Hospitalization is common in AF patients. In our assessment, we observed a hospitalization rate of 24.0 per 100 patient-years, and women aged ≥ 75 years possess the highest hospitalization rate. With the increase of age, elderly AF patients (≥ 65 years) were more frequently hospitalized for non-CVD. Age, AF type and symptoms, as well as several comorbidities were independent predictors for first all-cause hospitalization.
In China, there was few data focusing on the hospitalization rate in AF patients. The present study is the first study that analyzed the total frequency of hospitalizations to evaluate the incidence rate of hospitalization in AF patients based on real-world data in China. In 2014, the ORBIT-AF study revealed that the rate of all-cause hospitalization in AF patients was as high as 38.8 per 100 patient-years. Furthermore, data from the EORP-AF Pilot registry in European Society of Cardiology nine-member countries, showed that the annual hospitalization rate in AF patients was up to 39.3 per 100 patient-years. According to our study, the all-cause hospitalization rate in AF patients was 24.0 per 100 patient-years. Although the hospitalization rate of AF patients in China may not as high as that in western countries, we still can safely come to the conclusion that China is facing the same economic and health burden of hospitalization in AF patients as western countries.
To date, the main causes for hospitalization in AF patients are still highly controversial. The present study demonstrated that non-CVD were most responsible for hospitalizations in AF patients, which is similar to numerous previous researches[8, 15, 16]. However, some studies such as ROCKET AF study, ORBIT-AF Ⅰ and Ⅱ registry[13, 18] support opposite views to our results, showing that AF patients are hospitalized mainly for CVD. In patients aged < 65 years, due to few complicating diseases and high requirements for QoL, most young people may be hospitalized for improving AF-caused symptoms or seeking catheter ablation for maintaining sinus rhythm. The combined effects of the triggering or exacerbation of other diseases caused by pathophysiological alterations[19–21], old age, and the adverse events in the application of drugs during the treatment of AF[22–24], put older and multi-morbid patients at a greater risk of adverse outcomes across multiple organ systems than AF or cardiac events. Some of the conflicting findings in these studies about the main cause for hospitalization in AF patients may be attributable to different clinical setting and patient population in each study. Therefore, different therapeutic strategies are required for problems presented in different age groups. Symptoms improvements and treatment focusing on AF alone may be more effective in young AF patients, while the concomitant diseases should be paid more attention in elderly AF patients.
To improve our identification of predictors of hospitalization and focus areas for preventive efforts and intervention, we examined the association between patient baseline characteristics and hospitalization rate in AF patients. The risk of hospitalization increased substantially with the increase of age, suggesting that the burden of hospitalization for AF patients is anticipated to increase dramatically with the aging population. Of note, in the multivariate model, gender differences exhibited no or a weak effect on all-cause hospitalizations, but there was a significant difference in the trend of gender-related hospitalization rates. Among all age groups, the all-cause hospitalization rate of female AF patients was higher than that of male AF patients. A previous study has pointed out that women with AF tend to be more symptomatic and experience worse QoL than men. However, a meta-analysis of 17 articles provides an equivocal conclusion on gender differences in hospitalizations. Therefore, more researches should be done to evaluate these gender differences in AF hospitalization.
Consistent with numerous studies[27, 28],patients with worse symptoms by ERHA score were harbored a higher risk of hospitalization. When we modeled predictors of hospitalization for AF, symptom status was a major driving factor. Similarly, patients requiring antiarrhythmic drugs were also more likely to experience hospitalization for AF. These results suggested the need to manage patients with symptomatic and/or uncontrolled AF, so as to reduce the incidence of hospitalization. Although catheter ablation, a new treatment approach for AF, showed no significant association with all-cause hospitalization in our study, it does improve symptoms and reduce subsequent cardiovascular events.
Moreover, as indicated by our data, the combination of CVD (such as stroke, HF and CAD) in AF patients could significantly predict subsequent hospitalization, especially non-AF CVD hospitalizations. It is generally known that stroke, HF, and CAD are frequent comorbidities among AF patients. Given the common underlying pathophysiology and similar management concerns[31–33], AF patients are prone to a spectrum of cardiometabolic comorbidities, particularly HF and stroke, and the combination of AF with CVD also synergistically increases the risk of AF morbidity. Chamberlain et al. found that AF patients complicated with HF experienced an increased risk of hospitalization by up to about 70%, and those complicated with CAD and stroke also had an over 20% increased risk of hospitalization. Furthermore, these CVD themselves alone represent a significant burden of hospitalization. Accordingly, improving the integrated management of CVD and reducing the frequency of recurrent hospitalizations in AF patients complicated with CVD are in an urgent need.
In our cohort, it is worth noting that COPD patients had the highest risk of all-cause hospitalization, showing an increase of about 41%. Even so, COPD did not contribute to the increases risk of AF hospitalization and other CVD hospitalization, which may be due to that it exerted effects mainly on non-CVD such as lung diseases. In addition to increasing the risk of all-cause hospitalization by more than 30%, renal dysfunction and gastrointestinal disorder also elevated the risk of non-AF CVD hospitalization by more than 30%. As has been suggested by a previous study, renal diseases not only induce and aggravate CVD such as hypertension, HF and CAD, but also increase the risk of stroke, systemic thromboembolism and bleeding[35, 36]. Gastrointestinal disorders such as gastroesophageal reflux and gastroenteritis may also elevate the risk of bleeding or cardiovascular events due to inflammation, metabolic disorders or treatment[37, 38]. Moreover, renal dysfunction and gastrointestinal disorder could lead to the reduction of the drug compliance of AF patients[39, 40]. Therefore, when managing AF patients complicated with non-CVD, cardiology experts still have the opportunity to enhance the quality and value of AF care when their attention and insights extend to the careful appraisal, management and follow-up care of preexisting non-CVD.
Collectively, the majority of comorbidities (CVD/non-CVD) predicted a high prevalence of hospitalization, the care oriented to single disease treatment rather than targeting broad and interconnected care may make interventions and outcomes unsatisfying. Multidisciplinary management of AF and comorbidities is an inexorable trend of medical advances.