Introduction
For patients with acute ST-segment elevation myocardial infarction (STEMI), the key to treatment is to reperfuse the involved vessels promptly, which includes thrombolysis and primary percutaneous coronary intervention (PPCI) [1]. Compared with thrombolytic therapy, PPCI has been shown to improve patients’ prognosis. Keeley et al. [2] found that the short-term mortality, the incidence of nonfatal reinfarction, and the incidence of stroke in patients undergoing PPCI is much lower than that of patients who undergo thrombolytic therapy. However, the advantages of PPCI are not that obvious with a delay of the operation compared with thrombolytic therapy [3]. Abundant evidence has shown that the therapeutic effect and the prognosis of patients with STEMI strongly depends on the treatment time, especially the reperfusion time; that is, “time is myocardium.” Any delay in reperfusion will increase mortality [4]. Therefore, the treatment time is crucial. According to studies, the door-to-balloon time is an important indicator to measure PPCI efficiency [5, 6]. The American College of Cardiology/American Heart Association STEMI guideline [7] recommends that for STEMI the door-to-balloon time should be 90 min or less so that patients can obtain the maximum benefit from percutaneous coronary intervention (PCI) reperfusion [8]. Gibson et al. [9] found that a shorter door-to-balloon time reduces mortality. According to Rathore et al. [10], if the door-to-balloon time decreases from 90 min to 60 min, mortality will decline by 0.8 percentage points, and the decease will be 0.5 percentage points when the time is decreased to 30 min. However, the door-to-balloon time standard is not reached for a great number of patients with acute STEMI in China because of the late establishment of a chest pain center, inaccurate diagnosis, substandard treatment of STEMI and patients’ delay in seeking medical help. In addition, poor disease recognition in medical developing areas, bad cooperation among different departments, and the delay in patient referral are also reasons. Thus, complying with the requirements for the construction of China’s chest pain center, optimizing the treatment process and measurements would be conducive to more patients reaching the standard door-to-balloon time and improving their prognosis. As a certified and qualified chest pain center in China, we created a platform on WeChat, which includes medical staff of our hospital and of hospitals where PPCI cannot be performed to make transit more rapid for surrounding primary hospitals. During the treatment of STEMI, the WeChat group played an important role in shortening the time from the onset of chest pain to reperfusion. However, few studies about the chest pain center established on the WeChat platform would increase the treatment speed and improve the prognosis of STEMI patients undergoing PPCI are reported so far. Thus, this study aimed to explore the effect the WeChat platform has had on patients’ treatment time and prognosis. We hypothesized that it would reduce the treatment time and improve patients’ prognosis in comparison with routine visits.
Participants and Methods
Participants
This study involved patients with STEMI from January 2017 to November 2018 in the chest pain center of the First Affiliated Hospital of Chongqing Medical University. The inclusion criteria were as follows: (1) patients meet the STEMI diagnostic criteria; (2) patients with clear records of door-to-balloon time and of artery puncture to balloon dilation time. The exclusion criteria were as follows: (1) patients with incomplete door-to-balloon time records; (2) patients in whom PPCI treatment failed.
Methods
Treatment Process
The treatment process for patients in the WeChat pre-admission startup group was as follows:
Presentation of patients with onset of acute chest pain
STEMI diagnosed in the non-PCI hospital
Sharing of information, including information from the electrocardiograph and auxiliary examinations, on the WeChat platform
Transfer from the emergency department or cardiac care unit to the intervention room after consultation with physicians in the chest pain center
Interventional therapy
The treatment process for patients in the control group was as follows:
Presentation of patients with acute chest pain (by calling 120, self-visiting the emergency department/critical care unit or transferred from other departments)
STEMI diagnosed through related examinations
Reassessment by chief interventional cardiologists
Sent to the intervention room to undergo an interventional operation
Information Collection and Grouping Method
First, we gathered patients’ clinical information such as age, sex, body mass index, and medical history. According to different visiting methods, they were ad libitum divided into a WeChat pre-admission startup group and a routine treatment group (control group). The door-to-balloon time, standard door-to-balloon time achievement rate (percentage of door-to-balloon times that were 90 min or less), artery puncture to balloon dilation time, mortality, incidence of heart failure/malignant arrhythmia/cardiogenic shock, and length of stay were compared between patients in the two groups.
Statistical Analysis
All data were analyzed by PASW Statistics. Student’s t test was used to compare intergroup differences, and the measured data were presented as the mean ± standard deviation. The chi-square test was used to assess differences in categorical variables between groups, and the measured data were expressed as percentages; P values less than 0.05 were considered statistically significant.
Results
Comparison of Clinical Data of Patients in the Two Groups
There were 483 patients from January 2017 to November 2018 included in this study. They were included in the WeChat pre-admission startup group (n=311) and the non-WeChat pre-admission startup group (control group, n=172). Although patients in the WeChat pre-admission startup group had a higher hyperlipidemia rate, there was no statistical difference in age, sex, body mass index, Killip grades, cardiovascular complications (hypertension and diabetes mellitus), PCI history, family history of coronary heart disease, and time of first visit between the groups (P＞0.05) (Table 1).
Comparison of baseline data of patients in two groups (n, %).
| Item | WeChat pre-admission startup group (311, 64.39) | Non-WeChat pre-admission startup group (172, 35.61) | P value |
|---|---|---|---|
| Male | 231 (74.28) | 136 (79.07) | 0.238 |
| Age (Years, x±s) | 64.64±12.23 | 64.53±12.42 | 0.931 |
| BMI (Kg/cm2, x±s) | 23.77±2.98 | 24.00±3.2 | 0.433 |
| Smoking history | 199 (63.99) | 110 (64.0) | 0.994 |
| Diabetes mellitus | 98 (31.51) | 52 (30.23) | 0.771 |
| HTN | 169 (54.34) | 94 (54.65) | 0.948 |
| Hyperlipidemia | 149 (47.91) | 100 (58.14) | 0.013 |
| CHD family history | 21 (6.75) | 13 (7.6) | 0.740 |
| CHD | 23 (7.4) | 15 (8.7) | 0.604 |
| Past PCI history | 11 (3.5) | 7 (4.1) | 0.727 |
| Killip grade | 0.148 | ||
| I | 221 (67.85) | 124 (72.09) | |
| II | 40 (12.86) | 28 (16.28) | |
| III | 6 (1.9) | 6 (3.5) | |
| IV | 44 (14.15) | 14 (8.1) | |
| Time of first visit (Hours, x±s) | 3.64±0.34 | 4.01±0.49 | 0.532 |
Comparison of Treatment Efficiency–Related Index of Patients with STEMI between the Two Groups
The door-to-balloon time of the WeChat pre-admission startup group was significantly shorter than that of the control group (27.35±10.58 vs. 88.15±53.79, P<0.05), while the standard door-to-balloon time achievement rate was much greater (100% vs. 72.09%, P<0.05) (Table 2).
Comparison of the patients’ reperfusion time, recent prognosis and length of stay in two groups (n, %).
| Item | WeChat platform visit group (311, 64.39) | Control group (172, 35.61) | P value |
|---|---|---|---|
| D-to-B time (min, x±s) | 27.35±10.58 | 88.15±53.79 | P=3.6979E-64 |
| Compliance rate of D-to-B time | 311 (100) | 124 (72.09) | P=1.0402E-23 |
| Arteriopuncture to balloon dilation (min, x±s) | 19.97±8.68 | 21.40±12.26 | 0.138 |
| Incidence of heart failure | 64 (20.58) | 33 (19.19) | 0.714 |
| Incidence of malignant arrhythmia | 38 (12.21) | 14 (8.14) | 0.166 |
| Incidence of cardiogenic shock | 42 (13.5) | 16 (9.3) | 0.174 |
| Mortality rate | 13 (4.18) | 4 (2.32) | 0.29 |
| Length of staya (d, x±s) | 9.34±4.68 | 9.14±4.49 | 0.665 |
aThe patients who died or transferred to local hospital to continue treating were not included due to their length of stay were all short.
Comparison of Patients’ Prognosis and Length of Stay between the Two Groups
Compared with the control group, mortality in the WeChat pre-admission startup group was slightly higher, however, it was not statistically different (4.18% vs. 2.32%, P=0.29). There were also no statistical differences in the incidence of heart failure, cardiogenic shock, and arrhythmias between the two groups (P>0.05). Moreover, the overall length of stay was similar in the two groups (9.34±4.68 days vs. 9.14±4.49 days, P=0.665) (Table 2).
Discussion
This study showed that the method of seeking medical treatment has a significant impact on the reperfusion time of STEMI patients. Compared with the non-WeChat pre-admission startup group, the door-to-balloon time was significantly lower and the standard door-to-balloon achievement rate was higher in the WeChat pre-admission startup group. More specifically, the average door-to-balloon time in the WeChat group was obviously below the current guideline-recommended 90 min, which apparently reached the standard. The main reason for the shorter of door-to-balloon time was the instant message delivery of information on STEMI patients through the WeChat platform, so the interventional cardiologist in the chest pain center was timely prepared for the following interventional operations. Once the patients reached the center, they were directly transferred to the intervention room and coronary angiography was immediately performed. Before their arrival, the interventional cardiologists already knew who the patient was, when chest pain onset had occurred, and what kind of myocardial infarction the patient had, so the cardiologists could react to what happened quickly, and this shortened the time from chest pain onset to cardiac reperfusion therapy. The saying “information comes before the patient” was thus true. Meanwhile, on the way to our hospital, some cardiologists would inform the patients and their families of the necessity of performing cardiac angiography on the telephone, while some had the preoperational preparations done; those preparations included obtaining informed consent, making sure the patients take loading-dose drugs, and preparing operation-related equipment, which vastly avoided unnecessary waste of emergency resources and reduced the door-to-balloon time. Studies [11, 12] have shown that for patients with STEMI, the main way to shorten the treatment time is to achieve prehospital diagnosis and transfer from the emergency department or critical care unit. Only in this way can patients receive rapid reperfusion therapy, leading to smaller infarction size and improved short-term prognosis. For patients who come to our hospital on their own (often a long way) and are accepted by emergency or outpatient physicians, there was a significant increase in the overall time of myocardial ischemia. This is mainly because of the delay on their way. Besides, the operational preparation also takes a long time. Some studies have shown that mortality was only 1.6% if STEMI patients successfully achieved reperfusion within 1 h; however, the rate increased to 6% if the time was increased to 6 h [13]. Nonetheless, in our study, we found there was no difference between the WeChat pre-admission startup group and the control group (4.18% vs. 2.32%, P=0.29), which was in conformity with the conclusion of Menees et al. [14]. Menees et al. reported that even though the door-to-balloon time of STEMI patients who underwent PPCI treatment was reduced by 16 min, mortality did not decrease. A possible reason was that the door-to-balloon time made up of only a small part of the overall ischemic time, while the overall ischemic time was the key factor that determined the patients’ prognosis [15]. Furthermore, the study of Menees et al. also demonstrated that reduction of the door-to-balloon time may not have an obvious influence on infarction sizes if the overall ischemic time is too long; however, if the overall ischemic time is short, a reduction of the door-to-balloon time may significantly reduce infarction sizes and postmyocardial infarction complications. This indicates that other than establishing a chest pain center on WeChat, public education would also help reduce the door-to-balloon time, for public education probably improve patients’ awareness that they have myocardial infarction, which leads them to the closest hospital as soon as possible.
The results also suggested that there was no significant difference in the length of stay and the incidence of complications such as heart failure, malignant arrhythmia, and cardiogenic shock between the two groups. The reasons may include sample deviation and the short observation time. Apart from those reasons, in this study, the referral time of patients in the WeChat pre-admission startup group from a non-PCI hospital to a PCI hospital prolonged the overall time of myocardial ischemia. Further research should enroll more patients and observe the impact of a chest pain center on therapeutic efficiency and prognosis of patients with myocardial infarction through long-term follow-up.
In addition, the establishment of a WeChat group for a chest pain center has the following functions: (1) it creates the possibility to carry out the “linkage with primary hospitals and bidirectional referrals” so that graded diagnosis and treatment can be achieved; (2) it helps primary hospitals improve skills in diagnosis and treatments and minimizes the gap between these hospitals by sharing clinical data in the WeChat group; (3) it enhances quality management of the chest pain center, providing a more convenient service for patients with acute and critical diseases.
In conclusion, as a universal communication tool, WeChat can be used in clinical practice. The convenience of information exchange makes possible instant information delivery between different primary hospitals and chest pain centers, which greatly reduces the door-to-balloon time. Therefore, on the basis of previous studies and this study, to decrease the treatment time and improve STEMI patients’ prognosis, application of the WeChat platform in establishing a chest pain center should be strongly promoted.