Cardiovascular Disease Clinical Trial Results

The PRECISE Cardiac Clinical Trial and Stem Cell Treatment – Improving Heart Function

The PRECISE cardiac clinical trial was designed by a team of world renowned cardiac researchers, including Dr. Emerson Perin from Texas Heart Institute and Dr. Francisco Fernandez-Aviles. It examined the safety and feasibility of adipose-derived stem and regenerative cells (ADRCs) in the treatment of those with severe coronary artery diseaseHeart disease caused by plaque having built up in the arteries..

Results of the PRECISE Study

The 18 month study showed that treating patients with chronic coronary artery disease with ADRCsAdipose-derived stem and regenerative cells:

• Is safe and feasible
• Showed significant benefit in heart function

Improvement in Heart Function

The two key measures of heart function are:

1. MVO2, or maximum volume of oxygen consumed – the maximum amount of oxygen that a person can use. This is the best predictor of cardiac-related mortality.
2. MET score, or metabolic equivalent of task score – a way to measure a patient’s physical strength and a strong predictor of adverse cardiac-related events.

What Does This Mean to Patients with Chronic Coronary Artery Disease?

Patients who received stem cell therapy in the cardiac clinical trial showed

• Sustained improvement in MVO2
• Improvement in MET score
• Reduction in infarct size (the amount of the diseased heart tissue)

Maximum Amount of Oxygen Consumed – MVO2

In the PRECISE trial, one of the most important findings was the improvement in MVO2. The MVO2 levels define a measure of how efficiently the body’s tissue utilizes oxygen.

18 months after treatment:

• Those patients who received the stem cell therapy improved their MVO2 from approximately 16 to over 17, on average.
• Those patients who did not receive the stem cell therapy (control group) suffered a steep decline from approximately 19 to 15.

A patient with MVO2 of 14 or less has a 53% risk of dying within 12 months. The data suggests an MVO2 of 16 or greater suggests a lower risk of cardiac-related death.

The survival rate at 28 months of average follow up time was predicted by the trend in oxygen consumption.

• Stem cell treated patients had better survival: 1 out of 21 had a cardiac-related death in the trial.
• The placebo group mortality rate, however, was 2 out of 6 placebo patients died of cardiac causes in the trial.

Metabolic Equivalent of Task Score – MET Score

A MET (Metabolic Equivalent of Task) score describes the amount of energy required to carry out a task. A MET score is a strong predictor of cardiac-related adverse events as well as mortality.

The PRECISE study population had a MET score of approximately 5, which put them at high risk in the near term. Eighteen months after treatment:

• Patients who received the stem cell therapy improved their MET score from approximately 4.8 to 5.0 in 6 months, and sustained that through the 18 month period.
• Patients who did not receive the stem cell therapy (control group) suffered a decline in function. On average, their MET score fell from approximately 5.3 to 4.4 in the 6 month period, and continued to trend downward at 18 months.

Infarct Size

Infarct is the dead tissue tissue that results from the interruption of blood flow to the heart. Infarct size is also a strong predictor of patient mortality and adverse cardiac-related events.

The PRECISE trial also demonstrated a statistically significant improvement in infarct size in the heart. Infarct size is also a strong predictor of patient mortality and adverse cardiac-related events.

Rigorous Research – How It Was Done

The PRECISE study recruited patients with chronic myocardial ischemia, a severe form of coronary artery disease.

In order to function properly, the heart needs an adequate blood supply.  In those patients with chronic myocardial ischemiaChronic Myocardial Ischemia or CMI is another term for chronic coronary artery disease, blood flow to the heart has been compromised for years.  This weakens the heart muscle and leads to heart failure.

In the PRECISE study:

1. Adipose tissue (fat) was obtained by liposuction from the patients’ own abdomens.
2. ADRCs (adipose derived stem and regenerative cells) were then extracted from the fat tissue.
3. Access to the heart was gained via an artery in the groin and;
4. The cells were delivered via catheter into areas of damaged heart muscle.

One third of the patients did not receive an injection of cells but rather a placebo, an inactive substance with no effect on the heart.  This group of patients is the control group.  They allow researchers to show, by comparison, if the injection of stem cells in the cardiac clinical trial is effective.

References

Karnath, B. (2002, November 15). Preoperative Cardiac Risk Assessment. In American Family Physician. Retrieved March 9, 2012, from http://www.aafp.org/afp/2002/1115/p1889.html.

Lee, D. et al. (2011). Long-Term Effects of Changes in Cardiorespiratory Fitness and Body Mass Index on All-Cause and Cardiovascular Disease Mortality in Men The Aerobics Center Longitudinal Study. In Circulation. Retrieved March 9, 2012, from http://circ.ahajournals.org/content/124/23/2483.abstract.

Florea, V. (2000). Prognostic value of changes over time in exercise capacity and echocardiographic measurements in patients with chronic heart failure. European Heart Journal, 21(2), 146- 153.

Mancini, D. et al. (n.d.). Value of peak exercise oxygen consumption for optimal timing of cardiac transplantation in ambulatory patients with heart failure. In PubMed. Retrieved March 9, 2012, from http://www.ncbi.nlm.nih.gov/pubmed/1999029.

Wu, E. et al. (2008, June). Infarct size by contrast enhanced cardiac magnetic resonance is a stronger predictor of outcomes than left ventricular ejection fraction or end-systolic volume index: prospective cohort study. In PubMed. Retrieved March 9, 2012, from http://www.ncbi.nlm.nih.gov/pubmed/18070953.