Pre-hospital reperfusion therapy: a strategy to improve therapeutic outcome in patients with ST-elevation myocardial infarction

Impact of door in-door out time on total ischemia time and clinical outcomes in patients with ST-elevation myocardial infarction

INTRODUCTION

Patients with ST-elevation myocardial infarction (STEMI) requiring inter-hospital transfer for primary percutaneous coronary intervention (PCI) often have delays in reperfusion. The door in-door out (DIDO) time is recommended to be less than 30 min.

OBJECTIVES

To assess the DIDO time of hospitals that transfer patients with STEMI to a PCI center and to assess its impact on total ischemia time and clinical outcomes in patients with STEMI.

METHODS

We performed a retrospective study of 523 patients with STEMI transferred to a PCI center for primary PCI between January 1, 2013 and June 30, 2017.

RESULTS

Median DIDO time was 82 min (interquartile range, 61-132 min). Only seven patients (1.3%) were transferred in ≤30 min. Patients with DIDO times over 60 min had significantly longer system delays (207.3 min vs. 112.7 min; p<0.001) and total ischemia time (344.2 min vs. 222 min; p<0.001) than patients transferred in ≤60 min. Observed in-hospital mortality was significantly higher among patients with DIDO times >60 min vs. ≤60 min (5.1% vs. 0%; p=0.006; adjusted odds ratio for in-hospital mortality, 1.27 [95% CI 1.062-1.432]). By the end of follow-up, patients belonging to the >60 min group had a higher mortality (p=0.016), and survival time was significantly shorter (p=0.011).

CONCLUSION

A DIDO time ≤30 min was observed in only a small proportion of patients transferred for primary PCI. DIDO times of ≤60 min were associated with shorter delays in reperfusion, lower in-hospital mortality and longer survival times.

Impact of paramedic education on door-to-balloon times and appropriate use of the primary PCI pathway in ST-elevation myocardial infarction

OBJECTIVE

Evidence supports improved outcomes and reduced mortality with rapid reperfusion through primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction (STEMI). UK national audit data (Myocardial Ischaemia National Audit Project [MINAP]) demonstrates minor improvements in door-to-balloon times (DTB) of <90 min but increasing call-to-balloon times (CTB). We evaluate the effect of a regional Cardiologist delivered paramedic education programme (PEP) on DTB times and appropriate use of the PPCI pathway.

METHODS

This was a prospective single-centre study of patients with STEMI brought directly to hospital via ambulance services. Data sources included ambulance charts, in-patient notes, British Cardiovascular Interventional Society (BCIS) database and local MINAP data. All DTB breaches were investigated. A local PEP was implemented with focus on ECG interpretation, STEMI diagnosis and appropriate use of the PPCI pathway. Non-parametric Wilcoxon rank test was used for comparisons of DTB and CTB times between direct versus ED-associated cath lab transfer.

RESULTS

A total of 728 patients with STEMI were admitted directly to our centre via ambulance, 66% (n=484) directly to the Catheterisation Laboratory (Cath Lab) and 34% (n=244) via the Emergency Department (ED). There was a significant increase in median DTB, 83 vs 37 min (p<0.001) and median CTB 144 vs 97.5 min (p<0.001) when transfer to the Cath Lab occurred via the ED versus direct transfer. The PEP increased direct cath lab transfers (52%-85%) and generated annual reductions in median DTB times, with sustained improvement seen throughout the 7-year study period.

CONCLUSIONS

Paramedic education increases direct transfer of STEMI patients to the Cath Lab, and reduces DTB times. This is an effective and reproducible intervention to facilitate timely reperfusion in STEMI.

The use of reperfusion therapy in transition countries without fully applicable pharmacoinvasive strategy

Background/Aim. The pharmacoinvasive (PI) therapy is a recommended strategy in patients (pts) with ST elevation myocardial infarction (STEMI) unable to undergo timely primary percutaneous coronary intervention (p-PCI). The aim of the study was to find out the cohorts of pts who are not treated by any reperfusion therapy (RT) as well to determine the outcome of the pts treated with RT in a transition country without fully applicable PI therapy. Methods. The study analyzed data from the Hospital National Registry for Acute Coronary Syndrome of Serbia (HORACS). Results. The significant predictors of the withdrawing of the application of any RT in the model [c 75.6%, SE 0.004, 95% CI 0.748?0.761)] were a ge ( ? 6 5 years), heart failure (Killip II-IV), diabetes mellitus, and the time to first medical contact (FMC) (> 360 min). In patients without RT, mortality was 15.7%, in pts treated with fibrinolytic therapy (FT) was 10.5%, and in pts treated with pPCI, it was 6.2% (p < 0.000). Within 3 hours to FMC, higher in-hospital mortality was in FT pts (FT 8.7% vs p-PCI 4.3%). FT treated patients were older, had more comorbidities and heart failure (HF). However, after propensity score matching, in order to ad-just the differences among the pts, the mortality rate remained higher in FT pts but not statistically significantly higher than in p-PCI pts (FT 8.8% vs p-PCI 6.4%). Conclusion. The balance of the best cost-benefit strategies for better use of RT is difficult to achieve in transition countries. The possibility for timely p-PCI and PI therapy is especially not applicable in high-risk patients, older pts, pts with HF, and those with diabetes mellitus.

Role of Orai1 and L-type CaV1.2 channels in Endothelin-1 mediated coronary contraction under ischemia and reperfusion

Ischemia and Reperfusion (I/R) injuries are associated with coronary artery hypercontracture. They are mainly originated by an exacerbated response to agonists released by endothelium such as Endothelin (ET-1), involving the alteration in intracellular calcium handling. Recent evidences have highlighted the implication of Store-Operated Calcium Channels (SOCC) in intracellular calcium homeostasis in coronary artery. However, little is known about the role of SOCC in the regulation of coronary vascular tone under I/R. The aim of this study was to evaluate the role of SOCC and l-type Ca²⁺ channels (LTCC) in coronary artery vasoconstriction originated by ET-1 in I/R. We used Left Anterior Descendent coronary artery (LAD) rings, isolated from Wistar rats, to study the contractility and intracellular Ca²⁺ concentration ([Ca²⁺]_i) under a simulated I/R protocol. We observed that responses to high-KCL induced depolarization and caffeine-induced Ca²⁺ release are attenuated in coronary artery under I/R. Furthermore, ET-1 addition in ischemia promotes transient and small rise of [Ca²⁺]_i and coronary vascular tone. Meanwhile, these effects are significantly potentiated during reperfusion. The resulting ET-1-induced vasoconstrictions and [Ca²⁺]_i increase were abolished by; GSK-7975A and gadolinium, inhibitors of SOCC; and nifedipine a widely used inhibitor of LTCC. Interestingly, using in situ Proximity Ligation Assay (PLA) in isolated coronary smooth muscle cells we found significant colocalization of LTCC Ca_V1.2 isoform with Orai1, the pore forming subunit of SOCC, and TRPC1 under I/R. Our data suggest that hypercontraction of coronary artery induced by ET-1 after I/R involves the co-activation of LTCC and SOCC, which colocalize significantly in the sarcolemma of coronary smooth muscle cells.

Emergency management of patients with ST-segment elevation myocardial infarction in Eastern Austria: a descriptive quality control study

Background

Myocardial infarction is a time-critical condition and its outcome is determined by appropriate emergency care. Thus we assessed the efficacy of a supra-regional ST-segment elevation myocardial infarction (STEMI) network in Easternern Austria.

Methods

The Eastern Austrian STEMI network serves a population of approx. 766.000 inhabitants within a region of 4186 km². Established in 2007, it now comprises 20 pre-hospital emergency medical service (EMS) units (10 of these physician-staffed), 4 hospitals and 3 cardiac intervention centres. Treatment guidelines were updated in 2012 and documentation within a web-based STEMI registry became mandatory. For this retrospective qualitative control study, data from February 2012–April 2015 was assessed.

Results

A total of 416 STEMI cases were documented, and 99% were identified by EMS within 6 (4.0–8.0) minutes after arrival. Median time loss between onset of pain and EMS call was 54 (20–135) minutes; response, pre-hospital and door-to-balloon times were 14 (10–20), 46 (37–59) and 45 (32–66) minutes, respectively. When general practitioners were involved, time between onset of pain and balloon inflation significantly increased from 180 (135–254) to 218 (155–348) minutes (p < .001). A pre-hospital time < 30 min was achieved in 25.8% of all patients during the day vs. 11.6% during the night (p < .001). Three hundred forty-five patients (83%) were subjected to primary percutaneous coronary intervention (PPCI), and 6.5% were thrombolysed by EMS. Pre-hospital complication rate was 18% (witnessed cardiac arrest 7%, threatening arrhythmias 6%, cardiogenic shock 5%). Twenty-four hours and hospital mortality rate were 1.2 and 2.8%, respectively.

Discussion

Optimal patient care and subsequently outcome of STEMI is strongly determined by a short patient-decision time to call EMS and by the first medical contact to balloon time (FMCBT). Supra-regional networks are key in order to increase the efficacy and efficiency of health care. The goal of 120 min FMCBT was achieved in 78% of our patients immediately managed by EMS, thus indicating room for improvement.

Conclusion

In conclusion, results from the Eastern Austrian STEMI network shed light on the necessity of increasing patient awareness in order to minimize any time loss derived by delayed EMS calls. Involvement of family physicians resulted in prolonged FMCBT. A stronger utilization of rescue helicopters could further improve the efficacy of this supra-regional network. Nevertheless PPCI rates, time intervals and outcome rates compare well with international benchmarks.

Molecular signature of coronary stent thrombosis: oxidative stress and innate immunity cells

The clinical impact of in-stent thrombosis is high because it is associated with high mortality and 20 % of the patients suffer a recurrent event within the two following years. The aim of this study was to characterise the morphologic and proteomic profile of in-stent thrombi (IST) in comparison to thrombi developed on native coronary arteries (CT) to identify a differential molecular signature. The study included 45 patients with ST-elevation-myocardial-infarction (STEMI) treated by primary-percutaneous-intervention and thrombus aspiration: 21 had IST and 24 had CT. Thrombi were characterised by morphologic immunohistochemical analysis and differential proteomic profiling (2-DE+MALDI-TOF/TOF). Bioinformatic analysis revealed differences in proteins related to oxidative-stress and cell death/survival. IST showed a higher content of structural proteins (gelsolin, actin-cytoplasmic-1, tropomyosin, and myosin) together with an imbalance in redox-homeostasis related proteins (increased superoxide-dismutase and decreased peroxiredoxin-2 thrombus content), and a coordinated increase of chaperones (HSP60 and HSC70) and cellular quality control-related proteins (26S–protease-regulatory-subunit-7). These changes were reflected into a significant decrease in HSC70 systemic levels and a significant increase in advanced-oxidation-protein-products (AOPP) indicative of increased oxidative stress-mediated protein damage in IST. Our results reveal an imbalance in redox-related proteins indicative of an exacerbated oxidative-stress that leads to an accumulation of AOPP serum levels in IST. Moreover, the coordinated increase in chaperones and regulatory proteins reflects the activation of intracellular protection mechanisms to maintain protein integrity in IST. The failure to counterbalance the stress situation could trigger cellular apoptosis leading to the destabilization of the thrombus and to a worse prognosis of IST-STEMI-patients.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Developments in pre-hospital patient transport in ST-elevation myocardial infarction

INTRODUCTION

ST-elevation myocardial infarction (STEMI) is a medical emergency that benefits from rapid access to specialized care. The objective of this study was to describe developments in patient transport via the pre-hospital emergency medical system (EMS) and its impact on clinical outcomes.

METHODS

We retrospectively studied STEMI patients who underwent primary percutaneous coronary intervention between January 2008 and July 2015. Patients were divided according to type of admission. Total ischemic time (TIT), door-to-balloon time (DBT) and in-hospital and one-year clinical outcomes were assessed for each group.

RESULTS

A total of 764 patients were included, of whom 33.5% were transported by the EMS and 45.8% by their own means, 13.7% were transferred from another institution and 6.9% were transported by non-EMS ambulance. There was a trend for more frequent recourse to the EMS over the eight-year period. There was a higher percentage of patients with prior myocardial infarction and Killip class III/IV in the EMS group compared to the non-EMS group. Significant differences were seen between groups in reperfusion times, EMS patients having the shortest TIT and DBT (195 vs. 286 min, p<0.001 and 61 vs. 90 min, p<0.001, respectively), but no significant difference in event rates was observed. Patients presenting to the hospital early had higher rates of effective reperfusion and lower in-hospital mortality (6.9% vs. 33.9%, p<0.001).

CONCLUSIONS

Recourse to the EMS significantly reduced ischemic times. Although this improvement was not directly associated with significant differences in event rates, it was associated with higher rates of effective reperfusion that were reflected in lower in-hospital mortality.

The design and rationale of the primary angioplasty registry of Kerala

Background

ST-elevation myocardial infarction (STEMI) continues to be a major cause of cardiovascular mortality in Kerala, India. Timely primary percutaneous coronary intervention (PCI) is the recommended reperfusion strategy for STEMI. There is limited data on the safety, effectiveness, equity and efficiency of regional primary PCI services in India.

Methods/Design

The primary angioplasty registry of Kerala is a clinician-initiated prospective state-wide longitudinal hospital-based registry of patients undergoing primary PCI for STEMI. The registry aims to document the efficacy and safety of the real world use of primary PCI in Indian patients presenting with STEMI, in order to achieve regional adoption of global standard performance indicators. In addition, the registry would analyze procedural variations in the performance of primary PCI and assess its impact on relevant patient centered outcomes. We plan to enroll 6000 STEMI patients, undergoing primary PCI, across 48 hospitals. These patients would be followed up for a minimum of 1 year.

Conclusions

The primary angioplasty registry of Kerala would help analyze the quality and outcomes of primary PCI services in Kerala, thereby yielding insights that can help limit unacceptable procedural variations in the performance of primary PCI. Identifying deviations from guideline based therapies can form the basis of quality improvement programs, which in turn will enable hospitals to achieve better patient outcomes.

Prognostic impact of non-compliance with guidelines-recommended times to reperfusion therapy in ST-elevation myocardial infarction. The FAST-MI 2010 registry

AIMS

Current guidelines recommend short time delays from qualifying ECG to reperfusion therapy in ST-elevation myocardial infarction (STEMI) patients. Recently, however, it has been suggested that shortening door-to-balloon times might not result in lower mortality, thereby questioning the relevance of current guidelines. The aim of this study was to assess in-hospital and one-year mortality in patients with fibrinolysis or primary percutaneous coronary intervention (PPCI) according to guidelines-recommended times to reperfusion therapy.

METHODS AND RESULTS

FAST-MI 2010 is a nationwide French registry including 4169 patients, of whom 1580 had ST-elevation myocardial infarction and had PPCI ( n=1289) or fibrinolysis ( n=291) as part of a pharmaco-invasive strategy. Four groups were constituted: Gr1 (within recommended times from ECG to PPCI; n=708), Gr2 (beyond recommended times from ECG to PPCI; n=581), Gr3 (time from ECG to lysis ⩽30 min, n=196), and Gr4 (time from ECG to lysis >30 min, n=95). In-hospital mortality was 3.6% in Gr2 vs. 1.0% in Gr1 and 3.2% in Gr4 vs. 1.0% in Gr3. After adjustment, hospital mortality was higher for reperfusion therapy beyond recommended times: odds ratio (OR) 3.29, 95% confidence interval (CI) 1.32-8.18; for PPCI, OR: 4.13; 95% CI: 1.50-11.35 and for fibrinolysis, OR: 2.72; 95% CI: 0.34-21.96. Likewise, one-year mortality was higher in patients with reperfusion beyond recommended times (hazard ratio 2.13, 95% CI:1.29-3.50). The results were confirmed by propensity score analyses.

CONCLUSIONS

Early and one-year mortality were lower for ST-elevation myocardial infarction patients when the recommended timelines for reperfusion therapy were met, suggesting that, in spite of recent interrogations, compliance with current guidelines remains a clinically relevant objective.

Regional systems-of-care for primary percutaneous coronary intervention in ST-elevation myocardial infarction

ST-elevation myocardial infarction (STEMI) is a critical, time-dependent condition requiring immediate reperfusion of the coronary arteries to minimize mortality and morbidity. The preferred method of revascularization is a primary percutaneous coronary intervention (PCI) if this can be performed in a timely manner. This requires an effective and well-organized setup from symptom onset to revascularization. Such regional networks for the diagnosis and treatment of STEMI patients have been proven to be very effective in achieving the treatment goals stipulated by the international guidelines. Several trials have provided evidence that prehospital ECG recording and early diagnosis combined with direct referral to a primary PCI center reduces treatment delay considerably. In-hospital awareness with early notification of the PCI operator and technicians and admission directly to the catheterization laboratory also reduces time to treatment. There is solid evidence that the reduction in treatment delay achieved by dedicated STEMI networks is associated with a lower mortality and morbidity. Regional STEMI networks are now implemented in many countries with highly varying geographical challenges and healthcare systems, allowing patients everywhere to receive optimal treatment with primary PCI.

Current characteristics and management of ST elevation and non-ST elevation myocardial infarction in the Tokyo metropolitan area: from the Tokyo CCU network registered cohort

Limited data exists on ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) managed by a well-organized cardiac care network in a metropolitan area. We analyzed the Tokyo CCU network database in 2009–2010. Of 4329 acute myocardial infarction (AMI) patients including STEMI (n = 3202) and NSTEMI (n = 1127), percutaneous coronary intervention (PCI) was performed in 88.8 % of STEMI and 70.4 % of NSTEMI patients. Mean onset-to-door and door-to-balloon times in STEMI patients were shorter than those in NSTEMI patients (167 vs 233 and 60 vs 145 min, respectively, p < 0.001). Coronary artery bypass graft surgery was performed in 4.2 % of STEMI and 11.4 % of NSTEMI patients. In-hospital mortality was significantly higher in STEMI patients than NSTEMI patients (7.7 vs 5.1 %, p < 0.007). Independent correlates of in-hospital mortality were advanced age, low blood pressure, and high Killip classification, statin-treated dyslipidemia and PCI within 24 h were favorable predictors for STEMI. High Killip classification, high heart rate, and hemodialysis were significant predictors of in-hospital mortality, whereas statin-treated dyslipidemia was the only favorable predictor for NSTEMI. In conclusion, patients with MI received PCI frequently (83.5 %) and promptly (door-to-balloon time; 66 min), and had favorable in-hospital prognosis (in-hospital mortality; 7.0 %). In addition to traditional predictors of in-hospital death, statin-treated dyslipidemia was a favorable predictor of in-hospital mortality for STEMI and NSTEMI patients, whereas hemodialysis was the strongest predictor for NSTEMI patients.

Prehospital system delay in patients with ST-segment elevation myocardial infarction in Singapore

BACKGROUND

Timely reperfusion in ST-segment elevation myocardial infarction (STEMI) improves outcomes. System delay is that between first medical contact and reperfusion therapy, comprising prehospital and hospital components. This study aimed to characterize prehospital system delay in Singapore.

METHODS

A retrospective chart review was performed for 462 consecutive STEMI patients presenting to a tertiary hospital from December 2006 to April 2008. Patients with cardiac arrest secondarily presented were excluded. For those who received emergency medical services (EMS), ambulance records were reviewed. Time intervals in the hospital were collected prospectively. The patients were divided into two equal groups of high/low prehospital system delay using visual binning technique.

RESULTS

Of 462 patients, 76 received EMS and 52 of the 76 patients were analyzed. The median system delay was 125.5 minutes and the median prehospital system delay was 33.5 minutes (interquartile range [IQR]=27.0, 42.0). Delay between call-received-by-ambulance and ambulance-dispatched was 2.48 minutes (IQR=1.47, 16.55); between ambulance-dispatch and arrival-at-patient-location was 8.07 minutes (IQR=1.30, 22.13); between arrival-at- and departure-from-patient-location was 13.12 minutes (IQR=3.12, 32.2); and between leaving-patient-location to ED-registration was 9.90 minutes (IQR=1.62, 32.92). Comparing patients with prehospital system delay of less than 35.5 minutes versus more showed that the median delay between ambulance-dispatch and arrival-at-patient-location was shorter (5.75 vs. 9.37 minutes, P<0.01). The median delay between arrival-at-patient-location and leaving-patient-location was also shorter (10.78 vs. 14.37 minutes, P<0.01).

CONCLUSION

Prehospital system delay in our patients was suboptimal. This is the first attempt at characterizing prehospital system delay in Singapore and forms the basis for improving efficiency of STEMI care.

[Outcomes evaluation after the implementation of a pre-hospital thrombolysis protocol in rural areas]

INTRODUCTION

The aim is to evaluate the outcomes obtained from the implementation of a pre-hospital thrombolysis protocol in 3 rural emergency care teams, as well as delays and strategies of reperfusion applied in the treatment of the ST-segment elevation myocardial infarction.

MATERIAL AND METHODS

Retrospective cohort study (n=52) with historical control (n=20) of the patients assisted for ST-segment elevation myocardial infarction. Medical emergency care teams, hospital, computerized medical history and ARIAM register reports were revised, obtaining epidemiological and clinical features, off-hospital management, reperfusion, time intervals and mortality.

RESULTS

The baseline features in both groups were not significantly different. There was a non-significant improvement of emergency care teams-hospital diagnostic concordance (85.3 versus 76.9%). We found a similar use of nitroglycerin, morphine and aspirin; significant increase (P<0.0001) of clopidogrel/prasugrel (55 versus 90.4%) and enoxaparin/fondaparinux (35 versus 76.9%), as well as pre-hospital thrombolysis (5 versus 30,8%, P<0.03), that was applied within the first 2h to 71.4%, with a median door-needle of 40min, whereas in-hospital thrombolysis and primary angioplasty were performed after 3h from the symptoms onset (P<0.01). Delays are associated with the patient's own lateness (P<0.02). Pharmaco-invasive strategy increases (62.5 versus 84.6%) more than primary angioplasty (15 versus 17.3%), reducing in-hospital thrombolysis (35 versus 19.2%), all of them non-significant. Complications are similar and one-year mortality is reduced (P<0.67).

CONCLUSIONS

The protocol is effective, safe, and reliable. It reduces delays and improves pre-hospital attention. The pharmaco-invasive strategy is a valid option.

Enhancing the efficacy of delivering reperfusion therapy: a European and North American experience with ST-segment elevation myocardial infarction networks

Advances in technique and adjunctive medication have improved outcome of ST-segment elevation myocardial infarction (STEMI) patients. However, the timely delivery and administration of reperfusion strategies to all eligible patients remain challenging. Currently, up to one-third of eligible STEMI patients in industrialized countries worldwide receive no specific reperfusion treatment, a problem that is rectified by the development and implementation of STEMI networks, as also recommended by the latest European Society of Cardiology and American College of Cardiology/American Heart Association guidelines. Indeed, over the last 5 years, published figures demonstrate that STEMI networks increase the percentage of patients treated by any reperfusion strategy, and the percentage of patients receiving treatment within the recommended time frames has also improved, thereby reducing in-hospital and long-term mortality to very low levels. This manuscript demonstrates how STEMI networks can be adapted to local needs and circumstances against pre-existing barriers and despite the heterogeneity in local situations, patient's characteristics, treatment delays, and distances for transfer. Modern and efficacious networks must be prepared to offer both primary percutaneous coronary intervention and thrombolytic therapy, preferably prehospital, as long as primary percutaneous coronary intervention cannot be guaranteed to all individuals within the recommended timeline.

Aborted myocardial infarction after primary percutaneous coronary intervention: magnetic resonance imaging insights from the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) trial

BACKGROUND

Aborted myocardial infarction (AbMI) in patients with ST-elevation MI defined by ST resolution with less than 2-fold elevation in biomarkers has been previously reported. We examined the association among AbMI, other metrics of infarct size, and left ventricular (LV) function defined by cardiac magnetic resonance (CMR).

METHODS

A total of 5745 patients with ST-elevation MI enrolled in the APEX-AMI trial, and 73 who were part of the CMR substudy within 3 to 5 days of randomization were evaluated. Core laboratories analyzed electrocardiograms, angiograms, and CMR images.

RESULTS

Aborted MI (peak creatine kinase/creatine kinase MB <2× upper limit of normal) with typical evolutionary electrocardiogram changes was observed in 11% (437/3938) overall and in 19% (14/73) of patients within the CMR study. Patients with AbMI were older (62 vs 60 years, P = .003) and tended to achieve complete STE-resolution post-percutaneous coronary intervention (≥70% resolution: 64% vs 32%; P = .076) compared with patients with MI. Cardiac magnetic resonance revealed that patients with AbMI had a smaller infarct size (4.7% vs 14.9% LV, P < .001), less "no reflow" (0.9% vs 1.7% LV, P = .017), enhanced LV function (ejection fraction 54.4% vs 46.5%, P = .064), smaller LV end-systolic volumes (46.5 mL vs 67.2 mL, P = .009), and less transmurality (21.4% vs 50.9% with at least 1 segment with >75% wall thickness, P = .046) when compared with patients with MI.

CONCLUSIONS

Patients with AbMI had smaller subendocardial infarcts with enhanced LV size and function. Cardiac magnetic resonance provides corroborative evidence of AbMI and insights into its pathophysiology, specifically rapid successful reperfusion leading to limitation of the "wavefront" of infarct to the subendocardium.

Treatment-seeking delays in patients with acute myocardial infarction and use of the emergency medical service

OBJECTIVES

To investigate treatment-seeking delays in Chinese patients with acute myocardial infarction (AMI) and to compare sex differences in this behaviour.

METHODS

A descriptive cross-sectional study was undertaken in patients with AMI, admitted to one of three hospitals in Shanghai, China. A treatment-seeking behaviour questionnaire was administered to each patient within 48 h of hospital admission.

RESULTS

In total, 250 patients were included: 159 men and 91 women. The median time for patients with AMI to make a treatment-seeking decision was 130 min. Women took significantly longer to seek treatment than men (240 min versus 120 min). The majority of patients (70.8%) took >1 h to decide to seek treatment. The emergency medical service (EMS) was used by 77 (30.8%) of patients, and these patients had a significantly shorter prehospital delay time than those who transported themselves to hospital. Predictive factors for using the EMS were pain level and rating AMI symptoms as severe.

CONCLUSIONS

Chinese patients with AMI had a significant prehospital delay time and women took longer than men to seek treatment. Public awareness of the importance of seeking immediate medical assistance for AMI via the EMS needs to be increased in China.

Head-to-head comparison of eight late gadolinium-enhanced cardiac MR (LGE CMR) sequences at 1.5 tesla: from bench to bedside

PURPOSE

To compare-theoretically and experimentally-clinically available two-dimensional/three-dimensional (2D/3D), breathhold and non-breathhold, inversion-recovery (IR) gradient-echo (GRE) sequences used to differentiate between nonviable injured and normal myocardium with late gadolinium-enhanced techniques (IR-GRE2D sequence is used as a reference), and to evaluate their respective clinical benefit.

MATERIALS AND METHODS

Six breathhold (2D-IR-GRE, 3D-IR-GRE, balanced steady-state free precession 2D-IR-bSSFP and 3D-IR-bSSFP, phase-sensitive 2D-PSIR-GRE, and 2D-PSIR-bSSFP) and two non-breathhold late gadolinium-enhanced techniques (single-shot 2D-ssbSSFP and 2D-PSIR-ssbSSFP) were consecutively performed in 32 coronary artery disease patients with chronic myocardial infarction. Qualitative assessment and manual planimetry were performed by two independent observers. Quantitative assessment was based on percentage signal intensity elevation between injured and normal myocardium and contrast-to-noise ratio. Theoretical simulations were compared with experimental measurements performed on phantoms with various concentrations of gadolinium.

RESULTS

The 3D-IR-GRE image quality appeared better than the other 2D and 3D sequences, showing better delineation of complex nontransmural lesions, with significantly higher percentage signal intensity and contrast-to-noise ratio. PSIR techniques appeared more limited in differentiating sub-endocardial lesions and intracavity blood pool, but in all other cases were comparable to the other techniques. Single-shot PSIR-ssbSSFP appeared to be a valuable alternative technique when breathhold cannot be achieved.

CONCLUSION

We recommend 3D-IR-GRE as the method of choice for late gadolinium-enhanced cardiac magnetic resonance imaging in clinical practice.

Door-to-needle times in acute myocardial infarction

Thrombolytic therapy is still the fastest and most accessible treatment for patients presenting with acute ST-elevation myocardial infarction. The time to treatment is a pivotal parameter in reperfusion. We examined the effects of implementing a better organized team approach to reduce door-to-needle times in patients with acute myocardial infarction. Fully trained emergency department personnel with special equipment facilitated direct communication between offsite cardiologists and pre-hospital emergency personnel, allowing for patient triage directly to the coronary care unit. Demographic, laboratory, and time interval data were prospectively collected and compared with data from previous years. From April to December 2007, 60 patients with acute ST-elevation myocardial infarction were triaged to the coronary care unit and enrolled in this study. Improvements were seen in mean door-to-needle time (reduced from 80 to 30 min during regular hours, and 85 to 33 min outside regular hours) compared with 2005-2007 data. A better organized team-based approach with specifically trained personnel and equipment for early evaluation and triage of patients with suspected myocardial infarction decreased intervention times, with the potential to be broadly applied in clinical practice and to improve patient survival.

The NORwegian study on DIstrict treatment of ST-Elevation Myocardial Infarction (NORDISTEMI)

OBJECTIVES

Thrombolysis is the treatment of choice for patients with ST-elevation myocardial infarction (STEMI) living in rural areas with long transfer delays to percutaneous coronary intervention (PCI). This trial compares two different strategies following thrombolysis: to transfer all patients for immediate coronary angiography and intervention, or to manage the patients more conservatively.

DESIGN

The NORwegian study on DIstrict treatment of STEMI (NORDISTEMI) is an open, prospective, randomized controlled trial in patients with STEMI of less than 6 hours of duration and more than 90 minutes expected time delay to PCI. A total of 266 patients will receive full-dose thrombolysis, preferably pre-hospital, and then be randomized to either strategy. Our primary endpoint is the one year combined incidence of death, reinfarction, stroke or new myocardial ischaemia. The study is registered with ClinicalTrials.gov, number NCT00161005.

RESULTS

By April 2006, 109 patients have been randomized. Thrombolysis has been given pre-hospital to 52% of patients. The median transport distance from first medical contact to catheterization laboratory was 155 km (range 90-396 km). Results of the study are expected in 2008.

Assessment of Initiation Time of Thrombolytic Therapy in Patients with ST-Segment Elevation Myocardial Infarction in Hamad General Hospital

The elevation of reperfusion therapy for acute STsegment elevation myocardial infarction are time-related and there are decreasing benefits with increasing delays to therapy. To determine whether the time interval between a patient's arrival at the emergency department of Hamad General Hospital, Qatar and initiation of thrombolytic therapy in the coronary care unit (door-to-needle time) is within the 30 minutes recommended by American College of Cardiology!American Heart Association guidelines, the medical records were reviewed of 213 patients with STsegment elevation myocardial infarction who were admitted through the Emergency Department to receive thrombolysis in the Coronary Care Unit in the twelve months May 2006-April 2007. Medians were calculated for door-to-needle and painto-needle times and intermediate points. The median painto-needle and pain-to-door times were 211 and 143 minutes respectively, both increasing significantly with the age of the patient and were shorter in men than in women. The median door-to-needle time was 60 minutes with 11.7% of the sample having a door-to-needle time within the recommended 30 minutes. It is concluded that the need for transferring such patients from the emergency department to the coronary care unit of the hospital before the administration of thrombolysis incurs inevitable delays that can be minimized by administering thrombolysis in the emergency department.

The role of fibrinolytics in the prehospital treatment of ST-elevation myocardial infarction (STEMI)

The efficacy of fibrinolytics in the treatment of ST-elevation myocardial infarction is directly related to the time of administration, with the first 2 h after symptom onset seen as a critical period for greatest improvement in cardiovascular parameters and mortality. The American College of Cardiology/American Heart Association recommends a medical contact to treatment time of 30 min for fibrinolysis in patients with ST-elevation myocardial infarction. In selected patients, reperfusion goals may be expedited with prehospital administration of fibrinolytics. In clinical trials, prehospital fibrinolysis markedly reduced the time from symptom onset to treatment, allowed earlier ST-segment resolution, and reduced short- and long-term mortality compared with in-hospital treatment. Prehospital fibrinolysis has become more feasible with the introduction of prehospital 12-lead electrocardiography, improved skills of emergency medical services personnel, improved communication with the Emergency Department, and the advent of bolus fibrinolysis. Rapid and accurate administration of a fibrinolytic is vital for the success of prehospital fibrinolysis.

Does coronary angioplasty after timely thrombolysis improve microvascular perfusion and left ventricular function after acute myocardial infarction?

BACKGROUND

Recent data show that percutaneous coronary intervention (PCI) in patients with stable postthrombolytic ST-segment elevation myocardial infarction (STEMI) is better than no PCI or ischemia-guided PCI. These results still have to find a pathophysiologic explanation. We hypothesized that complete mechanical recanalization of infarct-related artery improves clinical benefits of thrombolysis as a result of more preserved and better perfused coronary microcirculation. To test this hypothesis, we studied a selected STEMI population presenting very early after symptom onset in whom successful infarct-related artery reperfusion was obtained by thrombolysis followed or not by elective PCI within 24 hours, and we compared these 2 groups with those underwent primary PCI.

METHODS

This study analyzed 96 patients with STEMI randomized within 3 hours from symptom onset to primary PCI (group A, n = 36), tenecteplase followed within 24 hours by PCI (group B, n = 30), or to tenecteplase alone (group C, n = 30). Microvascular perfusion was assessed by myocardial contrast echocardiography. Regional contrast score, endocardial length and area of contrast defect on day 2 (T1) and at predischarge (T2), left ventricular end-diastolic volume, regional wall motion score, extent of wall motion abnormalities, and ejection fraction at T1, T2, and at 3 months' follow-up were calculated.

RESULTS

Baseline clinical and angiographic characteristics were not statistically different between groups. The extent of microvascular damage and of myocardial salvage was similar in primary PCI-treated or in invasively treated patients after lytic administration. Conversely, group C patients, although treated very early with fibrinolytic therapy, showed higher extent of microvascular damage and infarct size and a more depressed left ventricular function after reperfusion and at follow-up.

CONCLUSIONS

Our data suggest that early PCI after lysis is more effective in preserving myocardial perfusion and function than lysis alone and may be a helpful alternative when primary PCI is not available.

Effects on mortality of abciximab in ST-elevation myocardial infarction treated with percutaneous coronary intervention including stent implantation

OBJECTIVES

To investigate the effects of abciximab on mortality in ST-elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention (PCI) including stent implantation.

DESIGN

Meta-analysis of three selected randomized studies and analysis of data from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR).

SUBJECTS

Pooled data from randomized studies containing in total 1,736 patients undergoing PCI with stent implantation because of STEMI with duration between symptom and treatment <12 h, and 7,436 patients from SCAAR treated with PCI because of STEMI (52% treated with abciximab) in Sweden 2000-2004.

RESULTS

Analyses of pooled data showed that abciximab was associated with a decreased risk of reinfarction [odds ratio (OR) 0.38] and urgent target vessel revascularization (OR 0.38) at 30 days. No effect was seen on mortality at 30 days or 6 months. Multivariate analysis of data from SCAAR showed that abciximab reduced the risk of death during 14 months of follow-up (hazard ratio 0.82).

CONCLUSIONS

The results are encouraging and support the ACC/AHA and ESC recommendation to use abciximab in treatment of STEMI with PCI including stent implantation. Considering that the pooled results from previous trials showed no effect of abciximab on mortality and the registry part of the present study was observational, the results encourage carrying out new randomized studies of abciximab in STEMI treated with PCI, including stent implantation, with sufficient size and length of follow-up.

Prehospital fibrinolysis

Reperfusion therapy for ST-elevation acute coronary syndromes aims at early and complete recanalization of the infarct-related artery to salvage myocardium and improve both early and late clinical outcomes. Prehospital diagnosis of ST-elevation acute coronary syndrome can be made by electrocardiography with or without transtelephonic transmission, and subsequent fibrinolytic therapy can be instituted at home or in the ambulance. Prehospital fibrinolysis decreases time to treatment by approximately 1 hour compared with in-hospital therapy resulting in a significant 15% relative risk reduction in early mortality. This may compare well with primary angioplasty for ST-elevation acute coronary syndrome, although more studies are necessary.

Implementation of Guidelines Improves the Standard of Care

Background— The purpose of this study was to determine whether implementation of recent guidelines improves in-hospital mortality from acute ST-elevation myocardial infarction (STEMI) in a metropolitan area.

Methods and Results— We organized a network that consisted of the Viennese Ambulance Systems, which is responsible for diagnosis and triage of patients with acute STEMI, and 5 high-volume interventional cardiology departments to expand the performance of primary percutaneous catheter intervention (PPCI) and to use the fastest available reperfusion strategy in STEMI of short duration (2 to 3 hours from onset of symptoms), either PPCI or thrombolytic therapy (TT; prehospital or in-hospital), respectively. Implementation of guidelines resulted in increased numbers of patients receiving 1 of the 2 reperfusion strategies (from 66% to 86.6%). Accordingly, the proportion of patients not receiving reperfusion therapy dropped from 34% to 13.4%, respectively. PPCI usage increased from 16% to almost 60%, whereas the use of TT decreased from 50.5% to 26.7% in the participating centers. As a consequence, in-hospital mortality decreased from 16% before establishment of the network to 9.5%, including patients not receiving reperfusion therapy. Whereas PPCI and TT demonstrated comparable in-hospital mortality rates when initiated within 2 to 3 hours from onset of symptoms, PPCI was more effective in acute STEMI of >3 but <12 hours’ duration.

Conclusions— Implementation of recent guidelines for the treatment of acute STEMI by the organization of a cooperating network within a large metropolitan area was associated with a significant improvement in clinical outcomes.

Aborted myocardial infarction: a new target for reperfusion therapy

Reperfusion therapy for ST-elevation acute coronary syndromes aims at early and complete recanalization of the infarct-related artery in order to salvage myocardium and improve both early and late clinical outcomes. Myocardial necrosis is usually confirmed and quantified by myocardial enzyme release in plasma. However, over 10% of patients treated with reperfusion therapy fail to develop an enzyme rise, but do exhibit transient ECG changes, which are consistent with an aborted myocardial infarction. The earlier the reperfusion therapy is instituted, the higher the incidence of aborted infarction. Treatment within an hour after symptom onset may result in 25% of aborted infarction and is in combination with complete (70%) ST-segment resolution associated with better survival. This endpoint is easy to define and occurs promptly in time. The faster that effective treatment is initiated, the more likely aborted infarction will occur. Given that mortality, re-infarction, and stroke are declining in incidence, we suggest the introduction of aborted infarction as an endpoint in clinical trials of ST-elevation acute coronary syndromes.

Primary versus tenecteplase-facilitated percutaneous coronary intervention in patients with ST-segment elevation acute myocardial infarction (ASSENT-4 PCI): randomised trial

BACKGROUND

Primary percutaneous coronary intervention (PCI) is more effective than fibrinolytic therapy for ST-segment elevation acute myocardial infarction (STEMI), but time to intervention can be considerable. Our aim was to investigate whether the administration of full-dose tenecteplase before a delayed PCI could mitigate the negative effect of this delay.

METHODS

We did a randomised study in which we assigned patients with STEMI of less than 6 h duration (scheduled to undergo primary PCI with an anticipated delay of 1-3 h) to standard PCI (n=838) or PCI preceded by administration of full-dose tenecteplase (n=829). All patients received aspirin and a bolus, without an infusion, of unfractionated heparin. Our primary endpoint was death or congestive heart failure or shock within 90 days. Analyses were by intention to treat. This study is registered with , number NCT00168792.

FINDINGS

We planned to enroll 4000 patients, but early cessation of enrollment was recommended by the data and safety monitoring board because of a higher in-hospital mortality in the facilitated than in the standard PCI group (6% [43 of 664] vs 3% [22 of 656], p=0.0105). Of those enrolled, six were lost to follow-up in the facilitated PCI group and seven in the other group. Median time from randomisation to first balloon inflation was similar in both groups. The median time from bolus tenecteplase to first balloon inflation was 104 min. We noted the primary endpoint in 19% (151 of 810) of patients assigned facilitated PCI versus 13% (110 of 819) of those randomised to primary PCI (relative risk 1.39, 95% CI 1.11-1.74; p=0.0045). During hospital stay, significantly more strokes (1.8% [15 of 829] vs 0, p<0.0001), but not major non-cerebral bleeding complications (6% [46 of 829] vs 4% [37 of 838], p=0.3118), were reported in patients assigned facilitated rather than standard PCI. We also noted more ischaemic cardiac complications, such as reinfarction (6% [49 of 805] vs 4% [30 of 820], p=0.0279) or repeat target vessel revascularisation (7% [53 of 805] vs 3% [28 of 818], p=0.0041) within 90 days in this study group.

INTERPRETATION

A strategy of full-dose tenecteplase with antithrombotic co-therapy, as used in this study and preceding PCI by 1-3 h, was associated with more major adverse events than PCI alone in STEMI and cannot be recommended.

Implementation of reperfusion therapy in acute myocardial infarction. A policy statement from the European Society of Cardiology

Reperfusion therapy in ST-segment elevation myocardial infarction (STEMI) is the most important component of treatment, as it strongly influences short- and long-term patient outcome. The main objective of healthcare providers should be to achieve at least 75% of reperfusion therapy applied to patients suffering from STEMI in a timely manner, and preferably within the first 3 h after onset of symptoms. Establishing networks of reperfusion at regional and national level, implying close collaboration between all the actors involved in reperfusion therapy, namely hospitals, departments of cardiology, PCI centres, emergency medical systems (EMS), (para)medically staffed ambulances, private cardiologists, primary care physicians, etc., is a key issue. All forms of reperfusion, depending on local facilities, need to be available to patients. Protocols must be written and agreed for the strategy of reperfusion to be applied within a network. Early diagnosis of STEMI is essential and is best achieved by rapid ECG recording and interpretation at first medical contact, wherever this contact takes place (hospital or ambulance). Tele-transmission of ECG for immediate interpretation by experienced cardiologists is an alternative. Primary PCI is the preferred reperfusion option if it can be performed by experienced staff within 90 min after first medical contact. Thrombolytic treatment, administered if possible in the pre-hospital setting, is a valid option if PCI cannot be performed in a timely manner, particularly within the first 3 h following onset of symptoms. Thrombolysis is not the end of the reperfusion therapy. Rescue PCI must be performed in the case of thrombolysis failure. Next-day PCI after successful thrombolysis has been proven efficacious. Quality control is important for monitoring the efficacy of networks of reperfusion. All elements that influence time to reperfusion must be taken into account, particularly transfer delays, in-hospital delays, and door-to-balloon or door-to-needle times. The rate of reperfusion achieved must also be taken into consideration. Professional organizations such as the European Society of Cardiology (ESC) have the responsibility to impart this message to the cardiology community, and inform politicians and health authorities about the best possible strategy to achieve reperfusion therapy.