Cardiologists at the University of Illinois Medical Center are using a new heart pump that can be inserted without the need for surgery and allows them to treat high-risk patients with a procedure to unblock their heart arteries.
The recently FDA-approved device was used to assist in three angioplasty procedures at the Medical Center last week.
Patients with the worst blockages are often the sickest, making it too dangerous to treat their coronary artery blockages with standard angioplasty or even with a bypass operation, says Dr. Adhir Shroff, assistant professor of cardiology at the UIC College of Medicine.
Shroff and his partners, Dr. Mladen Vidovich, assistant professor of cardiology, and Dr. John Kao, assistant professor of medicine, performed these procedures using the Abiomed Impella 2.5 ventricular assist device, which has been used only about 1,000 times in the country.
"Often these patients, who may have complicating conditions like cancer, renal failure, severe lung disease, or heart failure, are poor candidates for more invasive procedures like bypass surgery and are left with few options," said Shroff. "We only proceed with high-risk angioplasties after reviewing the patients with our heart surgeons."
Angioplasty is done by threading a thin, flexible tube, or catheter, into the coronary arteries through a small opening in a leg artery. It is much less invasive than open heart surgery, but has been largely restricted to managing low- to middle-risk patients.
The Impella heart pump makes it possible for cardiologists to offer the less invasive procedure to high-risk patients. "Our ability to continuously maintain blood flow will decrease complications during these high-risk cases where the patient had no other options to fix their heart arteries," Shroff said.
The Impella system uses a narrow catheter, which is threaded up from the groin, through the ascending aorta, and into the left ventricle. From this position, the Impella pumps blood from within the heart into the aorta, supplementing the weakened pumping of the patient's heart. The pump itself is smaller than a number-2 pencil eraser. Although it provides a large portion of the heart's work, it is silent and virtually imperceptible to the patient.
The Impella can be regulated during angioplasty to maintain blood flow, giving the physician the time needed to remove the blockage. If the patient needs further support, the Impella can be continued while the patient moves up to the ICU and until the heart is able to take on the task.
"We have created a seamless transition from the cath lab to the ICU," Shroff said. "We could not have done this without the collaboration of everyone who sees these patients as they move through the hospital, from the emergency room to the cath lab to the ICU. This exceptional effort on everyone's part, especially Nursing Services and the Cath Lab staff, allows UIC to offer the best possible care for patients with heart disease."
Source: University of Illinois at Chicago
5.11.09
19.8.09
World First New DeBakey VAD impanted in Heidelberg
At the end of July 2009, a team of cardiac surgeons headed by Professor Dr. Matthias Karck, Director of the Department of Cardiac Surgery at Heidelberg University Hospital, was the first in the world to implant the HeartAssist 5 ventricular assist device, the modern version of the DeBakey VAD. The device augments the pumping function of the left ventricle in an especially effective, gentle and quiet manner. The pump weighs 92 grams and is made of titanium and plastic. It pumps blood from the weakened or failed left ventricle into the aorta.
"Following the 3.5 hour surgery, the patient is doing fine," reports Professor Karck. The 50-year-old woman suffered from heart failure that could not be effectively treated with medication. Since a heart transplant was not an option due to medical reasons, the implanted heart pump will now assist her heart permanently.
Bridging the waiting time for a heart transplant
"The heart pump can also be used as a bridge-to-transplant while the patient waits for a matching donor heart," says Dr. Arjang Ruhparwar, senior registrar in the Department of Cardiac Surgery in Heidelberg. When a donor heart becomes available, the pump and the diseased heart are both removed and replaced by the new donor heart.
The DeBakey VAD was first developed in the 1990s in cooperation with NASA by Professor Michael DeBakey, the renowned American cardiac surgeon at the Baylor College of Medicine in Houston, who died in 2008 at the age of 99. The modern version of the device, the HeartAssist 5, is manufactured by US company MicroMed Cardiovascular. It is considered to be a fifth generation VAD because it can be implanted adjacent to the heart and has an exclusive flow probe that provides direct, accurate measurement of blood flow from the left ventricle to the aorta. The new miniature device is light, easy-to-handle and can be monitored and controlled externally.
Patients can live a normal life at home
"The new device has great advantages - at only 92 g, it is the smallest and lightest approved VAD in Europe that can completely replace the function of the left ventricle and it works very quietly and effectively with a high flow coefficient," explains Professor Karck. Thus, patients are able to live a nearly normal life at home.
In Europe, the HeartAssist 5™ has CE Marks for both adult and pediatric use. In the U.S., the HeartAssist 5, formerly DeBakey VAD® Child, is the only FDA-approved pediatric VAD. A bridge-to-transplant IDE clinical study is currently underway in the U.S. for adults.
Source:
Dr. Matthias Karck
University Hospital Heidelberg
29.7.09
Correct Placement Of Defibrillators Key To Effective Use
The appropriate placement of automated external defibrillators (AEDs) is critical to optimize their use in public places, according to two studies published in Circulation: Journal of the American Heart Association.
Sudden cardiac arrest is the sudden, abrupt loss of heart function. Without immediate bystander cardiopulmonary resuscitation (CPR), brain death and permanent death start to occur in just four to six minutes after someone experiences cardiac arrest. Cardiac arrest can be reversed by immediate bystander CPR and treatment within a few minutes with an electric shock to allow the heart to restore a normal heartbeat. More than 92 percent of out-of-hospital cardiac arrest victims don't survive to hospital discharge. In cities where bystander CPR and defibrillation is provided within 5 to 7 minutes, the survival rate from out-of-hospital sudden cardiac arrest is as high as 30 percent to 45 percent, according to the American Heart Association.
In one study, researchers found that school-based AED programs have a high rate of survival for students and others on school grounds.
Researchers found that 83 percent of 1,710 U.S. high schools with AED programs that they studied had an established emergency response plan for sudden cardiac arrest. However, only 40 percent practiced and reviewed their plans at least annually with potential school responders.
Of 36 cases of sudden cardiac arrests at the 1,710 schools:
94 percent received bystander CPR,
83 percent received an AED shock and
64 percent survived to hospital discharge including 9 of 14 student athletes and 14 of 22 non students.
Three factors - prompt recognition of sudden cardiac arrest, the presence of a trained rescuer to initiate CPR and access to early defibrillation through on-site AEDs - are critical to improving survival from sudden cardiac arrest in schools, said Jonathan A. Drezner, M.D., lead author of the study and associate professor and team physician in the Department of Family Medicine at the University of Washington-Seattle.
"It is not just about the AEDs - schools must have a comprehensive emergency response plan for sudden cardiac arrest that includes training anticipated responders in CPR and AED use, access to an AED, and practice and review of the response plan," Drezner said.
"It is crucial to recognize that AEDs permit early defibrillation not only in young athletes but also in other individuals who may experience an unexpected sudden cardiac arrest. We found that more than half of sudden cardiac arrest events reported in schools occur in adults working at the school or attending a school event. Schools are a strategic location for AED programs to serve large concentrations of people at risk for sudden cardiac arrest."
In a Danish study, researchers examined strategic placement of AEDs in public urban locations. A significant amount of interest and money is focused on AED deployment and public access defibrillation programs worldwide, but knowledge about where and how widespread AED deployment in the community should be is lacking, said Fredrik Folke, M.D., lead author of the study and a cardiology research fellow at Gentofte University Hospital, Hellerup, in Denmark.
To evaluate whether public AEDs were located where the majority of cardiac arrests occurred, Folke and colleagues digitally marked the exact locations of all arrests on a map and then analyzed the locations of 104 AEDs placed in municipal institutions in Copenhagen, Denmark, from 1994 through 2005. About 25 percent of out-of-hospital cardiac arrests occurred in public places.
According to the cardiac arrest analysis, carefully choosing AED coverage in 10 percent of the city area would provide coverage for about 67 percent of all cardiac arrests occurring in public. The highest rates of cardiac arrest in cities were in high-density public areas such as major train stations, large shopping centers, central bus terminals and sports centers.
"Our findings suggest that public access defibrillation programs should cover the greatest possible number of arrests in public, which is consistent with the recommendations from the American Heart Association," Folke said. "But if AED deployment in the community is driven by local or political initiatives and not on strategic AED placement, there is a high risk of AEDs being placed primarily in low-incidence areas of cardiac arrest and hence low likelihood of the AEDs ever being used."
Placing AEDs in about 10 percent of the city area cost an estimated $41,000 per extra year of a survivor's life - deemed "acceptable" by the researchers. However, unguided AED placement trying to cover the entire city had an estimated cost of $108,700 per extra life year.
In an accompanying editorial, Dianne L. Atkins, M.D., a pediatric cardiologist at the University of Iowa, wrote that the two "informative" studies demonstrate that the mere presence of an AED in the general area of an arrest does not guarantee success. Successful AED programs require immediate bystander CPR and non-equipment components in addition to AED-availability, she said.
"The need for ongoing CPR training, fully-developed and executed emergency plans and links to EMS are vital to the immediate and long-term outcomes of shock delivery," Atkins wrote.
Source:
Kate Lino
American Heart Association
23.6.09
Disparities In Arrhythmias Treatment Across Europe
The latest statistics regarding the use of pacemakers and implantable cardiac devices in Europe was presented on Sunday 21 June, at EUROPACE 2009, the meeting of the European Heart Rhythm Association (EHRA)1 which takes place in Berlin, Germany from 21 to 24 June.
"One of the roles of a European Association like the European Heart Rhythm Association (EHRA), a registered branch of the European Society of Cardiology (ESC), is to promote equal access to therapy for all patients across Europe. To do so, the first step is to compile data on the current situation in various ESC membership countries, compare them, and propose actions to move towards harmonization. The current leadership of EHRA agreed on the importance of obtaining as much current information as possible concerning the situation of the practice of electrophysiology in Europe" stressed Wolpert.
Under the leadership of Professors Christian Wolpert from Germany, Panos Vardas from Greece and Josep Brugada from Spain, a group worked to collect the most recent figures. To ensure up to date data, Presidents of the different Working Groups and National Societies were contacted and asked not only to provide data, but also to verify and authorize all the information that became available through various sources.
Wolpert declared that this data is also the point of comparison for the future: " By knowing where we are today, we will be able to benchmark in the future and see how diverse countries evolve. This means that this book must be an ongoing process, with updated information, new and additional data, and the inclusion of information from those countries that have not yet been able to collect and transmit their records."
Explaining the data, Prof Wolpert highlighted certain trends, such as the fact that "more and more, cardiologists represent the majority of implanters while surgeons are decreasingly active in these procedures."
There is a disparate coverage of diseases and treatments within the European Union and the European Society of Cardiology member countries outside of the EU. Some of the countries have no reimbursement e.g. for ICD or pacemaker therapy and the penetration of catheter ablation of atrial fibrillation is very different. Data shows big differences across ESC member countries in:
•Guideline implementation.
•The number of trained physicians and specialised centres
•The number of implantations which seems to depend not only on reimbursement and financial resources, but also to be a function of the number of centres and physicians dedicated to electrophysiology and implantation of devices.
•The numbers of ICD implanting centres range from less than 1 to 6.87 per million citizens.
•Pacemaker therapy is performed in the range of 88 to a maximum of around 1200/ million inhabitants.
•ICD implant rates including CRT-D devices range from approx. 2.5 to 354 per million inhabitants. The data shows an increase for a subset of 16 western and northern European countries around 15% from 2006 to 2007.
•Regarding a potentially different medical consensus in specific countries the use of biventricular pacemakers vs. biventricular ICDs shows a 8:1 ratio at the highest down to 1:1.2 ratio as the lowest.
•In the field of invasive electrophysiology and catheter ablation for supraventricular and ventricular arrhythmias the number of centres available is variable ranging from less than 0.2 to more than 3 centres/ million. The total number of catheter ablations is increasing and reaches a maximum of more than 200/ million in approx. half of the countries. However, there is a strong discrepancy comparing all 35 countries, displaying a wide range from less than 20 to more than 450/ million.
•The same is true for catheter ablation of atrial fibrillation which varies tremendously, linked to reimbursement policies but also to different approaches in the various EP societies.
"As an example, Germany, hosting the EUROPACE meeting this year, has one of the highest implant rates for ICD's in Europe with a total of 1037 centres which implant pacemakers; 200 centres implanting CRT resynchronisation devices and a total of 360 ICD implanting institutions" highlights Prof Wolpert.
"Within the Non-EU ESC member countries, there has been a steady increase of therapy availability and disease coverage, however, there are still many countries that struggle with reimbursement, trained personnel and technical support, which requires a strong effort and leaves much space for improvement. It is the task and the intention of EHRA to support any initiative to improve steadily the situation for these countries in order to reduce the disparities".
Source-Eurekalert
"One of the roles of a European Association like the European Heart Rhythm Association (EHRA), a registered branch of the European Society of Cardiology (ESC), is to promote equal access to therapy for all patients across Europe. To do so, the first step is to compile data on the current situation in various ESC membership countries, compare them, and propose actions to move towards harmonization. The current leadership of EHRA agreed on the importance of obtaining as much current information as possible concerning the situation of the practice of electrophysiology in Europe" stressed Wolpert.
Under the leadership of Professors Christian Wolpert from Germany, Panos Vardas from Greece and Josep Brugada from Spain, a group worked to collect the most recent figures. To ensure up to date data, Presidents of the different Working Groups and National Societies were contacted and asked not only to provide data, but also to verify and authorize all the information that became available through various sources.
Wolpert declared that this data is also the point of comparison for the future: " By knowing where we are today, we will be able to benchmark in the future and see how diverse countries evolve. This means that this book must be an ongoing process, with updated information, new and additional data, and the inclusion of information from those countries that have not yet been able to collect and transmit their records."
Explaining the data, Prof Wolpert highlighted certain trends, such as the fact that "more and more, cardiologists represent the majority of implanters while surgeons are decreasingly active in these procedures."
There is a disparate coverage of diseases and treatments within the European Union and the European Society of Cardiology member countries outside of the EU. Some of the countries have no reimbursement e.g. for ICD or pacemaker therapy and the penetration of catheter ablation of atrial fibrillation is very different. Data shows big differences across ESC member countries in:
•Guideline implementation.
•The number of trained physicians and specialised centres
•The number of implantations which seems to depend not only on reimbursement and financial resources, but also to be a function of the number of centres and physicians dedicated to electrophysiology and implantation of devices.
•The numbers of ICD implanting centres range from less than 1 to 6.87 per million citizens.
•Pacemaker therapy is performed in the range of 88 to a maximum of around 1200/ million inhabitants.
•ICD implant rates including CRT-D devices range from approx. 2.5 to 354 per million inhabitants. The data shows an increase for a subset of 16 western and northern European countries around 15% from 2006 to 2007.
•Regarding a potentially different medical consensus in specific countries the use of biventricular pacemakers vs. biventricular ICDs shows a 8:1 ratio at the highest down to 1:1.2 ratio as the lowest.
•In the field of invasive electrophysiology and catheter ablation for supraventricular and ventricular arrhythmias the number of centres available is variable ranging from less than 0.2 to more than 3 centres/ million. The total number of catheter ablations is increasing and reaches a maximum of more than 200/ million in approx. half of the countries. However, there is a strong discrepancy comparing all 35 countries, displaying a wide range from less than 20 to more than 450/ million.
•The same is true for catheter ablation of atrial fibrillation which varies tremendously, linked to reimbursement policies but also to different approaches in the various EP societies.
"As an example, Germany, hosting the EUROPACE meeting this year, has one of the highest implant rates for ICD's in Europe with a total of 1037 centres which implant pacemakers; 200 centres implanting CRT resynchronisation devices and a total of 360 ICD implanting institutions" highlights Prof Wolpert.
"Within the Non-EU ESC member countries, there has been a steady increase of therapy availability and disease coverage, however, there are still many countries that struggle with reimbursement, trained personnel and technical support, which requires a strong effort and leaves much space for improvement. It is the task and the intention of EHRA to support any initiative to improve steadily the situation for these countries in order to reduce the disparities".
Source-Eurekalert
18.6.09
Protecting Kidney Function During Heart Failure
• Mayo Clinic cardiology researchers have found a peptide that helps preserve and improve kidney function during heart failure, without affecting blood pressure. Earlier variations of this peptide caused blood pressure to drop limiting the potential benefits to the kidneys. The findings appear in the current Proceedings of the National Academy of Sciences.
"Heart failure itself and some of the approaches used to treat it can have detrimental effects on the kidneys," says Mayo cardiologist and lead researcher Robert Simari, M.D. "Our hope is that this compound will help protect kidney function while you're being treated, and possibly shorten your hospital stay and keep you out of the hospital."
This new peptide (a unique link of amino acids) has been tested in the laboratory and in animal models and is expected to move into clinical trials next year.
"One of the biggest additional concerns for patients with heart failure is the health of their kidneys," says Dr. Simari. "The extreme case is that it can lead to the kidneys shutting down completely." Nearly 5 million Americans are living with heart failure, a condition where the heart can't pump enough blood to meet the body's needs. Symptoms include shortness of breath, exercise intolerance and fluid retention. All can occur when heart function is impaired.
Seven Years of Research
The mapping of the human genome (2000-2003) revealed a gene that produces a protein called BNP (B-type natriuretic peptide). BNP was not only useful in diagnosing heart problems, it also proved therapeutic in treating heart failure. Unfortunately, says Dr. Simari, it had limited use because many heart failure patients experience low blood pressure and BNP lowered it further.
The Mayo investigators discovered an alternative splicing (AS) of BNP in messenger RNA (produced by the same gene). When they shortened the amino acid sequence of ASBNP for testing, they found that it had the same therapeutic benefits as BNP, but without the side effects to blood pressure. Positive impacts include increasing the kidney filtration rate, suppressing harmful protein production, and keeping water and salt flowing from the body. Potentially, this new drug would be given by IV to patients who are being treated in the hospital.
"There's an important reduction of kidney function every time one of these acute heart failure episodes happens," says Dr. Simari. "And by stopping one or more of those decrements, we hope there will be an overall improvement in long-term maintenance of kidney function."
Others on the team include Shuchong Pan, M.D., Ph.D., Horng Chen, M.D., Guido Boerrigter, M.D., Candace Lee, Laurel Kleppe, Amir Lerman, M.D., Margaret Redfield, M.D., John Burnett, Jr., M.D., all from Mayo Clinic, and Deborah Dickey, Ph.D., Jennifer Hall, Ph.D., and Lincoln Potter, Ph.D., all from the University of Minnesota. The research was funded by Mayo Clinic, the National Institutes of Health, and Anexon, Inc.
Mayo Clinic and five of the investigators associated with this research have a financial interest in the technology studied in the research. In accordance with the Bayh-Dole Act, that technology has been licensed to Anexon. Mayo Clinic and Drs. R. Simari and Dr. S. Pan have received royalties from the licensing of that technology of greater than the federal threshold for significant financial interest. Drs. J.Burnett, M.Redfield and H.Chen have received royalties less than the federal threshold for significant financial interest. In addition, Mayo Clinic holds an equity position in Anexon.
Source
Mayo Clinic
"Heart failure itself and some of the approaches used to treat it can have detrimental effects on the kidneys," says Mayo cardiologist and lead researcher Robert Simari, M.D. "Our hope is that this compound will help protect kidney function while you're being treated, and possibly shorten your hospital stay and keep you out of the hospital."
This new peptide (a unique link of amino acids) has been tested in the laboratory and in animal models and is expected to move into clinical trials next year.
"One of the biggest additional concerns for patients with heart failure is the health of their kidneys," says Dr. Simari. "The extreme case is that it can lead to the kidneys shutting down completely." Nearly 5 million Americans are living with heart failure, a condition where the heart can't pump enough blood to meet the body's needs. Symptoms include shortness of breath, exercise intolerance and fluid retention. All can occur when heart function is impaired.
Seven Years of Research
The mapping of the human genome (2000-2003) revealed a gene that produces a protein called BNP (B-type natriuretic peptide). BNP was not only useful in diagnosing heart problems, it also proved therapeutic in treating heart failure. Unfortunately, says Dr. Simari, it had limited use because many heart failure patients experience low blood pressure and BNP lowered it further.
The Mayo investigators discovered an alternative splicing (AS) of BNP in messenger RNA (produced by the same gene). When they shortened the amino acid sequence of ASBNP for testing, they found that it had the same therapeutic benefits as BNP, but without the side effects to blood pressure. Positive impacts include increasing the kidney filtration rate, suppressing harmful protein production, and keeping water and salt flowing from the body. Potentially, this new drug would be given by IV to patients who are being treated in the hospital.
"There's an important reduction of kidney function every time one of these acute heart failure episodes happens," says Dr. Simari. "And by stopping one or more of those decrements, we hope there will be an overall improvement in long-term maintenance of kidney function."
Others on the team include Shuchong Pan, M.D., Ph.D., Horng Chen, M.D., Guido Boerrigter, M.D., Candace Lee, Laurel Kleppe, Amir Lerman, M.D., Margaret Redfield, M.D., John Burnett, Jr., M.D., all from Mayo Clinic, and Deborah Dickey, Ph.D., Jennifer Hall, Ph.D., and Lincoln Potter, Ph.D., all from the University of Minnesota. The research was funded by Mayo Clinic, the National Institutes of Health, and Anexon, Inc.
Mayo Clinic and five of the investigators associated with this research have a financial interest in the technology studied in the research. In accordance with the Bayh-Dole Act, that technology has been licensed to Anexon. Mayo Clinic and Drs. R. Simari and Dr. S. Pan have received royalties from the licensing of that technology of greater than the federal threshold for significant financial interest. Drs. J.Burnett, M.Redfield and H.Chen have received royalties less than the federal threshold for significant financial interest. In addition, Mayo Clinic holds an equity position in Anexon.
Source
Mayo Clinic
2.1.09
CAFE-LLA: Statin Therapy Does Not Influence Central Aortic Pressure or Hemodynamics
December 31, 2008 (Leicester, United Kingdom) — The use of statin therapy in hypertensive patients has no impact on central aortic pressures, pulse-wave augmentation, the augmentation index, pressure amplification, or any other central hemodynamic parameter [1].
These are the findings of the Conduit Artery Function Evaluation-Lipid-Lowering Arm (CAFE-LLA) study, a large-scale, placebo-controlled substudy of the Anglo-Scandinavian Cardiac Outcomes Trial-Lipid Lowering Arm (ASCOT-LLA) designed to prospectively evaluate the effect of statin therapy on the relationship between brachial and central aortic pressures.
Publishing their findings online December 22, 2008 in Circulation, lead investigator Dr Bryan Williams (University of Leicester, UK) and colleagues state that the "favorable effects of statins in cardiovascular outcomes in hypertensive patients are via mechanisms that are independent of important effects on large-artery function and central pressure."
Looking at Large-Artery Function in ASCOT
Because statins reduce the risk of cardiovascular events in individuals with hypertension, there has been interest in the hypothesis that the lipid-lowering drugs modulate large-artery function and central aortic pressures independent of cholesterol lowering. With this in mind, the researchers assessed the effects of atorvastatin 10 mg daily in 891 patients enrolled in ASCOT-LLA.
Patients were, on average, 63 years old and enrolled in ASCOT if they had untreated hypertension or treated hypertension >140/90 mm Hg and three cardiovascular risk factors but no history of coronary heart disease. To be eligible for ASCOT-LLA, patients had to have total cholesterol concentrations <250 mg/dL and be untreated with any lipid-lowering medication.
After six months, treatment with atorvastatin reduced LDL cholesterol by 32 mg/dL and total cholesterol by 35 mg/dL from baseline, a relative reduction of approximately 33% and 25%, respectively, compared with placebo.
Despite the reductions in LDL- and total-cholesterol levels, atorvastatin did not have any effect on central aortic blood pressure or various hemodynamic measurements. Time-averaged brachial blood pressure was similar in the placebo and atorvastatin-treatment arms, as was the change in aortic-pulse pressure. The augmentation index and heart rate were also unaltered with statin therapy compared with placebo.
"The results of CAFE-LLA are unequivocal," write Williams and colleagues. The clinical-outcome benefits of atorvastatin in treated hypertensive patients are not mediated by direct effects on central aortic pressure and hemodynamics, they write.
Too Little, Too Late, and Too Short
In an editorial accompanying the published study [2], Drs Michel Safar, Athanase Protogerou, and Jacque Blacher (Hotel-Dieu Centre de Diagnostique et Thérapeutique, Paris, France) suggest that the results of the study are surprising, "because arterial stiffening and atherosclerosis, although different diseases, have overlapping processes due to common cardiovascular risk factors and complications."
The editorialists note that several studies have shown, although the results are not entirely consistent, that statins have a beneficial effect on central aortic stiffness, possibly because of pleiotropic effects on atherosclerotic plaques, such as improved endothelial function and increased nitric-oxide bioavailability. The negative results of CAFE-LLA might be partly attributed to a lack of power to evaluate hemodynamic outcomes, but for the most part, they say the findings are a case of "too little, too late, too short."
For example, the 10-mg statin dose used in CAFE-LLA might be too low. Although the dose was chosen because baseline cholesterol levels were only modestly elevated, previous studies have shown reductions of aortic stiffness with higher doses of statins, up to 80 mg of atorvastatin. Regarding too late, vascular damage might have already been established in these patients, given that their age was 63 years upon study entry. And finally, too short, in that longer follow-up is needed to observe significant pressure-independent effects on central hemodynamics.
In their paper, Williams and colleagues echo many of these possible explanations in reconciling the differences between large-artery function, hemodynamics, and plasma cholesterol reductions.
Although CAFE-LLA was not powered to assess statin-mediated differences in central pressures and hemodynamics relative to clinical outcomes, the researchers note that atorvastatin in ASCOT-LLA was associated with significant reductions in cardiovascular events compared with placebo.
Williams B, Lacy PS, Cruickshank JK, et al. Impact of statin therapy on central aortic pressures and hemodynamics. Circulation 2009; 119:53-61. Abstract
Safar ME, Protogerou AD, Blacher J. Statins, central blood pressure, and blood pressure amplification. Circulation 2009; 119:9-12. Abstract
The complete contents of Heartwire, a professional news service of WebMD, can be found at www.theheart.org, a Web site for cardiovascular healthcare professionals.
Source: Heartwire/Medscape
These are the findings of the Conduit Artery Function Evaluation-Lipid-Lowering Arm (CAFE-LLA) study, a large-scale, placebo-controlled substudy of the Anglo-Scandinavian Cardiac Outcomes Trial-Lipid Lowering Arm (ASCOT-LLA) designed to prospectively evaluate the effect of statin therapy on the relationship between brachial and central aortic pressures.
Publishing their findings online December 22, 2008 in Circulation, lead investigator Dr Bryan Williams (University of Leicester, UK) and colleagues state that the "favorable effects of statins in cardiovascular outcomes in hypertensive patients are via mechanisms that are independent of important effects on large-artery function and central pressure."
Looking at Large-Artery Function in ASCOT
Because statins reduce the risk of cardiovascular events in individuals with hypertension, there has been interest in the hypothesis that the lipid-lowering drugs modulate large-artery function and central aortic pressures independent of cholesterol lowering. With this in mind, the researchers assessed the effects of atorvastatin 10 mg daily in 891 patients enrolled in ASCOT-LLA.
Patients were, on average, 63 years old and enrolled in ASCOT if they had untreated hypertension or treated hypertension >140/90 mm Hg and three cardiovascular risk factors but no history of coronary heart disease. To be eligible for ASCOT-LLA, patients had to have total cholesterol concentrations <250 mg/dL and be untreated with any lipid-lowering medication.
After six months, treatment with atorvastatin reduced LDL cholesterol by 32 mg/dL and total cholesterol by 35 mg/dL from baseline, a relative reduction of approximately 33% and 25%, respectively, compared with placebo.
Despite the reductions in LDL- and total-cholesterol levels, atorvastatin did not have any effect on central aortic blood pressure or various hemodynamic measurements. Time-averaged brachial blood pressure was similar in the placebo and atorvastatin-treatment arms, as was the change in aortic-pulse pressure. The augmentation index and heart rate were also unaltered with statin therapy compared with placebo.
"The results of CAFE-LLA are unequivocal," write Williams and colleagues. The clinical-outcome benefits of atorvastatin in treated hypertensive patients are not mediated by direct effects on central aortic pressure and hemodynamics, they write.
Too Little, Too Late, and Too Short
In an editorial accompanying the published study [2], Drs Michel Safar, Athanase Protogerou, and Jacque Blacher (Hotel-Dieu Centre de Diagnostique et Thérapeutique, Paris, France) suggest that the results of the study are surprising, "because arterial stiffening and atherosclerosis, although different diseases, have overlapping processes due to common cardiovascular risk factors and complications."
The editorialists note that several studies have shown, although the results are not entirely consistent, that statins have a beneficial effect on central aortic stiffness, possibly because of pleiotropic effects on atherosclerotic plaques, such as improved endothelial function and increased nitric-oxide bioavailability. The negative results of CAFE-LLA might be partly attributed to a lack of power to evaluate hemodynamic outcomes, but for the most part, they say the findings are a case of "too little, too late, too short."
For example, the 10-mg statin dose used in CAFE-LLA might be too low. Although the dose was chosen because baseline cholesterol levels were only modestly elevated, previous studies have shown reductions of aortic stiffness with higher doses of statins, up to 80 mg of atorvastatin. Regarding too late, vascular damage might have already been established in these patients, given that their age was 63 years upon study entry. And finally, too short, in that longer follow-up is needed to observe significant pressure-independent effects on central hemodynamics.
In their paper, Williams and colleagues echo many of these possible explanations in reconciling the differences between large-artery function, hemodynamics, and plasma cholesterol reductions.
Although CAFE-LLA was not powered to assess statin-mediated differences in central pressures and hemodynamics relative to clinical outcomes, the researchers note that atorvastatin in ASCOT-LLA was associated with significant reductions in cardiovascular events compared with placebo.
Williams B, Lacy PS, Cruickshank JK, et al. Impact of statin therapy on central aortic pressures and hemodynamics. Circulation 2009; 119:53-61. Abstract
Safar ME, Protogerou AD, Blacher J. Statins, central blood pressure, and blood pressure amplification. Circulation 2009; 119:9-12. Abstract
The complete contents of Heartwire, a professional news service of WebMD, can be found at www.theheart.org, a Web site for cardiovascular healthcare professionals.
Source: Heartwire/Medscape
24.9.08
Sucking Out a Coronary Thrombus Before Stenting Seems Worthwhile
Previous work in The Netherlands has shown that percutaneous coronary intervention (PCI) can induce embolization of atherothrombotic material with resulting impaired myocardial reperfusion, and that thrombus aspiration before stenting can prevent this effect.
In this study, reported in The Lancet in 2008,[1] 12 investigators analyzed, by intention to treat, cardiac death or nonfatal myocardial reinfarction after 1 year in 1060 randomized patients.
In the group treated by conventional PCI, 6.7% suffered cardiac death vs only 3.6% in the thrombus aspiration group; the data for cardiac death or nonfatal reinfarction after 1 year were 5.6% vs 9.9%.
The intuitively sensible action of aspirating thrombus in acute myocardial infarction prior to stenting is supported by data.
This article is selected from Medscape Best Evidence. Dr George Lundberg.
In this study, reported in The Lancet in 2008,[1] 12 investigators analyzed, by intention to treat, cardiac death or nonfatal myocardial reinfarction after 1 year in 1060 randomized patients.
In the group treated by conventional PCI, 6.7% suffered cardiac death vs only 3.6% in the thrombus aspiration group; the data for cardiac death or nonfatal reinfarction after 1 year were 5.6% vs 9.9%.
The intuitively sensible action of aspirating thrombus in acute myocardial infarction prior to stenting is supported by data.
This article is selected from Medscape Best Evidence. Dr George Lundberg.
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