In the past decade, evidence has accrued suggesting functional MR can also be caused by left atrial enlargement. This underrecognized cause of secondary MR-atrial functional MR (AF-MR)-is mechanistically linked to annular enlargement, perturbations of annular contraction, and atriogenic leaflet tethering. AF-MR has been described in patients with atrial fibrillation and heart failure with preserved ejection fraction. Preliminary data suggest rhythm control may decrease MR severity in patients with atrial fibrillation. Additionally, several studies have reported reductions in MR and symptomatic improvement with restrictive annuloplasty and transcatheter edge-to-edge repair. This review discusses the pathophysiology, echocardiographic diagnosis, and treatment of AF-MR. AF-tricuspid regurgitation is also discussed.

Evolution of antithrombotic therapy for patients with atrial fibrillation: The prospective global GLORIA-AF registry program

Objective

To assess baseline characteristics and antithrombotic treatment (ATT) prescription patterns in patients enrolled in the third phase of the GLORIA-AF Registry Program, evaluate predictors of treatment prescription, and compare results with phase II.

Methods

GLORIA-AF is a large, global, prospective registry program, enrolling patients with newly diagnosed nonvalvular atrial fibrillation (AF) at risk of stroke. Patients receiving dabigatran were followed for two years in phase II, and all patients were followed for 3 years in phase III. Phase II started when dabigatran became available; phase III started when the characteristics of patients receiving dabigatran became roughly comparable with those receiving vitamin K antagonists (VKAs).

Results

Between 2014 and 2016, 21,241 patients were enrolled in phase III. In total, 82% of patients were prescribed oral anticoagulation ([OAC]; 59.5% novel/nonvitamin K oral anticoagulants [NOACs], 22.7% VKAs). A further 11% of patients were prescribed antiplatelets without OAC and 7% were prescribed no ATT. A high stroke risk was the main driver of OAC prescription. Factors associated with prescription of VKA over NOAC included type of site, region, physician specialty, and impaired kidney function.

Conclusion

Over the past few years, data from phase III of GLORIA-AF show that OACs have become the standard treatment option, with most newly diagnosed AF patients prescribed a NOAC. However, in some regions a remarkable proportion of patients remain undertreated. In comparison with phase II, more patients received NOACs in phase III while the prescription of VKA decreased. VKAs were preferred over NOACs in patients with impaired kidney function.

Ischaemic and bleeding risk in atrial fibrillation with and without peripheral artery disease and efficacy and safety of full- and half-dose edoxaban vs. warfarin: insights from ENGAGE AF-TIMI 48

AIMS

In patients with atrial fibrillation (AF), peripheral artery disease (PAD) is associated with higher rates of stroke and bleeding. Both higher dose edoxaban (60/30 mg) and lower dose edoxaban (30/15 mg) were non-inferior to warfarin for stroke and systemic embolism (SSE) and significantly reduced major bleeding in AF patients in the global study to assess the safety and effectiveness of edoxaban vs standard practice of dosing with warfarin in patients with atrial fibrillation (ENGAGE AF-TIMI 48) trial. Whether the efficacy and safety of these dosing strategies vs. warfarin are consistent in patients with AF and PAD has not been described.

METHODS AND RESULTS

Of 21 105 patients with AF randomized to warfarin, edoxaban 60/30 mg, or edoxaban 30/15 mg, 841 were identified with PAD. Endpoints included major adverse cardiovascular events (MACEs), SSE, and major bleeding. Patients with PAD had higher risk of MACEs [adjusted hazard ratio (HRadj) 1.33, 95% confidence interval (CI) 1.12-1.57, P = 0.001] and cardiovascular (CV) death (HRadj 1.49, 95% CI 1.21-1.83, P &lt; 0.001) than those without PAD, but not major bleeding. The efficacy of edoxaban 60/30 mg vs. warfarin was consistent regardless of PAD (SSE HR; PAD 1.16, 95% CI 0.42-3.20; no-PAD 0.86, 95% CI 0.74-1.02, P-interaction 0.57) as was major bleeding (PAD 0.96, 95% CI 0.54-1.70; no-PAD 0.80, 95% CI 0.70-0.91, P-interaction 0.54). Edoxaban 30/15 mg was inferior for SSE, with significant heterogeneity when stratified by PAD status (P-interaction 0.039).

CONCLUSION

Patients with AF and PAD are at heightened risk of MACEs and CV death vs. those without PAD. The efficacy and safety of edoxaban 60/30 mg vs. warfarin in AF are consistent regardless of PAD; however, edoxaban 30/15 mg is inferior for stroke prevention in AF patients with PAD. Clinical Trial Registration: ClinicalTrials.gov identifier: NCT00781391.

Rivaroxaban Plus Aspirin for Extended Thromboprophylaxis in Acutely Ill Medical Patients: Insights from the MARINER Trial

Background  The MARINER trial evaluated whether postdischarge thromboprophylaxis with rivaroxaban could reduce the primary outcome of symptomatic venous thromboembolism (VTE) or VTE-related death in acutely ill medical patients at risk for VTE. Although aspirin use was not randomized, approximately half of the enrolled patients were receiving aspirin at baseline. We hypothesized that thromboprophylaxis with once-daily rivaroxaban (10 mg or, if creatinine clearance was 30–49 mL/min, 7.5 mg) plus aspirin (R/A) would be superior to placebo without aspirin (no thromboprophylaxis [no TP]).

Methods  We compared the primary and major secondary outcomes in the intention-to-treat population in four subgroups defined at baseline: (1) R/A ( N  = 3,159); (2) rivaroxaban alone ( N  = 2,848); (3) aspirin alone ( N  = 3,046); and (4) no TP ( N  = 2,966). Major bleeding (MB) and nonmajor clinically relevant (NMCR) bleeding were assessed in the safety population on treatment plus 2 days.

Results  Patients on R/A had reduced symptomatic VTE and VTE-related death compared with no TP (0.76 vs 1.28%, p  = 0.042), and experienced less symptomatic VTE and all-cause mortality ( p  = 0.005) and all-cause mortality alone ( p  = 0.01) compared with no TP. Event incidences for rivaroxaban alone (0.91%) or aspirin alone (0.92%) were similar. MB was low in all groups but lowest in the no TP group. NMCR bleeding was increased with R/A compared with no TP ( p  = 0.009).

Limitations  Aspirin use was not randomized.

Conclusion  Extended postdischarge thromboprophylaxis with R/A was associated with less symptomatic VTE and VTE-related death compared with no TP in previously hospitalized medical patients at risk for VTE. NMCR bleeding was increased with R/A compared with no TP. These post hoc findings need confirmation in a prospective trial.

Dabigatran versus vitamin K antagonists for atrial fibrillation in clinical practice: final outcomes from Phase III of the GLORIA-AF registry

BACKGROUND

Prospectively collected, routine clinical practice-based data on antithrombotic therapy in non-valvular atrial fibrillation (AF) patients are important for assessing real-world comparative outcomes. The objective was to compare the safety and effectiveness of dabigatran versus vitamin K antagonists (VKAs) in patients with newly diagnosed AF.

METHODS AND RESULTS

GLORIA-AF is a large, prospective, global registry program. Consecutive patients with newly diagnosed AF and CHA2DS2-VASc scores ≥ 1 were included and followed for 3 years. To control for differences in patient characteristics, the comparative analysis for dabigatran versus VKA was performed on a propensity score (PS)-matched patient set. Missing data were multiply imputed. Proportional-hazards regression was used to estimate hazard ratios (HRs) for outcomes of interest. Between 2014 and 2016, 21,300 eligible patients were included worldwide: 3839 patients were prescribed dabigatran and 4836 VKA with a median age of 71.0 and 72.0 years, respectively; > 85% in each group had a CHA2DS2-VASc-score ≥ 2. The PS-matched comparative analysis for dabigatran and VKA included on average 3326 pairs of matched initiators. For dabigatran versus VKAs, adjusted HRs (95% confidence intervals) were: stroke 0.89 (0.59-1.34), major bleeding 0.61 (0.42-0.88), all-cause death 0.78 (0.63-0.97), and myocardial infarction 0.89 (0.53-1.48). Further analyses stratified by PS and region provided similar results.

CONCLUSIONS

Dabigatran was associated with a 39% reduced risk of major bleeding and 22% reduced risk for all-cause death compared with VKA. Stroke and myocardial infarction risks were similar, confirming a more favorable benefit-risk profile for dabigatran compared with VKA in clinical practice. Clinical trial registration https://www.

CLINICALTRIALS

gov . NCT01468701, NCT01671007.

Association of Bleeding Severity with Mortality in Extended Thromboprophylaxis of Medically Ill Patients in the MAGELLAN and MARINER Trials

Background: Extended thromboprophylaxis has not been widely implemented in acutely ill medical patients due to bleeding concerns. The MAGELLAN and MARINER trials evaluated whether rivaroxaban compared with enoxaparin or placebo could prevent venous thromboembolism (VTE) without increased bleeding. We hypothesized that patients with major bleeding (MB) but not those with non-major clinically relevant bleeding (NMCRB), would be at an increased risk of all-cause mortality (ACM). Methods: We evaluated all bleeding events in patients taking at least one dose of study drug and their association with ACM in 4 mutually exclusive groups: (1) no bleeding, or first event was (2) NMCRB, (3) MB, or (4) trivial bleeding. Using a Cox proportional hazards model adjusted for differences in baseline characteristics associated with ACM, we assessed the risk of ACM after such events. Results: Compared to patients with no bleeding, the risk of ACM for patients with NMCRB was not increased in MARINER (HR 0.43, p=0.235) but was increased in MAGELLAN (HR 1.74 p=0.021). MB was associated with a higher incidence of ACM in both studies, while trivial bleeding was not associated with ACM in either study. Conclusions: Patients with MB had an increased risk of ACM, while NMCRB was not consistently associated with an increased risk of death. These results inform the risk-benefit calculus of extended thromboprophylaxis in medically ill patients.

Correction to: Comparative effectiveness and safety of non-vitamin K antagonists for atrial fibrillation in clinical practice: GLORIA-AF Registry

In this article, the name of the GLORIA-AF investigator Anastasios Kollias was given incorrectly as Athanasios Kollias in the Acknowledgements. The original article has been corrected.

Comparative effectiveness and safety of non-vitamin K antagonists for atrial fibrillation in clinical practice: GLORIA-AF Registry

Background and purpose

Prospectively collected data comparing the safety and effectiveness of individual non-vitamin K antagonists (NOACs) are lacking. Our objective was to directly compare the effectiveness and safety of NOACs in patients with newly diagnosed atrial fibrillation (AF).

Methods

In GLORIA-AF, a large, prospective, global registry program, consecutive patients with newly diagnosed AF were followed for 3 years. The comparative analyses for (1) dabigatran vs rivaroxaban or apixaban and (2) rivaroxaban vs apixaban were performed on propensity score (PS)-matched patient sets. Proportional hazards regression was used to estimate hazard ratios (HRs) for outcomes of interest.

Results

The GLORIA-AF Phase III registry enrolled 21,300 patients between January 2014 and December 2016. Of these, 3839 were prescribed dabigatran, 4015 rivaroxaban and 4505 apixaban, with median ages of 71.0, 71.0, and 73.0 years, respectively. In the PS-matched set, the adjusted HRs and 95% confidence intervals (CIs) for dabigatran vs rivaroxaban were, for stroke: 1.27 (0.79–2.03), major bleeding 0.59 (0.40–0.88), myocardial infarction 0.68 (0.40–1.16), and all-cause death 0.86 (0.67–1.10). For the comparison of dabigatran vs apixaban, in the PS-matched set, the adjusted HRs were, for stroke 1.16 (0.76–1.78), myocardial infarction 0.84 (0.48–1.46), major bleeding 0.98 (0.63–1.52) and all-cause death 1.01 (0.79–1.29). For the comparison of rivaroxaban vs apixaban, in the PS-matched set, the adjusted HRs were, for stroke 0.78 (0.52–1.19), myocardial infarction 0.96 (0.63–1.45), major bleeding 1.54 (1.14–2.08), and all-cause death 0.97 (0.80–1.19).

Conclusions

Patients treated with dabigatran had a 41% lower risk of major bleeding compared with rivaroxaban, but similar risks of stroke, MI, and death. Relative to apixaban, patients treated with dabigatran had similar risks of stroke, major bleeding, MI, and death. Rivaroxaban relative to apixaban had increased risk for major bleeding, but similar risks for stroke, MI, and death.

Registration

URL: https://www.clinicaltrials.gov. Unique identifiers: NCT01468701, NCT01671007. Date of registration: September 2013.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-022-01996-2.

Direct Oral Anticoagulants Versus Warfarin in Patients With Atrial Fibrillation: Patient-Level Network Meta-Analyses of Randomized Clinical Trials With Interaction Testing by Age and Sex

BACKGROUND

Direct oral anticoagulants (DOACs) are preferred over warfarin for stroke prevention in atrial fibrillation. Meta-analyses using individual patient data offer substantial advantages over study-level data.

METHODS

We used individual patient data from the COMBINE AF (A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in Atrial Fibrillation) database, which includes all patients randomized in the 4 pivotal trials of DOACs versus warfarin in atrial fibrillation (RE-LY [Randomized Evaluation of Long-Term Anticoagulation Therapy], ROCKET AF [Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation], ARISTOTLE [Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation], and ENGAGE AF-TIMI 48 [Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48]), to perform network meta-analyses using a stratified Cox model with random effects comparing standard-dose DOAC, lower-dose DOAC, and warfarin. Hazard ratios (HRs [95% CIs]) were calculated for efficacy and safety outcomes. Covariate-by-treatment interaction was estimated for categorical covariates and for age as a continuous covariate, stratified by sex.

RESULTS

A total of 71 683 patients were included (29 362 on standard-dose DOAC, 13 049 on lower-dose DOAC, and 29 272 on warfarin). Compared with warfarin, standard-dose DOACs were associated with a significantly lower hazard of stroke or systemic embolism (883/29 312 [3.01%] versus 1080/29 229 [3.69%]; HR, 0.81 [95% CI, 0.74-0.89]), death (2276/29 312 [7.76%] versus 2460/29 229 [8.42%]; HR, 0.92 [95% CI, 0.87-0.97]), and intracranial bleeding (184/29 270 [0.63%] versus 409/29 187 [1.40%]; HR, 0.45 [95% CI, 0.37-0.56]), but no statistically different hazard of major bleeding (1479/29 270 [5.05%] versus 1733/29 187 [5.94%]; HR, 0.86 [95% CI, 0.74-1.01]), whereas lower-dose DOACs were associated with no statistically different hazard of stroke or systemic embolism (531/13 049 [3.96%] versus 1080/29 229 [3.69%]; HR, 1.06 [95% CI, 0.95-1.19]) but a lower hazard of intracranial bleeding (55/12 985 [0.42%] versus 409/29 187 [1.40%]; HR, 0.28 [95% CI, 0.21-0.37]), death (1082/13 049 [8.29%] versus 2460/29 229 [8.42%]; HR, 0.90 [95% CI, 0.83-0.97]), and major bleeding (564/12 985 [4.34%] versus 1733/29 187 [5.94%]; HR, 0.63 [95% CI, 0.45-0.88]). Treatment effects for standard- and lower-dose DOACs versus warfarin were consistent across age and sex for stroke or systemic embolism and death, whereas standard-dose DOACs were favored in patients with no history of vitamin K antagonist use (P=0.01) and lower creatinine clearance (P=0.09). For major bleeding, standard-dose DOACs were favored in patients with lower body weight (P=0.02). In the continuous covariate analysis, younger patients derived greater benefits from standard-dose (interaction P=0.02) and lower-dose DOACs (interaction P=0.01) versus warfarin.

CONCLUSIONS

Compared with warfarin, DOACs have more favorable efficacy and safety profiles among patients with atrial fibrillation.

Effect of Anticoagulant Therapy for 6 Weeks vs 3 Months on Recurrence and Bleeding Events in Patients Younger Than 21 Years of Age With Provoked Venous Thromboembolism: The Kids-DOTT Randomized Clinical Trial

IMPORTANCE

Among patients younger than 21 years of age, the optimal duration of anticoagulant therapy for venous thromboembolism is unknown.

OBJECTIVE

To test the hypothesis that a 6-week duration of anticoagulant therapy for provoked venous thromboembolism is noninferior to a conventional 3-month therapy duration in patients younger than 21 years of age.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial involving 417 patients younger than 21 years of age with acute, provoked venous thromboembolism enrolled at 42 centers in 5 countries from 2008-2021. The main exclusions were severe anticoagulant deficiencies or prior venous thromboembolism. Patients without persistent antiphospholipid antibodies and whose thrombi were resolved or not completely occlusive upon repeat imaging at 6 weeks after diagnosis underwent randomization. The final visit for the primary end points occurred in January 2021.

INTERVENTIONS

Total duration for anticoagulant therapy of 6 weeks (n = 207) vs 3 months (n = 210) for provoked venous thromboembolism.

MAIN OUTCOMES AND MEASURES

The primary efficacy and safety end points were centrally adjudicated symptomatic recurrent venous thromboembolism and clinically relevant bleeding events within 1 year blinded to treatment group. The primary analysis was noninferiority in the per-protocol population. The noninferiority boundary incorporated a bivariate trade-off that included an absolute increase of 0% in symptomatic recurrent venous thromboembolism with an absolute risk reduction of 4% in clinically relevant bleeding events (1 of 3 points on the bivariate noninferiority boundary curve).

RESULTS

Among 417 randomized patients, 297 (median age, 8.3 [range, 0.04-20.9] years; 49% female) met criteria for the primary per-protocol population analysis. The Kaplan-Meier estimate for the 1-year cumulative incidence of the primary efficacy outcome was 0.66% (95% CI, 0%-1.95%) in the 6-week anticoagulant therapy group and 0.70% (95% CI, 0%-2.07%) in the 3-month anticoagulant therapy group, and for the primary safety outcome, the incidence was 0.65% (95% CI, 0%-1.91%) and 0.70% (95% CI, 0%-2.06%). Based on absolute risk differences in recurrent venous thromboembolism and clinically relevant bleeding events between groups, noninferiority was demonstrated. Adverse events occurred in 26% of patients in the 6-week anticoagulant therapy group and in 32% of patients in the 3-month anticoagulant therapy group; the most common adverse event was fever (1.9% and 3.4%, respectively).

CONCLUSIONS AND RELEVANCE

Among patients younger than 21 years of age with provoked venous thromboembolism, anticoagulant therapy for 6 weeks compared with 3 months met noninferiority criteria based on the trade-off between recurrent venous thromboembolism risk and bleeding risk.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00687882.

Efficacy and Safety of Therapeutic-Dose Heparin vs Standard Prophylactic or Intermediate-Dose Heparins for Thromboprophylaxis in High-risk Hospitalized Patients With COVID-19: The HEP-COVID Randomized Clinical Trial

IMPORTANCE

Hospitalized patients with COVID-19 are at risk for venous and arterial thromboembolism and death. Optimal thromboprophylaxis dosing in high-risk patients is unknown.

OBJECTIVE

To evaluate the effects of therapeutic-dose low-molecular-weight heparin (LMWH) vs institutional standard prophylactic or intermediate-dose heparins for thromboprophylaxis in high-risk hospitalized patients with COVID-19.

DESIGN, SETTING, AND PARTICIPANTS

The HEP-COVID multicenter randomized clinical trial recruited hospitalized adult patients with COVID-19 with D-dimer levels more than 4 times the upper limit of normal or sepsis-induced coagulopathy score of 4 or greater from May 8, 2020, through May 14, 2021, at 12 academic centers in the US.

INTERVENTIONS

Patients were randomized to institutional standard prophylactic or intermediate-dose LMWH or unfractionated heparin vs therapeutic-dose enoxaparin, 1 mg/kg subcutaneous, twice daily if creatinine clearance was 30 mL/min/1.73 m2 or greater (0.5 mg/kg twice daily if creatinine clearance was 15-29 mL/min/1.73 m2) throughout hospitalization. Patients were stratified at the time of randomization based on intensive care unit (ICU) or non-ICU status.

MAIN OUTCOMES AND MEASURES

The primary efficacy outcome was venous thromboembolism (VTE), arterial thromboembolism (ATE), or death from any cause, and the principal safety outcome was major bleeding at 30 ± 2 days. Data were collected and adjudicated locally by blinded investigators via imaging, laboratory, and health record data.

RESULTS

Of 257 patients randomized, 253 were included in the analysis (mean [SD] age, 66.7 [14.0] years; men, 136 [53.8%]; women, 117 [46.2%]); 249 patients (98.4%) met inclusion criteria based on D-dimer elevation and 83 patients (32.8%) were stratified as ICU-level care. There were 124 patients (49%) in the standard-dose vs 129 patients (51%) in the therapeutic-dose group. The primary efficacy outcome was met in 52 of 124 patients (41.9%) (28.2% VTE, 3.2% ATE, 25.0% death) with standard-dose heparins vs 37 of 129 patients (28.7%) (11.7% VTE, 3.2% ATE, 19.4% death) with therapeutic-dose LMWH (relative risk [RR], 0.68; 95% CI, 0.49-0.96; P = .03), including a reduction in thromboembolism (29.0% vs 10.9%; RR, 0.37; 95% CI, 0.21-0.66; P < .001). The incidence of major bleeding was 1.6% with standard-dose vs 4.7% with therapeutic-dose heparins (RR, 2.88; 95% CI, 0.59-14.02; P = .17). The primary efficacy outcome was reduced in non-ICU patients (36.1% vs 16.7%; RR, 0.46; 95% CI, 0.27-0.81; P = .004) but not ICU patients (55.3% vs 51.1%; RR, 0.92; 95% CI, 0.62-1.39; P = .71).

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, therapeutic-dose LMWH reduced major thromboembolism and death compared with institutional standard heparin thromboprophylaxis among inpatients with COVID-19 with very elevated D-dimer levels. The treatment effect was not seen in ICU patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04401293.

Artificial Intelligence-Powered Blockchains for Cardiovascular Medicine

Clinical databases, particularly those composed of big data, face growing security challenges. Blockchain, the open, decentralized, distributed public ledger technology powering cryptocurrency, records transactions securely without the need for third-party verification. In the health care setting, decentralized blockchain networks offer a secure interoperable gateway for clinical research and practice data. Here, we discuss recent advances and potential future directions for the application of blockchain and its integration with artificial intelligence (AI) in cardiovascular medicine. We first review the basic underlying concepts of this technology and contextualise it within the spectrum of current, well known applications. We then consider specific applications for cardiovascular medicine and research in areas such as high-throughput gene sequencing, wearable technologies, and clinical trials. We then evaluate current challenges to effective implementation and future directions. We also summarise the health care applications that can be realised by combining decentralized blockchain computing platforms (for data security) and AI computing (for data analytics). By leveraging high-performance computing and AI capable of securely managing large and rapidly expanding medical databases, blockchain incorporation can provide clinically meaningful predictions, help advance research methodology (eg, via robust AI-blockchain decentralized clinical trials), and provide virtual tools in clinical practice (eg, telehealth, sensory-based technologies, wearable medical devices). Integrating AI and blockchain approaches synergistically amplifies the strengths of both technologies to create novel solutions to serve the objective of providing precision cardiovascular medicine.

Rivaroxaban for extended thromboprophylaxis in acutely ill medical patients 75 years of age or older

BACKGROUND

Although older patients are at increased risk for venous thromboembolism (VTE), thromboprophylaxis is underused because of bleeding concerns. The MARINER trial evaluated whether rivaroxaban reduced symptomatic postdischarge VTE in acutely ill medical patients.

OBJECTIVES

We hypothesized that rivaroxaban would have a favorable benefit/risk profile in patients ≥75 years of age.

METHODS

Patients were randomized in a double-blind manner at hospital discharge to rivaroxaban (10 mg/day for creatinine clearance ≥50 ml/min; 7.5 mg/day for ≥30-<50 ml/min) or placebo for 45 days. Using a Cox proportional hazard model including treatment as a covariate, we compared the risk of the primary efficacy outcome (symptomatic VTE plus VTE-related death in the intention-to-treat population) and safety outcome (International Society on Thrombosis and Haemostasis major bleeding in the safety population) in the prespecified subgroups of patients ≥ and <75 years of age.

RESULTS

The primary event rate in patients ≥75 years of age was 2-fold higher than that in those <75 years. The incidence of the primary efficacy outcomes in both age groups was numerically lower with rivaroxaban than with placebo (≥75: 1.2% and 1.6%, HR 0.73, 95% CI 0.43-1.22; <75 0.6% and 0.8%, HR 0.78, 95% CI 0.46-1.32; interaction p-value for age group = .85). The incidence of major bleeding was low and similar in the two age and treatment groups (interaction p value for age group = .35).

CONCLUSION

Symptomatic VTE and VTE-related death occur frequently in older patients with acute medical illness. The benefit/risk profile of rivaroxaban in patients ≥75 years of age appears consistent with that observed in the general population.

Termination Based on Event Accrual in Per Protocol Versus Intention to Treat in the ROCKET AF Trial

Background

In event‐driven clinical trials, study termination is based on accrual of a target number of primary efficacy events. For noninferiority trials in which superiority is conditionally examined, the ideal cohort in which to track event accrual is unclear. We used data from the ROCKET AF (Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation) trial to determine the effect of primary efficacy‐event tracking in the per‐protocol cohort during the on‐treatment period versus the intention‐to‐treat (ITT) cohort during the ITT period.

Methods and Results

ROCKET AF was terminated after accruing 429 primary efficacy events (stroke or systemic embolism) in the per‐protocol cohort during the on‐treatment period for noninferiority. We identified the date on which 429 events occurred in the ITT cohort during the ITT period. We performed noninferiority and superiority analyses based on hypothetical study termination on this date. ROCKET AF would have terminated 226 days earlier if events were tracked during the ITT period. Similar to the main trial findings, rivaroxaban would have met noninferiority versus warfarin for the primary efficacy end point (hazard ratio [HR], 0.77; 95% CI, 0.62–0.96; P<0.001). In contrast to the main trial findings, rivaroxaban would have met superiority for the primary efficacy end point (HR, 0.82; 95% CI, 0.68–0.99; P=0.038). In both termination scenarios, rivaroxaban was associated with a lower risk of intracranial hemorrhage and similar risk of other safety end points.

Conclusions

Clinical trial termination based on event accrual in the ITT cohort versus the per‐protocol cohort may have important implications on trial results depending on rates of study drug discontinuation and event rates off treatment.

Low bleeding and thromboembolic risk with continued dabigatran during cardiovascular interventions: the GLORIA-AF study

BACKGROUND

Prospective data on nonvitamin-K-antagonist oral anticoagulant (NOAC) management during cardiovascular interventions are limited. We therefore evaluated the safety and effectiveness of uninterrupted dabigatran therapy as well as dabigatran management during atrial fibrillation (AF)-cardioversions, AF-ablations, pacemaker implantations and coronary angiography and/or stenting procedures.

METHOD

GLORIA-AF is an international registry programme involving patients with newly diagnosed AF. Dabigatran users were followed for ≤2 years. The primary outcome was occurrence of stroke/systemic embolism and major bleeding ≤8 weeks after a cardiovascular intervention during uninterrupted dabigatran therapy.

RESULTS

During the 2-year follow-up, 599 cardiovascular interventions were identified in 479 eligible patients. 412/599 (69%) interventions were performed with uninterrupted dabigatran therapy: 299/354 (84%) AF-cardioversions, 38/89 (43%) AF-ablations, 25/58 (43%) pacemaker implantations, and 50/98 (51%) coronary angiography and/or stenting procedures. During an average follow-up of 8.4 weeks after intervention, one major bleed and one systemic embolic event occurred (risk 0.25% for both outcomes; 95% confidence interval, 0.01%-1.36%).

CONCLUSIONS

More than two thirds of the interventions were performed with uninterrupted dabigatran therapy, of which most were AF-cardioversions. Uninterrupted dabigatran therapy was associated with low major bleeding and stroke/systemic embolism risk, supporting the favourable safety and effectiveness profile of dabigatran in clinical practice-based settings.

Characteristics of patients with atrial high rate episodes detected by implanted defibrillator and resynchronization devices

Aims

Atrial high rate episodes (AHREs) are associated with increased risks of thromboembolism and cardiovascular mortality. However, the clinical characteristics of patients developing AHRE of various durations are not well studied.

Methods and results

This was an ancillary analysis of the multicentre, randomized IMPACT trial. In the present analysis, we classified patients according to the duration of AHRE ≤6 min, >6 min to ≤6 h, >6 to ≤24 h and >24 h, and investigated the association between clinical factors and the development of each duration of AHRE. Of 2718 patients included in the trial, 945 (34.8%) developed AHRE. The incidence rates of each AHRE duration category were 5.4/100, 12.0/100, 6.8/100, and 3.3/100 patient-years, respectively. The incidence rates of AHRE >6 h were significantly higher in patients at high risk of thromboembolism (CHADS₂ score ≥3) compared to those at low risk (CHADS₂ score 1 or 2). Using Cox regression analysis, age ≥65 years and history of atrial fibrillation (AF) and/or atrial flutter (AFL) were risk factors for AHRE >6 min. In addition, hypertension was associated with AHRE >24 h (hazard ratio 2.13, 95% confidence interval 1.24–3.65, P = 0.006).

Conclusion

Atrial high rate episode >6 min to ≤6 h were most prevalent among all AHRE duration categories. Longer AHREs were more common in patients at risk of thromboembolism. Age and history of AF/AFL were risk factors for AHRE >6 min. Furthermore, hypertension showed a strong impact on the development of AHRE >24 h rather than age.

Changes in anticoagulant prescription patterns over time for patients with atrial fibrillation around the world

BACKGROUND

Prescribing patterns for stroke prevention in atrial fibrillation (AF) patients evolved with approval of non-Vitamin K antagonist oral anticoagulants (NOACs) over time.

OBJECTIVES

To assess changes in anticoagulant prescription patterns in various geographical regions upon first approval of a NOAC and to analyze the evolution of oral anticoagulants (OACs) use over time in relation to CHA2DS2-VASc and HAS-BLED risk profiles.

METHODS

Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF) Phases II and III reported data on antithrombotic therapy for patients with newly diagnosed AF and ≥1 stroke risk factor. We focused on sites enrolling patients in both phases and reported treatment patterns for the first 4 years after initial NOAC approval.

RESULTS

From GLORIA-AF Phases II and III, 27 432 patients were eligible for this analysis. When contrasting the first year with the fourth year of enrolment, the proportion of NOAC prescriptions increased in Asia from 29.2% to 60.8%, in Europe from 53.4% to 75.8%, in North America from 49.0% to 73.9% and in Latin America from 55.7% to 71.1%. The proportion of Vitamin K antagonists (VKAs) use decreased across all regions over time, in Asia from 26.0% to 9.8%, in Europe from 35.5% to 16.8%, in North America from 28.9% to 12.1%, and in Latin America from 32.4% to 17.8%. In the multivariable analysis, factors associated with NOAC prescription were as follows: enrolment year, type of site, region, stroke and bleeding risk scores, and type and categorization of AF.

CONCLUSIONS

During 4 years after the approval of the first NOAC, NOAC use increased, while VKA use decreased, across all regions.

Antithrombotic treatment for newly diagnosed atrial fibrillation in relation to patient age: the GLORIA-AF registry programme

AIMS

To assess antithrombotic therapy choices in relation to patient age in a large, global registry on atrial fibrillation (AF).

METHODS AND RESULTS

Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF) is an international programme involving patients with newly diagnosed AF and ≥1 risk factors for stroke. We used Phase II data (from November 2011 through December 2014), which commenced immediately following first non-vitamin K antagonist oral anticoagulants (NOACs) approval in participating countries. Of 15 092 patients (mean age 70.5 ± 11.0 years), enrolled at 982 centres, 26.9% were aged <65 years, 33.9% 65-74, 30.5% 75-84, and 8.6% ≥85 years old. Oral anticoagulant (OAC) use was 73.5%, 81.4%, 83.3%, and 82.3% (overall NOACs use was 44.4%, 49.7%, 48.7%, and 45.6%) for those aged <65, 65-74, 75-84 and ≥85 years, respectively. Corresponding proportions for antiplatelet monotherapy and no treatment were: 16.2% and 10.2%; 11.2% and 7.3%; 10.0% and 6.5%; 10.5% and 7.0%, respectively. Of those aged 65-74, 75-84, and ≥85 years, respectively, 83.7, 86.8 and 85.4% received OAC unless bleeding risk was high (HAS-BLED ≥3), whereby 64.1%, 63.5%, and 64.5% were anticoagulated, and 31.1%, 30.3%, and 31.3% received antiplatelets only. Of patients ≥85 years, OAC use was 88.1% in Europe (NOAC 45.1%), 79.5% in North America (NOAC 44.8%), and 54.1% in Asia (NOAC 40.2%).

CONCLUSION

Despite geographic differences in OAC use, neither OAC nor NOAC uptake was lower for patients ≥85 years old compared with younger patients. Although the majority of patients was prescribed OAC at all ages, nearly one-third received antiplatelet monotherapy when bleeding risk was increased.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov. Unique identifier: NCT01468701.

Rivaroxaban versus warfarin in patients with atrial fibrillation enrolled in Latin America: Insights from ROCKET AF

BACKGROUND

ROCKET AF demonstrated the efficacy and safety of rivaroxaban compared with warfarin for the prevention of stroke and systemic embolism (SE) in patients with atrial fibrillation (AF). We examined baseline characteristics and outcomes in patients enrolled in Latin America compared with the rest of the world (ROW).

METHODS

ROCKET AF enrolled 14,264 patients from 45 countries. Of these, 1,878 (13.2%) were from 7 Latin American countries. The clinical characteristics and outcomes (adjusted by baseline characteristics) of these patients were compared with 12,293 patients from the ROW. Treatment outcomes of rivaroxaban compared with warfarin were also stratified by region.

RESULTS

The annual rate of stroke/SE was similar in those from Latin American and ROW (P= .63), but all-cause and vascular death were significantly higher than in ROW (HR 1.40, 95% CI 1.20-1.64; HR 1.38, 95% CI 1.14-1.68; P< .001). Rates of major or nonmajor clinically relevant bleeding tended to be lower in Latin America (HR 0.89, 95% CI 0.80-1.0; P= .05). Rates of stroke and/or SE were similar with rivaroxaban and warfarin in patients from Latin America and ROW (HR 0.83, 95% CI 0.54-1.29 vs HR 0.89, 95% CI 0.75-1.07; interaction P= .77).

CONCLUSIONS

Patients with AF in Latin America had similar rates of stroke and/or SE, higher rates of vascular death, and lower rates of bleeding compared with patients in the ROW. The effect of rivaroxaban compared with warfarin in Latin America was similar to the ROW. Further studies analyzing patient- and country-specific determinants of these regional differences in Latin America are warranted.

Machine learning and deep learning to predict mortality in patients with spontaneous coronary artery dissection

Machine learning (ML) and deep learning (DL) can successfully predict high prevalence events in very large databases (big data), but the value of this methodology for risk prediction in smaller cohorts with uncommon diseases and infrequent events is uncertain. The clinical course of spontaneous coronary artery dissection (SCAD) is variable, and no reliable methods are available to predict mortality. Based on the hypothesis that machine learning (ML) and deep learning (DL) techniques could enhance the identification of patients at risk, we applied a deep neural network to information available in electronic health records (EHR) to predict in-hospital mortality in patients with SCAD. We extracted patient data from the EHR of an extensive urban health system and applied several ML and DL models using candidate clinical variables potentially associated with mortality. We partitioned the data into training and evaluation sets with cross-validation. We estimated model performance based on the area under the receiver-operator characteristics curve (AUC) and balanced accuracy. As sensitivity analyses, we examined results limited to cases with complete clinical information available. We identified 375 SCAD patients of which mortality during the index hospitalization was 11.5%. The best-performing DL algorithm identified in-hospital mortality with AUC 0.98 (95% CI 0.97-0.99), compared to other ML models (P < 0.0001). For prediction of mortality using ML models in patients with SCAD, the AUC ranged from 0.50 with the random forest method (95% CI 0.41-0.58) to 0.95 with the AdaBoost model (95% CI 0.93-0.96), with intermediate performance using logistic regression, decision tree, support vector machine, K-nearest neighbors, and extreme gradient boosting methods. A deep neural network model was associated with higher predictive accuracy and discriminative power than logistic regression or ML models for identification of patients with ACS due to SCAD prone to early mortality.

Pharmacotherapy for diabetes and stroke risk: Results from ROCKET AF

Background

Insulin use may be a better predictor of stroke risk and morbidity and mortality than diabetes in patients with atrial fibrillation (AF).

Objectives

Determine if the increased risk of stroke observed in patients with AF and diabetes is restricted to those treated with insulin.

Methods

We analyzed the association between diabetes and treatment and the occurrence of stroke/systemic embolism, myocardial infarction (MI), all-cause death, vascular death, composite outcomes, and bleeding risk in the ROCKET AF trial.

Results

In a cohort of 14,264 patients, there were 40.3% (n = 5746) with diabetes, 5.9% (n = 842) on insulin, 18.9% (n = 2697) on oral medications, and 11.9% (n = 1703) diet-controlled. Compared to those without diabetes, patients with non–insulin-treated diabetes had increased risks of stroke (hazard ratio [HR] 1.33, 95% confidence interval [CI] 1.06–1.68), MI (HR 1.64, 95% CI 1.17–2.30), all-cause death (HR 1.26, 95% CI 1.08–1.46), vascular death (HR 1.33, 95% CI 1.11–1.60), and composite outcomes (HR 1.37, 95% CI 1.18–1.157). Patients with insulin-treated diabetes had a significantly higher risk of MI (HR 2.31, 95% CI 1.33–4.01) and composite outcomes (HR 1.57, 95% CI 1.19–2.08) compared to those without diabetes. There were no significant differences between insulin-treated and non–insulin-treated diabetes for any outcome.

Conclusion

Among patients with AF and diabetes, there were no significant differences in outcomes in insulin-treated diabetes compared to non–insulin-treated diabetes.

Relation of Antecedent Symptoms to the Likelihood of Detecting Subclinical Atrial Fibrillation With Inserted Cardiac Monitors

Atrial fibrillation (AF) comes to attention clinically during an evaluation of symptoms, an evaluation of its adverse outcomes, or because of incidental detection during a routine examination or electrocardiogram. However, a notable number of additional individuals have AF that has not yet been clinically apparent or suspect-subclinical AF (SCAF). SCAF has been recognized during interrogation of pacemakers and defibrillators. More recently, SCAF has been demonstrated in prospective studies with long-term monitors-both external and implanted. The REVEAL AF trial enrolled a demographically "enriched" population that underwent monitoring for up to 3 years with an insertable cardiac monitor. SCAF was noted in 40% by 30 months. None of these patients had AF known before the study; however, some had nonspecific symptoms common to patients with known AF. The current study assessed whether patients with versus without such symptoms were more likely to have SCAF detected. We found that only palpitations had an association with AF detection when controlling for other baseline symptoms (hazard ratio 1.61 (95% confidence interval 1.12 to 2.32; p = 0.011). No other prescreening symptoms evaluated were associated with an increased likelihood of SCAF detection although patients without detected SCAF had an even higher frequency of symptoms than those with detected SCAF. Thus, REVEAL AF demonstrated that the presence of palpitations is associated with an increased likelihood of SCAF whereas other common symptoms are not; and, symptoms, per se, may more likely be consequent to associated disorders than they are a direct consequence of SCAF.

Treatment-Dose LMWH versus Prophylactic/Intermediate Dose Heparins in High-Risk COVID-19 Inpatients: Rationale and Design of the HEP-COVID Trial

Coronavirus disease-2019 (COVID-19) has been associated with significant risk of venous thromboembolism (VTE), arterial thromboembolism (ATE), and mortality particularly among hospitalized patients with critical illness and elevated D-dimer (Dd) levels. Conflicting data have yet to elucidate optimal thromboprophylaxis dosing. HEP-COVID (NCT04401293) is a phase 3, multicenter, pragmatic, prospective, randomized, pseudo-blinded, active control trial to evaluate efficacy and safety of therapeutic-dose low-molecular-weight heparin (LMWH) versus prophylactic-/intermediate-dose LMWH or unfractionated heparin (UFH) for prevention of a primary efficacy composite outcome of VTE, ATE, and all-cause mortality 30 ± 2 days post-enrollment. Eligible patients have COVID-19 diagnosis by nasal swab or serologic testing, requirement for supplemental oxygen per investigator judgment, and Dd >4 × upper limit of normal (ULN) or sepsis-induced coagulopathy score ≥4. Subjects are randomized to enoxaparin 1 mg/kg subcutaneous (SQ)/two times a day (BID) (creatinine clearance [CrCl] ≥ 30 mL/min) or 0.5 mg/kg (CrCl 15-30 mL/min) versus local institutional prophylactic regimens including (1) UFH up to 22,500 IU (international unit) daily (divided BID or three times a day), (2) enoxaparin 30 and 40 mg SQ QD (once daily) or BID, or (3) dalteparin 2,500 IU or 5,000 IU QD. The principal safety outcome is major bleeding. Events are adjudicated locally. Based on expected 40% relative risk reduction with treatment-dose compared with prophylactic-dose prophylaxis, 308 subjects will be enrolled (assuming 20% drop-out) to achieve 80% power. Distinguishing design features include an enriched population for the composite endpoint anchored on Dd >4 × ULN, stratification by intensive care unit (ICU) versus non-ICU, and the ability to capture asymptomatic proximal deep venous thrombosis via screening ultrasonography prior to discharge.

Atrial Fibrillation in Patients Hospitalized With COVID-19: Incidence, Predictors, Outcomes and Comparison to Influenza

Objectives

The goal of this study is to determine the incidence, predictors, and outcomes of atrial fibrillation (AF) or atrial flutter (AFL) in patients hospitalized with coronavirus disease-2019 (COVID-19).

Background

COVID-19 results in increased inflammatory markers previously associated with atrial arrhythmias. However, little is known about their incidence or specificity in COVID-19 or their association with outcomes.

Methods

This is a retrospective analysis of 3,970 patients admitted with polymerase chain reaction–positive COVID-19 between February 4 and April 22, 2020, with manual review performed of 1,110. The comparator arm included 1,420 patients with influenza hospitalized between January 1, 2017, and January 1, 2020.

Results

Among 3,970 inpatients with COVID-19, the incidence of AF/AFL was 10% (n = 375) and in patients without a history of atrial arrhythmias it was 4% (n = 146). Patients with new-onset AF/AFL were older with increased inflammatory markers including interleukin 6 (93 vs. 68 pg/ml; p < 0.01), and more myocardial injury (troponin-I: 0.2 vs. 0.06 ng/ml; p < 0.01). AF and AFL were associated with increased mortality (46% vs. 26%; p < 0.01). Manual review captured a somewhat higher incidence of AF/AFL (13%, n = 140). Compared to inpatients with COVID-19, patients with influenza (n = 1,420) had similar rates of AF/AFL (12%, n = 163) but lower mortality. The presence of AF/AFL correlated with similarly increased mortality in both COVID-19 (relative risk: 1.77) and influenza (relative risk: 1.78).

Conclusions

AF/AFL occurs in a subset of patients hospitalized with either COVID-19 or influenza and is associated with inflammation and disease severity in both infections. The incidence and associated increase in mortality in both cohorts suggests that AF/AFL is not specific to COVID-19, but is rather a generalized response to the systemic inflammation of severe viral illnesses.

Anticoagulation Prescription and Outcomes in Relation to Renal Function in Patients with Atrial Fibrillation: Results from GLORIA-AF

Objective  Anticoagulation management in patients with atrial fibrillation (AF) and impaired renal function is challenging. This study aimed to evaluate anticoagulation prescription patterns in relation to renal function and to describe 2-year clinical outcomes among dabigatran users. Methods  Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF) is an international, prospective, and observational study program involving patients with newly diagnosed AF at risk for stroke. Prescription patterns were assessed by creatinine clearance (CrCl) at enrollment. Dabigatran users were followed for 2 years. Clinical outcomes were standardized for stroke and bleeding risk, based on CHA ₂ DS ₂ -VASc and HAS-BLED scores, with missing values imputed. Results  Baseline CrCl values were available for 12,056 of 15,308 eligible patients (79%). With declining renal function, prescriptions increased for vitamin K antagonists (VKAs) and decreased for dabigatran (30-47% and 34-12%, respectively). The prescription of other non-vitamin K antagonists remained similar across CrCl groups (14-19%). In 4,873 dabigatran users, standardized stroke rates were low across all CrCl groups; 0.58/100 patient-years (95% confidence interval [CI]: 0.30-0.90) in CrCl ≥80 mL/min, 0.85 (95% CI: 0.48-1.21) in CrCl 50 to 79 mL/min, and 0.33 (95% CI: 0.06-1.11) in CrCl 30 to 49 mL/min. Similarly, major bleeding rates were low and numerically increased with declining renal function (0.68/100 patient-years, 95% CI: 0.39-1.03; 0.92, 95% CI: 0.58-1.32; and 1.26, 95% CI: 0.66-1.97, respectively). Conclusion  In patients with AF, VKA prescriptions increased and dabigatran prescriptions decreased with declining renal function. Rates of stroke and major bleeding in dabigatran patients remained low across the categories of renal impairment.

Anticoagulant selection in relation to the SAMe-TT2R2 score in patients with atrial fibrillation: The GLORIA-AF registry

AIM

The SAMe-TT₂R₂ score helps identify patients with atrial fibrillation (AF) likely to have poor anticoagulation control during anticoagulation with vitamin K antagonists (VKA) and those with scores >2 might be better managed with a target-specific oral anticoagulant (NOAC). We hypothesized that in clinical practice, VKAs may be prescribed less frequently to patients with AF and SAMe-TT₂R₂ scores >2 than to patients with lower scores.

METHODS AND RESULTS

We analyzed the Phase III dataset of the Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF), a large, global, prospective global registry of patients with newly diagnosed AF and ≥1 stroke risk factor. We compared baseline clinical characteristics and antithrombotic prescriptions to determine the probability of the VKA prescription among anticoagulated patients with the baseline SAMe-TT₂R₂ score >2 and ≤ 2. Among 17,465 anticoagulated patients with AF, 4,828 (27.6%) patients were prescribed VKA and 12,637 (72.4%) patients an NOAC: 11,884 (68.0%) patients had SAMe-TT₂R₂ scores 0-2 and 5,581 (32.0%) patients had scores >2. The proportion of patients prescribed VKA was 28.0% among patients with SAMe-TT₂R₂ scores >2 and 27.5% in those with scores ≤2.

CONCLUSIONS

The lack of a clear association between the SAMe-TT₂R₂ score and anticoagulant selection may be attributed to the relative efficacy and safety profiles between NOACs and VKAs as well as to the absence of trial evidence that an SAMe-TT₂R₂-guided strategy for the selection of the type of anticoagulation in NVAF patients has an impact on clinical outcomes of efficacy and safety. The latter hypothesis is currently being tested in a randomized controlled trial.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov//Unique identifier: NCT01937377, NCT01468701, and NCT01671007.

Cardiovascular risk and complications associated with COVID-19

In December 2019, an unprecedented outbreak of pneumonia cases associated with acute respiratory distress syndrome (ARDS) first occurred in Wuhan, Hubei Province, China. The disease, later named Coronavirus disease 2019 (COVID-19) by the World Health Organization (WHO), was caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), and on January 30, 2020, the WHO declared the outbreak of COVID-19 to be a public health emergency. COVID-19 is now a global pandemic impacting more than 43,438,043 patients with 1,158,596 deaths globally as of August 26th, 2020. COVID-19 is highly contagious and has caused more deaths than SARS in 2002-2003 or the Middle East Respiratory Syndrome (MERS) in 2012-2013 combined and represents an unprecedented human affliction not seen since the influenza pandemic of 1918. COVID-19 has been associated with several cardiac complications, including hypercoagulability, acute myocardial injury and myocarditis, arrhythmias, and acute coronary syndromes. Patients with pre-existing cardiovascular disease (CVD) are at the highest risk for myocardial injury and mortality among infected patients. The mechanism by which COVID-infected patients develop cardiac complications remains unclear, though it may be mediated by increased ACE-2 gene expression. Despite initial concerns, there is no evidence that angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) therapy increases risk for myocardial injury among those infected with COVID-19. In the current report, we summarize the peer-reviewed and preprint literature on cardiovascular risks and complications associated with COVID-19, as well as provide insights into its pathogenesis and management.

Antithrombotic Therapy in Patients with Atrial Fibrillation Undergoing Percutaneous Coronary Intervention

Patients with atrial fibrillation who undergo percutaneous coronary intervention with drug-eluting stent implantation often require oral anticoagulation (OAC) and antiplatelet therapies. Triple antithrombotic therapy (OAC, a P2Y₁₂-receptor inhibitor, and aspirin) has been the default antithrombotic strategy. Evidence from randomized trials indicates, however, that a dual antithrombotic therapy strategy (OAC plus a P2Y₁₂-receptor inhibitor) reduces bleeding risk without increasing the risk of ischemic events. This review provides an overview of advancements in this field as well as European and North American guidelines and consensus documents to inform clinical decision making around antithrombotic therapies for patients with atrial fibrillation who undergo percutaneous coronary intervention.

Malignant Arrhythmias in Patients With COVID-19: Incidence, Mechanisms, and Outcomes

Supplemental Digital Content is available in the text.

Background:

Patients with coronavirus disease 2019 (COVID-19) who develop cardiac injury are reported to experience higher rates of malignant cardiac arrhythmias. However, little is known about these arrhythmias—their frequency, the underlying mechanisms, and their impact on mortality.

Methods:

We extracted data from a registry (NCT04358029) regarding consecutive inpatients with confirmed COVID-19 who were receiving continuous telemetric ECG monitoring and had a definitive disposition of hospital discharge or death. Between patients who died versus discharged, we compared a primary composite end point of cardiac arrest from ventricular tachycardia/fibrillation or bradyarrhythmias such as atrioventricular block.

Results:

Among 800 patients with COVID-19 at Mount Sinai Hospital with definitive dispositions, 140 patients had telemetric monitoring, and either died (52) or were discharged (88). The median (interquartile range) age was 61 years (48–74); 73% men; and ethnicity was White in 34%. Comorbidities included hypertension in 61%, coronary artery disease in 25%, ventricular arrhythmia history in 1.4%, and no significant comorbidities in 16%. Compared with discharged patients, those who died had elevated peak troponin I levels (0.27 versus 0.02 ng/mL) and more primary end point events (17% versus 4%, P=0.01)—a difference driven by tachyarrhythmias. Fatal tachyarrhythmias invariably occurred in the presence of severe metabolic imbalance, while atrioventricular block was largely an independent primary event.

Conclusions:

Hospitalized patients with COVID-19 who die experience malignant cardiac arrhythmias more often than those surviving to discharge. However, these events represent a minority of cardiovascular deaths, and ventricular tachyarrhythmias are mainly associated with severe metabolic derangement.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04358029.

Deep learning for cardiovascular medicine: a practical primer

Deep learning (DL) is a branch of machine learning (ML) showing increasing promise in medicine, to assist in data classification, novel disease phenotyping and complex decision making. Deep learning is a form of ML typically implemented via multi-layered neural networks. Deep learning has accelerated by recent advances in computer hardware and algorithms and is increasingly applied in e-commerce, finance, and voice and image recognition to learn and classify complex datasets. The current medical literature shows both strengths and limitations of DL. Strengths of DL include its ability to automate medical image interpretation, enhance clinical decision-making, identify novel phenotypes, and select better treatment pathways in complex diseases. Deep learning may be well-suited to cardiovascular medicine in which haemodynamic and electrophysiological indices are increasingly captured on a continuous basis by wearable devices as well as image segmentation in cardiac imaging. However, DL also has significant weaknesses including difficulties in interpreting its models (the 'black-box' criticism), its need for extensive adjudicated ('labelled') data in training, lack of standardization in design, lack of data-efficiency in training, limited applicability to clinical trials, and other factors. Thus, the optimal clinical application of DL requires careful formulation of solvable problems, selection of most appropriate DL algorithms and data, and balanced interpretation of results. This review synthesizes the current state of DL for cardiovascular clinicians and investigators, and provides technical context to appreciate the promise, pitfalls, near-term challenges, and opportunities for this exciting new area.

Machine learning prediction in cardiovascular diseases: a meta-analysis

Several machine learning (ML) algorithms have been increasingly utilized for cardiovascular disease prediction. We aim to assess and summarize the overall predictive ability of ML algorithms in cardiovascular diseases. A comprehensive search strategy was designed and executed within the MEDLINE, Embase, and Scopus databases from database inception through March 15, 2019. The primary outcome was a composite of the predictive ability of ML algorithms of coronary artery disease, heart failure, stroke, and cardiac arrhythmias. Of 344 total studies identified, 103 cohorts, with a total of 3,377,318 individuals, met our inclusion criteria. For the prediction of coronary artery disease, boosting algorithms had a pooled area under the curve (AUC) of 0.88 (95% CI 0.84-0.91), and custom-built algorithms had a pooled AUC of 0.93 (95% CI 0.85-0.97). For the prediction of stroke, support vector machine (SVM) algorithms had a pooled AUC of 0.92 (95% CI 0.81-0.97), boosting algorithms had a pooled AUC of 0.91 (95% CI 0.81-0.96), and convolutional neural network (CNN) algorithms had a pooled AUC of 0.90 (95% CI 0.83-0.95). Although inadequate studies for each algorithm for meta-analytic methodology for both heart failure and cardiac arrhythmias because the confidence intervals overlap between different methods, showing no difference, SVM may outperform other algorithms in these areas. The predictive ability of ML algorithms in cardiovascular diseases is promising, particularly SVM and boosting algorithms. However, there is heterogeneity among ML algorithms in terms of multiple parameters. This information may assist clinicians in how to interpret data and implement optimal algorithms for their dataset.

Stroke prevention in atrial fibrillation changes after dabigatran availability in China: The GLORIA-AF registry

Background

Until the approval of dabigatran etexilate, treatment choices for stroke prevention in patients with atrial fibrillation (AF) were vitamin K antagonists (VKAs) or antiplatelet drugs. This analysis explored whether availability of non-vitamin K antagonist oral anticoagulants post-dabigatran approval was associated with changing treatment patterns in China.

Methods

Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF) collected data on antithrombotic therapy choices for patients with newly diagnosed nonvalvular AF at risk for stroke. In China, enrollment in phase 1 (before dabigatran approval) and phase 2 (after dabigatran approval) occurred from 2011 to 2013 and 2013 to 2014, respectively. Analyses were restricted to sites within China that contributed patients to both phases. The weighted average of the site-specific results was estimated for standardization. Sensitivity analyses used multiple regression.

Results

Thirteen sites participated in both phase 1 (419 patients) and phase 2 (276 patients), 76.1% and 16.0% were known to be at high risk for stroke (CHA₂DS₂-VASc ≥2) and bleeding (HAS-BLED ≥3); 55.5% were male. In phase 1, 16.7%, 61.6%, and 21.7% of patients were prescribed oral anticoagulants (OACs), antiplatelet agents, and no treatment, respectively. Respective proportions were 26.4%, 40.6%, and 33.0% in phase 2. The absolute increase in the site-standardized proportion of patients prescribed OACs after dabigatran availability was 9.9% (95% confidence interval [CI]: 3.7%-16.0%). There was a standardized 17.3% (95% CI: -24.3% to -10.4%) absolute decrease in antiplatelet agent use.

Conclusions

There was an increase in OAC and decrease in antiplatelet agent prescription since dabigatran availability in China. However, a large proportion of AF patients at risk for stroke remained untreated.

Dabigatran Persistence and Outcomes Following Discontinuation in Atrial Fibrillation Patients from the GLORIA-AF Registry

Prospective studies evaluating persistence to nonvitamin K antagonist oral anticoagulants in patients with atrial fibrillation are needed to improve our understanding of drug discontinuation. The study objective was to evaluate if and when patients with newly diagnosed atrial fibrillation stop dabigatran treatment and to report outcomes following discontinuation. Patients prescribed dabigatran in diverse clinical practice settings were consecutively enrolled and followed for 2 years. Dabigatran persistence over time, reasons for discontinuation, and outcomes post discontinuation were assessed. Of 4,859 patients, aged 70.2 ± 10.4 years, 55.7% were male. Overall 2-year dabigatran persistence was 70.9% (95% confidence interval [CI] 69.6 to 72.2). Persistence probability was lower in the first 6-month period (83.7% [82.7 to 84.8]) than in subsequent periods for patients on dabigatran at the start of each period (6 to 12 months, 92.5% [91.6 to 93.3]; 12 to 18 months, 95.1% [94.3 to 95.8]; 18 to 24 months, 96.3% [95.6 to 96.9]). Of 1,305 patients (26.9%) who discontinued dabigatran, adverse events were reported as the reason for discontinuation in 457 (35.0%). Standardized stroke incidence rate post discontinuation (per 100 patient-years) in patients discontinuing without switching to another oral anticoagulant was 1.76 (95% CI 0.89 to 2.76) and 1.02 (95% CI 0.43 to 1.76) in those who switched, consistent with the expected benefit of remaining on treatment. Patients persistent with treatment at 1 year had >90% probability of remaining persistent at 2 years suggesting clinical interventions to improve persistence should be focused on the early period following treatment initiation.

Rhythm monitoring strategies in patients at high risk for atrial fibrillation and stroke: A comparative analysis from the REVEAL AF study

BACKGROUND

Reducing atrial fibrillation (AF)-related stroke requires timely AF diagnosis, but the optimal monitoring strategy is unknown.

OBJECTIVE

We used insertable cardiac monitor (ICM) data from the REVEAL AF study to compare AF detection rates by various short-term continuous monitoring (STM) strategies.

METHODS AND RESULTS

Patients without known AF, but with CHADS₂ scores ≥3 (or = 2 with ≥1 additional AF risk factor) received an ICM for AF detection. One-time STM strategies were assessed by computing AF incidence at 1, 2, 7, 14, and 30 days post-ICM insertion. Repeated STM strategies (quarterly 24-hour, 48-hour, 7-day, or monthly 24-hour monitoring) were modeled by randomly selecting day(s) within a 30-day window around each nominal evaluation date over a 1-year period (simulated 10,000 times). Endpoints included AF ≥6 minutes, AF ≥1 hour, and daily AF burden ≥1 and ≥ 5.5 hours. The impact of compliance on AF detection was evaluated using daily compliance rates of 85%, 75%, 65% and 55% during follow-up months 1-3, 4-6, 7-9, and 9-12, respectively. Based on data from 385 patients (71.5 ± 9.9 years; CHADS₂ score 3.0 ± 1.0) the incidence of AF ≥6 minutes via ICM at 12 months was 27.1% (95% CI, 22.5-31.5%). This exceeded the range of estimated rates from all modeled one-time and repeated STM strategies (0.8% for 24-hour Holter monitoring to 10.6% for quarterly 7-day monitoring). Findings were similar for all AF endpoints. Modeled non-compliance reduced AF detection by 4.5% to 22.9%.

CONCLUSIONS

Most AF episodes detected via ICMs would go undetected via conventional STM strategies, thus preventing optimal prophylaxis for adverse consequences.

Patient-Reported Satisfaction and Study Drug Discontinuation: Post-Hoc Analysis of Findings from ROCKET AF

INTRODUCTION

Patient-reported outcomes (PROs) and satisfaction endpoints are increasingly important in clinical trials and may be associated with treatment adherence. In this post hoc substudy from ROCKET AF, we examined whether patient-reported satisfaction was associated with study drug discontinuation.

METHODS

ROCKET AF (n = 14,264) compared rivaroxaban with warfarin for prevention of stroke and systemic embolism in patients with atrial fibrillation. We analyzed treatment satisfaction scores: the Anti-Clot Treatment Scale (ACTS) and Treatment Satisfaction Questionnaire for Medication version II (TSQM II). We compared satisfaction with study drug between the two treatment arms, and examined the association between satisfaction and patient-driven study drug discontinuation (stopping study drug due to withdrawal of consent, noncompliance, or loss to follow-up).

RESULTS

A total of 1577 (11%) patients participated in the Patient Satisfaction substudy; 1181 (8.3%) completed both the ACTS and TSQM II 4 weeks after starting study drug. Patients receiving rivaroxaban did not experience significant differences in satisfaction compared with those receiving warfarin. During a median follow-up of 1.6 years, 448 premature study drug discontinuations occurred (213 rivaroxaban group; 235 warfarin group), of which 116 (26%) were patient-driven (52 [24%] rivaroxaban group; 64 [27%] warfarin group). No significant differences were observed between satisfaction level and rates of patient-driven study drug discontinuation.

CONCLUSIONS

Study drug satisfaction did not predict rate of study drug discontinuation. No significant difference was observed between satisfaction with warfarin and rivaroxaban, as expected given the double-blind trial design. Although these results are negative, the importance of PRO data will only increase, and these analyses may inform future studies that explore the relationship between drug-satisfaction PROs, adherence, and clinical outcomes. CLINICALTRIALS.GOV: NCT00403767.

FUNDING

The ROCKET AF trial was funded by Johnson & Johnson and Bayer.

Net Clinical Benefit of Left Atrial Appendage Closure Versus Warfarin in Patients With Atrial Fibrillation: A Pooled Analysis of the Randomized PROTECT-AF and PREVAIL Studies

Background

The PROTECT‐AF (Watchman Left Atrial Appendage Closure Technology for Embolic Protection in Patients With Atrial Fibrillation) and PREVAIL (Evaluation of the Watchman LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy) trials demonstrated noninferiority of left atrial appendage closure (LAAC) to warfarin for the composite end point of stroke, systemic embolism, or cardiovascular death. This study aims to quantify the net clinical benefit (NCB) of LAAC versus warfarin, accounting for differences in clinical impact of different event types.

Methods and Results

We performed a post hoc analysis of the PROTECT‐AF and PREVAIL trials, which randomized atrial fibrillation patients to LAAC or warfarin in a 2:1 fashion. The trials enrolled patients in the United States and Europe between 2005 and 2012 with paroxysmal, persistent, or permanent atrial fibrillation and CHADS₂ risk scores ≥1. Relative to an index weight for death (1.0), events were assigned weights based on their disabling effect: (1) stroke event weights were based on modified Rankin scores in the base case analyses, and (2) major bleed (0.05) and pericardial effusion (0.05). NCB was calculated as the sum of weight‐adjusted events per 100 patient‐years. Among 1114 randomized subjects, the NCB of LAAC was 1.42% per year (95% CI 0.01–2.82, P=0.04) and a relative risk of 0.74 (95% CI 0.56–1.00). NCB point estimates favored warfarin early in follow‐up, but trended in favor of LAAC after 1 to 2 years. The benefit of LAAC was preserved across subgroups, with particular benefit observed in the subgroup of prior stroke and without diabetes mellitus.

Conclusions

This analysis demonstrates long‐term NCB of LAAC with Watchman over warfarin therapy, as the upfront risk of periprocedural events is counterbalanced over time by reduced bleeding events and mortality.

Clinical Trial Registration

UR: http://www.clinicaltrials.gov. Unique identifiers: NCT01182441 and NCT00129545.

Novel Oral Anticoagulant Based Versus Vitamin K Antagonist Based Double Therapy Among Stented Patients With Atrial Fibrillation: Insights From the PIONEER AF-PCI Trial

BACKGROUND

Among stented patients with atrial fibrillation, double therapy with a novel oral anticoagulant plus single antiplatelet therapy (SAPT) reduces bleeding or cardiovascular rehospitalizations compared with a vitamin K antagonist (VKA) based triple therapy regimen. A recent study demonstrated that apixaban based double therapy reduced bleeding compared with VKA based double therapy. However, it remains unknown whether rivaroxaban based double therapy is superior to a VKA based double therapy.

METHODS

Patient with stented atrial fibrillation (n=2124) were randomized to 3 groups: rivaroxaban 15 mg od plus a P2Y₁₂ inhibitor (Group 1, n=709); rivaroxaban 2.5 mg bid plus dual antiplatelet therapy (DAPT; Group 2, n=709); and warfarin plus DAPT (Group 3, n=706). Before randomization, subjects were stratified according to a prespecified duration of DAPT (1, 6, or 12 months). After the prespecified DAPT duration, subjects in Group 2 were switched to rivaroxaban 15 mg plus low dose aspirin, and those in Group 3 were switched to VKA plus low dose aspirin. The Wei, Lin, and Weissfeld time to multiple events method was used to compare the occurrence of all bleeding and cardiovascular rehospitalizations among subjects on a novel oral anticoagulant versus VKA based double therapy.

RESULTS

A total of 906 subjects were prespecified to a 1 or 6 months DAPT duration and received at least one dose of study drug. Twenty subjects (3.3%) assigned to novel oral anticoagulant+SAPT, and 15 (5.1%) subjects assigned to VKA+SAPT experienced multiple rehospitalizations. In total, 124 (20.3%) events occurred among subjects on novel oral anticoagulant+SAPT compared with 87 (29.6%) among subjects on VKA+SAPT (hazard ratio=0.65 [95% CI, 0.45-0.93], P=0.008).

CONCLUSIONS

Among stented patients with atrial fibrillation, rivaroxaban plus SAPT was superior to warfarin plus SAPT in lowering total bleeding and cardiovascular rehospitalization.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01830543.