Methods
vascular stenosis, blood coagulation dysfunction, alcoholism, CSX, hyperemia, cardiac valve diseases, cachexia, liver disease, infection, hepatic and renal insufficiency, congenital heart diseases, renal insufficiency, thrombophlebitis, arrhythmias, microvascular angina, substance abuse, stenosis, trauma
BLEEDING, ACUTE CORONARY SYNDROME, RENAL INSUFFICIENCY, SEPARATION, ARRHYTHMIAS, CORONARY HEART DISEASE, STENOSIS, TAG, HYPEREMIA, CEREBRAL HEMORRHAGE, HAND ISCHEMIA, THROMBOPHLEBITIS, INFECTION, UNCONTROLLED HYPERTENSION, DEEP VENOUS THROMBOSIS, LIVER DISEASE, MALIGNANT TUMOR, MICROVASCULAR ANGINA, PEPTIC ULCER
From September 2021 to February 2022, 129 patients in our institution were enrolled and randomly divided into the RIPC and control groups. In addition, each group was randomly divided further into the upper limb (UL) and lower limb (LL) subgroups. The inclusion criteria were as follows: (1) age ≤ 80 years and age ≥ 18 years; (2) requiring CAG; (3) left ventricular ejection fraction > 50%; (4) normal preoperative creatinine kinase-MB and cardiac troponin T level. The exclusion criteria were as follows: (1) age > 80 years or age < 18 years; (2) history of coronary artery bypass grafting; (3) acute coronary syndrome within 1 month; (4) long-term poorly controlled hypertension (systolic blood pressure > 180 mmHg or diastolic blood pressure > 110 mmHg or systolic blood pressure < 90mmHg or systolic blood pressure < 60mmHg) or poorly controlled heart rate (heart rate > 100 bpm or heart rate < 50 bpm); (5) cardiac valve diseases, congenital heart diseases, or severe arrhythmias; (6) deep venous thrombosis or thrombophlebitis of extremities; (7) history or existing severe trauma of the extremities; (8) active bleeding, peptic ulcer, blood coagulation dysfunction, cerebral hemorrhage, or craniotomy within 6 months; (9) poor systemic conditions, infection, severe hepatic and renal insufficiency, malignant tumor, or cachexia; (10) Creatinine clearance < 30 mL/min (or eGFR < 30 mL/min/1.73 m2), or renal insufficiency requiring dialysis; 11) Active liver disease or elevated persistent ALT or AST ≥ 3 x ULN; 12) history of alcoholism, substance abuse; and unable/unwilling to abstain from alcohol and stop substance abuse during the study; 13) have received a major organ transplant (e.g., lung, liver, heart, bone marrow, kidney); and 14) left coronary artery trunk or right coronary artery orifice lesions, excessive or severe tortuous overlap of target vessels, diffuse lesions of remote target vessels, or coronary artery with low quality CAG images (to ensure the accuracy of the QFR measurement). The definition of the diseased vessels was adopted from the current international diagnostic criteria for coronary heart disease (vascular stenosis > 50%), and the degree of stenosis was independently evaluated by two experienced interventional physicians. CSX was diagnosed according to the diagnostic criteria for microvascular angina in 2018 [The RIPC group included 71 patients, wherein 68 vessels were analyzed (eight right coronary arteries [RCAs], 32 left anterior descending arteries [LAD], and 28 left circumflex arteries [LCXs]) of 39 patients in the UL group and 63 vessels (eight RCAs, 28 LADs, and 27 LCXs) of 32 patients in the LL group. We randomly selected 58 patients for the control group, including 64 vessels (seven RCAs, 29 LADs, and 28 LCXs) of 30 patients in the UL group and 58 vessels (10 RCAs, 25 LADs, and 23 LCXs) of 28 patients in the LL group.This study was approved by the institutional ethical board [Approval Number:(2021)(13)], and written informed consent was also obtained from each participant,and this study is registered in ClinicalTrials.gov (Tag: NCT04766749).The RIPC instrument used in this study was the Yijiabao ischemic preconditioning therapeutic instrument, independently developed by the China Hongjing Medical Company. According to the standard CAG procedure, all patients received standardized treatment before the procedure, and two experienced clinicians performed CAG; IMR was further measured in patients without obvious vascular stenosis. Subsequently, those in the experimental group received four cycles of RIPC in the left upper or lower limb after completing the first CAG. The RIPC procedure comprised 5 min of compression and ischemia followed by 5 min of relaxation and reperfusion, and the cuff of the RIPC instrument was pressurized to 200 mmHg. The same therapeutic device was placed on the left upper or lower limb of patients in the control group, and the cuff was tied but not inflated. Immediately after completing RIPC, the second CAG (and IMR) was performed in the same position as the first.The AngioPlus system (Pulse Medical Imaging Technology, Shanghai, China) was used to calculate the QFR. We chose two planar angiographies close to the standard position and eliminated collateral interference, and the separation between the two planes was at least 25°. The three-dimensional reconstruction of the angiographic results was performed using the AngioPlus system. The software computed the following two QFR pullbacks: (a) fQFR pullback, a fixed empiric hyperemic flow velocity of 0.35 m/s derived from previous FFR studies was used for computation; and (b) cQFR pullback, a frame count analysis performed without pharmacologically-induced hyperemia and the modeled hyperemic flow velocity, which was derived according to the frame count used for computation [At the end of CAG, IMR was measured in patients with CSX with a thermodilution technique as described previously [SPSS25.0 was used to analyze the data. The data of continuous variables were expressed as means ± standard deviations or medians and interquartile ranges. The statistical description of classified variable data was expressed as quantities and percentages, and the differences between the groups were compared using the chi-square test. For data conforming to normal distribution, one-way anova was used for comparison between groups. The Kruskal-Wallis test was used to compare data that did not conform to the normal distribution. Two-tailed tests were used for statistical analysis, with 