Transfer for Primary Angioplasty Versus Immediate Thrombolysis in Acute Myocardial Infarction

Treatment delays in patients undergoing primary percutaneous coronary intervention for ST elevation myocardial infarction at the Quebec Heart and Lung Institute

BACKGROUND

Current guidelines for ST elevation myocardial infarction (STEMI) recommend performing primary percutaneous coronary intervention (PCI) within 90 min of hospital arrival. However, recent data suggest that in a real-world setting, median door-to-balloon (DTB) time is closer to 180 min for transfer patients, with less than 5% of patients being treated within 90 min. A retrospective observational study was conducted to assess time to treatment in patients undergoing primary PCI at the Quebec Heart and Lung Institute (QHLI).

METHODS

Consecutive lytic-eligible patients undergoing primary PCI at the QHLI for STEMI between April 2004 and March 2005 were included in the present analysis. The primary evaluation was DTB time measured from arrival at the first hospital to first balloon inflation. Clinical outcomes were in-hospital death, reinfarction and bleeding. DTB times and hospital outcomes of patients transferred from referring hospitals were compared with those of patients presenting directly to the QHLI.

RESULTS

During the study period, 203 lytic-eligible patients were treated with primary PCI. Sixty-nine patients presented directly to the QHLI and 134 were transferred from other hospitals. Six transfer patients were excluded because of missing time variables. The median DTB time was 114 min in transfer patients, compared with 87 min in patients presenting directly to the QHLI (P<0.001). DTB time was less than 90 min in 24% of the transfer population compared with 55% of patients presenting directly to the QHLI (P<0.001). In patients referred from hospitals within a radius of 30 km from the QHLI (n=100), median DTB time was 106 min with 30% receiving PCI within 90 min. In these patients, estimated PCI-related delay was 74 min. For patients presenting to hospitals beyond 30 km (n=28), median DTB time was 142 min with 4% receiving reperfusion within 90 min. In these patients, estimated PCI-related delay was 110 min. Median DTB time for patients presenting during off hours at the QHLI was 92 min compared with 79 min for patients presenting during regular business hours (P=0.02). In patients transferred from other hospitals, median DTB time was 118 min during off hours and 108 min during normal business hours (P=0.07).

CONCLUSIONS

A DTB time of less than 90 min can be achieved in the majority of patients presenting directly to a primary PCI centre. However, for patients presenting to community hospitals, transfer for primary PCI is often associated with delayed revascularization. The present study highlights the need for careful patient selection when deciding between on-site thrombolytic therapy and transfer for primary PCI for STEMI patients presenting to hospitals without PCI facilities.

Interhospital transfer of patients with ST-segment elevation myocardial infarction for percutaneous coronary intervention

We investigated in 277 consecutive patients, mean age 63 years, with ST-segment elevation acute myocardial infarction transferred from 25 community hospitals to a tertiary percutaneous coronary intervention (PCI) center from a median distance of 21 miles the incidences of in-hospital mortality, stroke, and recurrent myocardial infarction associated with transfer times. Of the 277 patients, 158 (57%) had thrombolytic therapy at the referring hospital. Of the 277 patients, 63 (23%) had adjunctive PCI, 119 (43%) had primary PCI, and 95 (34%) had rescue PCI. Of the 277 patients, 42 (15%) were hemodynamically unstable. Median transfer times were 102 minutes with primary PCI, 119 minutes with rescue PCI, and 144 minutes for adjunctive PCI (P < 0.0001 for adjunctive PCI versus primary PCI; P = 0.011 for adjunctive PCI versus rescue PCI). Median transfer time was 98 minutes for hemodynamically unstable patients and 121 minutes for hemodynamically stable patients (P = 0.005). In-hospital death occurred in eight of 277 patients (3%). In-hospital stroke occurred in three of 277 patients (1%). In-hospital recurrent myocardial infarction occurred in none of 277 patients (0%). There was no association of transfer times with in-hospital mortality or stroke. In-hospital mortality occurred in three of 112 patients (3%) who had bare metal stents and in five of 165 patients (3%) who had drug-eluting stents.

Systematic review of fibrinolytic-facilitated percutaneous coronary intervention: potential benefits and future challenges

BACKGROUND

Facilitated percutaneous coronary intervention (PCI) is defined as the administration of fibrinolytic therapy and/or glycoprotein (GP) IIb/IIIa inhibitors to minimize myocardial ischemia time while waiting for PCI. A pooled meta-analysis suggested that facilitated PCI was associated with higher rates of mortality and morbidity compared with nonfacilitated PCI.

OBJECTIVE

The heterogeneous and complex trials of facilitated PCI were systematically reviewed to identify where this strategy may be beneficial and deserving of further research.

METHODS

MEDLINE, EMBASE, the Cochrane database, the Internet and conference proceedings were searched to obtain relevant trials. Human studies that randomly assigned patients to fibrinolytic-facilitated PCI (administration of fibrinolytic therapy alone or in combination with GP IIb/IIIa inhibitors before angiography) versus nonfacilitated PCI were included.

RESULTS

Nine trials encompassing 3836 patients were reviewed. The facilitated PCI strategy was fibrinolytic therapy alone in seven trials and half-dose fibrinolytic therapy plus GP IIb/IIIa inhibitors in two trials. In patients who had fibrinolysis less than 2 h after symptom onset (mainly in the prehospital setting) and/or slightly delayed PCI 3 h to 24 h after fibrinolysis, facilitated PCI was associated with the greatest Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow and a trend toward reduced mortality. Overall, facilitated PCI was associated with increased intracranial hemorrhage and reinfarction. Combining half-dose fibrinolytic therapy and GP IIb/IIIa inhibitors reduced reinfarction but increased major bleeding.

CONCLUSIONS

Facilitated PCI cannot be recommended outside of experimental protocols at this time. Further research should focus on selecting patients with higher benefit-to-risk ratios and performing prehospital fibrinolysis with optimal antiplatelet or antithrombin therapy, as well as slightly delayed PCI in patients who are stable or geographically removed from PCI facilities.

Randomized trials of clinical networks in the management of ST-elevation MI: can they be performed?

PURPOSE OF THIS REVIEW

Mortality in ST segment elevation myocardial infarction is directly related to the degree of myocardial damage sustained as a result of vessel occlusion. It is well established that the temporal window during which myocardial salvage may be achieved is limited.

RECENT FINDINGS

Prehospital thrombolysis, facilitated percutaneous coronary intervention (PCI) and prompt transfer to institutions with primary PCI capabilities have all been proposed as strategies to augment the temporal window. These different approaches all seek to modify the way reperfusion is delivered, as opposed to the manner of restoring flow, but have been associated with mixed results. Hence, it has become clear that further mortality reductions will require system-based and highly coordinated clinical networks.

SUMMARY

The extent of the mortality benefit associated with the development of an integrated reperfusion network has yet to be established. Collection of robust data in the context of a clinical trial may be obtained by the random allocation of clinical networks as opposed to randomization of patients. Furthermore, such data would be applicable to 'real world' clinical practice, as optimal reperfusion could be examined in patients whose complex comorbidity would preclude their inclusion in conventional ST segment elevation myocardial infarction (STEMI) trials.

Reperfusion options in ST-elevation myocardial infarction patients with expected delays

Primary percutaneous coronary intervention (PPCI) is the optimal reperfusion strategy for ST-elevation myocardial infarction (STEMI) patients when performed in a timely manner by experienced providers. Unfortunately, only 25% of US hospitals have percutaneous coronary intervention (PCI) capability. Transfer for PPCI has also been shown to improve outcomes if transfer times are short and PCI can be performed within 90 minutes. However, many STEMI patients cannot be transferred in a timely fashion because of long distances, adverse weather, or process-of-care delays. Recent data support strategies that combine fibrinolysis with transfer for PCI under these circumstances. The critical issue that is still debated is the timing of PCI (immediate vs delayed vs rescue). The significance of time to reperfusion to mortality is important but less critical for PCI than for fibrinolysis, but time still matters. To optimize time to reperfusion for STEMI patients, all hospitals need to have predetermined protocols in place based on hospital characteristics and proximity to a catheterization laboratory.

Infarct size in primary angioplasty without on-site cardiac surgical backup versus transferal to a tertiary center: a single photon emission computed tomography study

BACKGROUND

Primary percutaneous coronary intervention (PCI) performed in large community hospitals without cardiac surgery back-up facilities (off-site) reduces door-to-balloon time compared with emergency transferal to tertiary interventional centers (on-site). The present study was performed to explore whether off-site PCI for acute myocardial infarction results in reduced infarct size.

METHODS AND RESULTS

One hundred twenty-eight patients with acute ST-segment elevation myocardial infarction were randomly assigned to undergo primary PCI at the off-site center (n = 68) or to transferal to an on-site center (n = 60). Three days after PCI, (99m)Tc-sestamibi SPECT was performed to estimate infarct size. Off-site PCI significantly reduced door-to-balloon time compared with on-site PCI (94 +/- 54 versus 125 +/- 59 min, respectively, p < 0.01), although symptoms-to-treatment time was only insignificantly reduced (257 +/- 211 versus 286 +/- 146 min, respectively, p = 0.39). Infarct size was comparable between treatment centers (16 +/- 15 versus 14 +/- 12%, respectively p = 0.35). Multivariate analysis revealed that TIMI 0/1 flow grade at initial coronary angiography (OR 3.125, 95% CI 1.17-8.33, p = 0.023), anterior wall localization of the myocardial infarction (OR 3.44, 95% CI 1.38-8.55, p < 0.01), and development of pathological Q-waves (OR 5.07, 95% CI 2.10-12.25, p < 0.01) were independent predictors of an infarct size > 12%.

CONCLUSIONS

Off-site PCI reduces door-to-balloon time compared with transferal to a remote on-site interventional center but does not reduce infarct size. Instead, pre-PCI TIMI 0/1 flow, anterior wall infarct localization, and development of Q-waves are more important predictors of infarct size.

Clinical impact of an inter-hospital transfer strategy in patients with ST-elevation myocardial infarction undergoing primary angioplasty: the Emilia-Romagna ST-segment elevation acute myocardial infarction network

AIMS

This study sought to evaluate the impact of an inter-hospital transfer strategy on treatment times and in-hospital and 1 year cardiac mortality of patients with ST-segment elevation acute myocardial infarction (STEMI) undergoing primary percutaneous intervention (p-PCI) in the Italian region of Emilia-Romagna, where an efficient region-wide system for reperfusion has been established.

METHODS AND RESULTS

3296 patients with STEMI, undergoing on-site p-PCI (2444 patients) (OS group) or p-PCI after inter-hospital transfer (852 patients) (T group) between 1 January 2004 and 30 June 2006 in the Italian region of Emilia-Romagna, were considered. During the study period, the number of patients undergoing p-PCI increased both for patients admitted to interventional centres and for those admitted to peripheral hospitals. At the same time, the proportion of patients with STEMI initially admitted to peripheral hospitals and not transferred and the door-to-balloon time delays of transfer patients decreased. In spite of longer door-to-balloon delay in the transfer group [112 min (86-147) vs. 71 min (46-104)], in-hospital cardiac mortality (OS 7.0 vs. T 5.4%, P = 0.10) did not significantly differ between the two groups. After multivariable adjustment, the transfer strategy was not associated with increased risk of in-hospital [odds ratio 0.956; 95% confidence interval (CI) 0.633-1.442] and 1 year (hazard ratio 0.817; 95% CI 0.617-1.085) cardiac mortality.

CONCLUSION

This study, concerning an established STEMI regional network, suggests that a strategy of inter-hospital transfer for p-PCI, when supported by an organized system of care, may be applied with rapid reperfusion times and favourable short- and long-term clinical outcomes.

Shifting from pharmacological to systematic mechanical reperfusion therapy for acute myocardial infarction via a cooperating network: impact on reperfusion rate and in-hospital mortality

BACKGROUND

Primary percutaneous transluminal coronary angioplasty is the preferred reperfusion strategy for acute ST-elevation myocardial infarction in selected settings. Limited data are available about the clinical impact of the implementation of a systematic primary angioplasty infarct reperfusion program in the real world.

METHODS AND RESULTS

We organized a comprehensive district network allowing the coordinated and timely transfer of patients with acute ST-elevation myocardial infarction to the hub hospital with catheterization facilities in order to expand the use of mechanical reperfusion. Implementation of the network resulted in increased numbers of patients receiving reperfusion therapies (from 57.5% to 74.1%; P < 0.001). In addition, the proportion of elderly individuals (those aged > or = 75 years) who received a reperfusion therapy significantly increased (from 25.7% to 66.3%; P < 0.001). Accordingly, the proportion of patients not receiving reperfusion therapy dropped from 42.5% to 25.9%. Primary percutaneous transluminal coronary angioplasty usage increased from 24.5% to 73.1% (P < 0.001). As a consequence, in-hospital mortality decreased from 13.5% before establishment of the network to 6.0% (P = 0.016), and major adverse cardiac events decreased from 17.5% to 7.8% (P = 0.005).

CONCLUSIONS

Implementation of a systematic primary angioplasty infarct reperfusion program improves reperfusion rate and reduces in-hospital mortality and total major adverse cardiovascular events.

Optimal reperfusion strategy for acute myocardial infarction

Primary percutaneous coronary intervention has proved to be a superior intervention strategy for acute myocardial infarction than pre-hospital thrombolysis. Both strategies are being used in the UK in parallel, and time to intervention is crucial with both strategies. The Myocardial Infarction National Audit Project registry is showing a gradual move towards percutaneous coronary intervention as the strategy of choice when available.

Time to treatment and ST-segment resolution in high-risk patients with acute myocardial infarction transferred from community hospitals for coronary angioplasty after pharmacological treatment

OBJECTIVE

To evaluate the impact of symptom-onset-to-balloon delay on ST-segment resolution (STR) in patients with acute myocardial infarction transferred from community hospitals for angioplasty after pharmacological treatment. The study design was prospective, single centre registry.

METHODS

Between October 2000 and December 2003, 330 consecutive patients aged < or =75 years with high-risk myocardial infarction were considered; 193 patients underwent primary percutaneous coronary intervention (PCI) (group P), whereas 137 patients were given pharmacological therapy and were immediately transferred to the hospital with PCI facilities (group F).

RESULTS

Compared with group P, group F showed a longer time to treatment (253 +/- 136 vs. 195 +/- 141 min; P < 0.0001) and a higher percentage of Thrombolysis In Myocardial Infarction flow grade 2-3 at pre-PCI angiography (107 [78.1%] vs. 48 [24.8%]; P < 0.0001). The rate of STR > or =70% was similar in groups P and F (121 [62.7%] vs. 94 [68.6%]; P = 0.41). Even after accounting for baseline variables, STR <70% was not significantly related to the transfer strategy (adjusted hazard ratio 0.94, 95% confidence interval 0.94-1.77; P = 0.8). Patients with incomplete STR showed a higher six-month mortality compared with patients with complete STR (10 [8.85%] vs. 6 [2.76%]; P = 0.027).

CONCLUSIONS

The STR index predicts survival in patients with ST-elevation myocardial infarction treated with angioplasty either directly or after pharmacological treatment and hospital transfer. Pharmacological facilitation seems to be able to counterbalance the negative consequences of the transfer-related time delay on myocardial reperfusion as evaluated by the STR index.

Rationale and design of the Trial of Routine ANgioplasty and Stenting After Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction (TRANSFER-AMI)

BACKGROUND

Most patients with ST-elevation myocardial infarction present to hospitals without percutaneous coronary intervention (PCI) facilities and receive fibrinolysis. The role of routine early PCI after fibrinolysis, using stents and contemporary pharmacotherapy, has not been studied in a large adequately powered randomized trial.

OBJECTIVE

To compare a pharmacoinvasive strategy of transfer for routine PCI within 6 hours after fibrinolysis with standard treatment after fibrinolysis (including predefined criteria for rescue PCI and delayed cardiac catheterization for patients who do not require rescue PCI).

METHODS

A total of 1200 patients with high-risk ST-elevation myocardial infarction presenting to non-PCI centers will be randomized to a pharmacoinvasive strategy (transfer for routine PCI within 6 hours of fibrinolysis) or to standard treatment after fibrinolysis. The primary end point is the 30-day composite of death, reinfarction, recurrent ischemia, heart failure, or shock.

RESULTS

More than 900 patients have been enrolled as of April 2007. An interim safety analysis of the first 536 patients demonstrated no safety concerns. Enrolment is expected to be completed in late 2007.

CONCLUSIONS

This study will provide important data on whether routine early PCI within 6 hours after fibrinolysis is safe and superior to the standard treatment of fibrinolysis with rescue PCI or delayed cardiac catheterization.

Transfer for primary angioplasty in elderly patients with acute myocardial infarction

INTRODUCTION

The aim of this study was the evaluation of an immediate transfer for primary angioplasty (PPCI) in elderly (age > or = 75 years) patients with ST elevation acute myocardial infarction (STEMI).

METHODS AND MATERIALS

All elderly patients with STEMI admitted for PPCI from June 2002 to October 2005, were enrolled. Major Adverse Cardiac Events (MACE) were collected at 6 months.

RESULTS

133 patients (group 1) were admitted directly and 154 patients (group 2) were transferred from peripheral hospitals. Ischemia time was 248 +/- 146 min in group 1 and 276 +/- 169 min in group two (P<0.001); door-to-balloon time was 60+/-30 min in group 1 and 90+/-45 min in group two (P<0.0001). At 6 months cardiac death occurred in 15 (11%) and 16 (10%) patients in group 1 and 2 respectively (P=NS), MI in 3(2%) and 2(1%) respectively (P=NS), clinically driven target lesion revascularization in 6(4%) and 5(3%) respectively, for an overall event-free survival rate of 82% in group 1 and 83% in group 2 (P=NS). Logistic regression analysis showed age (OR: 1.04.1; 95% CI: 1.0-1.2; P=0.049) Killip class > or = 2 (OR: 4.6; 95% CI: 1.3-16.4; P=0.01) to be the only independent predictors of 6-month cardiac mortality.

CONCLUSION

Systematic transfer of elderly STEMI patients for PPCI, with a door-to-balloon time <1 h, leads to clinical results similar to those achievable in patients who present directly in hospital with cath.-lab. facilities.

Assessing the effectiveness of primary angioplasty compared with thrombolysis and its relationship to time delay: a Bayesian evidence synthesis

BACKGROUND

Meta-analyses of trials have shown greater benefits from angioplasty than thrombolysis after an acute myocardial infarction, but the time delay in initiating angioplasty needs to be considered.

OBJECTIVE

To extend earlier meta-analyses by considering 1- and 6-month outcome data for both forms of reperfusion. To use Bayesian statistical methods to quantify the uncertainty associated with the estimated relationships.

METHODS

A systematic review and meta-analysis published in 2003 was updated. Data on key clinical outcomes and the difference between time-to-balloon and time-to-needle were independently extracted by two researchers. Bayesian statistical methods were used to synthesise evidence despite differences between reported follow-up times and outcomes. Outcomes are presented as absolute probabilities of specific events and odds ratios (ORs; with 95% credible intervals (CrI)) as a function of the additional time delay associated with angioplasty.

RESULTS

22 studies were included in the meta-analysis, with 3760 and 3758 patients randomised to primary angioplasty and thrombolysis, respectively. The mean (SE) angioplasty-related time delay (over and above time to thrombolysis) was 54.3 (2.2) minutes. For this delay, mean event probabilities were lower for primary angioplasty for all outcomes. Mortality within 1 month was 4.5% after angioplasty and 6.4% after thrombolysis (OR = 0.68 (95% CrI 0.46 to 1.01)). For non-fatal reinfarction, OR = 0.32 (95% CrI 0.20 to 0.51); for non-fatal stroke OR = 0.24 (95% CrI 0.11 to 0.50). For all outcomes, the benefit of angioplasty decreased with longer delay from initiation.

CONCLUSIONS

The benefit of primary angioplasty, over thrombolysis, depends on the former's additional time delay. For delays of 30-90 minutes, angioplasty is superior for 1-month fatal and non-fatal outcomes. For delays of around 90 minutes thrombolysis may be the preferred option as assessed by 6-month mortality; there is considerable uncertainty for longer time delays.

A Regional System to Provide Timely Access to Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction

Background— Percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) is superior to fibrinolysis when performed in a timely manner in high-volume centers. Recent European trials suggest that transfer for PCI also may be superior to fibrinolysis and increase access to PCI. In the United States, transfer times are consistently long; therefore, many believe a transfer for PCI strategy for STEMI is not practical.

Methods and Results— We developed a standardized PCI-based treatment system for STEMI patients from 30 hospitals up to 210 miles from a PCI center. From March 2003 to November 2006, 1345 consecutive STEMI patients were treated, including 1048 patients transferred from non-PCI hospitals. The median first door-to-balloon time for patients <60 miles (zone 1) and 60 to 210 miles (zone 2) from the PCI center was 95 minutes (25th and 75th percentiles, 82 and 116 minutes) and 120 minutes (25th and 75th percentiles, 100 and 145 minutes), respectively. Despite the high-risk unselected patient population (cardiogenic shock, 12.3%; cardiac arrest, 10.8%; and elderly [≥80 years of age], 14.6%), in-hospital mortality was 4.2%, and median length of stay was 3 days.

Conclusions— Rapid transfer of STEMI patients from community hospitals up to 210 miles from a PCI center is safe and feasible using a standardized protocol with an integrated transfer system.

Primary percutaneous coronary intervention in acute myocardial infarction

Primary percutaneous coronary intervention (PCI) has emerged as the preferred therapy for acute ST-segment elevation myocardial infarction (STEMI), as multiple randomized clinical trials and pooled analyses have shown improved clinical outcomes compared with medical reperfusion. Unfortunately, medical centers with 24-hour PCI capability are concentrated in urban areas, relegating many patients in the United States to inferior medical reperfusion. Ongoing substantial research efforts are directed at optimizing mechanical reperfusion, including refinements in adjuvant medical therapy and the use of drug-eluting stents in the catheterization laboratory. Research efforts are also focusing on the implementation of streamlined transfer systems from community centers to tertiary care centers, akin to systems used in the trauma model. Furthermore, experience with the performance of primary PCI at community centers without onsite surgical backup is growing. This article summarizes data regarding the current state, challenges, and future directions of primary PCI for STEMI, emphasizing adherence to current American College of Cardiology/American Heart Association guidelines.

The Vascular Therapist

My association with John Uther began when I was appointed as his Cardiology Research Fellow at Royal Prince Alfred Hospital in 1976. In 1983 John (then the Head of the Cardiology Unit at Westmead Hospital) appointed me as a cardiologist. John Uther and David Cody did the first coronary angioplasty at Westmead Hospital in 1983. By the end of the 1980s all of the cardiologists were fully trained in angioplasty. The first coronary stent was deployed at Westmead Hospital in 1993. In the mid to late 1990s coronary artery stenting led to a higher rate of procedural success with reduction in early complications and late restenosis. By the late 1990s stenting became routine treatment for any coronary artery where a stent could be technically placed. Drug eluting stents were developed to further reduce the risk of restenosis and the first stent was deployed at Westmead in 2002. We started primary coronary angioplasty in 1998 for patients presenting directly to Westmead Hospital with acute myocardial infarction. From November 1999 this was expanded as we began transferring patients from peripheral hospitals within the Area Health Service. In 1996 we began performing non-coronary artery angioplasty starting with carotid artery stenting followed by renal artery stenting in 1999. From early 2005 we have developed a collaboration with the vascular surgeons and we now perform a wide variety of non-coronary procedures as a team. In summary, vascular intervention has come a long way since John Uther did the first coronary procedure at Westmead Hospital 24 years ago.

Time to reperfusion in acute myocardial infarction. It is time to reduce it!

BACKGROUND AND OBJECTIVES

Mortality from ST-segment elevation myocardial infarction remains high, with most deaths occurring before hospital admission. Despite effective pre- and in-hospital reperfusion strategies becoming standard over the past 2 decades, time-to-admission and time-to-treatment remain prolonged. We reviewed temporal trends in these times in published clinical trials.

METHODS

All major randomized clinical trials reporting on reperfusion strategies for acute myocardial infarction published between 1993 and 2003 were evaluated. Strategies included pre- and in-hospital thrombolysis, primary percutaneous coronary intervention (pPCI) with or without transfer, and "facilitated" PCI. We generated overall estimates of time-to-admission, time-to-treatment, door-to-balloon (DTB), and door-to-needle (DTN) times and evaluated temporal trends in the length of time-to-admission and time-to-treatment.

RESULTS

In studies that evaluated only in-hospital thrombolysis, the time-to-admission was 149 +/- 45 minutes; the mean time-to-treatment was 181 +/- 29 minutes. In studies that considered only in-hospital pPCI (without transfer), the mean time-to-admission was 153 +/- 41 minutes; the mean time-to-treatment was 234 +/- 43 minutes. In studies that compared in-hospital pPCI with in-hospital thrombolytic therapy, the mean time-to-admission was 155 +/- 47 and 150 +/- 48 minutes, respectively. The DTN time was 65 +/- 10 minutes, whereas DTB time was 81 +/- 39 minutes. In other trials evaluating in-hospital thrombolysis and pPCI with transfer to a referral center, the time-to-admission in subjects treated with thrombolysis (n = 1345) was 127 +/- 32 minutes vs 131 +/- 36 minutes for pPCI (n = 1528). For in-hospital thrombolysis, time-to-treatment was 151 +/- 23 minutes vs 203 +/- 15 minutes for pPCI patients with transfer. The DTN time in the thrombolysis group was 44 +/- 28 minutes as compared with DTB time of 78 +/- 38 minutes in the pPCI group. Throughout the last decade, time-to-admission decreased significantly (P = .02) but time-to-treatment remained unchanged (P = .38) for patients undergoing thrombolysis. In the pPCI arm, time-to-admission remained unchanged (P = .11) but a insignificant trend toward reduction was demonstrated in time-to-treatment (P = .11).

CONCLUSION

Time-to-admission and time-to-treatment for ST-segment elevation myocardial infarction are still prolonged. Resources should be directed to early recognition of the acute myocardial infarction, improved utilization of emergency services for transportation, and prehospital diagnosis and triaging. Ambulances equipped with wireless capability to transmit electrocardiograms to the on-call cardiologist seem to be promising tools to achieve earlier diagnosis and triaging with high diagnostic sensitivity and specificity.

Patency of infarct related artery after pharmacological reperfusion during transfer to primary percutaneous coronary intervention influences left ventricular function and one-year clinical outcome

BACKGROUND

Time-to-treatment is an important determinant of mortality in primary angioplasty for ST-segment elevation myocardial infarction (STEMI). Thus, the benefits in outcome observed with transferring for primary angioplasty in comparison with on-site thrombolysis may be reduced or even lost when long-distance transportation is required. Even though pharmacological reperfusion might overcome this limitation, no data have been reported so far on the prognostic role of early pharmacological recanalization in STEMI patients undergoing long-distance transportation for primary angioplasty.

METHODS

We enrolled 225 consecutive STEMI patients without shock, eligible for thrombolysis, with at least 90-minute transport time to our primary PCI center. During transport, patients received i.v. heparin 40 U/kg, alteplase 15 mg+35 mg infusion and abciximab 0.25 mg/kg+0.125 microg/kg/min infusion for 12 h.

RESULTS

Patients were divided into two groups according baseline angiography, which showed early pharmacological reperfusion (preprocedural TIMI flow 2+3) in 193 patients (85.8%) and no reperfusion (preprocedural TIMI flow 0+1) in 32 patients (14.2%). Despite no difference in postprocedural TIMI flow, early reperfusion was associated with better postprocedural myocardial perfusion (TMPG 3: 54.9% vs. 18.7%, p<0.0001), better improvement in left ventricular ejection fraction (LVEF) (from 55.6+/-8.6% to 58.8+/-10.4% p<0.001 with early reperfusion vs. 52.9+/-13.4% to 50.4+/-15.8% with no early reperfusion, p=NS) and 1-year outcome (p=0.002 log rank). In multivariate analysis, preprocedural TIMI flow 0+1 independently predicted death and reinfarction at 1 year, and lack of LVEF improvement at 6 months.

CONCLUSIONS

Early pharmacological reperfusion in STEMI patients undergoing long-distance transportation for primary angioplasty is associated with better postprocedural myocardial perfusion, better LVEF recovery at 6 months and improved 1-year clinical outcome.

Transfer for urgent percutaneous coronary intervention early after thrombolysis for ST-elevation myocardial infarction: the TRANSFER-AMI pilot feasibility study

BACKGROUND

Most hospitals in Canada do not have percutaneous coronary intervention (PCI) facilities and use thrombolysis as reperfusion therapy for ST-elevation myocardial infarction (STEMI). Urgent PCI after thrombolysis may optimize reperfusion and prevent reinfarction and recurrent ischemia.

OBJECTIVE

To determine the feasibility of transferring high-risk STEMI patients from community hospitals in Ontario to PCI centres for urgent PCI within 6 h of thrombolysis.

METHODS

Patients with anterior or high-risk inferior STEMI received tenecteplase and were urgently transferred to PCI centres. PCI was performed if at least 70% stenosis was present in the infarct-related artery, regardless of flow, using coronary stents. Transfer of stable patients back to community hospitals was encouraged 24 h to 48 h after PCI.

RESULTS

Eighteen patients were transferred and underwent PCI a median of 3.9 h (range 2.7 h to 6.4 h) after thrombolysis. No complications occurred during transfer. One death occurred that was related to failed reperfusion and cardiogenic shock. Minor access-site bleeding occurred in five patients. Fifteen patients were transferred back to their community hospitals within 24 h of PCI. There were no further deaths or reinfarctions at one-year follow-up.

CONCLUSIONS

Transfer of high-risk STEMI patients for urgent PCI within 6 h after thrombolysis appears feasible. The randomized trial phase of the Trial of Routine ANgioplasty and Stenting after Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction (TRANSFER-AMI) will compare this strategy with standard treatment after thrombolysis.

Spontaneous thrombolysis: a forgotten determinant of life or death

Substantial evidence suggests that spontaneous thrombolytic activity of blood is an effective mechanism for protection against tissue damage that is the consequence of lasting arterial occlusion. Despite the generally held belief that coronary artery disease and stroke are preventable, a promising avenue of prevention, namely the identification and prophylactic treatment of those at risk of inefficient spontaneous thrombolysis, has been neglected. This is mainly due to the lack of physiologically relevant test. A recently described technique allows the measurement of spontaneous thrombolysis, that is, lysis of an autologous platelet-rich thrombus in the absence of added plasminogen activators. Early results suggest that this test may have significant clinical potential both in identifying those at risk from fatal thrombotic event and in finding new therapeutic avenues of improving spontaneous thrombolytic activity.

Broken bodies, broken hearts? Limitations of the trauma system as a model for regionalizing care for ST-elevation myocardial infarction in the United States

Many cardiovascular experts have called for the creation of specialized myocardial infarction centers and networks in the United States analogous to the current model for major trauma. Patients suffering ST-elevation myocardial infarction (STEMI) and trauma share an essential feature that makes the argument for regionalization persuasive: rapid triage and treatment by highly trained personnel improve survival in both conditions. Despite this similarity, however, the trauma system may be limited as a model for regionalizing STEMI care. First, the development of trauma systems has been hindered by the struggle for sufficient and stable funding, competing interests among individual stakeholders, and the overall lack of desire for state-sponsored healthcare planning in the United States. These same obstacles would need to be overcome if STEMI care is regionalized. Second, unique characteristics related to STEMI care, such as its varied clinical presentation and more lucrative reimbursement, will create new challenges. In this article, we briefly review the current status of trauma systems in the United States and describe why the regionalization of STEMI care may require different methods of healthcare organization.

Percutaneous Coronary Intervention After Fibrinolysis

OBJECTIVES

We performed a meta-analysis of randomized trials that enrolled ST-segment elevation myocardial infarction patients treated with fibrinolysis to assess the potential benefits of: 1) rescue percutaneous coronary intervention (PCI) versus no PCI; 2) systematic and early (< or =24 h) PCI versus delayed or ischemia-guided PCI; 3) fibrinolysis-facilitated PCI versus primary PCI alone.

BACKGROUND

The impact of PCI strategies after fibrinolysis on mortality or reinfarction remains to be established.

METHODS

The meta-analysis was performed using the odds ratio (OR) as the parameter of efficacy with a random effect model. Fifteen randomized trials (5,253 patients) were selected. The primary end point was mortality or the combined end point of death or reinfarction.

RESULTS

Rescue PCI for failed fibrinolysis reduced mortality (6.9% vs. 10.7%) (OR, 0.63; 95% confidence interval [CI], 0.39 to 0.99; p = 0.055) and the rate of death or reinfarction (10.8% vs. 16.8%) (OR, 0.60; 95% CI, 0.41 to 0.89; p = 0.012) compared with a conservative approach. Systematic and early PCI performed during the "stent era" led to a nonsignificant reduction in mortality compared with delayed or ischemia-guided PCI (3.8% vs. 6.7%) (OR, 0.56; 95% CI, 0.29 to 1.05; p = 0.07) and to a 2-fold reduction in the rate of death or reinfarction (7.5% vs. 13.2%) (OR, 0.53; 95% CI, 0.33 to 0.83; p = 0.0067). This benefit contrasted with a nonsignificant increase in the rate of both mortality (5.5% vs. 3.9%, p = 0.33) or death or reinfarction (9.6% vs. 5.7%, p = 0.06) observed in the "balloon era." Fibrinolysis-facilitated PCI was associated with more reinfarction as compared with primary PCI alone (5.0% vs. 3.0%) (OR, 1.68; 95% CI, 1.12 to 2.51; p = 0.013) without significant impact on mortality (OR, 1.30; 95% CI, 0.92 to 1.83; p = 0.13).

CONCLUSIONS

Our findings support rescue PCI and systematic and early PCI after fibrinolysis. However, the current data do not support fibrinolysis-facilitated PCI in lieu of primary PCI alone.

Rationale for establishing regional ST-elevation myocardial infarction receiving center (SRC) networks

Recent developments have provided a unique opportunity for the organization of regional ST-elevation myocardial infarction (STEMI) receiving center (SRC) networks. Because cumulative evidence has demonstrated that rapid primary percutaneous coronary intervention (PCI) is the most effective reperfusion strategy for acute STEMI, the development of integrated SRC networks could extend the benefits of primary PCI to a much larger segment of the US population. Factors that favor the development of regional SRC networks include results from recently published clinical trials, insight into contemporary STEMI treatment patterns from observational registries, experience with the nation's current trauma system, and technological advances. In addition, the 2004 American College of Cardiology/American Heart Association STEMI guidelines have specified that optimal "first medical contact-to-balloon" times should be <90 minutes, so a clear benchmark for timely reperfusion has been established. Achievement of this benchmark will require improvements in the current process of care as well as increased multidisciplinary cooperation between emergency medical services, emergency medicine physicians, and cardiologists. Two types of regional SRC networks have already begun to evolve in role-model cities, including prehospital cardiac triage and interhospital transfer. Regional coordination of SRC networks is needed to ensure quality monitoring and to delineate the ideal reperfusion strategy for a given community based on available resources and expertise.

Facilitated Percutaneous Coronary Intervention

The goal of the initial treatment for ST-segment elevation myocardial infarction is rapid and effective reperfusion. Randomized trials have demonstrated that primary angioplasty is preferred over thrombolysis if done in a timely manner and by an experienced team. However, due to many factors, performance of primary angioplasty within the goal of 90 min is often not possible. A combined strategy of immediate thrombolysis in the emergency room or in the ambulance followed by angioplasty theoretically could provide early reperfusion with subsequent angioplasty to insure complete reperfusion. Over 17 clinical trials have been reported. Compared with thrombolysis, facilitated angioplasty in the most recent trials has been shown to have a more favorable long-term outcome. Trials comparing facilitated angioplasty with full- or half-dose thrombolysis versus primary angioplasty have been far less favorable with the largest trial to date, the ASSENT (Assessment of the Safety and Efficacy of a New Treatment Strategy with Percutaneous Coronary Intervention)-4 trial, demonstrating a worse outcome in the primary end point of death, congestive heart failure, or shock at 90 days. Pending the results of the FINESSE (Facilitated Intervention with Enhanced Reperfusion Speed to Stop Events) trial, current data suggest that facilitated angioplasty does not offer any advantage over primary angioplasty and may be harmful.

Clinical Guidelines and Practice

Data from randomized clinical trials, non-randomized studies, and registries, as well as expert panel consensus are appropriately weighted and woven into the context of clinical practice guidelines. Recent guidelines for the care of patients with ischemic heart disease have emphasized both risk stratification and early coronary angiography with revascularization of patients with high-risk indicators. Advances in our understanding of the pathogenesis of acute coronary syndromes and the dynamics of therapeutic innovation (improvement in catheter-based technologies and adjunctive pharmacotherapy) mandate the timely update and revision of practice guidelines. We believe that the weight of evidence remains clearly in support of an early invasive treatment strategy based on risk stratification. Arguments regarding treatment strategy (invasive vs. conservative) are misguided, and greater focus should be placed on improving the treatment-risk paradox demonstrated in clinical practice as well as on strategies to enhance current guideline compliance and utilization. Interest exists in establishing regional centers of excellence for care of patients with acute ischemic heart disease, analogous to the regionalized approach already established for patients with trauma or stroke. This approach is supported by data that demonstrate an inverse relationship between both institutional and operator procedural volumes and mortality, as well as by existing constraints in resources such as specialized nurses and subspecialty-trained physicians. It is appropriate at this time to briefly review specific aspects of the American College of Cardiology/American Heart Association practice guidelines and the current process of care for acute ischemic heart disease.