Food and Gut Microbes Acting together in Enhancing Production of TMAO (Trimethylamine N-Oxide) may Increase Risk of Heart Attack

Food and gut microbes acting together in increasing production of TMAO (Trimethylamine N-Oxide) may increase the risk of Heart Attack from atherosclerosis.

Structure of Trimethylamine oxide (TMAO) (Photo credit: Wikipedia)

A study published online in the Cleveland Clinic on April, 2013 establishes the link between carnivorous/omnivorous food habit with predisposition to atherosclerosis and heart attack, to be TMAO (Trimethylamine Nitric-Oxide), a by-product of gut microbial action on certain foods containing lecithin and carnitine.

The researchers have proved that cholesterol cannot only be indicted to be the culprit in atherosclerosis, TMAO is the new found main facilitator for the plaque formation in the arterial walls.

Diets such as red meat and egg (Yolk) etc. when acted upon by the certain gut microbiota, produce TMAO, which is absorbed to the system and adversely affecting the reverse cholesterol transport; interferes with the metabolism of cholesterol in liver, only to facilitate its' deposition in the arterial walls, altering the macrophage foam cell function.

It is not precisely known which microbes from about a trillion of gut microbiota are responsible for increased TMAO production. In the study, when the gut flora was suppressed by antibiotics, production of this by-product was decreased. However, the Bacteroid type enterotype are associated with meat fat and protein eaters.

However, antibiotics are not recommended for prevention on heart attack because the gut flora recoups soon after the initial suppression by developing resistance.

The TMAO production was less in vegetarians and people on Mediterranean diet, in comparison to meat eaters. It is also interesting to observe that two different people can experience the same food differently because they have different gut flora. One person may generate a little more of a compound like TMAO than the other.

This concept is a new way of thinking about complex diseases like atherosclerosis and other cardiometabolic diseases. It can also apply to obesity and insulin resistance. Data links intestinal flora involvement in those phenotypes in both mice and humans.

There have been very exciting data from a gut flora transplant in persons with metabolic syndrome who received either their own fecal samples or those from a lean donor. Persistent changes in insulin sensitivity occurred just by transplanting the intestinal flora from one individual to another.

With the present level of knowledge, there has not been any recommendation on stopping meat eating for the purpose. But, promoting vegetarian diet is not a bad idea.

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Is Coronary Angioplasty the Ultimate Solution to Future Heart Attack?

I came across an article in The New York Times titled Heart Stents Still Overused is thought provoking and actually may be a fact too.
If somebody understands the actual mechanism of the heart arterial blockade, he/she should not be happy after inserting a stent in a narrowed artery as an elective procedure or in emergency.

PTCA

A narrowed artery does not mean a blocked artery. Blocked artery usually needs clearing of the clot/thrombus and a stent; called angioplasty, percutaneous coronary intervention (PCI), coronary balloon angioplasty or percutaneous transluminal coronary angioplasty (PTCA).
But, should this assure patient of any further heart attack or myocardial infarction arising out of blockade in some other part of coronary arteries? The answer is definitely no. That is because the root cause of this blockade is not addressed only by stenting.
The thrombus formation or narrowing of coronary artery by so called deposit of bad fat, cholesterol is over simplification of the events leading to the infarction or death of some muscle of heart termed as Myocardial Infarction, in the down stream territory of a particular blood vessel.
The main cause may be the inflammation in the coronary arteries, which leads to atherosclerotic plaque formation, then rapture that leads to thrombus formation and ultimately to blockade.
Stenting after clearing the thrombus/clot by various available means is only to re-establish blood supply through that particular part/segment of the artery in question; and nothing beyond that.
There may be inflammation in many other parts of the arterial network in heart. The patient has to be clearly informed that he/she should to adhere to the advice of health care provider and use medications prescribed to suppress/halt the ongoing inflammation.
Again elective angioplasty may not be required at all in some cases, at least where the patient is able to manage himself.
While treating heart attack, the target should be how to reduce/halt inflammation in coronary arteries so that those can work properly without being used as foundation stone for further atherosclerotic plaque formation.

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Coronary CT Angioghaphy can be a Better Idea to Evaluate Chest Pain of Non-Cardiac Origin

Traditionally, acute heart attack presenting with the symptoms like chest pain is evaluated by means of ECG (Electrocardiography) and cardiac enzyme assays like cardiac troponin test (A Blood test).

Sometimes, those tests may give equivocal results necessitating further hospital stay for observation and repeat tests; and additional procedures.

Incorporating coronary CT angiography (CCTA) into the initial evaluation of low-risk patients coming to hospital emergency departments with chest pain appears to reduce the time patients spend in the hospital without incurring additional costs or exposing patients to significant risks, concludes one study from Massachusetts General Hospital (MGH).

They found that the use of CCTA in emergency department evaluation of acute chest pain very effectively identified which patients did or did not have coronary artery obstruction, allowing clinicians to focus the use of resources on patients with heart disease.

CCTA combines advanced CT scanning with the use of intravenous contrast material to produce detailed images of blood vessels supplying the heart without the need for cardiac catheterization.

The investigators found that participants in the CCTA group had significant reductions in the amount of time from ED arrival until discharge either from the ED or after a hospital stay, with half of the CCTA group being discharged within 8.6 hours but only 10 percent of the control group being released so quickly.

The amount of time until a diagnosis of heart disease was either ruled out or confirmed was also shorter for the CCTA group than for the controls, and more patients receiving CCTA were discharged directly from the ED rather than being admitted to an observation unit.

The percentage of patients actually diagnosed with heart disease was similar in both groups at around 8 percent, and there were no missed diagnoses in either group.

The issue of radiation dose can be addressed by more improved technique, small dose CT.

The original article published in Massachusetts release can be accessed here

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Symptoms of Heart Attack in Women Below 55 may be Misdiagnosed and Treatment Delayed

The classical symptom of heart attack that forces one to get consultation with a doctor the chest pain is often missing in women below 55, which even can bias a doctor to settle for some other diagnosis, rather than the heart attack.This is according to a study of more than one million people in the US.

Image via Wikipedia; Changes in Cardiac Troponin and CK-MB In Acute MI

Heart attack is not as common in women below 55 as in men in that age group. Often, instead of chest pain women of this age group experience discomfort or heaviness in chest. The women and the attending doctor must be suspicious enough to consider the myocardial infarction (MI) in these patients.

In the said study it was seen that overall, 42% of women did not experience chest pain compared with 30% of men. Once admitted, the study found that women were more likely to die than men from the same age group because of bias, and consequent delay in diagnosis and initiation of proper treatment. Some 14% of women died compared with 10% of men.

The bias is because of atypical symptoms in younger ladies, and the fact that attacks among younger women are relatively rare. In fact the average age of women admitted to hospital in the study was 74, compared with 67 for men.

Younger women may need to heed that advice more than most because they appear to be less likely to have chest pains. Their symptoms can be overlooked by inexperienced medical staff because heart attacks in young women are rare. 

The symptoms can be;

• A dull pain, ache or 'heavy' feeling in the chest
• A mild discomfort in the chest that makes one feel generally unwell
• Pain that spreads to the back, arm or stomach
• Pain that feels like a bad episode of indigestion
• Chest pain accompanied by feeling light-headed or dizzy

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Bad Oral and Dental Hygiene may contribute to Heart Attack

Image via WikipediaBacteria are normally found through the body surface and in the whole gastrointestinal tract. Bad oral hygiene may allow bacteria to grow and get an access to the blood stream. Those may also come from intestine to the blood stream.
Atherosclerotic plaques formed in the blood vessels rapture to form blood clots which obstruct the coronary arteries to cause heart attack. The plaques rapture as a result of inflammation there.
Now it has been seen that the bacteria found in the plaques are similar to those found in the mouth and intestine. Scientists presume those might have accessed from the gut. Pseudomonas luteola and Chlamydia pneumoniae were present in all atherosclerotic plaques they searched for.
The researchers also found that some of the bacteria in the mouth and gut correlated with biomarkers associated with cardiovascular disease.
It may open up new doors to fight against heart attack

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Better to Quit Smoking Late than Never

Myocardial infarction, heart attack is due to atherosclerotic changes following dysfunction of the inner cell layer of the coronary arteries, those supply blood to the heart. The most common cause of the dysfunction is due to direct effect of smoking.
Smokers advance so many pleas to continue smoking even after a heart attack, if asked to explain the habit. Many quit smoking after heart attack. Now it has been seen by a group of researchers that quitting smoking even after a heart attack is also beneficial for those people in decreasing the risk of second attack.
Tobacco contains as many as 4000 ingredients which include some radioactive materials also. To list a few, tobacco smoke contains; tobacco specific nitrosamine, nicotine, ammonia, pesticides like DDT, benzene, arsenic, cadmium, lead, polonium, methyl isocyanate, formaldehyde, butane, carbon monoxide, ethyl furoate and etc.

Lead and polonium are radioisotopes known to cause cancer. Benzene is a dye blamed for urinary bladder cancer. Arsenic is a metal poison. Cadmium is used in battery factory. Formaldehyde is a germicidal used for sterilization purpose and preservation of dead body. Methyl isocyanate used in carbide factory is very poisonous. Its leak killed around 2000 people in Bhopal, India in 1984. Carbon monoxide is a lethal poison.
Still, after seeing the frightening list of harmful ingredients in tobacco, some smokers may not like to quit smoking, thinking that they are not going to suffer; but perhaps a false self assurance. At least the first time heart attack survivors try to learn from their mistakes.

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