“The artifactual disease” is the phrase George Pickering coined to describe hypertension in the 1950’s and 60’s. In those days, he dominated the debate about the nature of hypertension, arguing against those who thought hypertensive patients who developed complications comprised a distinct entity of subjects. “The higher the pressure, the worse the prognosis,” he would repeatedly affirm. To my knowledge, he did not expound on the J-curve phenomenon, but he surely made a convincing case that defining a disease on the basis of arbitrary cut-off numbers is most foolish indeed.
But since the 1970’s, after clinical trials established the success of anti-hypertensive therapy, and with the growing enthusiasm for “risk-factor modification” and the inexorable rise of population medicine, any attempt to expect rational nomenclature or clarity of thought has seemed increasingly futile.
Instead, we must be impressed by discussions of studies where “Patients were categorized by their mean SBP level over follow-up as very low normal (<120 mm Hg), low normal (120 to <130 mm Hg), high normal (130 to <140 mm Hg), high (140 to <150 mm Hg) and very high (>150 mm Hg). ”
I recently tested myself on a 24-h ambulatory blood pressure monitor. My SBP varied from 90 to 142 mmHg.
No wonder I was feeling out of sorts.
The USDA introduces its food guide pyramid
The USDA modifies its food guide pyramid to more accurately reflect knowledge in nutrition science…. Continue reading A brief history of official dietary recommendations
In the current issue of Clinical Cardiology, Nanette Wenger, Professor Emeritus of Cardiology at Emory University and regular fixture on the AHA and ACC guideline-writing committees, offers us a “guide to the guidelines” article that summarizes the pertinent recommendations in the 2011 Update to the AHA Guidelines for Prevention of Cardiovascular Disease in Women.
Now it may puzzle the lay person that a guideline would need its own guide Continue reading Interpreting Scripture
A “reader’s comment” on an opinion piece by William C. Roberts in the American Journal of Cardiology, kindly published by the editor. Roberts’ editorial focuses on the large body of evidence favoring the cholesterol hypothesis and laments what he considers the distracting effect of complementary hypotheses (eg. inflammation, “multifactorial” nature of atherosclerosis, etc.). I offer a few points regarding the difficulties of dealing with strictly risk-based diagnoses that rely on arbitrary cut-off numbers and have no defining pathological correlates. Unfortunately not free online, but I’m happy to provide reprints upon request.
…is that it reveals the opaque logic of public interest policies…
While the NIH is tightening its rules concerning what financial ties university researchers must disclose before getting public grants, the FDA may be loosening its own criteria for excluding potential advisors based on their industry connections. It seems that as a consequence of the disclosure business, the only experts who would pass muster were no experts after all…
Meanwhile a story in Cardiology News this month tags yet again Dr. Paul Ridker with the issue of conflict of interest. It seems the inflammatologist felt obligated to elaborate once more on his “lengthy disclosure slide” before giving a lecture at a scientific meeting. But Ridker is now taking a more offensive stance and argues Continue reading The problem with transparency…
Cardiology News for July…
“Niacin Questioned After AIM_HIGH Is Halted.” Another “disappointing” trial on raising HDL, except, of course, for those patients currently taking the “vitamin” who may be allowed to flush it down the commode once and for all. Naturally, Antonio Gotto (in an accompanying editorial) does not lose hope that another pharmacological intervention may revive the “HDL hypothesis.” He encourages us to wait for the UK HPS2-THRIVE trial of niacin plus laropiprant. HPS2-THRIVE has an expected enrollment of 25,000 patients. Given that magnitude of benefit is inversely proportional to trial size, we’re not holding our breath… Continue reading Cardiology News for July…
This week’s JACC offers an excellent paper by Kitzman and co-workers on what is now called “Heart Failure with Preserved Ejection Fraction,” or HFPEF, (or huff-puff…).
The article reports on the cardiopulmonary physiology of 48 patients with “pure” huff-puff (no amyloid or hypertrophic cardiomyopathy) compared to 25 healthy controls. All were subjected to measurement of VO2 max and echocardiography, and the echo-derived cardiac output estimate was validated (to a reasonable extent) by radionuclide angiography.
The findings were surprising but confirm some earlier studies: Huff-puff does not seem to be due to an inability to expand diastolic volume (although end-diastolic volume at rest is decreased in Huff-puff compared to controls). Key pathophysiologic components seem to be 1) inability to increase heart rate with exercise (chronotropic incompetence); 2) inability to reduce end-systolic volume at peak exercise (yielding a relatively lower stroke volume, likely due to decreased contractility); 3) some peripheral phenomenon that interferes with oxygen extraction (calculated A-v O2 difference was reduced at peak exercise in huff-puff patients).
The accompanying editorial also offers a helpful review on the subject and on the evolution of the nomenclature.
A key unanswered question/speculation regards the role of calcium-channel blockers in this condition and to a lesser extent, beta-blockers. Both are currently “class IIb” therapies for huff-puff.
Drs. Marc Pfeffer and Marianne Bowler are commenting on the Supreme Court’s ruling in Matrixx vs. Siracusano, which upheld a lower court’s decision that a drug manufacturer must disclose to shareholders information regarding adverse effects, even absent any measure of statistical significance. But the authors would like to go beyond the court’s mandate. They advocate for “more open and better reporting” of any potential adverse effects (calling for drug companies to deliver any available piece of information “transparently,” e.g. directly to their desktop). Continue reading Gotta love them data!
CHICAGO—June 16, 2011—The American Board of Medical Specialties (ABMS) has announced the creation of a new certifying body, the American Board of Database Medicine (ABDM). The announcement was made jointly by ABMS and the American Association of Database Doctors (AADD), the leading professional organization representing database medicine specialists.
“The last decades have witnessed an unprecedented epidemic of data,” said Dr. Numbar Kruntsher, president of AADD. “Studies are published everyday, and new data is produced before the old data is even digested. Thankfully, growing numbers of dedicated physicians have stepped forward to help manage data by harnessing the power of statistics and information technology. We are delighted this work is getting the recognition it deserves, and we are confident the certification pathway will ensure that data will continue to receive the high quality of care the public has come to expect.” Continue reading Database doctors form new board
In the June 21 issue of JACC, Dr. Harold E. Bays argues for establishing “adiposopathy” as a full-fledged disease to provide a coherent understanding of the role of fat tissue in cardiovascular disease, dispel the confusion related to the many-named “metabolic syndrome,” and resolve the obesity paradox. Does he succeed in this task? What would Virchow have to say? Continue reading Adiposopathy: is the evidence too thin?