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Exercise Test for Evaluation of the Functional Efficacy of the Pig Cardiovascular System
Published on: May 12, 2023
The level I cardiovascular center: is it time?
Richard W Smalling1, Gregory Giesler
1Division of Cardiovascular Medicine, The University of Texas Medical School at Houston and The Memorial Hermann Heart Center, Houston, TX 77030, USA. richard.w.smalling@uth.tmc.edu
Insights
Expedited treatment for acute myocardial infarction (AMI) using prehospital thrombolysis and rapid percutaneous coronary intervention (PCI) can significantly reduce mortality. This strategy has the potential to save thousands of lives daily in the US.
Area of Science:
- Cardiology
- Emergency Medicine
- Clinical Trials
Background:
- Acute myocardial infarction (AMI) affects 1.5 million Americans annually with no uniform treatment approach.
- Current treatment rates for ST-elevation AMI with reperfusion therapies (thrombolysis or PCI) are suboptimal, leaving many patients at higher risk.
- Existing trauma systems efficiently manage critically injured patients, highlighting a need for similar efficiency in AMI care.
Purpose of the Study:
- To evaluate the efficacy of prehospital thrombolytic therapy followed by immediate transfer for facilitated percutaneous coronary intervention (PCI) in reducing mortality for ST-elevation AMI patients.
- To propose a randomized clinical trial, the Prehospital Administration of Thrombolytic Therapy With Urgent Culprit Artery Revascularization (PATCAR) trial, to validate this expedited treatment strategy.
Main Methods:
- Review of findings from trials such as ER-TIMI 19, SPEED, and PAMI investigating early reperfusion strategies.
- Analysis of time to treatment, ST-elevation resolution, infarct-related artery flow rates (TIMI 3), and in-hospital mortality.
- Proposed model: Prehospital, partial-dose thrombolysis followed by direct transport to a Level I cardiovascular center for facilitated PCI.
Main Results:
- ER-TIMI 19 showed a 32-minute reduction in treatment time and ST-elevation resolution with prehospital thrombolysis, associated with 4.7% in-hospital mortality.
- SPEED investigators demonstrated improved infarct-related artery TIMI 3 flow (86%) with facilitated PCI and combination therapy.
- PAMI data indicate <1% 6-month mortality for patients achieving TIMI 3 flow during primary PCI.
Conclusions:
- Implementing a strategy of prehospital thrombolysis and facilitated PCI at a specialized center could reduce ST-elevation AMI mortality from 6%-10% to <4%.
- This approach has the potential to save approximately 500 lives per day in the United States.
- A randomized clinical trial (PATCAR) is necessary to confirm the benefits of this proposed AMI treatment pathway.
Abstract:
There is no uniform approach to treating the 1.5 million US citizens who have an acute myocardial infarction (AMI) each year. This contrasts with the trauma system developed to efficiently triage and treat the critically injured accident victim. Only two thirds of patients with ST-segment elevation AMI in the United States are treated with thrombolytic therapy or primary angioplasty (percutaneous coronary intervention [PCI]) which can reduce the 30-day mortality rate from approximately 15% to 6%-10%. The Early Retavase-Thrombolysis in Myocardial Infarction (ER-TIMI) 19 trial demonstrated that AMI patients who received prehospital thrombolytic therapy and were brought to the nearest receiving hospital experienced a 32-minute reduction in the time to treatment and time to ST-elevation resolution compared with those treated at their time of hospital arrival. This expedited therapy was associated with a low in hospital mortality rate (4.7%). The potential benefit of facilitated PCI with partial-dose thrombolysis and abciximab administration was demonstrated by the Strategies for Patency Enhancement in the Emergency Department (SPEED) investigators who found that double bolus recombinant plasminogen activator (reteplase) (5 + 5 megaunits) and abciximab with the addition of early PCI, resulted in a final infarct-related artery TIMI 3 flow rate of 86% compared with 77% with combination therapy alone. The Primary Angioplasty in Acute Myocardial Infarction (PAMI) investigators have shown that patients admitted with infarct-related artery TIMI 3 flow at the time of primary PCI had less than a 1% 6-month mortality. Treating AMI patients with prehospital, partial dose thrombolysis followed by immediate transport to a Level I cardiovascular center (bypassing the closest hospital if necessary) for facilitated infarct-related artery PCI has the potential to reduce the mortality in ST-elevation AMI patients from 6%-10% to less than 4% which could translate into saving approximately 500 lives per day in the United States. It is time to validate this strategy with a randomized clinical trial, the Prehospital Administration of Thrombolytic Therapy With Urgent Culprit Artery Revascularization trial (PATCAR).
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