Due to recent advances, door-to-balloon time (D2BT) has been reduced significantly for patients with ST-segment elevation myocardial infarction (STEMI). However, whether this reduction can be translated into a concrete mortality or morbidity benefit is still the subject of controversy. We conducted a before-and-after study to determine the impact of in-hospital tele-electrocardiography (ECG) triage and interventional cardiologist activation of the infarct team on D2BT and long-term clinical outcomes in STEMI patients undergoing primary percutaneous coronary intervention (PPCI). A total of 272 consecutive patients with acute STEMI undergoing PPCI were enrolled in our study, comprising 102 tele-ECG patients and 170 conventional triage patients. Major adverse cardiovascular and cerebral vascular events (MACCE), including death, recurrent nonfatal MI, nonfatal stroke, and angina-driven target vessel revascularization were recorded during a 3-year follow-up. The median D2BT of the tele-ECG group was significantly shorter than control group (79 minutes vs. 109 minutes, p < 0.001). The tele-ECG triage group had a higher percentage of patients reaching the D2BT goal (< 90 minutes) (78% vs. 55%; p < 0.001). The MACCE rate was significantly lower in the Tele-ECG versus the control group (23.5% vs. 38.2%, p = 0.012). Tele-ECG group had a lower mortality rate which did not reached statistical significance (2% vs. 5.9%, p = 0.102). In multivariable Cox proportional hazards analyses, the implementation of tele-ECG triage (HR = 0.43, p = 0.003) and the presence of moderate or severe mitral regurgitation at presentation (HR = 1.87, p = 0.029) were discovered as independently associated with MACCE. In-hospital tele-ECG triage and interventional cardiologist activation can shorten D2BT and is associated with improved late clinical outcomes during a 3-year follow-up in STEMI patients undergoing PPCI.