To analyze the clinical characteristics, prognosis and prognostic predictors in Chinese HFimpEF patients.

Participants included in this case-control study were chronic HF inpatients who were recruited from Department of Heart Center, Hebei General Hospital from June 1, 2018, to May 1, 2020. Demographic data and baseline clinical information were obtained from the electronic medical record, in particular, clinical phenotypes of HF classified by baseline and follow-up LVEF included four: HF with preserved EF (HFpEF) , HF with mid-range EF (HFmrEF) , HF with reduced EF (HFrEF) and HFimpEF. Follow-up was conducted via electronic medical record review, outpatient department and telephone since the last reexamination with echocardiography. The follow-up continued through 2021-06-01, with all-cause death and all-cause readmission as endpoint events. Predictors of HFimpEF were explored by binary Logistic regression. Kaplan-Meier estimator was used to describe the survival of patients with all-cause death and all-cause readmission. Cox regression model was used to identify risk factors for all-cause death and all-cause readmission.

A total of 530 cases were included, including 245 (46.2%) with HFpEF, 55 (10.4%) with HFmrEF, 133 (25.1%) with HFrEF, and 97 (18.3%) with HFimpEF. HFimpEF patients had lower mortality than did HFpEF patients (P=0.014) and HFmrEF patients (P<0.001) . The readmission rate was lower in HFimpEF patients than that of HFpEF (P=0.011) or HFmrEF patients (P=0.001) . Elevated systolic blood pressure〔OR=1.036, 95%CI (1.019, 1.053) , P<0.001〕, and left ventricular end-systolic diameter (LVESD) ≤37 mm〔OR=0.245, 95%CI (0.118, 0.507) , P<0.001〕 at baseline, and treatments with beta-blockers〔OR=2.868, 95%CI (1.304, 6.305) , P=0.009〕 and aldosterone antagonists〔OR=2.691, 95%CI (1.316, 5.503) , P=0.007〕 were associated with increased probability of LVEF improvement. HFrEF, older age, heart valve disease, chronic kidney disease, anemia, non-use of beta-blockers and oral anticoagulants were independently associated with increased risk of all-cause death in HF patients (P<0.05) . HFpEF, HFmrEF and chronic kidney disease were independently associated with increased risk of all-cause readmission in HF patients (P<0.05) . Concomitant valvular heart disease〔HR=6.499, 95%CI (1.504, 28.089) , P=0.012〕and anemia〔HR=4.884, 95%CI (1.242, 19.208) , P=0.023〕were independently associated with increased risk of all-cause death in HFimpEF patients. The use of beta-blockers〔HR=2.868, 95%CI (1.304, 6.305) P=0.009〕 and aldosterone antagonists〔HR=2.691, 95%CI (1.316, 5.503) , P=0.007〕 were associated with increased probability of LVEF improvement.

We consider that HFimpEF is a clinical phenotype of HF manifested as milder clinical symptoms, less ventricular remodelling and a better prognosis. Elevated systolic blood pressure, LVESD≤37 mm and treatments with beta-blockers and aldosterone receptor antagonists may be independent predictors of improved LVEF, while valvular heart disease and anaemia may be risk factors for all-cause death in HFimpEF patients.

分析我国HFimpEF患者临床特点、预后及预后的预测因素。

纳入于2018年6月至2020年5月在河北省人民医院心内科住院治疗的慢性心力衰竭（CHF）患者，从电子病历中获取患者的人口学数据和基线临床信息，根据基线及复查时的LVEF分为射血分数保留（HFpEF）组、射血分数中间值（HFmrEF）组、射血分数降低（HFrEF）组、射血分数改善（HFimpEF）组。自最后一次复查超声心动图开始，通过电子病历、门诊及电话进行随访，终点事件为全因死亡及全因再住院，随访时间截至2021-06-01。采用二元Logistic回归分析探讨LVEF改善的影响因素，采用Kaplan-Meier法绘制全因死亡和全因住院的生存曲线，采用Cox比例风险回归模型分析全因死亡和全因再入院的危险因素。

最终纳入患者530例，HFpEF组245例（占46.2%），HFmrEF组55例（占10.4%），HFrEF组133例（占25.1%），HFimpEF组97例（占18.3%）。HFimpEF组死亡率低于HFpEF组（P=0.014）和HFrEF组（P<0.001）。HFimpEF组再住院率低于HFpEF组（P=0.011）和HFmrEF组（P=0.001）。基线时收缩压较高〔OR=1.036，95%CI（1.019，1.053），P<0.001〕、左心室收缩末内径（LVESD）≤37 mm〔OR=0.245，95%CI（0.118，0.507），P<0.001〕、应用β-受体阻滞剂〔OR=2.868，95%CI（1.304，6.305），P=0.009〕和醛固酮受体拮抗剂〔OR=2.691，95%CI（1.316，5.503），P=0.007〕是LVEF改善的影响因素。HFrEF、年龄较大、合并心脏瓣膜病、慢性肾脏病、贫血、未应用β-受体阻滞剂及口服抗凝药是CHF患者全因死亡的独立风险因素（P<0.05），HFpEF、HFmrEF、慢性肾脏病是CHF患者全因再入院的独立风险因素（P<0.05）。合并心脏瓣膜病〔HR=6.499，95%CI（1.504，28.089），P=0.012〕、贫血〔HR=4.884，95%CI（1.242，19.208），P=0.023〕是HFimpEF患者死亡的风险因素。

HFimpEF是一组独立的HF表型，此类患者临床表现较轻、心室重构程度较小、预后较好，收缩压较高、LVESD≤37 mm、应用β-受体阻滞剂和醛固酮受体拮抗剂是LVEF改善的独立预测因子，而合并心脏瓣膜疾病、贫血是HFimpEF患者全因死亡的风险因素。