Impact of inflammatory reaction levels and culprit plaque characteristics on preprocedural thrombolysis in myocardial infarction flow grade in patients with ST-segment elevation myocardial infarction / 中华心血管病杂志

Objective: To determine the impact of inflammatory reaction levels and the culprit plaque characteristics on preprocedural Thrombolysis in Myocardial Infarction (TIMI) flow grade in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Methods: The is a retrospective study. A total of 1 268 STEMI patients who underwent pre-intervention optical coherence tomography (OCT) examination of culprit lesion during emergency PCI were divided into 2 groups by preprocedural TIMI flow grade (TIMI 0-1 group (n =964, 76.0%) and TIMI 2-3 group (n =304, 24.0%)). Baseline clinical data of the 2 groups were collected; blood samples were collected for the detection of inflammatory markers such as high sensitivity C-reactive protein (hsCRP), myocardial injury marker, blood lipid, etc.; echocardiography was used to determine left ventricular ejection fraction; coronary angiography and OCT were performed to define the lesion length, diameter stenosis degree of the infarct-related arteries, presence or absence of complex lesions, culprit lesion type, area stenosis degree and vulnerability of culprit plaques. Multivariable logistic regression analysis was performed to identify independent correlation factors. The receiver operating characteristic (ROC) curve of continuous independent correlation factors was analyzed, and the best cut-off value of TIMI 0-1 was respectively determined according to the maximum value of Youden index. Results: The mean age of 1 268 STEMI patients were (57.6±11.4) years old and 923 cases were males (72.8%). Compared with TIMI 2-3 group, the patients in TIMI 0-1 group were older and had higher N-terminal-pro-B-type natriuretic peptide level, lower cardiac troponin I (cTnI) level, lower left ventricular ejection fraction, and higher hsCRP level (5.16(2.06, 11.78) mg/L vs. 3.73(1.51, 10.46) mg/L). Moreover, the hsCRP level of patients in TIMI 0-1 group was higher in the plaque rupture subgroup (all P<0.05). Coronary angiography results showed that compared with TIMI 2-3 group, the proportion of right coronary artery (RCA) as the infarct-related artery was higher, the angiographical lesion length was longer, minimal lumen diameter was smaller, and diameter stenosis was larger in TIMI 0-1 group (all P<0.05). The prevalence of plaque rupture was higher (75.8% vs. 61.2%) in TIMI 0-1 group. Plaque vulnerability was significantly higher in TIMI 0-1 group than that in TIMI 2-3 group with larger mean lipid arc (241.27°±46.78° vs. 228.30°±46.32°), more thin-cap fibroatheroma (TCFA, 72.4% vs. 57.9%), more frequent appearance of macrophage accumulation (84.4% vs. 70.7%) and cholesterol crystals (39.1% vs. 25.7%). Minimal flow area was smaller [1.3(1.1-1.7)mm2 vs. 1.4(1.1-1.9)mm2, all P<0.05] and flow area stenosis was higher (78.2%±10.6% vs. 76.3%±12.3%) in TIMI 0-1 group. Multivariable analysis showed that mean lipid arc>255.55°, cholesterol crystals, angiographical lesion length>16.14 mm, and hsCRP>3.29 mg/L were the independent correlation factors of reduced preprocedural TIMI flow grade in STEMI patients. Conclusions: Plaque vulnerability and inflammation are closely related to reduced preprocedural TIMI flow grade in STEMI patients.

Correlation between heart rate variability and exercise ability in patients with cardiac syndrome X / 中国实用内科杂志

OBJECTIVE: To investigate whether heart rate variability(HRV) can assess exercise ability in patients with cardiac syndrome X(CSX). METHODS: A total of 246 subjects(55.2 ± 12.2 years, 68.3% male), who were diagnosed with CSX by the positive exercise stress test and normal coronary angiogram in Cardiovascular Department of the Second Affiliated Hospital of Harbin Medical University from March 2016 to August 2017 were enrolled. The 24-hour dynamic ECG monitoring was used to analyze HRV for long-time frequency domain analysis. The HRV power spectrum index included total power(TP),very low frequency(VLF), low frequency(LF) and high frequency(HF). RESULTS: VLF, LF and TP, but not LF/HF, were higher in the patients with good exercise capacity(≥90% of the age predicted maximal heart rate). After accounting for age, sex, systolic blood pressure and heart rate, VLF, LF and TP remained significantly associated with good exercise capacity. In addition, increased VLF, LF and TP were also associated with increased exercise duration, rate-pressure product, and heart rate recovery. In subgroup analysis, VLF, LF and TP demonstrated similar predictive values related to exercise capacity across various subpopulations, especially in the young. CONCLUSION: In patients with CSX, HRV is independently associated with exercise capacity, and is an independent predictor of ischemic tolerance in CSX patients, which can be used as an important index for evaluating the exercise ability of CSX patients.