Abstract: Background　Epidemiologic studies have found that the morbidity of heart failure with preserved ejection fraction（HFpEF） is increasing significantly，approximately accounting for one-half of those with symptomatic heart failure，with a mortality similar to that of heart failure with reduced ejection fraction.Yet，up to now，we lack proven therapies to improve the outcomes.Objective　To evaluate the effects of isosorbide mononitrate on exercise tolerance and quality of life in patients with HFpEF.Methods　From the First People's Hospital of Yunnan Province from September 1，2016 to April 30，2018，92 chronic heart failure inpatients（NYHA classⅡ-Ⅲ） meeting the diagnostic criteria of HFpEF were enrolled，and were equally and randomly stratified into the control group and the isosorbide mononitrate group，treated with basic treatment，previous pharmacological treatment plus isosorbide dinitrate sustained-release tablets（30 mg once daily），for 4 consecutive weeks，respectively.The primary end points were exercise capacity and quality of life，assessed by 6-minute walk test，symptom-limited cardiopulmonary exercise testing（peak VO2，anaerobic threshold，maximum workload and maximum exercise time），the Minnesota Living with Heart Failure Questionnaire（MLHFQ） score，and N-terminal pro-B-type natriuretic peptide（NT-proBNP）.During the intervention，five cases in the isosorbide mononitrate group dropped out the trial within one week due to intolerant headache caused by taking the isosorbide mononitrate，so the remaining 87 cases were finally included.Results　There were no significant differences in sex ratio，mean age，body mass index，heart rate，systolic blood pressure，diastolic blood pressure，distribution of NYHA class，early mitral filling velocity/early diastolic mitral annular velocity ratio，left atrial volume index，left ventricular mass index，left ventricular ejection fraction，the prevalence of three chronic diseases（diabetes，hypertension，coronary heart disease） and use of two types of drugs（diuretics，calcium antagonists） between the two groups（P>0.05）.Furthermore，no significant differences were found in mean pre- and post-treatment peak VO2，VO2AT，maximum exercise power，maximum exercise time，6-minute walk distance，MLHFQ score and NT-proBNP level in either group，and between the two groups（P>0.05）.Conclusion　Oral administration of isosorbide mononitrate 30 mg once daily did not improve the exercise tolerance and quality of life in patients with HFpEF.

Key words: Heart failure, Ejection fraction, Isosorbide mononitrate, Exercise capacity, Quality of life

摘要： 背景　流行病学研究发现射血分数保留心力衰竭患者的发病率明显升高，约占症状性心力衰竭患者的50%，其死亡率与射血分数降低患者相差无几。然而到目前为止，对于射血分数保留心力衰竭患者没有明确有效的药物治疗方案。目的　探讨单硝酸异山梨酯是否能改善射血分数保留心力衰竭患者的运动耐力，提高其生活质量。方法　选取2016-09-01至2018-04-30在云南省第一人民医院住院治疗的满足射血分数保留心力衰竭诊断标准、纽约心功能分级（NYHA分级）Ⅱ~Ⅲ级的慢性心力衰竭患者92例为研究对象。随机分为对照组和单硝酸异山梨酯组，每组46例。对照组采用基础治疗；单硝酸异山梨酯组患者入组后在已用药物治疗的基础上每日加用单硝酸异山梨酯缓释片30 mg，持续4周（有5例患者在服用单硝酸异山梨酯1周内有不能耐受的头疼，故退出该组）。所有患者在入组前及4周随访期结束时行症状限制性心肺运动试验〔观察指标：峰值氧耗量（Peak VO2）、无氧阈氧耗量（VO2AT）、最大运动功率及最大运动时间〕、6 min步行试验、明尼苏达心力衰竭生活质量问卷（MLWHFQ）评估、N末端B型利钠肽原（NT-proBNP）检查。比较治疗前后两组组内和组间上述指标的差异。结果　对照组和单硝酸异山梨酯组性别、年龄、体质指数（BMI）、心率、收缩压（SBP）、舒张压（DBP）、NYHA分级、舒张早期左房室瓣血流速度与舒张早期左房室瓣环运动速度比（E/e'）、左心房容积指数（LAVI）、左心室心肌质量指数（LVMI）、左心室射血分数（LVEF）、合并疾病（糖尿病、高血压、冠心病）及药物使用情况（利尿剂、钙离子拮抗剂）比较，差异无统计学差异（P>0.05）。治疗前后，两组Peak VO2、VO2AT、最大运动功率、最大运动时间、6 min步行距离、MLWHFQ评分及NT-proBNP组内和组间比较，差异无统计学意义（P>0.05）。结论　每日服用单硝酸异山梨酯30 mg未能改善射血分数保留心力衰竭患者的运动耐力和生活质量。

关键词: 心力衰竭, 射血分数, 单硝酸异山梨酯, 运动耐力, 生活质量