Acute reperfusion therapy is critical for improving the outcomes of patients with ST-elevation myocardial infarction (STEMI). The guidelines have advocated that timely primary percutaneous coronary intervention (PPCI) in experienced centers is a superior mode of therapy compared to thrombolytic therapy (TT) [1,2]. Quality improvement initiatives, such as the “Stent for Life” in Europe, the “D2B Alliance” and the “Mission:Lifeline” in the USA, were established to improve the rate of timely PPCI for patients with STEMI [3–7]. However, adopting a pharmaco-invasive approach has also been considered a reasonable therapeutic strategy in cases where PPCI could not be achieved within 90–120 min from first medical contact. The pharmaco-invasive approach involves treatment with anti-platelets and TT (pre- or in-hospital), followed immediately by a rescue PCI, when reperfusion fails, or by an elective PCI within 6–24 h, when reperfusion is successful [8–10]. Integrated, well-organized STEMI networks facilitate choosing the optimal acute reperfusion strategy according to the individual clinical scenario [11–16].

Emergency Medical Services (EMS) is a major cornerstone in the acute STEMI chain of survival. EMS provides prompt recognition and early management of acute STEMI, which are critical in reducing morbidity and mortality [1,2]. We demonstrated previously that only one in four patients with STEMI used the EMS system in the Arabian Gulf region; also, short and long-term outcomes were similar to patients that used other means of transport (non-EMS). However, in that study, the majority of patients that used EMS were treated with in-hospital TT rather than PPCI [17]. Accordingly, we intended to develop STEMI networks across our region with a major emphasis on increasing the rate of timely PPCI. To that end, we acknowledged that an intimate understanding of the EMS triaging system for patients with acute STEMI in our communities was required to establish an effective STEMI system of care. Thus, we undertook the third phase of the project termed the Gulf Registry of Acute Coronary Events: Primary PCI Programs (Gulf RACE-3Ps), with the following objectives: (1) Assess temporal changes in clinical arrivals and EMS usage rates compared to our previous reports; (2) describe the EMS system (Red Crescent and Inter-Hospital); (3) compare the clinical presentation, management, and outcomes in the emergency department (ED) and in the hospital between patients that used EMS (EMS group) and those that used other means of transport (non-EMS group), and between hospitals that provided PCI (PCI-hospitals) and those that did not provide PCI (non-PCI hospitals).

We evaluated the medical history, clinical presentation, socio-demographic variables, anthropometric measurements, in-hospital course, treatments, and patient outcomes, including mortality. These data were compared between the EMS and non-EMS groups. Categorical data were summarized as frequency and percentages; continuous data were summarized as the mean and SD or median and IQR, based on whether the distribution satisfied the normality assumption. We used a Chi-square test or Fisher’s exact test to compare categorical variables, as appropriate. Between-group comparisons of quantitative variables were carried out with independent t-tests or the Mann-Whitney U test, based on the normality assumption. Multiple logistic regression models, with stepwise selection and backward elimination, were used to identify predictors of EMS use. The predictors included in the full model were age, gender, nationality, ethnicity, education, monthly income, type of STEMI, diabetes, hypertension, history of MI, history of angina, and history of PCI. We reported summary statistics and p-values. All Statistical analyses were performed with SAS version 9.2 (SAS Institute, Inc, Cary, NC). All data were doubled-checked for errors prior to analyses. We considered a p <0.05 to indicate statistical significance.

The present report of the Gulf RACE-3Ps study was the first in our region to provide results from a systematic exploration of EMS care for patients with acute STEMI. Our results confirmed our previous findings that, among patients with STEMI in our region, most were relatively young males, and two-thirds were non-Gulf citizens; moreover, these patients had a high prevalence of coronary artery disease risk factors [17]. The current report also showed that most of these patients had relatively low SES and educational levels. This finding was most likely related to the fact that large sectors of the population that live in the Arabian Gulf countries (30% in Saudi Arabia, 60% in Kuwait, 80% in UAE and Qatar) are foreign “blue-collar” workers, with limited access to health care. This observation was supported by our finding that half of the patients with acute STEMI that did not receive acute reperfusion therapies had been subject to “hospital eligibility issues” and limited access to hospital admission and treatment. This highlights the urgent need for major changes in health care policy, including adoption of universal (foreign workers included) health care insurance coverage. In particular, health insurance should cover life-saving procedures, such as reperfusion therapy for patients with acute STEMI.

We showed that the median time delay from symptom-onset-to-ED arrival was 175 min. System delay (sum of EMS and DBT delay) has not changed much over the years. In our study, the system delay was 130 min (mainly related to EMS delay), which was within the range of 60 to 177 min reported in the Stent for Life survey that was undertaken in 30 European countries [3]. In addition, we observed patient-related delays (median, 120 min), which contributed to the other half of the total ischemic time prolongation. These delays would be considered in the “high range”, compared to patient-related delays reported in other international studies. In the GRACE registry, patient-related delays were 104 to 120 min [19]; in France, delays decreased from 120 to 74 min over a 10- year period in a nation-wide registry [20]. Furthermore, among our patients with STEMI, only 30% had DNTs ≤30 min, 65% had DBTs ≤90 min, and only 25% had rescue PCIs for failed reperfusion. However, in a large CathPCI Registry in the USA, which represented patients from 2005 to 2009, the in-hospital mortality had remained unchanged, despite an increase (from 60% to 83%) in the percentage of patients with DBTs ≤ 90 min [21]. A re-analysis of the same registry for patients between 2005 and 2011 showed that patient-specific DBTs were associated with lower mortality over time, but there were trends for increased mortality risk at the population level [22]. Thus, major emphasis should be placed on prompt initiation of acute reperfusion therapies upon first medical contact as well as improving the total ischemic time. It is essential to launch public educational campaigns to raise public awareness of acute coronary syndromes symptoms and the importance of early arrival to the nearest hospital, particularly hospitals that offer 24/7 PPCI-capability.

Around one in four patients with acute STEMI arrived at the ED by EMS. This rate did not improve over the rate found in our previous report. A more disturbing finding was the fact that only 10.2% of EMS use was via the Red Crescent (or 3.7% of the overall acute STEMI cohort). This is an extremely low utilization rate; almost all patients that used EMS were transported in ambulances that operated under the authority of clinics and/or non-PCI hospitals. Thus, it was not surprising to find that the EMS response times were quite rapid, because these were clinic/hospital-related ambulances that transferred patients to other hospitals after patients had arrived at the hospital in their own cars. In contrast, ambulances operated by the Red Crescent had transferred patients directly from the scene to the hospital. In a Swedish multicenter study, only 51% reported that the first medical contact was with EMS; 14% went directly to the ED; and the remaining patients chose to discuss their symptoms first by either going to a clinic or consulting a public health care advisory service [23]. In a recent registry of 14,518 patients with STEMI in the USA, only 25% used EMS, and more than one third of those transferred for PPCIs failed to achieve a first door-to-device time ≤120 min, despite estimated transfer times of ˂60 min [24]. This study also clearly demonstrated that high-volume STEMI PCI centers were 20% more likely than low-volume centers to achieve timely acute reperfusion.

A significant proportion of the ambulance paramedics in our study lacked BLS and ACLS certifications. Most ECGs were performed in the clinics or non-PCI hospitals, rather than in the ambulance. It has been shown that, when pre-hospital ECGs were transmitted to hospitals by the EMS, the total ischemic time could be reduced and false-positive activations of the PCI hospital could be avoided [25–28]. State-of-the-art tertiary care hospitals were established in our region over the last few decades. The new health care system priorities should be to improve primary prevention of cardiovascular diseases and establish an efficient, robust EMS infrastructure under the authority of a single national health care provider.

Patients in the EMS group were less likely than those in the non-EMS group to have coronary artery disease risk factors or a history of ischemic heart disease. Therefore, the majority of patients that used EMS were most likely uncertain of their diagnosis when they became symptomatic. Consequently, they were self-transported, first to a clinic or a peripheral non-PCI hospital; then, subsequently, they were transferred by ambulance to another, larger non-PCI hospital or to a PCI hospital. Therefore, unlike patients in western countries with well-developed EMS systems and organized STEMI networks, our patients that used EMS were mostly in the Inter-Hospital EMS group rather than in the Red Crescent EMS group, and subsequently had to go through “several stops” prior to being diagnosed and transferred for acute reperfusion; thus, these patients experienced longer total ischemic times than patients that did not use EMS. The delay in arrival by EMS might have off-set a potential benefit in clinical outcomes gained with shorter DNTs and DBTs. In fact, in the EMS group, the mortality rate was much higher for those that initially went to non-PCI hospitals than for those that initially went to PCI hospitals (14.7% vs. 5.2%). However, this difference in mortality was most likely related to a combination of factors, including the disease severity in the patient population, the pre-hospital delay times, and the relatively lower standards of care in the non-PCI hospitals. Furthermore, low to moderate SES and “other” ethnicity were predictors of EMS use; thus, many patients with acute STEMI, particularly foreign workers, might have tried to access hospital care by arriving in an ambulance, because otherwise, they would be declined admission to the ED; in contrast, Gulf citizens and/or those with a history of ischemic heart disease relied on rapid self-transport to the nearest hospital, because they were unlikely to face eligibility issues regarding their hospital admission or management.