11 May 2001
PROJ01\AMAHEART.MS
1,900 words
NEW YORK -- "It's like what women have been telling men -- while excitement is important, it's performance that really counts," said Milton Packer, MD, Director of the Center for Heart Failure Research and Chief of the Division of Circulatory Physiology, Columbia University College of Physicians and Surgeons and Columbia-Presbyterian Medical Center, to groans of the audience.
Dr. Packer was illustrating the point, at the American Medical Association's "Heart Disease Media Briefing" on 10 May 2001, that there are exciting new developments in congestive heart failure, but what really counts is how well they hold up in the long run.
Dr. Packer, a standup comedian, quickly recovered and went on with his act. "It worked in rehearsals," he said bravely.
Packer's central life-saving public health message was, "If you are short of breath and fatigued, you need to see your physician to determine if you have heart failure so you can be treated." Patients dismiss it as a consequence of aging. "It's not a consequence of aging," said Packer. Only 20% of heart failure patients are getting beta-blockers, and it should be 80%, he added.
So how does your physician tell whether you've got heart failure? I asked Packer (so I could tell if my own physician is cutting corners). He'll know, said Packer. Diagnostic tools include history, X-ray, ECG, and ultrasound.
I also got a reaction from a cardiologist to the Science article on cholesterol, and heard about ranolazine, a new drug manufactured by the company whose educational grant paid for the briefing.
In an impromptu improv, Packer picked up on a suggestion from the audience that the term "heart failure" is too negative. Perhaps a less frightening term would encourage patients to see their physicians. Dr. Packer reflected that this could be a problem, especially for him.
"I'm director of the heart failure center," Packer reflected. Perhaps they should be called, "Heart Success Centers."
Heart failure (pardon the expression), also known as congestive heart failure, is the end result of several diseases. The most common is atherosclerosis in the coronary arteries, which in turn is the result of inflammation and (maybe) diet. Atherosclerosis constricts the small arteries that tap the aorta and supply the heart itself. A repair mechanism helps in the short run but destroys the heart in the long run. Adrenergic hormones, which served us well in our battles against the cave bears, make the heart pump harder, but then it stretches and weakens, in a process called remodeling. The lungs and ankles often fill with fluid (thus "congestive"). There are proven treatments, basically diuretics and vasodilators to lower blood pressure, and blockers to interrupt those adrenergic hormones. But mortality is still high. Getting the right treatment can mean the difference between being in the 12% or 15% mortality group. Those aren't great odds, but, as Packer explained, people will take another pill every day for 3%.
According to the Merck Manual and other sources, mortality for congestive heart failure is 70% over 10 years. That's wrong, said Packer. "It depends on the severity of the disease." (According to a review by Lonn and McKelvie, BMJ 20 April 2000, the risk of death annually is 5-10% in patients with mild symptoms and 30-40% in advanced disease.)
In the old days, said Packer, medical schools taught that beta-blockers are contraindicated in treating heart failure. They were wrong. Beta-blockers are now mandated. 20 years ago, they used to tell patients with heart failure to go home and "settle your affairs." Now evidence-based medicine says they can reduce mortality with digitalis, diuretics, ACE inhibitors and beta-blockers.
A report in the 5 May 2001 Lancet concluded that the beta-blocker carvedilol, in addition to standard treatment, improved survival. That was the Carvedilol Post-Infarct Survival Control in LV Dysfunction (CAPRICORN) study. "Effect of carvedilol on outcome after myocardial infarction in patients with left-ventricular dysfunction: the CAPRICORN randomised trial," Lancet 2001;357:1385-90 (requires free registration). Patients with previous MI, mean ejection fraction 33%, age 63, already treated optimally with ACE inhibitors, nitrates, aspirin, diuretics and other drugs, were randomized to added carvedilol or placebo. After median 1.3 years, all-cause mortality was 15% placebo, 12% carvedilol, or a 23% reduction in relative risk. In previous trials, corresponding mortality was 10% placebo, 8% beta-blockers, they said.
[A good review in JAMA, 20 Feb 2002, 287(7):883-897 [MEDLINE] of the scientific and clinical basis of beta-blockers found a "remarkably consistent" 30% reduction in mortality in 7 large trials, 3 of which were stopped early because of obvious benefit.]
(A major exception is that black men often don't respond well to ACE inhibitors or beta-blockers. The BEST trial, of 2,708 patients, found no statistically significant benefit to beta-blockers. According to principal investigator Michael Domanski, "When we did the subgroup analysis, blacks did not gain benefit, but other subgroups do.")
(Incidentally, the ejection fraction, usually left ventricle, is the percentage of blood from the full left ventricle that the ventricle actually pumps out during systole. This is an important concept. Normal is 50-75%. Advanced heart failure is 25% or less. It can improve with treatment.)
(Congestion is another important concept. When the left ventricle doesn't pump properly, the blood backs up into the left atrium, and then backs up into the lungs. This causes fluid to build up in the lungs, which causes shortness of breath.)
The artificial heart, the "unbelievable dream," was oversold, admitted Dr. Packer. They thought it would be like an artificial knee. Even if they did develop an artificial heart, "we wouldn't be able to afford it." Heart transplants replace one disease with another disease, and we don't have near enough donors anyway. (See discussion in "Prognosis after heart transplantation" BMJ, 8 March 2003;326:509-510) So the only dependable strategy is prevention.
[But on 15 November E.A. Rose et al. reported (N Engl J Med 2001;345(20):1435-43) a randomized trial (N=129) in which a left ventricular assist device extended life in patients with New York Heart Association class IV heart failure (and ejection fraction 17%) from median survival 150 days in the control to 408 days in the treatment group, 1-year survival from 25% to 52%, with improved quality of life. Science, 8 Feb 2002, 295(5557):998-1001, in its special issue on "Bionic parts," favorably reviewed heart replacement and assist devices.]
Dr. Packer is a consultant to so many drug companies that the biases all cancel out.
On to the lipids. A news story in Science, 30 March 2001, "The Soft Science of Dietary Fat," Gary Taubes, which was widely pirated on the Internet, noted that cholesterol-lowering drugs prolong survival in heart disease patients with high cholesterol. However, Taubes said, there is no published scientific evidence that lowering dietary fat, or dietary cholesterol, has any survival benefit for the general population. It's easy to show that diet changes secondary markers, like serum lipids, but in order to make the scientific claim that it delays death, you have to show in prospective studies that it delays death.
Panelist Henry Ginsberg, MD, Irving Professor of Medicine, Columbia University School of Medicine, had qualified praise for Taubes' story, which he called "half right," and a great historical study, but cited 3 articles Taubes left out, which, he said, demonstrated that controlling dietary fat can lengthen lifespan, all from The Lancet:
1: Watts GF, Lewis B, Brunt JN, Lewis ES, Coltart DJ, Smith LD, Mann JI, Swan AV. Effects on coronary artery disease of lipid-lowering diet, or diet plus cholestyramine, in the St Thomas' Atherosclerosis Regression Study (STARS) Lancet. 1992 Mar 7;339(8793):563-9.
2: Ornish D, Brown SE, Scherwitz LW, Billings JH, Armstrong WT, Ports TA, McLanahan SM, Kirkeeide RL, Brand RJ, Gould KL. Can lifestyle changes reverse coronary heart disease? The Lifestyle Heart Trial. Lancet. 1990 Jul 21;336(8708):129-33.
3: Hjermann I, Velve Byre K, Holme I, Leren P. Effect of diet and smoking intervention on the incidence of coronary heart disease. Report from the Oslo Study Group of a randomised trial in healthy men. Lancet. 1981 Dec 12;2(8259):1303-10.
Not quite. None of those studies were of dietary intervention with endpoint of death, which was the point of Taubes' story. The STARS and Ornish study had endpoint of coronary artery stenosis observed on angiograms, not death. The Oslo group did show an improved endpoint of death, but in high-cholesterol, smoking men, with intervention of diet plus smoking cessation.
(Endpoint is another important concept. There were drugs that improved endpoints like ejection fraction or exercise tolerance, but didn't improve the endpoint of survival.)
(For a recent review, see "Dietary fat intake and prevention of cardiovascular disease: systematic review," Lee Hooper et al., BMJ 2001 March 31;322:757-763 , which concludes there is "little effect on total mortality" and "limited and inconclusive evidence" of effects on cardiovascular mortality.)
Dr. Ginsberg is also a consultant to so many drug companies that the biases all cancel out.
Not that there's anything wrong with that. According to Taubes, one of the problems with the debate on lipid research was that industry grantees were unfairly dismissed as biased. People said the industry had an obligation to pay for nutrition research, so they did, said Taubes. The only problem is setting up a system to make sure that sponsors don't improperly influence the research conclusions, which has been known to happen. So there are safeguards to prevent improper influence.
Funding for the conference was provided by an educational grant from CV Therapeutics , manufacturer of ranolazine, a drug for myocardial ischemia which has completed Phase III trials and is awaiting FDA approval.
As you all know, muscles can use either of 2 oxidation pathways: fatty acid or glucose. Damaged, ischemic heart muscle shifts to the low-oxygen fatty acid metabolism, but the fatty acid pathway doesn't work well and the glucose pathway gets blocked, said Marc David Thames, MD, Brigham and Women's Hospital, who has received honoraria from CV Therapeutics. Ranolazine partially blocks the fatty acid pathway and drives the metabolism back to the glucose pathway. In animals, ranolazine produced a dramatic improvement in heart failure, said Thames. His mood was cautious excitement. (I'd have to check my tape, but I don't think he mentioned any off-label indications. He seemed to be erring on the side of caution, which is prudent when the FDA is considering your new drug.)
Public relations for CV Therapeutics was by Fleishman-Hillard. (They did a good job. I asked a doctor a question, and before the panel was over, one of their people passed me a good article on the subject.)
The AMA, like other medical societies, has made a faustian bargain with the drug and device companies. The AMA sponsors press briefings, contributing its credibility. The grantor pays for the press briefings, contributing its money. The grantor is typically a drug company with important research that can be (and is) legitimately included in a program. If CV Therapeutics hadn't paid for the conference, would the AMA have included ranolazine in a 1-day press briefing on the most exciting new developments in heart disease? (Ranolazine does seem to be a promising drug.) Would the AMA have been able to offer this 1-day briefing at all? (It was indeed a useful, informative briefing.) Is this a reasonable compromise? Is it good to take corporate money to promote medical education? Is there an alternative? How can medical writers get a piece of it? I dunno. I'm part of the system too. I go to meetings free. They give me a free lunch. I wouldn't want to be an ungracious guest at the AMA's table.
I guess my safe harbor is: If they follow the rules of the Accreditation Council for CME, rules that include fairness, balance, and financial disclosure, I'm OK. (If the AMA wants to adopt the Caesar's wife standard, they could improve their financial disclosure. At other medical meetings, speakers disclose their financial interests before each presentation. At this briefing, the financial disclosures were printed in small type at the end of the press releases.)
The dessert buffet included creamy Italian pastries, chocolate cake, soft cheese, and (for those on the DASH diet) fresh fruit. I only report; I do not judge.
I was not able to find out what Ginsberg ate for dessert.
(Some of these links may no longer be working, but the important ones still are.)
1. For an objective, dignified account of this meeting, see Anne Harding, Reuters, 10 May, "Many Suffer From Untreated Heart Failure in US" , and "Quick Cooling Could One Day Avert 'Sudden Death'".
2. For the official announcement of the media briefing and some press releases that give a pretty good summary of the meeting, see the AMA web site.
3. For a good review of drugs used to treat heart failure, see "Regular review: Drug treatment in heart failure," Eva Lonn and Robert McKelvie, BMJ 20 April 2000; 320: 1188-1192.
4. For more general clinical information about treating heart disease, see "Collections of BMJ articles by specialty and topic", at the entry "Cardiovascular Medicine".
5. For physician-oriented meeting reports and CMEs, see Medscape Cardiology.
6. For a good basic background on cardiology, start with the Merck Manual Home Edition and then read the professional edition.
7. To learn how to read X-rays and ultrasound images, see Introduction to Cardiothoracic Imaging at the Yale School of Medicine. Good to know if you ever go to a cardiology conference.
8. For a few good gross and histological heart anatomy illustrations, see the Internet Pathology Lab.
9. For a good webcast lecture on basic heart physiology, aimed at high school seniors, see "Brave Heart: Circle of Life" by Christine ("Cricket") E. Seidman at the Howard Hughes Medical Institute web site.
10. For a current study and discussion of racial differences in treatment, see "Lesser Response to Angiotensin-Converting-Enzyme Inhibitor Therapy in Black as Compared with White Patients with Left Ventricular Dysfunction," (N Engl J Med 3 May 2001;344:1351-7.) [SUMMARY]
11. For an exciting recent review of the last 25 years of cardiovascular research, and prospects for the next 25 years, see JAMA, 7 February 2001, "Prospects for Cardiovascular Research," Robert J. Lefkowitz and James T. Willerson.
12. Circulation, the AHA journal, on-line free! Articles are free on-line after 1 year, but sometimes they make them free earlier. Good place to start: 50 most often read and 50 most often cited . For a good historical review, see Volume 102, Supplement 4; November 14, 2000 Special Anniversary Issue
13. For a good patient page, with first-hand accounts of how congestive heart failure affects peoples' lives, see Jon's Place.
Dissect a real heart! Giovanni Esposito & Sons Meat Shop, 500 Ninth Ave. (corner 38th St.), sells frozen lamb hearts for $1.75 a pound (about 1.75 pounds apiece).
They're chopped off right above the ventricles, so you can see the aorta, the pulmonary artery, and the valves, but the atria are gone. (The pork hearts in contrast are chopped into pieces and not suitable for these purposes.)
Major arteries. The most striking feature of the specimen is the pulmonary artery and aorta at the top, each about 3 cm in diameter, tough, and parchment-like. The arteries and the ventricles that supply them are in perpendicular planes: The heart has a basic left-right symmetry around the mid-sagittal plane, but the pulmonary artery twists to the front (anterior) while the aorta twists to the back (posterior).
Coronary arteries. Like the human, the lamb heart has 3 main coronary arteries, starting in the aorta, flowing under a cap of epicardial fat, dissipating in a fractal tree. The largest coronary vessels are about 4 mm in diameter, and the walls are thin enough to be colorless. The grossly-visible vessels are confined to the surface. From inside the aorta, the source of the left coronary artery begins a few mm above the aortic valve, and an impromptu probe (the temple of my glasses) through the opening confirmed its path through a fatty valley and down the surface of the heart.
Muscle wall. Using a small, sharp blade of a pocket knife, I cut in a coronal plane through the side of, first the left ventricle, then the right ventricle, and finally the septum between them, to expose the heart in the classic anatomy book pose.
The muscles are massive, with walls 1 cm thick in the smaller ventricle, and 2.5 cm thick in the larger ventricle, homogeneous with no obvious vascularization. In contrast, the inner surface of the ventricle chambers are covered with a spongy, trabecular inner muscle.
Valves. There are 2 kinds of valves: flat and cup-shaped. The flat, sheet-like valves (the tricuspid and mitral) are between the atria and ventricles, and seal off the powerful ventricles under pressure. The cup-shaped valves (the pulmonary and aortic) are between the ventricles and the largest arteries, and prevent regurgitation.
The flat valves are restrained by thin tendons, the chordae tendineae, anchored in muscle papulae, like a parachute held in shape by shroud lines. The valves are automatically drawn across the atrium to seal the entry chamber shut during systole, when the left ventricle squirts its contents at 130 mm Hg pressure into the aorta. The valves are paper-thin and transparent, like the lingual frenulum restraining the tongue. The papulae roots pull out easily with finger pressure. The cup-shaped valves, like trap doors, flop together from the sides of the arteries to prevent regurgitation, and open under pressure to allow flow from below. Computer imaging has identified the flapping motion of the valves responsible for abnormal stethoscope sounds.
Pumping. In cross-section, the left ventricle squeezes shut during its systolic pumping stroke like a fat-walled triangle, with the muscle walls coming together in 3 or at least 2 bulges thickening to fill the space like a crescent till they not quite meet.
During embryological development, the heart muscle is wrapped in a helix, and the pumping motion that propels the blood is like wringing a dishrag, according to a radiologist who modeled it on computer.
If you don't live near Ninth Ave., you can get hearts (and other cool organs) from Fisher Science Education and Carolina Biological Supply. You can also get live frogs at Lucky Seafood, 135 Mott St. (between Grand and Hester), for $3 a pound. Or you can get zebrafish (Dania rerio), used extensively to study heart development, at pet stores. Unlike mammals, the zebrafish heart regenerates when injured (Science 298:2188-2190).