ABSTRACT
Objective:To explore the prognostic predictive value of deep neural network (DNN) assisted myocardial contrast echocardiography (MCE) quantitative analysis of ST-elevated myocardial infarction (STEMI) patients after successful percutaneous coronary intervention(PCI).Methods:A retrospective analysis was performed in 97 STEMI patients with thrombolysis in myocardial infarction-3 flow in infarct vessel after primary PCI in Renmin Hospital of Wuhan University from June to November 2021. MCE was performed within 48 h after PCI. Patients were followed up to 120 days. The adverse events were defined as cardiac death, hospitalization for congestive heart failure, reinfarction, stroke and recurrent angina. The framework consisted of the U-net and hierarchical convolutional LSTMs. The plateau myocardial contrast intensity (A), micro-bubble rate constant (β), and microvascular blood flow (MBF) for all myocardial segments were obtained by the framework, and then underwent variability analysis. Patients were divided into low MBF group and high MBF group based on MBF values, the baseline characteristics and adverse events were compared between the two groups. Other variables included biomarkers, ventricular wall motion analysis, MCE qualitative analysis, and left ventricular ejection fraction. The relationship between various variables and prognosis was investigated using Cox regression analysis. The ROC curve was plotted to evaluate the diagnostic efficacy of the models, and the diagnostic efficacy of the models was compared using the integrated discrimination improvement index (IDI).Results:The time-cost for processing all 3 810 frames from 97 patients was 377 s. 92.89% and 7.11% of the frames were evaluated by an experienced echocardiographer as "good segmentation" and "correction needed". The correlation coefficients of A, β, and MBF ranged from 0.97 to 0.99 for intra-observer and inter-observer variability. During follow-up, 20 patients met the adverse events. Multivariate Cox regression analysis showed that for each increase of 1 IU/s in MBF of the infarct-related artery territory, the risk of adverse events decreased by 6% ( HR 0.94, 95% CI =0.91-0.98). There was a 4.5-fold increased risk of adverse events in the low MBF group ( HR 5.50, 95% CI=1.55-19.49). After incorporating DNN-assisted MCE quantitative analysis into qualitative analysis, the IDI for prognostic prediction was 15% (AUC 0.86, sensitivity 0.78, specificity 0.73). Conclusions:MBF of the area supplied by infarct-related artery after STEMI-PCI is an independent protective factor for short-term prognosis. The DNN-assisted MCE quantitative analysis is an objective, efficient, and reproducible method to evaluate microvascular perfusion. Assessment of culprit-MBF after PCI in STEMI patients adds independent short-term prognostic information over qualitative analysis.It has the potential to be a valuable tool for risk stratification and clinical follow-up.
ABSTRACT
Objective To observe the effects and feasibility of using walking and breathing exercises to help patients with chronic obstructive pulmonary disease in the community.Methods A hundred and one communitydwelling patients with moderate to severe chronic obstructive pulmonary disease were randomized into an experimental group (51 cases) and a control group (50 cases).The control group was given conventional pharmacotherapy,while the experimental group was given quantified walking (i.e.walking for a pre-set number of steps daily) and breathing exercises (15 minutes,3 sessions daily) to do at home for 48 weeks in addition to the conventional pharmacotherapy,.Both groups were evaluated before and after the 48 weeks of treatment using the 6-minute walk test (6MWT),a clinical COPD questionnaire,Medical Research Council (MRC) dyspnea scoring,a general anxiety/depression questionnaire and a pulmonary function test.In addition,days of hospitalization and incidence of acute exacerbation were also recorded and compared between the 2 groups.Results Among the 101 cases,92 (91.1％) completed the study (45 in the experimental group,47 in the control group,a difference which was not statistically significant).After treatment,the average 6MWT distance in the experimental group was significantly increased and significantly greater than that in the control group.No statistically significant intra-group or inter-group differences were observed with regard to the pulmonary function test or the MRC dyspnea scores.Intra-group comparison and inter-group comparison of the clinical COPD questionnaire scores and anxiety/depression scores did,however,reveal statistically significant differences.There was no significant difference in the average number of acute attacks or in the length of hospital stays.Conclusions Quantified walking and breathing exercises are effective and feasible therapy for patients with chronic obstructive pulmonary disease in the community.