Working to Improve STEMI Care Around the Globe
Dr. Mehta, you have focused on taking care of ST-elevation myocardial infarction (STEMI) patients for almost 20 years now. It is a passion that has taken you around the world.
STEMI interventions have completely changed the global epidemiology. As a result of the amazing work by interventional cardiologists performing STEMI interventions, acute MI is no longer the biggest killer in the United States. It has been an incredible journey. In the past few years, there have been so many notable developments: the management of cardiogenic shock, the applications and use of the Impella, a de-emphasis on door-to-balloon time and more appropriate recognition of symptom-to-balloon time, and the emergence of more regional systems of care in developing parts of the world, including the contributions made by the Lumen Foundation. I recently looked at the agenda from the 2004 LUMEN meeting in Miami. One of the debates we were having that year was whether STEMI should be performed at big academic centers. This is a struggle that many countries in the world are still having. The U.S., at that time under the American Heart Association’s Mission: Lifeline with Dr. Alice Jacobs, said that performing the intervention at the nearest hospital makes more sense, even if they do not have the most elegant surgical standby. It was an outstanding move. Legislatively, the move thereafter to take the patient with an acute MI from the ambulance to a PCI-capable hospital was a transformational event in the management of STEMI in the U.S. The country and leadership societies also made numerous changes in the prehospital alert system. At that time, in 2004-2008, there were two pathways: either we could train the paramedic to better take care of STEMI, as was being done in Ottawa, Canada, mainly by Dr. Michel Le May, who encouraged the creation of advanced paramedics, or there was the strategy of putting technology in the ambulance for a prehospital alert. The tremendous advances include the work of emergency physician Dr. Ivan Rokos, who recognized the need to create a prehospital alert and an excellent, intelligent EMS system. With the development of that system, we now take the patient not to the nearest hospital, but to a primary percutaneous coronary intervention (PCI) center, and that has evolved into the STEMI network. The success has happened so gradually, without cardiologists singing their own praises. What has it meant for the nation? In a crude calculation, numerous interventional cardiologists who treated STEMI around the country over the past 20 years have saved almost half a million lives. Yet there are still areas that require far greater penetration. We are needlessly following the old dictum that the emergency department (ED) stabilizes patients. Almost 85-90% of patients are stable enough that they should not go through the process of two bed changes. They should not have to go from the ambulance stretcher to the ED bed, and from the ED bed to the cath lab table. Eliminating this move could save anywhere from 20-30 minutes, which is the single biggest reduction in the door-to-balloon (D2B) process. Most institutions in the country should be doing ED bypass, which itself is a powerful metric that will contribute to many lives being saved. We have to get a little more creative around supporting it. For example, when the Lumen Foundation created the PRINCE (Puerto Rico Infarct Nationwide Collaborative Experience) program in Puerto Rico, the first person reaching the cath lab pressed a button that lit a green light in the ED, signaling to the ED as well as to EMS that the cath lab is directly available for bypass. Something similar should be standard practice. Patient awareness, another area, has significantly improved, but there is no limit as to how much we can educate the patient. We also need to focus on the false alarm. There has been the concept that if there is any doubt, we should take a patient to the cath lab. That was how we trained the paramedics, the cath lab, and the ED. That strategy is not the strategy to adopt for 2018. We have become so good that now we need to become far more accurate; my personal feeling is that our false alarm rate nationwide is not the 9-10% that people expect or the <15% requested by the guidelines. I think the false alarm rate is closer to 25%; it may even be higher, and all of that cannot be justified by saying, “we have a system that is trying to put its best foot forward and that we are not going to let a patient fall through the cracks.” There are numerous steps that can be taken, starting with better evaluation of the patient in the emergency department. Another area that will offer a fantastic amount of progress is the incorporation of machine learning and artificial intelligence (AI) to further increase the accuracy of the electrocardiogram (EKG) when the patient is having an acute MI. The Lumen Foundation now has an entire Department of Telemedicine and AI devoted to this specific topic and we expect tremendous applications of AI to improve the STEMI process. Standardized algorithms software is able to diagnose appropriately in about 85% of cases, but in areas of doubt, which include early repolarization, pericarditis, pacemaker rhythm, left ventricular hypertrophy, left anterior hemiblock, left bundle branch block, and patients with left ventricular aneurysms, machine learning processes can augment STEMI accuracy significantly. If you can take 70-80% accuracy and bring it to 90% accuracy, imagine the tens of thousands of unnecessary STEMI alerts and procedures that will be eliminated. Our patients are often being taken through a very challenging, complicated procedure with the risk of complications, often in the middle of the night, and are subjected to enormous stress without the system having a foolproof diagnosis. This is unacceptable. For me, increasing the accuracy of STEMI interventions by decreasing the false alarms nationwide is an important requirement and responsibility for all of us involved in taking care of a patient with an acute MI.
STEMI intervention, because of its power and ability to save lives, is a movement that cannot be stopped. Today, irrespective of the financial status of a country, or its economic, infrastructure, and ambulance deficits, because of social networking, even the poorest country will not allow a 40-year-old to die from a heart attack. Even in the poorest countries, the citizens have become extremely aware and they will mandate it upon their healthcare systems and politicians that primary PCI should be made available to just about everybody. Where does that leave thrombolysis? In several countries around the world, there is still the horrible, nascent practice of “thrombolysis during the night and PCI during the day”. In countries such as India, China, and several other large Asian countries, the societies have not yet mobilized to strongly encourage primary PCI as the best method of treatment. Even as we talk today, more patients around the world are being treated with thrombolysis than with primary PCI. The beauty of thrombolysis is when a third-generation agent can be given prehospital for patients presenting very early. This differentiation is so important, because otherwise, on the surface, you can make an argument that thrombolysis and PCI are similar. It is this pseudoscientific argument that is being advanced in poor countries that do not want to commit immediate resources to primary PCI, and who are using this as an excuse to continue to push thrombolysis. As a result, the worst actions are occurring in the poorest countries where patients are presenting at 6 and 8 hours, and getting streptokinase. This is absolutely unconscionable and this awful practice should stop. I have even come to the conclusion that thrombolysis has its best application in the most advanced countries that have excellent ambulance systems, and where patients are highly educated and they present immediately after having chest pain. An example is a patient in Denmark who gets chest pain 15 minutes ago and who presents to a non-PCI center. For this patient, thrombolysis and PCI have similar outcomes — in fact, thrombolysis may even be superior. However, this situation is completely different that a patient in India where the time to presentation is 6.5 hours, patients are getting streptokinase, and people are trying to convince you by giving you examples of the STREAM trial that thrombolysis works just as well as primary PCI. Thrombolysis works as well if it is given very early, prehospital, and a third-generation agent is utilized. One of the worst practices in developing countries is the use of thrombolysis (of course, off hours) in PCI-capable facilities. Yet I am very encouraged at the progress that is being made. Every year at the Lumen Global meeting, we have been charting the progress of 13 countries in the Southeast Asian region, including India, Pakistan, Sri Lanka, Bangladesh, Cambodia, Myanmar, Indonesia, Malaysia, Thailand, the Philippines, and Vietnam. Their progress over the past 10 years has been absolutely dazzling, and I believe this is the single largest contribution of Lumen Global, which is going to be completing 20 years this January. For example, in Myanmar, the country has two PCI centers, in Yangon and in Mandalay. There is probably more primary PCI being done in Myanmar than PCI itself. Almost the same thing can be said in Cambodia, which got started with its PCI program in the last few years. With two centers for the entire country, they are also doing primary PCI. More countries are recognizing (and the politicians are also understanding), that the greater availability of PCI not only saves lives and improves life with preserved left ventricular function, but it restores the patient in a cost-effective manner. The cost savings from an early STEMI intervention are sustained for several years in return for the initial investment that the country has to make. Many of the countries that are more advanced, such as Malaysia, Indonesia, Philippines, Thailand, and Vietnam, have also started robust STEMI networks with or without the participation of their cardiovascular societies, and that has also been a fantastic step forward. When the LUMEN meeting first began in Miami, it made a tremendous contribution in training hundreds of nurses, doctors, and technologists in the country, and globally, it has tried to do the same. A program initiative at Lumen Global called “empowering the general physician” has also been extremely effective. In many parts of the world, it is the general physicians, particularly those in the countries that do not have the STEMI systems of care and a reliable ambulance system, that have first contact with the patient. Efforts to educate the general physician are a step forward. As a result, they are able to diagnose STEMI early, hold a sensible academic triage in their mind as to which patients are candidates for thrombolysis and which should go for PCI, and they have a firsthand, working knowledge of the available center in the area that offers one or both options.
How has the growth of telemedicine impacted global STEMI interventions?
Telemedicine is an amazing opportunity. There are two major things I realized over the past 20 years working with Lumen Global. One is the disparity occurring between the genders. In response, we created a not-for-profit organization, GLOW, or Global Lumen Organization for Women. My co-chair is Dr. Alexandra Lansky at Yale. We have already published a meta-analysis of more than 750,000 women that demonstrates outcomes are much worse for women. We also believe it is because of several definite reasons that prevent short door-to-balloon times and create barriers for women. These are personal, social, cultural, financial, and even religious barriers. There are also the disparities occurring between developed and developing countries. Your outcome from a STEMI depends on your zip code. If I am having a STEMI in New York City, chances are that somebody will save my life with a door-to-balloon time of about 50 minutes; I will be out of the hospital on day 2 with an in-hospital mortality of 1.2%, and an excellent long-term outcome. However, if my STEMI occurs in the zip code where I was born in New Delhi, chances are I will never reach the hospital. Even if I reach the hospital, chances are they will not be doing primary PCI, and my in-hospital and long-term outcome are not going to be good. Telemedicine is a pathway that is able to reduce the disparities between developed and developing countries. The Lumen Foundation has now created telemedicine programs in several countries. The biggest one is in South America, known as LATIN, Latin America Telemedicine Infarct Network, and it has just completed telemedicine encounters for 675,000 patients, with almost 7,600 STEMIs treated with short door-to-balloon times. We have been able to access areas that have had no previous access at all. Seventy-five million patients are now under the umbrella of LATIN. We started the LATIN program in Colombia, took it to Brazil and Mexico, and will be expanding to Argentina and Chile. In Colombia, the program is now covering almost a quarter of the population. D2B times are significantly reduced, now averaging about 54 minutes. The most important metric we measure is TTD, or time to telemedicine diagnosis, that is now down to 3.8 minutes. LATIN has 62 centers in Mexico, all being managed through Colombia — this is the power of telemedicine! We believe we have created a scalable model that can be hugely expanded to sub-Saharan Africa, to the Middle East, and to several parts of Asia. In of these models where we have performed economic forecasting, we would set up about 5,000 telemedicine centers that would provide AMI coverage to >250 million poor patients that presently have no viable management for AMI. Our objectives have been to demonstrate increased access, accuracy, and cost effectiveness, and provide comprehensive management with both pharmaco-invasive and primary PCI. Demonstrating cost effectiveness has been the most challenging, but our recent work in this area has just been peer-reviewed and I will be presenting this work at the upcoming scientific meeting of the European Society of Cardiology. The cost of transmitting a single electrocardiogram (EKG) is less than a dollar. The cost of utilizing the entire telemedicine process, from the patient recognizing symptoms to taking them through the entire management pathway, works out to be roughly hundred-plus dollars. The cost savings in 7 years of LATIN in 3 countries is almost 93 million dollars in funds saved.
We have also created a similar telemedicine-based program for India’s largest state, Rajasthan. The program is known as RAHAT, or Rajasthan Heart Attack Treatment. It is a program developed indigenously, using Indian IT people, and the costs have been reduced to almost one-third of the costs of the telemedicine program in South America, because of the IT prowess available in India.
How does the telemedicine system work?
It is a hub-and-spoke strategy. The spokes are primary care centers and small clinics in remote, poor regions where often there is no physician. We have the telemedicine device in place there, which performs the EKG and transmits it to the telemedicine command center, which can be located several hundred miles away. If a patient goes to the center or clinic with symptoms and an unclear presentation, he or she is quickly hooked up to the telemedicine device to perform the EKG. A button is pressed to transmit it. We are now getting 2,000 EKGs a day. At the command center, there are 24-hour operators who quickly screen the EKGs, remove the artifacts and assign a red, yellow, or orange code to the patient. Red means it needs to be replied to in two minutes and the EKG immediately shows up on the screen of the cardiologist who is on call. The cardiologist immediately performs the diagnosis. There are two text messages that go simultaneously out in addition to the diagnosis. One goes to the spoke and one goes to the hub. This notification automatically triggers ambulance dispatch and the telemedicine acute MI management process. If there is clarification needed as to whether the patient should get thrombolysis or be transferred, the device operator picks up the phone and speaks to the remote cardiologist, who guides them through the process. In the several large centers we have been monitoring in Brazil, mortality has been reduced almost by 50% (this data was presented at TCT in 2017). In different countries, various models can be tailored to specific requirements. Our experience has shown that in areas with a shortage of experts, telemedicine provides a rapid and cost-effective way to help people.
Can you tell us about your work treating STEMIs and some of the challenges you see?
My work still goes under the heading of the SINCERE database, or Single INdividual Community Experience REgistry. I started the database in 2001 and it now holds >2000 short D2B STEMI interventions performed by a single physician. In SINCERE, from the first 10 years to the present, the time to presentation has been dramatically reduced in a linear fashion. It used to be almost 3 hours and 20 minutes. That number easily has gone below an hour. At our hospital, just like in any other center that does good STEMI work, teamwork is important. The D2B time used to be 187 minutes in 2003, it has come down as low as 37, and now it is down to a mean of 51 minutes. Overall, mortality has come down significantly. The mean length of stay is now down to slightly less than three days and that is being replicated around the country. I still use a fair amount of thrombectomy, I also continue to use 100% bivalirudin, with about 10-12% use of intravenous cangrelor, an ultra short-acting intravenous ADP-receptor blocker. I use it in patients who are having a very large anterior wall MI, in patients who are intubated and cannot take oral agents, and some subsets with cardiogenic shock.
There are two procedural areas I think the field still needs to improve upon: managing thrombus is one, and the other is the use of intracoronary vasodilators, specifically the use of nitroprusside, to augment the myocardial perfusion grade. Operators who perform STEMI interventions need to rigorously monitor the myocardial perfusion grade, MPG, which is an independent predictor of early and long-term mortality, and it can be improved through a compulsive management of thrombus and with very liberal doses of intracoronary vasodilators. I use a compulsive thrombus management strategy, which is a selective strategy based on thrombus grade. If there is low-grade thrombus, then I will direct stent. For moderate thrombus, aspiration works well, and for high-grade thrombus, particularly in large vessels, the AngioJet device (Boston Scientific) is an elegant strategy. Every year, I gather 8 to 10 of my most challenging cases for teaching purposes. For nearly the last 15 years, my best 10 teaching cases of the year are those performed with the AngioJet. For all these cases, aspiration therapy had failed and the large thrombus was not something for which I would use a balloon. The AngioJet is not a device you should be thinking of at 3 in the night if you have never used it before. It is also a device the technologists in the cath lab should be very conversant with and should not take more than 2-3 minutes to set up. It works easily through a 6 French transradial or femoral sheath. The few clinical trials have not done justice to how effective this device can be for patients with bulky thrombus and large vessels where, as far as I am concerned, it is the only device which works. We cannot put a stent in the middle of residual thrombus grade 2 or 3, and it is for these cases that the AngioJet continues to be an effective device.
The two groups most at risk of mortality with acute myocardial infarction in the U.S. are those with cardiogenic shock and those with delayed presentation. Cardiogenic shock remains an area open to discussion, particularly after the elegant CULPRIT-SHOCK trial by Dr. Holger Thiele from Germany, which concluded that even for the patients presenting with STEMI and cardiogenic shock, we should be treating only the culprit lesion.
We are also seeing less use of an intra-aortic balloon pump and more use of the Impella device. I have long believed that the way to use left ventricular assist devices is to first place the Impella, start the management of the left ventricular end diastolic pressure and shock, and then do the STEMI intervention. This approach is now being evaluated in both a registry and in a clinical trial.
Any final thoughts?
Developing countries need to take up STEMI interventions as a public health problem rather than as a specific cardiovascular morbidity to be tackled just by the cardiologist and interventional cardiologist. I am also surprised and disappointed in the progress of ambulance systems globally. If you were to ask me today what the single biggest factor is that makes a difference in acute MI care, without the least hesitation, I would say it is the availability and caliber of the ambulance system and the training of the paramedics. It is something that should be a number-one target and goal for any healthcare society. To have a reliable ambulance system meets three goals: it takes care of trauma, which is always a big problem, it takes care of patients with STEMI, and of course, it also helps with stroke, which is exactly the same process and procedure, overlapping with STEMI interventions. Treating STEMI as a public health problem also helps encourage the spread of education and patient awareness.
Clearly, what separates the U.S. from the rest of the world has been the fantastic job done by the American Heart Association and American College of Cardiology. The STEMI procedure, over the last 20 years, has become amazingly predictable. When I started, about 70-80% of the hospitals were using thrombolysis. In the last 10 years, I have not touched thrombolytic therapy. That only a very small minority of patients in the U.S. are getting thrombolysis is a result of the fabulous job that STEMI operators are doing in this country. With a single page, teams are being alerted, everyone shows up to the cath lab, and we are taking care of thousands of patients. To have taken the biggest cause of mortality and reduced it is one of the most overlooked achievements of cardiologists in the United States.
Dr. Sameer Mehta can be contacted at email@example.com.