The Year in Cardiology, 2005 - CME Teaching Brief - MedPage Today: DALLAS, Dec. 30 - In 2005 heart disease killed more Americans than cancer, accidents or HIV infection, and it did so despite continued advances in heart disease diagnosis and treatment.
Those advances have made a dent in mortality, which declined from 322 per 100,000 in 1990 to 241 per 100,000 in 2002, but heart disease is unlikely to lose its No. 1 killer title any time soon.
The reason, authorities say, is that prevention is an elusive goal, not yet within the grasp of the cardiology's considerable reach.
For example, according to the CDC's National Center for Health Statistics, about half of America's aging baby boomers have hypertension and almost 40% are obese-a combination that is likely to spell cardiovascular mortality for many.
And yet another study found that nearly one in five Americans from the age of 12 through 49 -- an estimated 16 million -- can't pass a simple physical fitness treadmill test.
Nearing Medicare, Boomers Need Diets and Blood Pressure Control
Americans in Droves Flunk Fitness Test
While the diet-and-fitness message continues to be ignored by many Americans, researchers have been investigating mechanisms of heart disease progression as way to develop secondary prevention strategies.
Inflammation is considered a major contributor to plaque instability, which led many researchers to suggest that infection may be a trigger for cardiovascular events. And if infection could trigger an event, then antibiotics might prevent events.
That was the theory anyway, and 2005 was the year that it was debunked.
In a National Heart, Lung, and Blood Institute (NHLBI) trial, patients with stable coronary artery disease who underwent a year-long course of weekly azithromycin therapy were no less likely to have a heart attack or stroke than patients taking placebo.
Likewise, in a study sponsored by Bristol-Myers Squibb and Sankyo, acute coronary syndrome patients treated with Tequin (gatifloxacin) for a mean of two years had no reduction in cardiac events compared to patients randomized to placebo.
In announcing the negative results, NHLBI Director Elizabeth G. Nabel, M.D., said it was clear the antibiotics did not work, and it is time to focus prevention efforts on "the controllable risk factors for preventing coronary events."
No Role for Antibiotics in Cardiovascular Secondary Prevention
Another popular theory, that aggressive lipid lowering with high-dose Lipitor (atorvastatin) is better than standard therapy with Zocor (simvastatin) or other less potent statins, retained its adherents even though it was not confirmed in one major study.
That study, Incremental Decrease in End Points Through Aggressive Lipid Lowering (IDEAL) trial, found that high dose Lipitor did not achieve a statistically significant benefit compared with usual-dose treatment with Zocor (simvastatin) in patients with a history of acute myocardial infarction.
Patients randomized to 80 mg of Lipitor had an 11% relative reduction in major coronary events versus patients randomized to 20 mg of Zocor (P=0.07).
Moreover the aggressive treatment failed to achieve a significant benefit even though high-dose Lipitor lowered LDL to 81 mg/dL versus 104 mg/dL in the Zocor group. There were no significant differences in either cardiovascular or all-cause mortality.
But those results did little to dampen the enthusiasm of many cardiologists who said they will stick to high=dose Lipitor regimens, and they have solid evidence to back up that clinical decision. In the Treating to New Targets (TNT) trial, which enrolled 10,001 patients with stable coronary disease, treatment with high-dose Lipitor to mean LDL levels of 77 mg/dL was associated with a 22% reduction in risk of major cardiovascular events compared with patients treated to a mean LDL of 101 mg/dL.
When he reported the TNT findings at the American College of Cardiology meeting in March, principal investigator John C. LaRosa, M.D., of the State University of New York Health Science Center in Brooklyn said, "We have entered a new era in the treatment of established coronary disease from starting at an LDL of 100."
AHA: High-Dose Lipitor Does Not Outdo Standard-Dose Zocor
ACC: LDL Cholesterol of Less than 80 mg/dL Reduces Risk of Heart Attack and Stroke
But a big-stick statin may not always be the safest treatment choice, according to an analysis of post-marketing safety reports from patients using Crestor (rosuvastatin), a super-potent statin, Lipitor (atorvastatin), Zocor (simvastatin), or Pravachol (pravastatin).
Patients taking Crestor were eight times more likely to develop rhabdomyolysis, nephropathy, renal failure or proteinuria than patients taking Pravachol, and 6.5 times more likely to develop those complications than patients taking Lipitor.
Richard H. Karas, M.D., Ph.D., director of preventive cardiology and the Woman's Heart Center at Tuft-New England Medical Center, noted that the absolute risk remains low: 28 events per million prescriptions for Crestor, versus 13 per million for Zocor, 3.5 per million for Pravachol, and 4.3 per million for Lipitor.
Safety and efficacy of devices was also a big issue this year, and most of the news for Guidant was bad. The device maker was forced to recall 170,000 pacemakers and implantable defibrillators, which was more than half of the company's devices. Moreover, Guidant's problems triggered a months' long series of events that included a demand by cardiologists for a reworking of device safety alerts and recalls and a two-day FDA conference on device safety.
Implantable Devices Take a Licking but Don't Always Keep on Ticking
Cardiologists Urge Changes in Safety Regs and Guidelines for ICD Use
Crestor Called Less Safe Than Other Statins
But while the year was a rocky one for the heart-device industry, it was another boom year for drug-eluting stents. These stents-Cypher, which delivers sirolimus to the endothelium and Taxus, which carries a payload of paclitaxol-now are the stents of choice for most interventionists. What remains, of course, is heavy competition between the two.
In this head-to-head race, Cypher came away as the winner in trials reported this year.
ACC: Cypher Stent Edges Ahead of Taxus in Head-to-Head Trials
ACC: Cypher Bests Taxus in All Comers Comparison Study
Just as Cypher was the odds-on-favorite in the world of stents, Plavix (clopidogrel) was this year's winner for the drug reporting the most positive trial results. It was difficult to find a cardiology journal, or a cardiology conference that didn't feature a positive Plavix study. The take home message was clear: give it early and often.
ACC: Adding Plavix to Clot-Busting Regimen Saves Lives
ESC: Pretreatment with Plavix Reduces MI, Stroke, and Death Before and After Stenting
Plavix-Aspirin Combo Reduces Acute Heart Attack Deaths
Finally, a pair of low-tech but significant observations: dyspnea is not a benign symptom, and for men heart rate reveals volumes.
First, a study of almost 18,000 patients referred for cardiac stress testing found that people with no known coronary artery disease who report a history of dyspnea are four times more likely to die from heart disease than asymptomatic patients.
Second, a study of 5,713 French men found that when a man's heart rate is too fast at rest, he had a 3.5-fold increase in risk of sudden cardiac death. Moreover, if a man had less than an optimum increase in heart rate during exercise, his risk of sudden death was 20% higher than men whose hearts speeded up appropriately during exercise.
Dyspnea Is Predictive of Cardiac and All-Cause Mortality
Sudden Death in Healthy Men Can Be Predicted by Heart Rate
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