Dr. Joe talks about the BPro (by HealthStats), its accuracy, output readings and blood pressure.

Study suggests excess angiograms, which carry stroke, heart attack risk

 
NEW YORK – A troublingly high number of U.S. patients who are given angiograms to check for heart disease turn out not to have a significant problem, according to the latest study to suggest Americans get an excess of medical tests.

The researchers said the findings suggest doctors must do better in determining which patients should be subjected to the cost and risks of an angiogram. The test carries a small but real risk — less than 1 percent — of causing a stroke or heart attack, and also entails radiation exposure.

“We can do better. There is no doubt in my mind,” said Dr. Ralph Brindis of the University of California, San Francisco , one of the study’s authors.

Every year in the United States, more than a million people get an angiogram, in which a thin tube is inserted in the arm or groin and threaded up to the heart to check for blocked arteries that could lead to a heart attack. Dye is injected through the tube to make blockages show up on X-rays.

‘We fear doing too little’
Angiograms are often given to patients who might be having a heart attack or have symptoms that suggest a serious blockage. They are also sometimes done on people who may have some less clear-cut symptoms, like shortness of breath, or no symptoms but some risky traits like high cholesterol and an abnormal result on another heart test. This group accounts for about 20 to 30 percent of angiogram cases.

In the study, nearly two-thirds of the patients in this second group were found to have no serious blockages.

The researchers could not establish why so few proved to have heart disease. But Dr. Harlan Krumholz, a Yale cardiologist and health-outcomes researcher unconnected to the study, said he thinks the problem arises because doctors are afraid of missing something, and also getting sued.

“We fear doing too little,” he said. “I think that we developed a culture where people feel that doing more and knowing more is always the proper course. What that does is sometimes lead us to overuse.”

Researchers said more study is needed to sort out how to better select patients for an angiogram. For now, experts suggest patients in the category studied by the researchers question their doctors about the need for the test and the risks and alternatives.

Who really needs the exam?
To decide whether someone needs an angiogram, a doctor assesses a patient’s medical status and symptoms, and usually tries a noninvasive test, such as an ultrasound of the heart or having the patient run on a treadmill. It is this gatekeeper process that needs improvement, researchers suggested in Thursday’s issue of the New England Journal of Medicine.

They sifted through records of nearly 2 million angiograms performed at 663 U.S. hospitals between 2004 and April 2008. The data came from a registry kept by the American College of Cardiology, which sponsored the study.

The researchers focused on about 400,000 patients who raised doctors’ suspicions but had no known heart disease and weren’t getting emergency heart treatment.

In those people, the test revealed no significant artery blockages 62 percent of the time. That doesn’t mean all those tests were unnecessary, but the rate is high enough to suggest doctors could do a better job of choosing who really needs the exam, researchers said.

The researchers suggested doctors should be less willing to order an angiogram for symptom-free patients, a group that made up 30 percent of the study sample.

Beyond that, further study might help doctors better gauge heart disease risk from a patient’s symptoms and characteristics like age and history of other diseases, said lead author Dr. Manesh Patel of Duke University .

Doctors could also use more research to help them choose the right noninvasive test, which might reduce the need for angiograms, he said.

Choices now include the treadmill test, injecting a radioactive solution to trace blood flow within the heart, doing an ultrasound to watch the walls of the heart moving, and doing a specialized CT scan that has recently shown promise.

 “We still haven’t figured out, in all honesty, the best way of applying these technologies,” Brindis said.

In fact, one of the study’s co-authors — Dr. Pamela Douglas of Duke — just received a $32.5 million federal grant, the largest ever for heart imaging, to compare various heart imaging tests and see which ones do the most to prevent heart attacks, deaths and hospitalization.

Experts praised Patel’s study.

Some previous reports have found similar results, but the new study is so huge “we can now feel comfortable these aren’t isolated findings, this is for real,” said Dr. Michael Lauer, director of the division of cardiovascular sciences at the National Heart, Lung and Blood Institute.

Taken from MSNBC.com at http://www.msnbc.msn.com/id/35802585/ns/health-heart_health/

BPro (by HealthStats): A Cardio Pulse Wave Analyzer – science and research

Below are a number of scientific research articles on Cardio Pulse Wave analysis technology. Although it is only a sample of the vast amount of research, it will give you some a good idea of what research is available.

Pulse wave analysis: from the basic sciences to clinical applications

Is there any additional prognostic value of central blood pressure wave forms beyond peripheral blood pressure?

Pulse wave analysis and arterial stiffness.

Noninvasive measurements of central arterial pressure and distensibility by arterial applanation tonometry with a generalized transfer function: implications for nursing.

Arterial stiffness and stroke in hypertension: therapeutic implications for stroke prevention.

Antihypertensive therapy and wave reflections

Analyzing the radial pulse waveform: narrowing the gap between blood pressure and outcomes.

Assessment of outcomes other than systolic and diastolic blood pressure: pulse pressure, arterial stiffness and heart rate.

Systolic blood pressure, pulse pressure and arterial stiffness as cardiovascular risk factors.

Central arterial pressure and arterial pressure pulse: new views entering the second century after Korotkov.

Pulse wave analysis and pulse wave velocity: a review of blood pressure interpretation 100 years after Korotkov.

Mechanical principles. Arterial stiffness and wave reflection.

Arterial pressure waveforms in hypertension.

Pulse wave analysis.

Aortic pulse wave velocity: an independent marker of cardiovascular risk.

Arterial stiffness and cardiovascular outcome.

The indirect assessment of arterial compliance in hypertension patients by tonometric sphygmography

Measurement of pulse wave “augmentation index (AI) “and its clinical application

Arterial stiffness and wave reflection in hypertension: pathophysiologic and therapeutic implications.

Pulse wave analysis in the assessment of patients with left ventricular assist device.

Large-artery stiffness, hypertension and cardiovascular risk in older patients.

Effect of antihypertensive agents on arterial stiffness as evaluated by pulse wave velocity: clinical implications

Mechanisms, pathophysiology, and therapy of arterial stiffness.

Arterial elasticity in cardiovascular disease: focus on hypertension, metabolic syndrome and diabetes.

Pulse Wave Velocity Is an Independent Predictor of the Longitudinal Increase in Systolic Blood Pressure and of Incident Hypertension in the Baltimore Longitudinal Study of Aging

Noninvasive assessment of arterial stiffness and risk of atherosclerotic events.

Clinical value of the study of stiffness of arterial wall. Part I

Arterial hemodynamics and pulse wave propagation

Arterial compliance (stiffness) as a marker of subclinical atherosclerosis

Arterial stiffness in diabetes and the metabolic syndrome: a pathway to cardiovascular disease.

Influence of arterial pulse and reflected waves on blood pressure and cardiac function.

Clinical measurement of arterial stiffness obtained from noninvasive pressure waveforms.

Effects of arterial stiffness, pulse wave velocity, and wave reflections on the central aortic pressure waveform.

BPro (by HealthStats): A Cardio Pulse Wave Analyzer – medical device information

When you go to the following link below it will take you to the governments FDA site that has the document showing the registration of the BPro (which is the BPro and A-Pulse software (by HealthStats) as found in this document): A Cardio Pulse Wave Analyzer  as a class II medical device. Please click on the link below to find this document:

http://www.accessdata.fda.gov/cdrh_docs/pdf7/K072593.pdf

Commentary on the Conduit Artery Function Evaluation (CAFE) Study

^{(Full original article with notations, references and links found here: http://www.circ.ahajournals.org/cgi/content/full/113/9/1162)}

Suzanne Oparil, MD; Joseph L. Izzo, Jr, MD

From the Vascular Biology and Hypertension Program (S.O.), Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, and Erie County Medical Center and the Division of Clinical Pharmacology (J.L.I.), Department of Medicine, State University of New York at Buffalo School of Medicine and Biomedical Sciences, Buffalo, NY.

Correspondence to Suzanne Oparil, MD, Vascular Biology and Hypertension Program, University of Alabama at Birmingham, 703 19th St S, ZRB 1034, Birmingham, AL 35294-0007.

Nearly everything that modern practicing clinicians know about hypertension and its treatment is based on simple noninvasive measurement of brachial artery blood pressure. As the study by Williams and colleagues¹ illustrates, however, additional knowledge of pulse-wave characteristics may be important in the future to fully assess optimal cardiovascular drug therapy.

The study of pulse-wave characteristics is far older than the study of absolute pressure values, dating back thousands of years to the Chinese masters who used their fingertips and their powers of observation to associate “hardening of the pulse” with adverse outcomes in people who ingested too much salt. These qualitative observations were less well developed in Western medicine, but as early as the 1870s, the sphygmocardiogram was developed as a reproduction of a peripheral pulse wave on a rotating drum via a tonometer attached to a levered stylus.^1a Morrell and other early investigators were clearly able to differentiate the effects of nitrovasodilators from digitalis using this early equipment, but interpretations remained largely qualitative. Within a few decades, the development of sphygmomanometry by Korotkovand Riva-Rocci allowed quantitation of brachial cuff blood pressures, and the more descriptive methods largely disappeared.

Article p 1213

Indeed, brachial cuff blood pressure has become an enduring clinical variable. Actuarial data from the life insurance industry and subsequent prospective observational data have clearly shown that hypertension, or elevated cuff blood pressure, is closely related to many forms of cardiovascular disease.^2–4 Most recently, a very large meta-analysis by the Prospective Studies Collaborators that involved almost 1 million persons enrolled in 61 prospective observational studies demonstrated a log-linear relationship between cuff systolic or diastolic blood pressure and mortality due to ischemic heart disease or stroke in middle-aged and elderly adults who did not have overt vascular disease at the beginning of the observation period.⁵

Abundant clinical trial data indicate that lowering cuff blood pressure with antihypertensive drugs effectively reduces the risk of a variety of cardiovascular outcomes, including cardiovascular death, as well as total mortality.^6–10 Regarding the benefits of individual drug classes, a meta-analysis of data by the Blood Pressure Lowering Treatment Trialists’ Collaboration from randomized, controlled trials did not show significant differences in total major cardiovascular events among regimens based on angiotensin-converting enzyme inhibitors, calcium antagonists, diuretics, or ß-blockers, as long as similar cuff blood pressure reductions were achieved, although there were some differences in cause-specific outcomes.¹⁰ When specifically tested in randomized trials, however, ß-blockers have fallen short of other therapies in preventing hypertensive complications. The Losartan Intervention For Endpoint reduction (LIFE)¹¹ and the Anglo-Scandinavian Cardiovascular Outcomes (ASCOT)¹² trials compared active treatments based on an angiotensin receptor blocker (losartan with or without a diuretic) or a calcium antagonist (amlodipine with or without perindopril) with treatment based on a ß-blocker (atenolol). Brachial cuff blood pressure differences between the treatment arms in LIFE and ASCOT were very small and were judged by the investigators to be insufficient to explain the large treatment-related differences in outcomes, which favored the other drugs over the ß-blocker. However, the editorial accompanying the ASCOT main results publication attributes the benefits of amlodipine-based treatment to superior cuff blood pressure reduction,¹³ whereas others, including the main investigators of the ASCOT trial, have adduced effects beyond blood pressure lowering to explain the results.¹⁴

In this issue, Williams et al¹ describe results of the Conduit Artery Function Evaluation (CAFE) study, a substudy of the ASCOT trial, which compared the effects of the ASCOT blood pressure-lowering regimens on central aortic pressure and hemodynamics in more than 2000 patients in 5 ASCOT centers. The CAFE study, using radial applanation tonometry and pulse-wave analysis to calculate derived central blood pressures using the Sphygmacor system, describes a subtle but important difference in arterial pulses in hypertensive patients treated with ß-blockers compared with those taking calcium antagonists. The central finding of the CAFE study is that ß-blockers do not lower central systolic pressure as much as calcium antagonists, an observation that is predictable based on the relative inability of ß-blockers to reduce the magnitude of the reflection (augmentation) wave. This observation is similar to that of Morgan and colleagues,¹⁵ who used a 5-way crossover study to determine that only ß-blockers (compared with thiazides, angiotensin-converting enzyme inhibitors, and calcium antagonists) increased the placebo-subtracted magnitude of the reflected wave. Compared with ß-blockers, calcium antagonists and other vasodilators are thus more effective in reducing central systolic pressure, cardiac afterload, and left ventricular mass.¹⁶ The results from the CAFE study parallel those of the LIFE trial, in which angiotensin receptor blocker-based therapy was more effective than ß-blocker-based therapy in reducing left ventricular hypertrophy and its consequences.¹¹

The present application of “pulsology” to clinical trials would no doubt please the Chinese masters and the sphygmocardiologists. With ß-blocker-based therapy, as with aging or hypertension in general, the arterial pulse taken at the wrist is more “sustained,” because of a larger reflected wave in late systole. The absence of “pulsology” in Western medical curricula probably contributes to the skepticism of many physicians, along with the ongoing debate over the validity of the techniques currently used.

Although technical questions remain problematic in interpretation of the CAFE results, the overall conclusions drawn by the investigators are reasonably conservative. Radial tonometry, without question, produces a high-fidelity pulse contour that is identical to high-frequency catheter-based data. It easily can be shown that the radial or brachial systolic pulse contour in aging is essentially a “sustained” systolic pulse composed of an increased first peak followed by a secondary shoulder peak (due to wave reflection) that is generally lower.¹⁷ In contrast, the central systolic contour in aging or hypertension is composed of a lower first peak followed by a higher second systolic peak (augmentation pressure). It has been proposed that a generalized transfer function can be applied to a radial tonogram to yield a derived central pulse waveform¹⁸; this technique has been well validated to estimate peak central systolic blood pressure.¹⁹ Although there is ongoing debate over whether the transfer function can be applied to interindividual comparisons,²⁰ in the CAFE study, each individual was compared with his/her own baseline, so the data are probably valid. Other alternative explanations for the differences between treatment arms in CAFE also exist, including differences in 24-hour blood pressure control or other “tissue” mechanisms yet to be described.

What is the overall value of the CAFE study? At the very least, it opens our eyes to alternative explanations beyond the reach of conventional sphygmomanometry. In the context of clinical trials, radial tonometry adds to our knowledge of the pharmacodynamic effects of vasoactive drugs. Present findings have importance in describing why some classes of antihypertensive agents yield better profiles of target-organ protection than others. For example, the observation that ß-blockers do not reduce central systolic pressure as much as most other antihypertensive drug classes may account for the finding from meta-analyses of antihypertensive trials that ß-blocker-based treatment is no better than placebo for prevention of cardiovascular disease.^21,22 This has led many authorities to recommend that ß-blockers not be prescribed as first-line treatment for hypertensive treatment patients in the absence of compelling indications (heart failure, post myocardial infarction, high coronary heart disease risk, angina) for their use. Whether radial tonometry should be performed routinely in individual patients as a diagnostic or therapeutic indicator, however, remains a matter of considerable debate. At present, the technique is probably not quite ready for “prime time” in routine clinical practice.

^{Full original article with notations, references and links found here: http://www.circ.ahajournals.org/cgi/content/full/113/9/1162}

Great video to introduce doctors and health care professionals to the Bpro (BPro and A-Pulse software by HealthStats): A Cardio Pulse Wave Analyzer. The CEO, Dr. Ting of HealthStats the manufacturer of the BPro, gives a brief explanation of the device.

The ABC affiliate show ‘Good Morning Northwest’ hosted Dr. Don Woods and Bill Styles on thier show highlighting heart health month. This has been a great tool to get the word out on the BPro (by HealthStats) and the benefits of early detection of cardio vascular disease.

The ‘Good Morning Northwest’ program in Richland, WA on the ABC affiliate invited two of our team members, Dr. Don Woods and Bill Styles, to be on the show to learn more about the BPro (by HealthStats) and heart disease. What a great opportunity to have our message out to the pubic. (This is part 1 of 3 parts)

A-PULSE CASP is a revolutionary product patented by HealthSTATS International Pte Ltd. It is able to measure accurately the Central Aortic Systolic Pressure (CASP), which is the blood pressure at the root of the aorta. It is the only device which can be used in common clinical setting. CASP has been shown in many recent studies as an important determinant for strokes and CVS events. It has been validated via invasive study and achieved an accuracy (co-relation) R= 0.9917 independently. A-PULSE CASP is FDA and CE MDD approved. It is also being used in large drug trials by Pharmaceutical companies.

What is arterial pulse waveform?

When the left ventricle ejects blood into the aorta in systole, the perturbation generates a wave that initially travels through the arteries from the heart towards the arterial tree.

Pulse waveform has 2 components.
1) Forward travelling wave when the left ventricle contracts and
2) Reflected wave returning back from the peripheral.

Diagrammatic Representation of a Radial Arterial Pulse Wave

What is CASP (Central Aortic Systolic Pressure)?
This is the blood pressure at the root of the aorta or the largest artery in the body, as the blood is being pumped out of the heart. This pressure is called Central Aortic Systolic Pressure or CASP. CASP has been shown to be an important factor in the relation to strokes and cardiovascular events, more so than the brachial pressure, or the pressure at the arm commonly.

How to measure CASP?

Invasive method

This is direct measurement and has been considered as the most accurate method. To perform the measurement, a catheter must be inserted into the aortic root from brachial or femoral artery, which is obviously an invasive method and could result in complications (Fig. 1). This invasive method of measuring CASP is not available in clinical setting. However, A-PULSE CASP can be used in clinic and the accuracy has been validated against this invasive method, the result is R= 0.9917 (co-relation). (What this means, for those of you who are like me and don’t quite get the point, is the CPW is 99.17% as accurate as the cathater method!)

Fig. 1 Direct measurement of CAP using catheter

Non-invasive method

HealthSTATS (HS) invented a device named BPro which is able to capture radial pressure waveforms. Furthermore, HS developed a proprietary formula to derive central aortic systolic pressure (CASP) from the calibrated radial pressure waveform (Fig. 2).

Fig. 2 Non-invasive measurement of CASP using the Cardio Pulse Wave Analyzer (which is the combination of HealthSTATS BPro device and A-PULSE software)

What is augmentation index?

The difference between the second and first systolic peaks expressed as a percentage of the pulse pressure.

What is the arterial compliance?

The ability of an artery to increase the volume in response to a given increase in blood pressure is called compliance.

What is pulse wave velocity?

PWV is the speed at which the pressure waveform travels (wave propagation) along the aorta and large arteries, during each cardiac cycle.

What is applanation tonometry?

The principle of applanation tonometry is that the force acting on the plunger is proportional to the pressure in the artery when where the artery surface is flattened.