Acute myocardial infarction (AMI) is the leading cause of mortality in the western world.(2) Following a myocardial infarction, restoring blood flow to the heart is critical to the survival of heart tissue.(3) However, this process may cause additional damage to the heart tissue, known as reperfusion injury.(4) Preventing tissue damage is arguably the most significant unmet medical need in the treatment of AMI and new standards of care are being investigated with the goal of improving patient outcomes.
According to researchers at Lund University in Sweden, one of the CHILL-MI study centers, the key to reducing infarct size is to cool patients with therapeutic hypothermia to <35°C prior to reperfusion or opening of the blocked artery.
"The success of the RAPID MI-ICE study was a breakthrough in the treatment of STEMI patients. With the initiation of CHILL-MI, we aim to confirm the results in a larger multi-center trial. We hope this study will help to demonstrate the positive impact that therapeutic hypothermia can have on the outcomes of patients suffering acute MI and bring us a step closer to making it a standard of care," says David Erlinge, M.D., Ph.D., head, department of cardiology at Lund University in Sweden and principle investigator for the CHILL-MI study.
"One of our goals with endovascular cooling is to offer a new treatment option for patients with STEMI," said Derek Smith, senior vice president, Therapeutic Care, at Philips Healthcare. "This novel therapy leverages Philips’ strong presence and capabilities in both the emergency department and cath lab. Endovascular cooling is one of our growth initiatives and illustrates our strategy to offer new therapies in high-potential markets with the goal of improving the quality of life for patients."
The potential impact of improving treatment for STEMI is significant. In the U.S., the incidence of STEMI is approximately 77 per 100,000 individuals.(5) In Europe, this rate ranges from 44 to 142 individuals per 100,000 depending on the country, with Turkey having the highest and the U.K. having the lowest rates.(6)
The CHILL-MI study
The Phase II/III CHILL-MI study will enroll 120 patients from multiple centers in Europe. Patients in the treatment group will receive endovascular cooling therapy in combination with 1-2 L of cold saline. The control group will receive the current standard of care. The primary endpoint will be the myocardial infarct size as a percentage of at-risk myocardium at 4 days (± 2 days), as measured by cardiac MRI. Secondary safety and efficacy endpoints will also be evaluated.
The RAPID MI-ICE study
The RAPID MI-ICE study enrolled 20 STEMI patients who were randomized to receive immediate percutaneous coronary intervention with or without adjunct rapid endovascular cooling. The study demonstrated that the induction of mild hypothermia (<35°C) in STEMI patients prior to performing an angioplasty can save up to 38 percent more heart tissue than the current standard of care. Data showed that, in the control group, more patients experienced heart failure (n=3) and ventricular tachycardia/ventricular fibrillation (VT/VF; n=2) than in the endovascular cooling group, which had no instance of either complication (P=0.21). Three patients in the endovascular cooling group experienced infections, while no patients in the control group had infections (P=0.21). The conclusion that the rapid induction of hypothermia with endovascular catheter is safe and feasible in patients with acute MI prompted the initiation of the CHILL-MI study to investigate this technology in a larger multi-center trial.
Background on the Philips InnerCool RTx endovascular cooling system
The Philips InnerCool RTx endovascular cooling system quickly and effectively cools patients from the inside out, even those with high body mass index (>30kg/m2) who often are considered "difficult-to-cool".(7) A unique catheter with an integrated temperature sensor is placed below the heart via the femoral vein. Once in place, the closed-loop system modulates whole body temperature without fluid introduction or exchange by circulating cool saline in the catheter. This technology offers the fastest cooling rates of any temperature modulation therapy approach.(7)
Use of the Philips RTx endovascular cooling system for the treatment of myocardial infarction is investigational and is not approved for this indication in the U.S.
Related news articles:
About Royal Philips Electronics
Royal Philips Electronics of the Netherlands (NYSE: PHG, AEX: PHI) is a diversified health and well-being company, focused on improving people's lives through timely innovations. As a world leader in healthcare, lifestyle and lighting, Philips integrates technologies and design into people-centric solutions, based on fundamental customer insights and the brand promise of "sense and simplicity." Headquartered in the Netherlands, Philips employs over 120,000 employees with sales and services in more than 100 countries worldwide. With sales of EUR 22.3 billion in 2010, the company is a market leader in cardiac care, acute care and home healthcare, energy efficient lighting solutions and new lighting applications, as well as lifestyle products for personal well-being and pleasure with strong leadership positions in male shaving and grooming, portable entertainment and oral healthcare.
1. Götberg, M et al. A pilot study of rapid cooling by cold saline and endovascular cooling before reperfusion in patients with ST-elevation myocardial infarction. Circulation: Cardiovascular Interventions. 2010(3), 400-407.
2. World Health Organization. The Top 10 Causes of Death, 2011. Available at http://www.who.int/mediacentre/factsheets/fs310/en/. Accessed January 2012.
3. MedicineNet.com. Reperfusion. Available at http://www.medterms.com/script/main/art.asp?articlekey=5308. Accessed January 2012.
4. Fernandy, P et al. Interaction of cardiovascular risk factors with myocardial ischemia/reperfusion injury, preconditioning, and postconditioning. Pharmacological Reviews. 2007(59), 418-458.
5. McManus, DD et al. Recent trends in the incidence, treatment, and outcomes of patients with STEMI and NSTEMI. The American Journal of Medicine. 2011(124), 40-47.
6. Widimsky, P et al. Reperfusion therapy for ST elevation acute myocardial infarction in Europe: description of the current situation in 30 countries. European Heart Journal. 2010(31), 943-957.
7. Steinberg, GK et al. Comparison of endovascular and surface cooling during unruptured cerebral aneurysm repair. Neurosurgery. 2004(55), 307-315.