Clinical trial for endovascular cooling system

Philips Electronics announces study on InnerCool RTx

Philips Electronics has announced enrolment of the first patients in its CHILL-MI clinical study designed to further evaluate the safety and effectiveness of its InnerCool RTx endovascular cooling system in patients suffering from ST-elevation myocardial infarction (STEMI).

The study will enrol 120 patients at multiple sites in Europe with a primary endpoint of reducing infarct size as a percentage of myocardium at risk, as assessed by cardiac magnetic resonance imaging (MRI). The study will also reinforce the safety and efficacy data demonstrated in the RAPID MI-ICE trial in a larger patient group. This showed a 38% reduction in infarct size in STEMI patients who were cooled to a temperature of <35°C prior to performing angioplasty1.

Acute myocardial infarction (AMI) is the leading cause of mortality in the western world2. Following a myocardial infarction, restoring blood flow to the heart is critical to the survival of heart tissue3. However, this process may cause additional damage to the heart tissue, known as reperfusion injury4. 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 centres, 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-centre trial. We hope this 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," said David Erlinge, head of the department of cardiology at Lund University in Sweden and principle investigator for the study.

“One of our goals with endovascular cooling is to offer a new treatment option for patients with STEMI,” added Derek Smith, senior vice president of 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 US the incidence of STEMI is approximately 77 per 100,000 individuals5. In Europe, this rate ranges from 44 to 142 individuals per 100,000 depending on the country, with Turkey having the highest and the UK having the lowest rates6.

Under the study, 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 four days as measured by cardiac MRI. Secondary safety and efficacy endpoints will also be evaluated.


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 click here. Accessed January 2012

3. Reperfusion. Available at click here. 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