The influence of system delay on 30-day and on long-term mortality in patients with anterior versus non-anterior ST-segment elevation myocardial infarction: a cohort study

Door-to-device time and mortality in patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention: insight from real world data of Thai PCI Registry

Background

Timely reperfusion therapy is recommended for patients with ST-segment elevation myocardial infarction (STEMI), and system delay <90 minutes and door-to-device (D2D) time <60 minutes are recommended by the 2017 ESC Guidelines for the management of STEMI patients and have been proposed as a performance measure for triaging patients for primary percutaneous coronary intervention (PCI). However, previous research produced contradictory results regarding the association between D2D time and mortality. Therefore, this study aimed to examine the associations between D2D time and mortality in Thailand.

Methods

This cohort study included STEMI patients treated with primary PCI in 39 PCI centres in Thailand from February 27, 2018, to August 1, 2019. Patients were eligible if they met the following criteria: primary STEMI diagnosis, symptom onset within 12 hours, and ST-segment elevation of at least 0.1 mV in 2 or more contiguous leads (at least 0.2 mV in V1-V3) or a new left bundle branch block.

Results

Within 12 hours of symptom onset, 3,874 patients underwent primary PCI. The median D2D time was 54 minutes [interquartile range (IQR) 29-90], and there was a significant difference between patients transferred from other hospitals (44 minutes, IQR 25-77, n=2,871) and patients presented directly to PCI centres (81 minutes, IQR 56-129, n=1,003) (P<0.001). Overall, in-hospital mortality was 7.8%. In a multivariable analysis, adjusting for other predictors of mortality and stratifying according to intervals of D2D time, cumulative in-hospital mortality was significantly higher in patients with a D2D time greater than 90 minutes [hazard ratio (HR) 1.5, 95% confidence interval (CI): 1.0-2.1, P=0.046] but not associated with D2D time shorter than 60 minutes (HR 1.2, 95% CI: 0.8-1.8, P=0.319).

Conclusions

A D2D time greater than 90 minutes was related to in-hospital mortality in patients with STEMI treated with primary PCI, but a D2D time less than 60 minutes was not consistently associated with D2D time-improved survival in real-world, contemporary practice in Thailand.

Sharing primary percutaneous coronary intervention care: first experiences with South Limburg ST-elevation myocardial infarction network

Background

In the region of South Limburg, the Netherlands, a shared ST-elevation myocardial infarction (STEMI) networking system (SLIM network) was implemented. During out-of-office hours, two percutaneous coronary intervention (PCI) centres—Maastricht University Medical Centre and Zuyderland Medical Centre—are supported by the same interventional cardiologist. The aim of this study was to analyse performance indicators within this network and to compare them with contemporary European Society of Cardiology guidelines.

Methods

Key time indicators for an all-comer STEMI population were registered by the emergency medical service and the PCI centres. The time measurements showed a non-Gaussian distribution; they are presented as median with 25th and 75th percentiles.

Results

Between 1 February 2018 and 31 March 2019, a total of 570 STEMI patients were admitted to the participating centres. The total system delay (from emergency call to needle time) was 65 min (53–77), with a prehospital system delay of 40 min (34–47) and a door-to-needle time of 22 min (15–34). Compared with in-office hours, out-of-office hours significantly lengthened system delays (55 (47–66) vs 70 min (62–81), p < 0.001), emergency medical service transport times (29 (24–34) vs 35 min (29–40), p < 0.001) and door-to-needle times (17 (14–26) vs 26 min (18–37), p < 0.001).

Conclusions

With its effective patient pathway management, the SLIM network was able to meet the quality criteria set by contemporary European revascularisation guidelines.

Comparison of Left Ventricular Global Strain in Anterior and Non-anterior Wall Myocardial Infarction With CMR Tissue Tracking

Left ventricular (LV) myocardial dysfunction occurs after myocardial infarction (MI) is associated with the location, infarct size, and transmurality degrees of MI. The myocardial strain is a sensitive index used for the quantification of myocardium dysfunction. This study used Tissue-Tracking to evaluate whether the different location of MI would result in different myocardial dysfunction. One hundred patients diagnosed with MI who underwent cardiovascular magnetic resonance examination were included. The tissue-tracking indices, LV global radial strain (GRS), global circumferential strain (GCS), global longitudinal strain (GLS), and the infarct size (IS,% of LV mass) were quantified. There were 42 cases of anterior wall MI (AWMI) and 58 cases of non-anterior wall MI (NAWMI). The GCS of AWMI was significantly lower than that of NAWMI (P = 0.036). In the same level of infarct size, the myocardial strain of AWMI was not significantly different from NAWMI group (P > 0.05). The GRS and GCS were significantly different between transmurality > 50% group with transmurality ≤ 50% group (P < 0.05). The present study demonstrated that LV MI is associated with reduced myocardial strain, and the infarct size and degrees of transmurality were both related to the decline of myocardial strain in patients with MI.

Changes in ST, QT and RR ECG intervals during acute stress in firefighters: a pilot study

Firefighting is a stressful occupation. The monitoring of psychophysiological measures in those professionals can be a way to prevent and early detect cardiac diseases and other stress-related problems. The current study aimed to assess morphological changes in the ECG signal induced by acute stress. A laboratory protocol was conducted among 6 firefighters, including a laboratory stress-inducer task - the Trier Social Stress Task (TSST) - and a 2-choice reaction time task (CRTT) that was performed before (CRTT1) and after (CRTT2) the stress condition. ECG signals were continuously acquired using the VitalJacket®, a wearable t-shirt that acts as a medical certified ECG monitor. Results showed that ECG morphological features such as QT and ST intervals are able to differentiate stressful from non stressful events in first responders. Group mean Visual Analogue Scale (VAS) for stress assessment significantly increased after the stress task (TSST), relatively to the end of CRTT2 (after TSST: 4.67±1.63; after CRTT2: 3.17±0.75), a change that was accompanied by a significant increase in group mean QT and ST segments corrected for heart rate during TSST. These encouraging results will be followed by larger studies in order to explore those measures and its physiological impact under realistic environments in a higher scalability.

Distance-related Differences in Critical Times, Protocol Activation and Mortality in a Regional STEMI Network

Introduction: The aim of the study was to assess the differences in critical network times and mortality in STEMI patients presenting to hospitals in the same STEMI network, but located at different distances from the pPCI center.

Methods: Four-hundreed sixteen patients with STEMI were studied. Group 1: 101 patients presenting to any of the six regional hospitals in the network located at less than 70 km from the pPCI center, with a maximum transport time of 30 minutes. Group 2: 81 patients presenting to any of the three territorial hospitals in the network located at 70–150 km from the pPCI center, with a transport time between 30 and 70 minutes. Group 3: 93 patients presenting to any of the four territorial hospitals in the network located at 150–250 km from the pPCI center, with a transport time between 70 and 150 minutes. Group 4: 141 patients presenting directly to the emergency room of the pPCI center. The following time intervals were recorded: presentation time (PT), from the onset of symptoms to arrival at the pPCI center; protocol initiation time (PIT), from arrival at the pPCI center to STEMI protocol initiation; ischemic time (IT), from the onset of symptoms to repermeabilisation; door to balloon time (DTB), from arrival in the pPCI center to balloon.

Results: PT showed no significant difference between the groups – 183.08 ± 25.2 minutes vs. 199.1 ± 32.4 minutes vs. 166.7 ± 42.5 minutes vs. 161.91 ± 36.8 minutes, respectively (p=0.4). PIT was significantly lower in Group 3 (61.66 ± 15.4 minutes in Group 3 vs. 92 ± 11.5 minutes in Group 2 vs. 107.4 ± 12.5 minutes in Group 1, p = 0.002). DTB time was significantly longer for patients presenting directly to the pPCI center compared to those arriving from Zone 1, 2 or 3 hospitals, 86.96 ± 11.6 minutes vs. 52.27 ± 11.2 minutes vs. 39.94 ± 10.3 minutes vs. 43.9 ± 5.3 minutes, p <0.001). Despite the differences in distance to the pPCI center, there was no significant difference in total IT between the groups (Group 1, 344.6 ± 53.4 minutes; Group 2, 369.3 ± 42.6 minutes; Group 3, 366.65 ± 36.4 minutes; and 340.2 ± 26.9 minutes in the pPCIcenter, p = 0.2), and this was reflected in similar rates of mortality (Group 1, 3.9%; Group 2, 3.7%; Group 3, 3.2%; and 3.5% in the pPCI center).

Conclusion: A well organized STEMI network can shorten protocol initiation and DTB times, achieving similar ischemic times and resulting in similar mortality rates with the centers located closer to the pPCI center. Early activation of the STEMI protocol could lead to superior results even in areas situated at longer distances from the pPCI center.

Factors Associated With Emergency Services Use by Patients With Recurrent Myocardial Infarction: From the Monitoring Trends and Determinants in Cardiovascular Disease/Cooperative Health Research in the Region of Augsburg Myocardial Infarction Registry

BACKGROUND

Although emergency medical services (EMS) use is the recommended mode of transport in case of acute coronary symptoms, many people fail to use this service.

OBJECTIVE

The objective of this study was to determine factors associated with EMS use in a population-based sample of German patients with recurrent acute myocardial infarction (AMI).

METHODS

The sample consisted of 998 persons with a first and recurrent AMI, recruited from 1985 to 2011. Logistic regression modeling adjusted for sociodemographic, situational, and clinical variables, previous diseases, and presenting AMI symptoms was applied.

RESULTS

Emergency medical services was used by 48.8% of the patients at first, and 62.6% at recurrent AMI. In first AMI, higher age, history of hyperlipidemia, ST-segment elevation AMI, more than 4 presenting symptoms, symptom onset in daytime, and later year of AMI were significantly related with EMS use. Pain in the upper abdomen and pain between the shoulder blades were significantly less common in EMS users. In recurrent AMI, EMS use at first AMI, presence of any other symptom except chest pain, ST-segment elevation myocardial infarction, and later year of AMI were significantly related with EMS use. Significant predictors of EMS use in recurrent AMI in patients who failed to use EMS at first AMI were unmarried, experience of any symptom except chest symptoms at reinfarction, bundle branch block (first AMI), any in-hospital complication (first AMI), longer duration between first and recurrent AMI, and later year of reinfarction.

CONCLUSIONS

Patients with AMI and their significant others may profit by education about the benefits of EMS use.

Pre-hospital electrocardiographic severity and acuteness scores predict left ventricular function in patients with ST elevation myocardial infarction

OBJECTIVES

System delay (time from first medical contact to primary percutaneous coronary intervention) is associated with heart failure and mortality in patients with ST segment elevation myocardial infarction (STEMI). We evaluated the impact of system delay on left ventricular function (LVF) according to the combination of ischemia severity (Sclarovsky-Birnbaum grades) and acuteness (Anderson-Wilkins scores) in the pre-hospital electrocardiogram (ECG).

METHODS

In a predefined secondary analysis of a prospective study, the severity and acuteness scores were performed on the pre-hospital ECG. Patients were assessed with respect to 4 classifications which were not mutually exclusive: severe ischemia (+SI) or non-severe ischemia (-SI) and acute ischemia (+AI) or non-acute ischemia (-AI). LVF was assessed by global longitudinal strain (GLS) within 48hours of admission. Adjusted linear regression investigated the association of system delay with GLS in each group.

RESULTS

In total 262 patients were eligible for analysis of the ECG, which resulted in 42 (16%) with (+SI, -AI), 110 (42%) with (-SI, -AI), 90 (34%) with (-SI, +AI), and 20 (8%) patients with (+SI, +AI). Although system delay did not differ between groups, patients with severe and non-acute ischemia had the most impaired LVF. System delay correlated weakly with GLS in the entire population (r=0.133, p=0.031), and well with GLS in the (+SI, +AI) group (r=0.456, p=0.04), while there was no correlation in the other groups. By adjusted analysis, system delay predicted impaired GLS only in the (+SI, +AI) group (β=0.578, p=0.002).

CONCLUSION

Pre-hospital risk stratification by ECG identifies patients with acute and severe ischemia who are at increased risk for reduced ventricular function (assessed by GLS) after STEMI. Optimizing reperfusion delays in these patients can therefore be of particular benefit in improving clinical outcome after STEMI.