Abstract
Background
Worsening of heart failure (HF) symptoms is the leading cause of medical contact and hospitalization of patients with mildly reduced ejection fraction (HFmrEF). The prognostic value of signs and symptoms for patients with HFmrEF is currently unclear. This study investigated the prognostic impact of signs and symptoms in HFmrEF patients.
Methods
A Cox proportional risk regression model analyzed the relationship between the number of signs/symptoms and outcomes in 1691 hospitalized HFmrEF patients. Ten significant signs and symptoms were included. Patients were divided into three groups (A: ≤2, B: 3–5, C: ≥6 signs/symptoms). Stratified analysis on male and female patients was performed. The primary endpoint was all-cause mortality, and the secondary outcome was a composite of cardiovascular death and heart failure readmission (CV events) post-discharge.
Results
After a median follow-up of 33 months, all-cause mortality occurred in 457 patients and CV events occurred in 977 patients. Incidence of all-cause mortality was 20.7%, 32.3%* and 49.4%*† in group A, B and C of male patients, (*P < 0.05 vs. A, †P < 0.05 vs. B) and 18.8%, 33.6% and 55.8%* in group A, B and C of female patients. Incidence of CV events was 64.8%, 70.1%* and 87.5%* in group A, B and C of male patients, 61.9%, 75.3%, and 86.1%* in group A, B and C of female patients. Multivariate Cox regression showed older age, renal insufficiency, higher number of signs and symptoms (≥ 3, hazard ratio [HR] 1.317, 95% confidence interval [CI] 1.070–1.621, P = 0.009; ≥6, HR 1.982, 95% CI 1.402–2.801, P < 0.001), myocardial infarction, stroke, faster heart rate on admission, and diabetes were independently associated with all-cause mortality(all P < 0.05). Similarly, higher number of signs and symptoms (≥ 3, HR 1.271, 95% CI 1.119–1.443, P < 0.001; ≥6, HR 1.955, 95% CI 1.524–2.508, P < 0.001), older age, renal insufficiency, atrial fibrillation, and diabetes were independently associated with cardiovascular events (all P < 0.05).
Conclusions
Higher number of symptoms and signs is associated with increased risk of all-cause mortality and CV events in HFmrEF patients. Our results highlight the prognostic importance of careful inquiry on HF symptoms and related physical examination in HFmrEF patients.
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Introduction
Chronic heart failure (CHF) is characterized by decline in exercise capacity and dyspnea, serves as a common etiology of repeated hospitalizations [1]. It is estimated that around 26 million people worldwide suffer from chronic heart failure [2]. In China, the prevalence rate of age-standardized heart failure (HF) is 1.10%, and the incidence rate is 275 cases per 100,000 person-years [3]. The China-HF study showed that the mortality rate was 4.1% in hospitalized HF patients [4]. Aging population and advances in the treatment of HF may further increase the number of patients with HF, CHF is also associated with huge financial burden on family and the healthcare system [2].Heart failure is a clinical syndrome, the signs and symptoms of which are primarily due to functional or structural heart disease. These functional or structural diseases can include, but are not limited to, cardiomyopathies, coronary artery disease, hypertension, or valvular heart disease [5].
Nowadays, physicians rely more and more on imaging and laboratory tests results to guide the diagnosis and treatment of HF [6], rational use of these modalities are essential, but adds unavoidably to the financial burden on the healthcare system. Independent of imaging and laboratory tests, previous studies have shown that signs and symptoms, which could be obtained by careful and thorough inquiry and physical examination, can also guide the diagnosis and treatment of patients with HF in an economic way [6, 7]. Besides, information on signs and symptoms is valuable for decision making regarding the need of hospitalization or not [8]. In a post-hoc analysis of the PARAGON-HF trial, more HF signs and symptoms were associated with higher risk of HF hospitalization and cardiovascular death in HF patients with preserved ejection fraction (HFpEF) [9]. A similar risk relationship has been shown in studies examining various combinations of signs and symptoms in patients with reduced ejection fraction (HFrEF) [10,11,12]. The prognostic value of signs and symptoms in patients with heart failure with mildly reduced ejection fraction (HFmrEF) is currently unclear. In this study, we observed the prognostic impact of signs and symptoms in HFmrEF patients.
Methods
Study design and population
A total of 1691 patients with HFmrEF admitted to our hospital from 1 to 2015 to 31 August 2020 were included. All patients included in this study were diagnosed with heart failure according to standard AHA and ESC guidelines [5, 13]. In our study [Full size image
Clinical outcomes
After a median follow-up of 33 months (20–50 months), all-cause deaths occurred in 457 patients, and CV events occurred in 977 patients.
Comparison on incidence of all-cause mortality and CV events between groups is presented in Table 2. All-cause mortality in Group A was 20.69%, compared to 32.33% in Group B and 49.45% in Group C, revealing significant differences among the three groups (P < 0.05 for all comparisons). This discrepancy persisted in the male patient population; however, a statistically significant difference was only observed among female patients between Group C, and Group A. Cardiovascular events were 62.83% in Group A, 73.71% in Group B, and 86.81% in Group C, with significant differences noted among the three groups (P < 0.05 for all comparisons). Group B and Group C exhibited significant differences in male patients compared to Group A, while no notable difference was observed between Group B and Group C. In female patients, a statistically significant difference was only observed between Group C and Group A.
Before confounder adjustment, analysis showed that the risk of all-cause mortality increased with each increase on the number of symptoms and signs (HR 1.18; 95% CI 1.12–1.24; P < 0.0001; male HR 1.24, 95% CI 1.16–1.33, P < 0.0001; female HR 1.10; 95% CI 1.01–1.19; P = 0.0262) (Table 3, model IA). Similarly, each increase on the number of symptoms and signs was also associated with an increased risk of CV events (HR 1.13; 95% CI 1.10–1.17; P < 0.0001) (male HR 1.15, 95% CI 1.10–1.20, P < 0.0001; female HR 1.11; 95% CI 1.05–1.17; P = 0.0001) (Table 3, model IIA). When symptoms and signs were analyzed as categorical variables, in male patients, risk of all-cause mortality was significantly higher in group B (HR 1.96; 95% CI 1.53–2.50; P < 0.0001) and group C (HR 4.05; 95% CI 2.61–6.30; P < 0.0001) than in group A (Fig. 3A; Table 3, model IB). In female patients, risk of all-cause mortality was significantly higher in group C than in group A (HR 1.94; 95% CI 1.19–3.15; P = 0.0075), which was similar between group B and group A (HR 1.27; 95% CI 0.92–1.75; P = 0.1444) (Fig. 3B; Table 3, model IB). In male patients, risk of CV events was significantly higher in group B (HR 1.48; 95% CI 1.28–1.72; P < 0.0001) and group C (HR 2.19; 95% CI 1.56–3.07; P < 0.0001) than in group A (Fig. 3C; Table 3, model IIB). In female patients, risk of CV events was significantly higher in group C than in group A (HR 2.20; 95% CI 1.57–3.07; P < 0.0001), which was similar between group B and group A (HR 1.20; 95% CI 0.98–1.47; P = 0.0821) (Fig. 3D; Table 3, model IIB).
After adjusting for age (model I), each increase in the number of symptoms and signs was associated with an increased risk of all-cause mortality (HR 1.14; 95% CI 1.08–1.20; P < 0.0001) and CV events (HR 1.12; 95% CI 1.08–1.16; P < 0.0001) in both sexes. When symptoms and signs were treated as categorical variables, compared to group A, male patients in groups B (HR 1.58; 95% CI 1.23–2.02; P = 0.0003) and C (HR 3.13; 95% CI 2.01–4.89; P < 0.0001) faced an increased risk of all-cause mortality. In female patients, the risk of all-cause mortality was higher in group C than in group A (HR 1.90; 95% CI 1.17–3.09; P = 0.0097), but there was no significant difference in all-cause mortality between group B and group A (HR 1.24; 95% CI 0.90–1.71; P = 0.1891). Compared to group A, male patients in groups B (HR 1.41; 95% CI 1.21–1.63; P < 0.0001) and C (HR 2.05; 95% CI 1.46–2.88; P < 0.0001) were associated with an increased risk of CV events. In female patients, the risk of CV events was higher in group C than in group A (HR 2.21; 95% CI 1.58–3.09; P < 0.0001), but there was no significant difference in CV events between group B and group A (HR 1.20; 95% CI 0.98–1.47; P = 0.0810) (Table 3).
After adjusting for all covariates (model II), the risk of all-cause mortality increased with the increasing number of symptoms and signs in male patients (HR 1.10; 95% CI 1.02–1.19; P = 0.0094), while the risk increase was not significant in female patients (HR 1.05; 95% CI 0.96–1.15; P = 0.2692) (Fig. 4A, B; Table 3). Each increase on number of symptoms and signs was associated with an increased risk of cardiovascular (CV) events (HR 1.10; 95% CI 1.06–1.14; P < 0.0001) in both male patients (HR 1.11, 95% CI 1.06–1.17, P < 0.0001) and female patients (HR 1.09; 95% CI 1.03–1.16; P = 0.0032) (Fig. 4C, D; Table 3). When symptoms and signs were treated as categorical variables, compared with group A, the increase of symptoms and signs was still associated with increased risk of all-cause mortality in group B (HR 1.36; 95% CI 1.05–1.77; P = 0.0195) and in group C (HR 2.41; 95% CI 1.51–3.85; P = 0.0002) in male patients (Table 3, Model IB). In female patients, the differences in all-cause mortality between group A and group B (HR 1.07; 95% CI 0.75–1.51; P = 0.7086) and between group A and group C (HR 1.36; 95% CI 0.81–2.30; P = 0.2489) were not significant (Table 3). Compared with group A, male patients in group B (HR 1.33; 95% CI 1.14–1.56; P = 0.0003) and group C (HR 1.89; 95% CI 1.33–2.68; P = 0.0004) faced increased risk of CV events (Table 3). In female patients, the risk of CV events was higher in group C than that in group A (HR 1.96; 95% CI 1.37–2.82; P = 0.0003), but there was no significant difference between group B and group A (HR 1.13; 95% CI 0.90–1.41; P = 0.2824) (Table 3).
Independent risk factors of outcomes
Multivariate Cox regression models were used to identify risk factors independently associated with outcome events (Table 4). Parameters with a significance level of P < 0.05 from univariate Cox regression analysis were included in the multivariate model. Results showed that following factors were independently associated with all-cause death, including older age, renal insufficiency, higher number of signs and symptoms (≥ 3, hazard ratio [HR] 1.317, 95% confidence interval [CI] 1.070–1.621, P = 0.009; ≥6, HR 1.982, 95% CI 1.402–2.801, P < 0.001), myocardial infarction, stroke, faster heart rate on admission, and diabetes (all P < 0.05). Similarly, higher number of signs and symptoms (≥ 3, HR 1.271, 95% CI 1.119–1.443, P < 0.001; ≥6, HR 1.955, 95% CI 1.524–2.508, P < 0.001), older age, renal insufficiency, atrial fibrillation, and diabetes were independently associated with cardiovascular events (all P < 0.05).
In patients with ≥ 3 symptoms or signs, the following characteristics were associated with increased risk of all-cause mortality: male sex, age ≥ 75 years, systolic blood pressure ≥ 140 mmHg, heart rate < 100 beats/min, NYHA III + IV, presence of coronary heart disease, myocardial infarction, hypertension, stroke, even in the absence of hyperlipidemia, atrial fibrillation, diabetes, and renal insufficiency (Fig. 5).
Impact of individual signs and symptoms on outcome events
We investigated the relationship between individual signs and symptoms and clinical outcomes in our patients. Results showed that chest pain, dyspnea, cough, hepatojugular reflux sign, and pleural effusion were independently associated with all-cause mortality in male patients. Dyspnea, cough, rales, and edema were independently associated with cardiovascular events (CV events) in all patients regardless of sex. Chest pain, ascites, and pleural effusion were independently associated with CV events in male patients, while jugular venous distension was independently associated with CV events in female patient (all P < 0.05) (Table 5).
Additionally, we observed the impact of initial LVEF on the outcome of our patients. The patients were divided into constant mrEF (mEF) group (n = 1168), patients from rEF to mrEF (rEF) group (n = 125) and from pEF to mrEF (pEF) group (n = 398). As shown in Table S2, compared to constant mrEF group, risk for all-cause death and cardiovascular events was significantly higher in rEF and pEF groups as compared to mrEF group. Table S3 illustrates the association between symptom burden and clinical outcomes in these groups. We used both continuous and categorical analysis to establish the hazard ratio of symptoms. The results showed a trend of increasing hazard ratio with an increasing number of symptoms for both all-cause death and cardiovascular events across all groups.