Anticoagulant vs. Antiplatelet Therapy in Cryptogenic Stroke

Study Questions:

What is the comparative effectiveness of oral anticoagulation (OAC) compared with antiplatelet therapy (APT) for secondary prevention in patients with cryptogenic stroke (CS) and patent foramen ovale (PFO)?

Methods:

Individual participant data from 12 databases of medically treated patients with CS and PFO were analyzed with Cox regression models, to estimate database-specific hazard ratios (HRs) comparing OAC with APT, for both the primary composite outcome (recurrent stroke, transient ischemic attack [TIA], or death) and stroke alone. Propensity scores were applied via inverse probability of treatment weighting to control for confounding. The investigators synthesized database-specific HRs using random-effects meta-analysis models.

Results:

This analysis included 2,385 (OAC = 804 and APT = 1581) patients with 227 composite endpoints (stroke/TIA/death). The difference between OAC and APT was not statistically significant for the primary composite outcome (adjusted HR, 0.76; 95% confidence interval [CI], 0.52-1.12) or for the secondary outcome of stroke alone (adjusted HR, 0.75; 95% CI, 0.44-1.27). Results were consistent in analyses applying alternative weighting schemes, with the exception that OAC had a statistically significant beneficial effect on the composite outcome in analyses standardized to the patient population who actually received APT (adjusted HR, 0.64; 95% CI, 0.42-0.99). Subgroup analyses did not detect statistically significant heterogeneity of treatment effects across clinically important patient groups.

Conclusions:

The authors concluded that there was no significant difference comparing OAC with APT for secondary prevention in patients with CS and PFO.

Perspective:

This individual patient data meta-analysis incorporating 12 studies with over 2,000 patients did not detect a statistically significant difference in the composite outcome of stroke, TIA, or death with OAC versus APT in patients with CS and PFO. Despite the fact that this is the largest analysis comparing antithrombotic strategies for secondary prevention of CS in patients with PFO, the CIs of the effect estimates were wide and did not rule out clinically important benefits of OAC over APT. Randomized clinical trials would be anticipated to provide more precise treatment effect estimates, even with similar sample sizes and event rates, and are indicated to further define optimum therapy.

Clinical Topics: Anticoagulation Management, Congenital Heart Disease and Pediatric Cardiology, Prevention, Congenital Heart Disease, CHD and Pediatrics and Arrhythmias

Keywords: Anticoagulants, Foramen Ovale, Patent, Heart Defects, Congenital, Heart Septal Defects, Atrial, Ischemic Attack, Transient, Platelet Aggregation Inhibitors, Secondary Prevention, Stroke


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