Objective To explore the effect of remote ischemic preconditioning (RIPC) on preoperative heart rate variability in patients with heart valves. Methods Patients scheduled to undergo on-pump cardiac valve surgery in the Department of Cardiovascular Surgery, General Hospital of Northern Theater Command, between January and July 2022 were initially enrolled. Eligible patients were randomly assigned at a 1 : 1 ratio to either the RIPC group or the control group. Relevant indicators of heart rate variability [standard deviation of NN interval (SDNN), standard deviation of mean value of NN interval in every five minutes (SDANN), mean square root of difference between consecutive NN intervals (RMSSD), percentage of adjacent RR interval>50 ms (PNN50), low frequency (LF) component, high frequency (HF) component and LF/HF] at 8 hours in the morning on the surgical day between two groups were compared. Results A total of 118 patients were initially assessed. After screening, 58 patients were excluded, and 60 patients provided written informed consent and were enrolled in the trial, with 30 allocated to the RIPC group and 30 to the control group. Seven patients in the control group and 5 patients in the RIPC group were subsequently excluded due to missing heart rate variability data resulting from cancelled operations. Finally, 23 patients in the control group and 25 patients in the RIPC group were included in the analysis. There was no statistical difference in baseline characteristics between the two groups, and there was no significant difference in heart rate variability 24 hours before intervention (P>0.05). After the intervention measures were taken, the comparison of the results of heart rate variability at 8 hours on the day of operation showed that SDNN and SDANN of patients in the RIPC group were higher than those in the control group, with statistical differences (P<0.05). Conclusion RIPC can stabilize the preoperative heart rate variability of patients undergoing cardiac valve surgery.

Objective To compare the mid- and long-term clinical results of mitral valve plasty (MVP) and mitral valve replacement (MVR) in the treatment of functional mitral regurgitation (FMR). Methods Patients with FMR who underwent surgical treatment in the Department of Cardiovascular Surgery of the General Hospital of Northern Theater Command from 2012 to 2021 were collected. The patients who underwent MVP were divided into a MVP group, and those who underwent MVR into a MVR group. The clinical data and mid-term follow-up efficacy of two groups were compared. Results Finally 236 patients were included. There were 100 patients in the MVP group, including 53 males and 47 females, with an average age of (61.80±8.03) years. There were 136 patients in the MVR group, including 72 males and 64 females, with an average age of (61.29±8.97) years. There was no statistical difference in baseline data between the two groups (P＞0.05). There was no statistical difference between the two groups in the extracorporeal circulation time, aortic occlusion time, postoperative hospital and ICU stay, intraoperative blood loss, or hospitalization death (P＞0.05), but the time of mechanical ventilation in the MVP group was significantly shorter than that in the MVR group (P=0.022). The total follow-up rate was 100.0%, the longest follow-up was 10 years, and the average follow-up time was (3.60±2.55) years. There were statistical differences in the left atrial diameter, left ventricular end-diastolic diameter, left ventricular end-systolic diameter and cardiac function between the two groups compared with those before surgery (P<0.05). The postoperative left ventricular ejection fraction in the MVP group was statistically higher than that before surgery (P=0.002), but there was no statistical difference in the MVR group before and after surgery (P=0.658). The left atrial diameter in the MVP group was reduced compared with the MVR group (P=0.026). The recurrence rate of mitral regurgitation in the MVP group was higher than that in the MVR group, and the difference was statistically significant (10.0% vs. 1.5%, P=0.003). There were 14 deaths in the MVP group and 19 in the MVR group. The cumulative survival rate (P=0.605) and cardiovascular events-free survival rate (P=0.875) were not statistically significant between the two groups by Kaplan-Meier survival analysis. Conclusion The safety, and mid- and long-term clinical efficacy of MVP in the treatment of FMR patients are better than MVR, and the left atrial and left ventricular diameters are statistically reduced, and cardiac function is statistically improved. However, the surgeon needs to be well aware of the indications for the MVP procedure to reduce the rate of mitral regurgitation recurrence.

Objective To investigate the safety and efficacy of mitral valve replacement combined with cryoablation Maze surgery in patients with atrial functional mitral regurgitation (AFMR). Methods From January 2014 to June 2020, patients with AFMR who underwent mitral valve replacement in our department were enrolled. They were divided into two groups, a cryoablation Maze group who received cryoablation Maze surgery during mitral valve replacement, and a non-cryoablation Maze group who did not receive cryoablation Maze surgery. The baseline data, surgical data, efficacy, and prognosis between the two groups were compared. Results Finally 85 patients were enrolled. There were 16 males and 24 females with an average age of 58.65±6.86 years in the cryoablation Maze group, and 24 males and 21 females with an average age of 61.29±8.30 years in the non-cryoablation Maze group. There was no statistical difference in baseline data between the two groups (P＞0.05). The aortic occlusion time and extracorporeal circulation time of the cryoablation Maze group were longer than those of the non-cryoablation Maze group with statistical differences (P＜0.01). There was no statistical difference in postoperative ICU retention time, ventilator assistance time, length of hospital stay, intraoperative blood loss, drainage volume on the first day or occurrence rate of complications (temporary pacemaker application, electrical cardioversion, thoracic puncture drainage, hospitalization death) between the two groups (P＞0.05). At the time of discharge, postoperative 3-month, 6-month, 12-month, and 24-month, the maintenance rates of sinus rhythm in the non-cryoablation Maze group were statistically different from those of the cryoablation Maze group (P＜0.001). Compared with the non-cryoablation Maze group, the decrease values of left atrial diameter, left ventricular end-diastolic diameter, left ventricular end-systolic diameter and pulmonary artery systolic pressure were statistically different (P＜0.05). Postoperative cardiac function grading of both groups was grade Ⅰ or Ⅱ, which was significantly improved compared with preoperative level, but there was no statistical significance between the two groups (P＞0.05). There was no statistical difference in the incidence of adverse events during follow-up (P＞0.05). Conclusion Cryoablation Maze surgery combined with mitral valve replacement is safe and effective in the treatment of AFMR patients, which is conducive to the recovery and maintenance of sinus rhythm, and is beneficial to the remodeling of the left atrium and left ventricle, the reduction of pulmonary systolic blood pressure, and the improvement of life quality of the patients.