Research on genetics underlying atherosclerosis and coronary artery disease as well as new data on use of coronary stents are among major cardiology advances in 2007, according to the American Heart Association. Other major milestones included promising research on differentiation of myocytes from stem cells and a study on improved survival after modified cardiopulmonary resuscitation.

In 1996, the American Heart Association began compiling an annual list of the
top 10 major advances in heart disease and stroke research.

This year's top ten list follows:

1. Genome-wide association study of 14,000 cases of seven common diseases and 3,000 shared controls: Findings on atherosclerotic heart disease, coronary artery disease, hypertension, type 2 diabetes.

Genome-wide association studies identify genes that may cause specific diseases and represent a powerful approach in identifying genes involved in common human diseases. This large-scale study found consistent and replicable genetic markers for several complex diseases of adulthood, including atherosclerotic heart disease. Study authors said their analysis of some 17,000 people for seven common familial diseases (bipolar disorder, coronary artery disease, Crohn's disease, hypertension, rheumatoid arthritis, type 1 diabetes, and type 2 diabetes) confirms previously identified loci and provides strong evidence for many novel disease susceptibility genes.

Original publication: Nature, June 7, 2007; 447:661-678; http://www.nature.com.

2. Genome-wide association analysis of coronary artery disease.

This joint analysis used data from two genome-wide association studies of coronary artery disease. Researchers used genetic data for cases in the Wellcome Trust Case Control Consortium study (described above as Number 1) and tried to replicate the genetic patterning in another genome-wide association study - the German Myocardial Infarction Family Study. Results identified several genetic loci that, individually and in aggregate, substantially affect the risk of developing coronary artery disease.

Original publication: New England Journal of Medicine, Aug. 2, 2007; 357:443-453; http://www.nejm.org.

3. Cardiopulmonary resuscitation by bystanders with chest compression only (SOS-Kanto): an observational study.

This observational study represents the first meaningful chance to improve cardiopulmonary resuscitation in more than 50 years. Results indicate chest compression-only resuscitation by bystanders may be the preferable approach to resuscitation for adult patients with witnessed out-of-hospital cardiac arrest, especially those with apnea, shockable rhythm or short periods of untreated arrest.

Original publication: The Lancet, March 17, 2007; 369:920-926; http://www.thelancet.com.

4. Implementation of a statewide system for coronary reperfusion.

This U.S. study found that a statewide program focused on regional systems for quickly treating ST-elevation myocardial infarctions can significantly improve quality of care. The research sets the stage for collaborative, non-competitive care for patients in a region, expanding door-to-balloon initiatives into the community for a systems approach. The American Heart Association's Mission: Lifeline program, created to establish systems to provide emergency care for ST-elevation infarctions, promotes this strategy for improving patient care.

Original publication: Journal of the American Medical Association, Nov. 28, 2007; 298(20);2371-23809; http://www.jama.org.

5. Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP).

This was the first major trial to document that a reduced sodium intake lowers the risk of clinical cardiovascular disease outcomes, not just outcomes related to blood pressure.

Original publications: British Medical Journal, April 20, 2007; 334; 885.
http://www.bmj.com.

6. Optimal medical therapy with or without percutaneous coronary intervention for stable coronary artery disease (COURAGE).

The COURAGE trial compared the initial management strategy of percutaneous coronary intervention plus intensive pharmacologic therapy and lifestyle intervention (that is, optimal medical therapy) versus optimal medical therapy alone in reducing the risk of cardiovascular events. The authors concluded that, as an initial management strategy in patients with stable coronary artery disease, intervention did not reduce the risk of death, myocardial infarction or other major cardiovascular events when added to optimal medical therapy.

Original publication: New England Journal of Medicine, April 12, 2007; 35;(15);1503-1516; http://www.nejm.org.

7. Generation of functional cardiomyocytes from adult mouse spermatogonial
stem cells.
This study analyzed the complex functional properties of cardiomyocytes derived from adult mouse spermatogonial stem cells in vitro and the behavior of undifferentiated stem cells in normal hearts of mice in vivo after transplantation. The authors concluded that adult mouse spermatogonial stem cells provide a new source of distinct types of cardiomyocytes for basic research and potential therapeutic application.

Original publication: Circulation Research, June 8, 2007; 8;100(11):1615- 25; http://www.ahajournals.org.

8. HORIZONS: Harmonizing Outcomes with RevascularIZatiON and Stents.

The large HORIZONS study examined the safety and effectiveness of anticoagulation medications and drug-eluting stents in patients experiencing ST-elevation infarcts, without significantly increasing the rate of death or recurrent infarction among these patients.

Original presentation: Late-breaking trial at the Transcatheter Cardiovascular Therapeutics 2007; http://www.tct2007.com.

9. Effectiveness and safety of drug-eluting stents in Ontario.

This large Canadian study found that drug-eluting stents are effective in reducing the need for target-vessel coronary artery bypass in patients at highest risk for re-stenosis of previously blocked arteries, without a significantly increased rate of death or myocardial infarction.

Original publication: New England Journal of Medicine, Oct. 7, 2007; 14;357:1393-1402; http://www.nejm.org.

10. Underdiagnosis of Hypertension in Children and Adolescents.

This study of more than 14,000 children found that hypertension and prehypertension were often undiagnosed in the pediatric population. Patient age, height, obesity-related diagnoses, and magnitude and frequency of abnormal blood pressure readings all increased the odds of developing hypertension.

Original publication: Journal of the American Medical Association, Aug. 22, 2007; 298(8):874-879; http://www.jama.org.