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

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