Most Heart Attack Patients' Cholesterol Levels Did Not Indicate Cardiac Risk

Ruzanna Harutyunyan's picture
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A new national study has shown that nearly 75 percent of patients hospitalized for a heart attack had cholesterol levels that would indicate they were not at high risk for a cardiovascular event, based on current national cholesterol guidelines.

Specifically, these patients had low-density lipoprotein (LDL) cholesterol levels that met current guidelines, and close to half had LDL levels classified in guidelines as optimal (less than 100 mg/dL).

"Almost 75 percent of heart attack patients fell within recommended targets for LDL cholesterol, demonstrating that the current guidelines may not be low enough to cut heart attack risk in most who could benefit," said Dr. Gregg C. Fonarow, Eliot Corday Professor of Cardiovascular Medicine and Science at the David Geffen School of Medicine at UCLA and the study's principal investigator.

While the risk of cardiovascular events increases substantially with LDL levels above 40–60 mg/dL, current national cholesterol guidelines consider LDL levels less than 100–130 mg/dL acceptable for many individuals. The guidelines are thus not effectively identifying the majority of individuals who will develop fatal and non-fatal cardiovascular events, according to the study's authors.

Researchers also found that more than half of patients hospitalized for a heart attack had high-density lipoprotein (HDL) cholesterol levels characterized as poor by the national guidelines.

Published in the January issue of the American Heart Journal, the study suggests that lowering guideline targets for LDL cholesterol for those at risk for cardiovascular disease, as well as developing better treatments to raise HDL cholesterol, may help reduce the number of patients hospitalized for heart attack in the future.

"The study gives us new insight and intervention ideas to help reduce the number of heart attacks," said Fonarow, who is also director of the Ahmanson–UCLA Cardiomyopathy Center.

"This is one of the first studies to address lipid levels in patients hospitalized for a heart attack at hospitals across the entire country."

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The research team used the national database sponsored by the American Heart Association's Get with the Guidelines program. The database includes information on patients hospitalized for cardiovascular disease at 541 hospitals across the country.

Researchers analyzed data from 136,905 patients hospitalized for a heart attack nationwide between 2000 and 2006 whose lipid levels upon hospital admission were documented. This accounted for 59 percent of total hospital admissions for heart attack at participating hospitals during the study period.

Among individuals without any prior cardiovascular disease or diabetes, 72.1 percent had admission LDL levels less than 130 mg/dL, which is the current LDL cholesterol target for this population. Thus, the vast majority of individuals having their first heart attack would not have been targeted for effective preventative treatments based on the criteria used in the current guidelines.

The team also found that half of the patients with a history of heart disease had LDL cholesterol levels lower than 100 mg/dL, and 17.6 percent of patients had LDL levels below 70 mg/dL, which are guideline targets for LDL cholesterol in those at fair risk and at high risk for cardiovascular disease, respectively.

The study also showed that HDL cholesterol, or "good cholesterol," levels have dropped in patients hospitalized for heart attack over the past few years, possibly due to increasing rates of obesity, insulin resistance and diabetes.

Researchers found that 54.6 percent of patients had HDL levels below 40 mg/dL. Developing more effective treatments to boost HDL levels may help reduce the number of patients hospitalized for heart attacks, according to the authors.

"We found that less than 2 percent of heart attack patients had both ideal LDL and HDL cholesterol levels, so there is room for improvement," said Fonarow.

Fonarow said that only 59 percent of patients in the database had their lipid levels checked upon admission, which should be increased, since these early measurements can often help guide treatment decisions.

He also noted that only 21 percent of patients in the study were taking lipid-lowering medications before admission, despite almost half having a prior history of cardiovascular events, which would prompt treatment.

The national cholesterol guidelines are set by the National Cholesterol Education Program, part of the National Heart, Lung and Blood Institute of the National Institutes of Health.

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Comments

Facts Believed to be Associated With All Statin Medications: Statins are a class of medications specifically prescribed to lower LDL- one of five lipid parameters of a person’s lipid profile. There are 6 available statins to choose- with three that are combination drugs that have a statin as a component of these medications. There are other classes of medications for lipid management, such as bile acid sequestrants and nicotinic acid, which is known as niacin. Yet the side effect profile is more unfavorable of these classes of medications compared with the statin class. One’s cholesterol level is primarily due to how they produce cholesterol in their liver, which is overall genetically determined. This level is also determined by one’s lifestyle and diet as well. If a person has too much cholesterol in their blood, it can lead to hardening and narrowing of their arteries, which can lead to cardiovascular events. To measure one’s cholesterol, a blood test called a lipid profile is obtained from a person after they have fasted for at least 12 hours. The test should also be performed only if the person is free of any acute illness, as this may affect true lipid measures. If the results prove to be abnormal, lipid lowering therapy may be initiated, according to the discretion of the person’s health care provider. This therapy usually involves a statin medication. Adverse events associated with the statin class of pharmaceuticals are thought to occur more often than they are reported- with high doses of statins prescribed to patients in particular at times that may not be necessary to control their dyslipidemia based on their lipid profile. However, since this class of drugs has existed for use for over 20 years, statins are considered safe and effective for enhancing the clearance of LDL noted to be elevated in the lipid profiles of patients. Also, they have proven to reduce cardiovascular mortality with one who is treated with a statin that has dyslipidemia. In addition to lowering LDL by up to 60 percent- depending on the statin- this class of drugs also raises HDL and lowers triglycerides, which are two other lipid parameters. Both of these effects from taking a statin drug are beneficial for the patient on a statin drug for lipid management. Statin therapy is also recommended for those patients who have a greater than twenty percent risk of developing cardiovascular disease, or those patients that have clinical evidence of this disease Additionally, there appears to be no comparable reduction in cardiovascular morbidity or mortality, as well as a difference in the increase of one’s lifespan, if one is on any particular statin medication for their lipid management over another, others have concluded. So caution should perhaps be considered if one chooses to prescribe a statin for a patient if they are absent of, or have only mild dyslipidemia to a significant degree. Furthermore, research should be done by the health care provider if they are under the belief that one statin medication provides a greater cardiovascular benefit over another. In other words, the health care provider should be assured that any choice of statin therapy for their patients is considered reasonable and necessary if the LDL in their patients need to be reduced, and the statin selection should be determined by the results that have been shown with a particular statin. Abstract etiologies for those who choose to prescribe statin drugs on occasion for reasons not indicated by these statin drugs- such as reducing CRP levels, or for Alzheimer’s treatment, or anything else not involved with LDL reduction with prevention if not delaying the progression of cardiovascular disease, should be thoroughly evaluated by the health care provider. As statin therapy for such patients may not be considered appropriate prophylaxis at this point for any patient who does not have the indications for which statins are approved for and treat with patients. All other benefits that appear to have favorable effects in such areas are speculative at this point due to minimal research in other areas aside from lipid management, and require further research for these disease states aside from dyslipidemia, according to many. Statins as a particular class of drugs that seem to in fact decrease the risk of cardiovascular events significantly, it has been proven. Statins also decrease thrombus formation as well as modulate inflammatory responses (CRP) as additional benefits of the medication. For those patients with dyslipidemia who are placed on a statin, the effects of that statin on reducing a patient’s LDL level can be measured after about five weeks of therapy on a particular statin drug. Liver Function blood tests are recommended for those patients on continued statin therapy, and most are chronically taking statins for the rest of their lives to manage their lipid profile in regards to maintaining the suitable LDL level for a particular patient presently. Patients should be made aware of potential additional side effects as well, such as muscular issues. Yet some have said that about half of all strokes and heart attacks that do occur are not because of increased cholesterol levels of these patients. Others believe that it is oxidized cholesterol that causes vulnerable plaques to form on coronary arterial walls, which is the catalyst for a heart attack, and that there is no medicinal treatment for the formation or stabilization of these plaques to prevent heart attacks or strokes. Others who promote and support statin medicinal therapy claim that these drugs, do, in fact, stabilize these plaques, and therefore are beneficial. As stated previously, in regards to other uses of statins besides just primarily LDL reduction, there is some evidence to suggest that statins have other benefits besides lowering LDL. These other disease states include aside from what has been stated already, those patients with dementia or Parkinson's disease, as well as those patients who may have certain types of cancer or even cataracts. Yet again, these other roles for statin therapy have only been minimally explored, comparatively speaking. Because of the limited evidence regarding additional benefits of statin medications, the drug should again be prescribed for those with dyslipidemia only at this time involving elevated LDL levels as detected in the patient’s bloodstream. Yet overall, the existing cholesterol lowering recommendations or guidelines should possibly be re-evaluated, as they may be over-exaggerated upon tacit suggestions from the makers of statins to those who create these current lipid lowering guidelines. This is notable if one chooses to compare these cholesterol guidelines with others in the past. The cholesterol guidelines that exist now are considered by many health care providers and experts to be rather unreasonable, unnecessary, and possibly detrimental to a patient’s health, according to others. Yet statins are beneficial medications for those many people that exist with elevated LDL levels that can cause cardiovascular events to occur because of this abnormality. What that ideal LDL level is may have yet to be empirically determined. Finally, a focus on children and their lifestyles should be amplified so their arteries do not become those of one who is middle-aged, and this may prevent them from being candidates for statin therapy now and in the future, regarding the high cholesterol issue. Treating children with a statin drug for dyslipidemia is controversial presently. Dietary management should be the first consideration in regards to correcting lipid dysfunctions that may exist in patients, Dan Abshear