Promising Basic Science, New Devices, Improved Protocols & Prevention Hold the Potential to Upgrade Outcomes
The science, basic understanding, and treatment protocols of cardiovascular disease and stroke have come light years in a matter of decades. Yet, heart disease remains the number one killer of both men and women in America and stroke, a leading cause of disability.
The 2013 statistical update from the Centers for Disease Control and Prevention (CDC), American Heart Association (AHA) and National Institutes of Health (NIH) notes that approximately 600,000 people die from heart disease in the United States each year … one of every four deaths. Additionally, more than 900,000 Americans have a heart attack each year, with roughly one-third of those occurring in someone who has had at least one prior heart attack.
More than 795,000 Americans suffer a stroke annually. While mortality rates have improved, nearly one in every 18 deaths is still attributable to stroke. Furthermore, stroke remains a primary cause for serious long-term disability and costs the United States an estimated $54 billion annually.
Statistics on the spectrum of cardiovascular behaviors and disease states among varied populations are available for download through the AHA journal Circulation (http://circ.ahajournals.org/content/127/1/e6). Data is also accessible through the AHA’s website for healthcare professionals and researchers at www.myamericanheart.org.
While turning the tide on America’s top killer remains a daunting task, researchers have much to celebrate when it comes to improved treatments, earlier detection and better options for primary and secondary prevention. Since 1949, the AHA has spent more than $3.4 billion on research to increase the understanding of heart disease and stroke.
Each November, that knowledge is showcased at the organization’s Scientific Sessions … and each December since 1996, the AHA has compiled a list of top 10 advances from the year. For 2012, resuscitation, cell regeneration, a new high blood pressure treatment and developments in stroke devices were listed among the year’s key scientific findings.
Extended CPR Saves Lives
How long should medical personnel attempt resuscitation before terminating efforts during in-hospital cardiac arrests? Perhaps longer than you’d think. A study of hospitals using the Get With The Guidelines resuscitation quality improvement program found higher survival rates among cardiac arrest patients who received CPR for longer times compared to those hospitals with shorter duration rates.
At 435 U.S. hospitals within the GWTG-Resuscitation registry, researchers identified more than 64,000 patients who suffered cardiac arrest between 2000 and 2008. Overall, the median duration of resuscitation efforts was 12 minutes for patients achieving spontaneous return to circulation compared to 20 minutes for non-survivors. However, patients at the hospitals with the longest median duration of 25 minutes for resuscitation efforts had a 12 percent higher likelihood of being revived than those at hospitals with the shortest median time of 16 minutes.
While more research is needed to provide definitive answers, the study raises interesting questions that could change standard medical practice.
(The Lancet, vol. 280, issue 9852, Oct. 27, 2012, Goldberger, et al.)
Converting ‘Non-Beating’ Heart Cells into ‘Beating’ Ones
The emerging frontier of myogenesis holds great promise that damaged or lost heart muscle due to congenital defects, heart attack or other disease might one day be replaced. Two studies in mouse models published in 2012 demonstrated methods to reprogram readily available cardiac fibroblasts into beating heart muscle cells in vivo. The authors concluded their findings suggest a potential regenerative strategy in the human heart of reprogramming non-cardiomyocytes using cardiogenic transcription factors or other molecules into cardiomyocte-like cells.
(Nature, vol. 485, April 18, 2012, pp. 593-598, Qian, et al and pp. 599-604, Song, et al.)
Biopsied Heart Cells
Two separate human trials showed that cells from heart biopsies could be purified and replaced in the patient’s heart with improved heart function and reduced scarring.
In the phase 1 trial using an intracoronary infusion of autologous cardiac stem cells, patients receiving the CSCs typically had improved LV systolic function and reduced infarct size.
In the second phase 1 trial (randomized CArdiosphere-Derived aUtologous stem CELLs to reverse ventricUlar dysfunction – CADUCEUS), patients were enrolled 2-4 weeks after myocardial infarction with left ventricular ejection fraction of 25-45 percent. In comparison with the control group at six months, those receiving infused CDCs showed reduction in scar mass, increases in viable hart mass and regional contractility, and regional systolic wall thickening. However four patients (24 percent) in the CDC group had serious adverse events compared to one (13 percent) in the control group, and there were not notable differences in end-diastolic volume, end-systolic volume and LVEF between the two groups at six months.
(The Lancet, vol. 378, issue 9806, Nov. 26, 2011, Bolli, et al. and vol. 379, issue 9819, March 10, 2012, Makkar, et al.)
‘Disconnecting’ the Kidneys to Treat Hypertension
A hyperactive sympathetic nervous system is believed to be a major contributor to hypertension. Four recent studies have concluded that renal denervation is a safe and effective means of lowering high blood pressure that has proven to be resistant to other treatments.
The Simplicity HTN-1 investigators followed 153 patients treated with catheter-based renal sympathetic denervation at 19 centers in Australia, Europe and the United States for two years. Post-procedure office blood pressure readings were reduced by 20/10 at 1 month, 25/11 at 6 months, 26/14 at 18 months and 32/14 at 24 months without significant adverse events. Studies out of the Netherlands, Germany and Belgium had similar findings.
(Simplicity HTN-1, Hypertension, vol. 57, p. 911, March 14, 2011)
Pediatric Progress in Transplant Bridging, Kawasaki Disease
A U.S. study highlighted a new procedure to dramatically extend the life of children under the age of 16 awaiting a heart transplant. Traditionally, the children would have been placed on an ECMO device, but the study showed the smaller ventricular assist device (VAD) might buy significantly more time for these children.
At best, ECMO, which is highly restrictive and almost always requires children to be completely anesthetized, has given children a few extra weeks of survivability. The smaller Excor pediatric VAD (Berlin Heart) usually allows children to be taken off mechanical ventilation, get out of bed and move around, eat normally and take part in physical therapy.
The study’s lead author, Charles Fraser, Jr., MD, surgeon-in-chief at Texas Children’s Hospital, noted that in one group, in which the average age was 1 year, the longest duration on the pediatric VAD was 174 days compared with 21 days among previous heart failure patients with similar disease and severity on ECMO. In the second group, average age of 9, the longest duration was 192 days compared with 28 days on ECMO.
A Japanese study found a new, highly effective treatment to prevent coronary abnormalities in children suffering from the rare but fatal autoimmune disorder Kawasaki disease, which causes inflammation and long-term damage to blood vessels. In the randomized study, the experimental group of 125 patients received prednisone in addition to the standard intravenous immunoglobulin given to the 123 children in the control group. Incidence of coronary artery abnormalities was significantly lower in the group that also received prednisone (3 percent vs. 23 percent in the control group).
(New England Journal of Medicine, vol. 367, p. 532, Aug. 9, 2012, Fraser, et al. and The Lancet, vol. 379, issue 9826, April 28, 2012, Kobayashi, et al.)
Say ‘No’ to Sugary Drinks
Two clinical trials in 2012 provided definitive evidence of what was intuitively known … consuming sugar-sweetened beverages is linked to overweight and obesity. Randomized controlled studies out of the Netherlands and United States both found reducing the consumption of sugar-sweetened beverages reduced or slowed weight gain and fat accumulation in children and adolescents.
The Massachusetts study was conducted among overweight and obese adolescents and included a one-year active intervention in the experimental group (provision of non-caloric beverages) followed by a second year of follow-up with no intervention. After the first year, there were significant differences in weight and BMI between the two groups. However, after the second year without the intervention, those differences had almost vanished.
(New England Journal of Medicine, vol. 367, p. 1397, October 11, 2012, de Ruyter, et al. and vol. 367, p. 1407, Sept. 21, 2012, Ebbeling, et al.)
Global Health Impact of ECHO Screening
Rheumatic heart disease is a global health issue effecting more than 15 million. Particularly hard hit are those in Africa, Asia and the Pacific. Using ECHO screening in a clinical trial in Uganda caught three times as many children with rheumatic heart disease than the traditional use of a stethoscope only.
(Circulation, vol. 125, p. 3127, June 26, 2012, Beaton, et al.)
New Stroke Devices
Clinical trials for stroke patients found two new improvements and one traditional method to be preferential. The SOLITAIRE and TREVO devices were found to be more effective at clearing blocked blood vessels in the brain than the MERCI device. However, the randomized, multicenter CLOSURE trial found that percutaneous devices used to close small holes between the upper chambers of the heart in cryptogenic stroke patients and those presenting with a transient ischemic attack who had a patent foramen ovale didn’t prevent subsequent strokes any better than less invasive standard medical therapy.
(CLOSURE, New England Journal of Medicine, vol. 366, p. 991, March 15, 2012, Furlan, et al.)
Benefits of Ideal Cardiovascular Health
Two studies in 2012 highlighted the huge impact of modifying behaviors to decrease the risk of heart disease and stroke.
Ideal cardiovascular health is determined by seven components — not smoking, getting regular exercise, consuming a healthy diet, and achieving normal ranges for body mass index, cholesterol, blood pressure and blood glucose. The CDC’s 2012 statistics note that about half of all Americans (49 percent) have at least one of three key risk factors for heart disease — high blood pressure, high LDL cholesterol readings, or tobacco use.
In a meta analysis using data from 18 cohort studies led by Jarett D. Berry, MD, of UT Southwestern Medical Center in Dallas, researchers found marked lifetime risk differences for those with an optimal risk-factor profile that held true across gender and race. For 55-year-old men who achieved ideal cardiovascular health, the risk of death from cardiovascular disease through age 80 compared to those who had two or more of the major risk factors was 4.7 percent vs. 29.6 percent. For women, the risk was 6.4 percent vs. 20.5 percent. Those with optimal cardiovascular health also had a dramatically lower risk of fatal coronary heart disease, nonfatal heart attack and fatal or nonfatal stroke.
In the second study led by Earl Ford, MD, of the CDC, researchers found “the number of ideal metrics was significantly and inversely related to mortality from all causes and diseases of the circulatory system.” Compared to those who met none of the seven ideal metrics, those who met five or more had a 78 percent reduction in risk for all-cause mortality and an 88 percent reduction in risk of death from circulatory diseases.
(New England Journal of Medicine, vol. 366, p. 321, Jan. 26, 2012, Berry, et al. and Circulation, vol. 125, p. 987, Feb. 28, 2012, Ford, et al.)
Bypass vs. Drug-Coated Stents for Diabetics
A large clinical trial found diabetic patients with multiple clogged arteries, who represent about 25 percent of all patients undergoing cardiac procedures in cath labs, fared significantly better when treated with bypass surgery than with drug-coated stents. The bypass group was less likely to die or have a heart attack within five years compared to those receiving drug-coated stents.
However, other researchers have pointed out the statistics for this trial were mainly gathered from diabetics with triple vessel disease and that additional research needs to be conducted on diabetic patients with single or double vessel disease.
(FREEDOM Trial, New England Journal of Medicine, vol. 367, p. 2375, Dec. 20, 2012, Farkouh, et al.)