Give us peace in our time..

1. It is very disheartening to see images of war. Let alone seeing it done to innocent people. About 700 poeple have been killed and thousands more injured in this recent bout of attack on Gaza. This is not millitary mission, this is ethnic cleansing.

2. Israeli backed by US have been very verocious in clearing the Gaza from traces of Palestine. What have the innocent people has to do with it?

3. So I call upon everyone, boycot US products. Boycot companies directly contribute to Israeli. Regardless who you are, muslim or non muslims. The bottom line is killing innocent people is wrong. We have other companies which produce similar quality or even better then them.

4. We should start buying local produce. There are a lot of variety of nice local produce. They are fresh, healthy and cheap. Furthermore, the buck stops here...

5. Let us all pray for peace in Palestine in what ever religion you are..

MSCT is not very accurate after all

Diagnostic Accuracy of 64-Slice computed tomography coronary angiography: Prospective, Multicenter, Multivendor Study. Meijboom et. al. JACC 2008 52:2135 - 44.

1. This trial assess how accurate is 64 multislice CT angiography (MSCT) in detecting significant coronary artery disease when compared to the conventional coronary angiogram (CCA). CCA is the gold standard for diagnosing coronary artery disease.

2. The study recruited 360 patients with stable and unstable angina. All patients underwent both MSCT and CCA. Out of 360 patients, 246 have significant coronary artery narrowing (using the gold standard CCA).

3. Out of 246 with significant coronary artery narrowings, 244 were detected with MSCT (99% sensitive). So it is fairly accurate in thse group of patients which are symptomatic.

4. Of those without significant coronary artery narrowings, 114 patients, 41 of then were wrongly labelled as having significant narrowings by MSCT (64% specific).

5. If you have angina with negative MSCT, the chance of you not having significant coronary narrowings is 97%. When you angina and have a positive MSCT, the chance of you having significant coronary narrowing is 86%.

Summary

1. The patients in this study have symptoms, so there are quite a lot of them would have significant coronary heart disease. I would usually subject them directly to coronary angiogram espcially if they have ECG changes or elevated cardiac markers. MSCT in this situation is rather redundant. If the patient do not have ECG or ecardiac markers changes, I would subject them to either stress testing with or without imaging.

2. MSCT is not really that accurate in this group of patients especially if it is positive.

3. Nevertheless, if you have clear, negative MSCT, rest assured, you dont have significant coronary artery narrowing.

4. So back to square one, I only reserve MSCT to patient with chest pain who cannot exercise and for those with interconduction delay (eg bundle branch blocks).

5. With judicious and careful CCA, the amount of contrast use and total radiation can be significantly less than MSCT. The average radiation exposure from MSCT varries from 9.5 to 13.6 mSv, compared to CCA, 0.8mSv (which is about 10 times of routine CCT). The average amount of contrast for CCA is about 30 mls, as compared to 75 to 100 mls for MSCT.

How to look at your cholesterol profile?

Elevated cholesterol level (hyperlipidaemia) is an important cardiovascular risk factor. Most of us would go to doctor or “pathology labs” requesting to check our cholesterol (lipid) levels. Patients fast for at least 12 hours (excluding medications and clear fluids) before blood taking. Hence, Fasting Serum Lipid (FSL) or Fasting Lipid Profile (FLP). There would be at least 4 parameters that we look at. Three of them are cholesterol-bound-protein (lipoproteins); Total Cholesterol (TC), High Density Lipoprotein (HDL) and Low Density Lipoproteins (LDL). The final parameter would be Triglyserides (TG).

Lipoprotein is produced by liver and excreted into the bloodstream. These lipoproteins have essentially two main components, lipid and protein. Immediately after being released in the blood, these lipoproteins have low lipid but high protein content. Hence it is called HDL. As these lipoprotein moves around the circulation, it absorbs lipids or cholesterol. This will increase the quantity of lipid in these lipoproteins. Hence it is called LDL. LDL then is reabsorbed by liver. Cholesterol then is excreted or released as bile.

TG is actually fatty acid which comes from our diet. The excessive energy which is not used up by our body is converted into TG which then stored in fat cells.

pathways of lipids..

So we actually measure the lipoprotein levels as a reflection of our cholesterol profile. This is because free cholesterol is absent from our blood. It is a hydrophobic molecule.

HDL and LDL have low and high lipid content respectively. Hence increased HDL level is a good sign as it acts as a scavenger to lipid. Increase LDL however is a sign that there is too much cholesterol in our circulation. The higher the LDL, the high the risk of cardiovascular event (eg stroke or heart attack). The FSL measurements are given in either µmol/L or mmol/L.

Of these 4 parameters, LDL has the strongest link to cardiovascular disease. Numerous studies have shown that the lower the LDL level the lower the risk of cardiovascular event. TC, HDL and TG levels are not as strong predictor of cardiovascular events.

These measurements should take into account the patient profile too. Each patient has his or her own target cholesterol levels. The high the risk, the lower the LDL level should be.

LDL targets

High Risk Patients (previous heart attack / type II DM) less than 2.0mmol/l

Intermediate Risk Patients (hypertension) less than 2.5mmol/l

Low Risk Patients less than 3.0mmol/l

Until these targets are reached, only then one should consider modifying the other lipid profile parameters, namely TG and HDL.