Impact of a prehospital mobile cloud ECG transmission system on door-to-balloon time, myocardial damage and mid-term all-cause mortality in patients with ST-elevation myocardial infarction
Authors: Anai M , Unoki T , Inamori T , Sato T , Nakayama T , Konami Y , Suzuyama H , Inoue M , Horio E , Kodama K , Taguchi E , Sawamura T , Sakamoto T , Nakao K , Koyama J 
Published: October 2024

Abstract

Background
Guidelines recommend to establish a regional reperfusion strategy to maximize the efficiency of care for patients diagnosed with ST-elevation myocardial infarction (STEMI). In Addition, the recently developed mobile cloud-based 12-lead electrocardiogram (ECG) transmission system enables the transmission of prehospital ECGs at a low cost. Medical staff can use electronic devices to access and review ECGs from anywhere. However, the effectiveness of the prehospital mobile cloud ECG system has not yet been clearly established.

Objective
This single-center study aims to evaluate the impact of the prehospital mobile cloud ECG system on reducing Door-to-Balloon Time (DTBT), myocardial damage, and mid-term all-cause mortality in patients with STEMI.

Methods
In June 2018, eight prehospital Mobile Cloud ECG Transmission systems were integrated into the regional Emergency Medical Service (EMS) in our region. This study examined and compared Door-to-Catheterization Laboratory Time (DTCT), DTBT, Onset-to-Reperfusion Time (OTRT), peak creatine kinase-MB (CK-MB) levels, and one-year mortality rates of STEMI patients in the five years before and after introducing the prehospital mobile cloud ECG system. From June 2013 to May 2023, our institute received a total of 426 STEMI patients via ambulances from these two EMS departments. After excluding 23 patients with OTRT exceeding 24 hours and 76 patients who were transferred without the system post-introduction, 327 consecutive STEMI patients who underwent emergency percutaneous coronary intervention (PCI) were included in the study. The patients were divided into two groups: 169 patients before the prehospital mobile cloud ECG system introduction and 158 patients after that.

Results
There were no significant differences in age, gender, past medical history, and Killip Class IV between the two groups, except for the proportion of left main trunk (LMT) lesions, which was significantly higher in the ECG group. Significant reductions were observed in both DTCT and DTBT in the group after introduction, with differences noted as (DTCT: 42 min vs. 26 min; p &lt; 0. 001, and DTBT: 74 min vs. 56 min; p &lt; 0.001, respectively). However, the OTRT did not show a significant difference. Peak creatine kinase-MB (CK-MB) levels did not differ between the two groups, and Kaplan-Meier analysis revealed no significant difference in one-year mortality between them. Multivariate Cox regression analysis, which included variables such as age, peak CK-MB levels, Killip Class IV, LMT lesions, OTRT and the prehospital mobile cloud ECG transmission system usage, revealed that only Killip Class IV was significantly associated with one-year mortality (hazard ratio of 2.82 and a 95% confidence interval of 1.61-4.94; p=0.0003).

Conclusion
The prehospital mobile cloud ECG transmission system significantly reduced DTBT, but did not lead to a reduction in myocardial damage or an improvement in mid-term prognosis.Effect of the ECG Transmission SystemKaplan-Meier analysis