Predicting stroke in heart failure and preserved ejection fraction without atrial fibrillation

Background: The rate of stroke in patients with heart failure (HF) and preserved ejection fraction but without atrial fibrillation (AF), is uncertain as is whether it is possible to reliably predict the risk of stroke in these patients. Methods: We validated a previously developed simple risk model for stroke among patients enrolled in the I-Preserve trial (Irbesartan in Heart Failure With Preserved Systolic Function) and PARAGON-HF trial (Efficacy and Safety of LCZ696 Compared to Valsartan, on Morbidity and Mortality in Heart Failure Patients With Preserved Ejection Fraction). The risk model consisted of 3 variables: history of previous stroke, insulin-treated diabetes, and plasma N-terminal pro-B-type natriuretic peptide level. Results: Of the 8924 patients included in the pooled trial dataset, 5126 patients did not have AF at baseline. Among patients without AF, 190 (3.7%) experienced a stroke over a median follow-up of 3.6 years (rate 10.5 per 1000 patient-years). The risk for stroke increased with increasing risk score: second tertile hazard ratio, 1.78 (95% CI, 1.17–2.71); third tertile hazard ratio, 3.03 (95% CI, 2.06–4.47), with the first tertile as reference. For patients in the third tertile, the occurrence rate of stroke was 17.7 per 1000 patient-years, similar to that in patients with AF not receiving anticoagulation (20.7 per 1000 patient-years), and those with AF who were receiving anticoagulation (14.5 per 1000 patient-years). Model discrimination was good with a C index of 0.81 (0.68–0.91) and a simple score could be created from the model. Conclusions: A simple risk model can detect a subset of HF and preserved ejection fraction patients without AF who have a higher risk for stroke. The balance of risk-to-benefit in these individuals may justify the use of prophylactic anticoagulation, but this hypothesis needs to be prospectively evaluated. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifiers: NCT00095238 and NCT01920711