Outcomes After Cardioversion in Atrial Fibrillation Patients Treated with Non-Vitamin K Antagonist Oral Anticoagulants (NOACs): Insights from a Meta-Analysis

BACKGROUND

There are limited data on outcomes following cardioversion in atrial fibrillation (AF) patients treated with non-vitamin K antagonist oral anticoagulants (NOACs). A meta-analysis was performed to evaluate the efficacy and safety of NOACs in patients with AF undergoing cardioversion.

METHODS

PubMed, Cochrane Library, EMBASE, Web of Science and CINAHL databases were searched from January 1, 2001 through to October 30, 2014. Randomized controlled trials (RCTs) comparing NOACs (apixaban, rivaroxaban and dabigatran) with warfarin in AF patients undergoing cardioversion were selected. The primary efficacy outcome was stroke and systemic embolism, and the primary safety outcome was major or clinically relevant non-major (CRNM) bleeding. We used random-effects models.

RESULTS

Four RCTs were included, involving a total of 3635 randomized participants who underwent a total of 4257 cardioversions. A total of 12 events of stroke and systemic embolism were found in the NOAC group and ten events in the warfarin group [odds ratio (OR) 0.73, 95% confidence interval (CI) 0.31-1.72]. Risk of major or CRNM bleeding was not different with NOACs, when compared with warfarin (OR 1.41, 95% CI 0.87-2.28).

CONCLUSIONS

Data from patients enrolled in RCTs, showed that NOACs are effective and safe for AF patients undergoing cardioversion.

Impact of intraprocedural thrombotic events on short- and long-term outcomes following percutaneous coronary intervention. Evidence from a meta-analysis

BACKGROUND

Data regarding the effects of intraprocedural thrombotic events (IPTE) are scarce. Hence we aim to perform a meta-analysis to examine the outcomes of IPTE compared to non-IPTE during PCI.

METHODS

We performed a literature search of all published full-length articles of studies that reported data on patients with IPTE compared with non-IPTE during PCI. We calculated odd ratios via random effects model.

RESULTS

A total of 26,697 patients, of which 1572 patients had IPTE, were included in this analysis. In-hospital, IPTE was associated with higher mortality (odds ratio (OR) 5.36, 95% confidence interval (CI) [2.31, 12.41]; p<0.0001), myocardial infarction (MI) and major bleeding compared to non-IPTE. At 30 days, IPTE was also associated with higher mortality (OR 4.57, 95% CI [2.43, 8.60]; p<0.0001), MI, repeat revascularization, stent thrombosis and major bleeding compared to non-IPTE group. IPTE was also associated with higher long-term mortality (OR 2.19, 95% CI [1.35, 3.53]; p=0.001). Among IPTE patients, intraprocedural stent thrombosis was associated with greater odds of MI compared to both no reflow and distal embolization events.

CONCLUSION

IPTE during PCI is associated with more adverse ischemic events, including mortality, during the index hospitalization, at 30 days and long-term.

Patient Taking A Novel Oral Anticoagulant Presents With Major GI Bleeding

Novel Oral Anticoagulants (NOACs) such as Dabigatran, Rivaroxaban, Apixaban and Edoxaban are becoming increasingly popular choices for anticoagulation in place of oral Vitamin K Antagonists in various clinical settings. However, they are thought to be associated with an increased risk of gastrointestinal bleeding. Moreover, no specific antidote is available which can rapidly reverse the anti-coagulant action of NOACs raising concern that gastrointestinal bleeding with NOACs could carry a worse prognosis than that associated with conventional agents. In this review, we describe a case of gastrointestinal bleeding in the setting of NOAC use, followed by a brief overview of the pivotal trials involving NOACs. Clinical issues such as pathophysiology, diagnosis and management of NOAC induced GI bleeding have been described. Future trials will help elucidate the true incidence, risk factors and preventive strategies for NOAC associated gastrointestinal bleeding.

Effect of Intensive Versus Standard Blood Glucose Control in Patients With Type 2 Diabetes Mellitus in Different Regions of the World: Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Regional variation in type 2 diabetes mellitus care may affect outcomes in patients treated with intensive versus standard blood glucose control. We sought to evaluate these differences between North America and the rest of the world.

METHODS AND RESULTS

Databases were searched from their inception through December 2013. Randomized controlled trials comparing the effects of intensive therapy with standard therapy for macro- and microvascular complications in adults with type 2 diabetes mellitus were selected. We calculated summary odds ratios (ORs) and 95% CIs with the random-effects model. The analysis included 34 967 patients from 17 randomized controlled trials (7 in North America and 10 in the rest of the world). There were no significant differences between intensive and standard therapy groups for all-cause mortality (OR 1.03, 95% CI 0.93 to 1.13) and cardiovascular mortality (OR 1.09, 95% CI 0.90 to 1.32). For trials conducted in North America, intensive therapy compared with standard glycemic control resulted in significantly higher all-cause mortality (OR 1.21, 95% CI 1.05 to 1.40) and cardiovascular mortality (OR 1.41, 95% CI 1.05 to 1.90) than trials conducted in the rest of the world (all-cause mortality OR 0.93, 95% CI 0.85 to 1.03; interaction P=0.006; cardiovascular mortality OR 0.89, 95% CI, 0.79 to 1.00; interaction P=0.007). Analysis of individual macro- and microvascular outcomes revealed no significant regional differences; however, the risk of severe hypoglycemia was significantly higher in trials of intensive therapy in North America (OR 3.52, 95% CI 3.07 to 4.03) compared with the rest of the world (OR 1.45, 95% CI 0.85 to 2.47; interaction P=0.001).

CONCLUSION

Randomization to intensive glycemic control in type 2 diabetes mellitus patients was associated with increases in all-cause mortality, cardiovascular mortality, and severe hypoglycemia in North America compared with the rest of the world. Further investigation into the pathobiology or patient variability underlying these findings is warranted.

Short- and long-term outcomes in diabetes patients undergoing percutaneous coronary intervention with bivalirudin compared with heparin and glycoprotein IIb/IIIA inhibitors: A meta-analysis of randomized trials

BACKGROUND

Diabetes patients undergoing percutaneous coronary intervention (PCI) have more complications than nondiabetes patients, including increased long-term mortality. Use of bivalirudin versus heparin and glycoprotein IIb/IIIa inhibitors (GPI) in diabetes patients undergoing PCI and its effect on long-term mortality were evaluated in few randomized trials, but with conflicting results.

METHODS

We searched the literature for randomized controlled trials that compared heparin and GPI therapy with bivalirudin in diabetes patients undergoing PCI. The incidence of major adverse cardiovascular events (MACE), death from any cause, myocardial infarction (MI), urgent revascularization, major and minor bleeding (at 30 days), as well as all-cause mortality at 1 year were included, and meta-analysis was performed.

RESULTS

A total of 5,137 patients with diabetes were included in four randomized trials. At 30 days, bivalirudin, compared with heparin and GPI, caused less major bleeding (odds ratio (OR), 0.68; 95% confidence interval (CI), 0.52-0.89; P = 0.005) and less minor bleeding (OR, 0.48; 95% CI, 0.41-0.57; P < 0.00001) and similar rates of MACE (OR, 0.87; 95% CI, 0.70-1.08; P = 0.21), MI (OR, 0.87; 95% CI, 0.68-1.10; P = 0.25), and urgent revascularization (OR, 1.12; 95% CI, 0.76-1.65; P = 0.57). Death from any cause at 30 day was numerically lower with bivalirudin use but not statistically significant (OR, 0.72; 95% CI, 0.46-1.13; P = 0.15). Mortality at 1 year was significantly lower in diabetes patients treated with bivalirudin compared with heparin and GPI (OR, 0.72; 95% CI, 0.52-0.99; P = 0.04). A secondary analysis suggests that the major bleeding benefit with bivalirudin may be driven by mandated use of GPI in heparin arm.

CONCLUSION

Among patients with diabetes undergoing PCI, bivalirudin caused less major and minor bleeding compared with heparin and GPI, with similar rates of MACE, death, MI, and urgent revascularization at 30 days, but significantly lower mortality rates at 1 year.

Meta-analysis of risk of stroke and thrombo-embolism with rivaroxaban versus vitamin K antagonists in ablation and cardioversion of atrial fibrillation

BACKGROUND

Anticoagulation in cardioversion and ablation of atrial fibrillation is imperative for reducing thrombo-embolic events. Ample information is available about the use of warfarin and vitamin K antagonists (VKA) but few trials examine safety and efficacy of rivaroxaban in these procedures. We aim to explore the hypothesis that rivaroxaban causes equal thrombo-embolic and bleeding events when used in atrial fibrillation patients undergoing ablation or cardioversion compared to VKA.

METHODS

We searched the online databases as well as conference abstracts till December 2014 for studies comparing rivaroxaban with VKA in atrial fibrillation patients undergoing catheter ablation or cardioversion. We report events as Odds ratio using random effects model except when event rates were less than 1% we used Peto Odds Ratio.

RESULTS

A total of 8872 atrial fibrillation patients in 15 studies undergoing either catheter ablation or cardioversion were included in this analysis. There were significantly lower stroke events with rivaroxaban compared with VKA (Peto Odds Ratio (POR) 0.33, 95% confidence interval (CI) [0.11, 0.95]; P=0.04), and significantly less thrombo-embolic events with rivaroxaban compared with VKA (POR 0.46, 95% CI [0.21, 0.97]; P=0.04). Major and minor bleeding were equal with rivaroxaban versus VKA (Odds Ratio (OR) 0.92, 95% CI [0.62, 1.36]; P=0.68) and (OR 0.81,95% CI [0.58, 1.11]; P=0.19) respectively.

CONCLUSION

The use of rivaroxaban in ablation and cardioversion of atrial fibrillation may be associated with decreased risk of stroke and thromboembolism with equal bleeding risk compared to VKA.

Risk of major bleeding in different indications for new oral anticoagulants: insights from a meta-analysis of approved dosages from 50 randomized trials

BACKGROUND

A meta-analysis was performed to evaluate the risk of major bleeding with the use of New Oral Anticoagulants (NOACs).

METHODS

Randomized controlled trials (RCTs) comparing NOACs (rivaroxaban, dabigatran, apixaban, edoxaban and darexaban) with comparators were selected.

RESULTS

Fifty trials included 155,537 patients. Pooled analysis of all NOACs for all indications together demonstrated no significant difference between NOACs and comparators for risk of major bleeding (odds ratio [OR] 0.93, 95% CI 0.79-1.09). Pooled analysis also showed that NOACs caused significantly less major bleeding compared to vitamin K antagonists (VKA) (0.77, 0.64-0.91). The analysis for individual NOACs showed risk of major bleeding were not different with rivaroxaban, apixaban or dabigatran compared to pharmacologically active comparators or VKA. Indication specific analysis showed that NOACs were associated with significantly higher major bleeding after hip surgery (1.43, 1.02-1.99), in patients with acute coronary syndrome (ACS), (compared against placebo) (2.89, 2.01-4.14), and for medically ill patients (2.79, 1.69-4.60). For the treatment of acute venous thromboembolism (VTE) or pulmonary embolism (PE), NOACs were associated with significantly less bleeding (0.63, 0.44-0.90). No significant difference was found between NOACs and comparators in treatment of atrial fibrillation and for extended treatment of VTE.

CONCLUSIONS

Risk of major bleeding with new oral anticoagulants varies with their indication for use. New agents may be associated with comparatively less major bleeding compared to VKA. NOAC may increase the risk of major bleeding after hip surgery, ACS and acute medically ill patients; but may be associated with less bleeding in treatment of acute VTE/PE.