This blog is rather short, because the basic facets and results are quite clear. The biggest risk factor for stroke in the general public is high blood pressure. The first anti-hypertensive to conclusively demonstrate a reduction in stroke risk was thiazide diuretics. They apparently work by lowering the total amount of salt in the body. We also know that thiazide diuretics are synergistic with every other anti-hypertensive medicine, in that diuretics potentiate the effect of every other hypertensive treatment. In fact, if you are on two anti-hypertensive drugs, one of them should be a diuretic, unless you have some very unusual medical condition.
So the message of this blog is that diuretics prevent strokes. I raise this point because recent medical studies have been trumpeted in the newspapers as being more effective or more potent than thiazides in lowering blood pressure. But the question to ask your doctor is if this new and "better" anti-hypertensive treatment has been shown to lower the risk of stroke. If it hasn't, then either ask him to add a diuretic, or see a specialist in hypertension, to see if yours is a special case.
This is a small example of substituting an endpoint for a clinical result. We have seen similar problems in whether or not lowering cholesterol prevents heart attacks, or if lowering CPR is beneficial. To use my favorite analogy, just because you have a better "tool" for returning the arrow over the elevator to the lobby than simply pushing the lobby button, it doesn't mean that your tool will get the elevator down any faster.