High D-dimer level on admission for heart failure may indicate higher short-term stroke risk

The study found the optimal D-dimer cutoff value for the risk of ischemic stroke in the hospital or within 30 days was 3.5 µg/mL, and no patients with a D-dimer level under the reference limit of normal had a stroke during follow-up.

Patients with elevated D-dimer levels at admission for acute heart failure had increased short-term risk of ischemic stroke, according to a recent study.

The retrospective registry study included 721 consecutive patients hospitalized for acute heart failure between January 2013 and May 2016 at a single center in Japan. All had their plasma D-dimer levels measured on admission. The patients' mean age was 76 years, 60% were men, and 54% had atrial fibrillation. The mean left ventricular ejection fraction was 38%, and the median length of hospitalization was 21 days. Compared to a normal D-dimer level of <1.0 µg/mL, the patients' median level on admission was 2.1 µg/mL (interquartile range, 1.1 to 4.2 µg/mL). Results were published by Stroke on June 7.

An ischemic stroke occurred during hospitalization in 18 patients (2.5%), and 16 patients (2.2%) had an ischemic stroke within 30 days. The study found the optimal D-dimer cutoff value for the risk of stroke in the hospital or within 30 days was 3.5 µg/mL. No patients with a D-dimer level less than the reference limit of normal (1.0 µg/mL) had a stroke. A higher D-dimer level on admission was an independent determinant of risk of in-hospital ischemic stroke even after adjustment for CHA2DS2-VASc score (odds ratio [OR], 2.29; 95% CI, 1.46 to 3.60; P<0.001) and major confounders, including age, atrial fibrillation, and antithrombotic therapy (OR, 2.31; 95% CI, 1.43 to 3.74; P<0.001). The results were similar in the subgroups of patients without atrial fibrillation (OR, 2.46; 95% CI, 1.39 to 4.54; P=0.002) and those not on antithrombotic therapy (OR, 2.79; 95% CI, 1.53 to 5.57; P<0.001) and when 30-day risk of stroke was the outcome.

The results suggest that a high D-dimer level at admission may be useful to identify patients with acute heart failure who have high thromboembolic risk, and conversely, that a normal level may exclude short-term risk of stroke, the study authors said. They noted that the study found high risk of thromboembolism in the immediate period after an acute heart failure event and thus, “risk stratification for short-term ischemic stroke events is strongly warranted for the management of hospitalized patients with [acute heart failure].”

Current guidelines do not recommend routine antithrombotic therapy for patients with heart failure without atrial fibrillation, said the authors, who suggested that biomarkers like D-dimer could potentially be used to identify patients who would benefit. Limitations of the study include that it was conducted at a single center with a relatively small sample size and that it was retrospective, with the use of antithrombotic therapy decided by the treating physicians.