P3758Clinical characteristics and outcomes of atrial fibrillation patients with thrombocytopenia: the Fushimi AF Registry
Authors: Ishigami K , Aono Y , Ikeda S , Doi K , An Y , Ishii M , Iguchi M , Masunaga N , Ogawa H , Esato M , Wada H , Hasegawa K , Abe M , Akao M 
Published: October 2019

Background

Thrombocytopenia is sometimes found in routine blood tests and is reported as a risk factor of major bleeding events and incidence of all-cause death after percutaneous coronary intervention. However, the influence of thrombocytopenia on clinical outcomes in patients with atrial fibrillation (AF) remains unknown.

Purpose

We aimed to investigate relationship between baseline platelet count and clinical outcomes such as all-cause death, hospitalization for heart failure, and the major bleeding event in AF patients.

Methods

The Fushimi AF Registry was designed to enroll all of the AF patients in Fushimi-ku, Kyoto. Fushimi-ku is densely populated with a total population of 283,000 and is assumed to represent a typical urban community in Japan. Follow-up data with baseline platelet counts were available in 4,179 patients from March 2011 to November 2018. We divided the entire cohort into 3 groups according to baseline platelet level: No thrombocytopenia (≥150,000/μL, n=3,323), Mild thrombocytopenia (100,000–149,999/μL, n=707), and Moderate/severe thrombocytopenia (≤99,999/μL, n=149).

Results

In the entire cohort, the mean age was 73 years, 40% were women, and the mean body weight and body mass index was 59 kg and 23.1 kg/m2, and the median platelet count were 192,000/μL (interquartile range 156,000 to 232,000/μL), respectively.

Compared to No thrombocytopenia, patients with thrombocytopenia were older (No vs. Mild vs. Moderate/severe; 73.3 years vs. 76.5 years vs. 75.8 years, p<0.0001), more likely to have heart failure (27.0% vs. 32.8% vs. 41.6%, p<0.0001), more likely to have chronic renal disease (35.7% vs. 42.6% vs. 57.7%, p<0.0001), and had higher CHADS2 score (2.05 vs. 2.17 vs. 2.34, p=0.0039) and CHA2DS2-VASc score (3.40 vs. 3.52 vs. 3.71, p=0.0416). Patients with thrombocytopenia had lower hemoglobin (13.0 vs. 12.8 vs. 11.6, p<0.0001) than No thrombocytopenia. However, prevalence of previous major bleeding events was comparable between three groups (4.66% vs. 4.67% vs. 5.37%, p=0.92)

On Kaplan-Meier analysis, the incidence of all-cause death was higher in Mild group (hazard ratio [HR] 1.51; 95% confidence interval [CI] 1.28–1.77) and Moderate/severe group (HR 2.97; 95% CI 2.28–3.80) than No group (Figure 1). The incidence of hospitalization for heart failure was higher in Mild group (HR 1.62; 95% CI 1.31–1.99) and Moderate/severe group (HR 2.64; 95% CI 1.76–3.81) than No group (Figure 2). The incidence of major bleeding event was higher in Mild group (HR 1.46; 95% CI 1.11–1.91) and Moderate/severe group (HR 2.45; 95% CI 1.41–3.91) than No group (Figure 3).

Conclusion

Thrombocytopenia in AF patients was associated with higher incidence of all-cause death, hospitalization for heart failure, and major bleeding event in the Fushimi AF Registry.

Acknowledgement/Funding

Pfizer, Bristol-Myers Squibb, Boehringer Ingelheim, Bayer Healthcare,and Daiichi-Sankyo