Introduction

The time from symptom onset to reperfusion critically influences outcomes in patients undergoing primary percutaneous coronary intervention (PCI) for ST‑segment elevation myocardial infarction (STEMI).^1,2 Notably, treatment times serve as a benchmark for the efficiency and quality of care in systems managing suspected STEMI cases.³ The system delay, defined as an interval from health care system contact to reperfusion, can be optimized through organizational strategies.^3,4 Conversely, patient delay is influenced by various sociodemographic, clinical, cognitive, and emotional factors, impacting the time from symptom onset to the initial request for medical assistance.^5-8 Factors such as political voting preferences^9,10 and historical background,¹¹ including the late 18th‑century partitions of Poland, might affect health care attitudes and propensity to seek timely help. These partitions led to regional political culture variations and institutional and economic development differences.^12,13 The influence of such historical factors on treatment delays and outcomes of STEMI patients undergoing primary PCI remains unclear. Our study aims to identify predictors of treatment delays in a large, unselected cohort of STEMI patients included in the Polish National Registry of PCI (ORPKI).

Patients and methods

The ORPKI, managed by the Jagiellonian University Medical College, Kraków, Poland, is a comprehensive national registry documenting all percutaneous interventional cardiology procedures in Poland. From January 2014 to December 2022, data from 154 cardiology centers were compiled, encompassing a broad patient population without restrictive selection criteria.^14,15 For this analysis, data on 123 829 consecutive patients presenting with acute STEMI, who had undergone one‑stage coronary angiography and primary PCI, were retrieved from the database. Patients experiencing out‑of‑hospital cardiac arrest or presenting with cardiogenic shock were excluded. The patients were divided into 3 groups based on the geographic location of their respective primary PCI centers, aligning with the historical (late 18th‑century) partitions of Poland (Supplementary material, Figure S1). These partitions include the Russian, Austrian, and Prussian parts. Then, sex‑based stratification was applied. STEMI diagnosis adhered to standard guidelines,¹⁶ and all angiographic / PCI procedures conformed to contemporary medical practices. The operators determined the specifics of pharmacotherapy and procedural techniques. The first medical contact (FMC) was marked by the patient’s first assessment by a qualified medical professional capable of electrocardiogram (ECG) interpretation and initiating treatment, occurring either prehospital or upon the hospital arrival. The time of reperfusion was noted at the moment of a wire passage through the occlusion. Patient and system delays, constituting the total ischemic time, were defined as the intervals from symptom onset to FMC, and from FMC to reperfusion, respectively. The primary end point was all‑cause periprocedural (in a catheter laboratory) mortality. Additional data on complications, such as stroke, cardiac arrest, coronary artery perforation, dissection, no‑reflow, and puncture site bleeding were documented. Assessment of complications and evaluation of epicardial flow using the Thrombolysis in Myocardial Infarction scale, both prior to and following PCI, were conducted by the operators.

Results

We analyzed data from 123 829 consecutive nonshock STEMI patients who underwent coronary angiography and primary PCI. Distribution of patients across primary PCI centers was as follows: 60 822 (49.1%) in the Prussian partition, 46 268 (37.4%) in the Russian partition, and 16 739 (13.5%) in the Austrian partition. Sex‑specific analysis of baseline and procedural characteristics showed significant differences between the groups (Supplementary material, Tables S1 and S2). The patients from the Austrian partition, regardless of sex, were less likely to be pretreated with P2Y₁₂ inhibitors before angiogram. In women, the median (IQR) time from FMC to reperfusion was similar across groups (Austrian vs Prussian vs Russian partition, 82 [55–130] vs 84 [58–135] vs 81 [60–130] minutes; P = 0.3). However, there were differences in the median (IQR) time from symptom onset to FMC (120 [60–275] vs 120 [60–300] vs 120 [60–300] minutes; P <⁠0.001). This resulted in notable differences in total ischemic time (P <⁠0.001). In men, there were considerable differences in median patient delays (Austrian vs Prussian vs Russian partition, 78 [53–120] vs 80 [55–125] vs 80 [55–120] minutes; P <⁠0.001), system delays (120 [60–240] vs 120 [60–240] vs 120 [60–265] minutes; P <⁠0.001), and total ischemic time. The multivariable model identified typical factors influencing the time (ln‑transformed) from symptom onset to FMC (detailed in Table 1). Factors that prolonged the patient delay included, among others, female sex (increased by 6.1%), older age (increase by 0.6% by 1‑year increase), diabetes mellitus (increase by 12.5%), and chronic kidney disease (increase by 8.4%). Conversely, previous PCI and direct transfer to a primary PCI center were associated with shorter patient delays (by 19% and 13.9%, respectively). Notably, the patients from the Austrian and Prussian partitions experienced shorter times from symptom onset to FMC (by 6.4% and 4%, respectively) than those from the Russian partition. Treatment in cities with populations exceeding 50 000 did not influence the time from symptom onset to FMC. No difference in periprocedural mortality was noted (Supplementary material, Figure S2).

Discussion

The main finding of our study is the variation in delays from symptom onset to FMC across Polish regions, potentially due to historical influences. Importantly, identifying factors that prolong reperfusion time is vital, as prolonged ischemia correlates with increased infarct size and myocardial damage in STEMI, negatively impacting long‑term outcomes.^1,2 Significant contributors to delayed FMC in our study included diabetes mellitus, chronic kidney disease, advanced age, and female sex, often presenting atypically and complicating timely diagnosis.^5-7 Women and older individuals typically experience greater delays in seeking medical care, a trend consistent with broader health care patterns and possibly reflective of sex disparities in cardiac care.^5-7,17Surprisingly, arterial hypertension and smoking were associated with prolonged time to FMC. This contrasts with previous research, which indicated that these factors did not significantly influence the duration of ischemia. Notably, recent studies suggested that active smokers experiencing STEMI tended to have shorter delays than nonsmokers.^18,19 Patients with a history of PCI, being more familiar with STEMI symptoms, tend to have shorter delays, highlighting the importance of effective patient education.²⁰ However, existing postprocedural education models fall short in enhancing patient knowledge and promoting lifestyle changes. Additionally, while direct transfer primarily addresses system‑related delays, it may also reduce patient‑related delays by decreasing the delays casued by patient visits to nonprimary PCI center emergency rooms.⁴ Moreover, some selection bias may be present, as very late presenters are more likely to be transferred to the emergency department for additional assessments. On the other hand, patients with more severe and typical symptoms are more likely to seek medical help earlier and, consequently, are more frequently transferred directly to PCI‑capable facilities. Despite the benefits of direct transfer and clear recommendations,¹⁶ its utilization remains limited in certain regions of Poland, underscoring the need for improved protocols based on ECG teletransmission for patient selection.^3,21 This is crucial, as even in well‑organized networks in Poland, system‑related delays may exceed the recommended time of 120 minutes from FMC to PCI, particularly for women. However, the overall rate of direct transfer was similar to that noted in various other STEMI‑treatment networks.¹⁸

Although there were variations in reperfusion times, periprocedural mortality rates remained consistent across groups. Unlike long‑term mortality, short‑term mortality may be more influenced by the baseline risk profile than the intervention timing. Additionally, it is possible that patients presenting early are at a higher risk than those who present later.² Moreover, the noted differences in the risk of periprocedural complications should be approached cautiously, as they are predominantly linked to baseline and procedural characteristics, along with the operators’ experience. The influence of historical background on these specific outcomes appears to be improbable.

The historical partitions of Poland have had a lasting impact on various aspects of life in contemporary Poland. The partitions, which occurred in the late 18th century, consisted in a division of Polish territory among Prussia, Russia, and Austria for a period of over 120 years. The time of partition not only reshaped the political landscape but also had profound socioeconomic and cultural implications that are still perceptible today. While establishing a direct link between the historical partitions of Poland and current health care systems, particularly in the context of STEMI treatment networks, may be challenging, it is plausible that these historical events indirectly influence the observed regional variations in patient delays. For instance, economically, the partitions led to divergent development paths in different regions of Poland, which were governed by different powers.^12,13 These historical differences in economic development and policies have left a legacy that can be seen in regional disparities in economic performance, infrastructure, and social conditions within Poland today. The historically influenced development of space, particularly in rural areas, may hold significant importance. Notably, despite the contemporary uniformity in educational approaches across the 3 regions, students from the Austrian partition exhibited statistically superior performance as compared with their counterparts in the Russian partition.¹² In addition, the historical partitions of Poland fostered distinct regional variances in political culture, subsequently impacting both inclination to engage in parliamentary elections and shaping of political preferences.¹³ Political ideology can play a crucial role in shaping health behaviors.^9,10 Unfortunately, the design of our study did not enable identification of underlying factors that could explain the observed correlation between delays from symptom onset to FMC and the historical partitions of Poland. Since the distribution of catheter laboratory services in Poland across different partitions in the current analysis is similar in terms of 1 catheter laboratory per the number of inhabitants (Austrian vs German vs Russian, 215 000 vs 204 000 vs 213 000, respectively), and the laboratories are well in line with the European Society of Cardiology guideline recommendations,¹⁶ we do not believe these aspects could have influenced our results. Previous studies have also confirmed equal efficacy of STEMI treatment across Poland in terms of administrative and technical aspects of hospital networking. The times from patient call to FMC of emergency medical services has not been shown to differ in Poland in previous studies.²¹

The primary limitation of our study lies in categorizing patient groups based on the location of the primary PCI center rather than the patient’s actual residence or birth. This methodology raises the possibility that factors such as migration or tourism might have influenced our results. Also, we could not completely disprove the impact of other sociodemographic variables, including education level and urban vs rural living, as these data were not collected. Furthermore, the current geographic boundaries of Poland do not align precisely with those from the time of the partitions, which may affect the accuracy of our group allocations.