Effectiveness - Aspirin, Meds, Diet and so on..

A recent New York Times article deals with how effective meds, diets etc are in dealing with medical problems. NNT is the statistical measure that illustrates some surprising reults

For example- regarding the heart;

One heart attack is prevented when 2000 people take a daily aspirin for two years - NNT = 2000

One death is avoided in four years when 30 heart attack survivors adopt the popular mediterranean diet. It does not prevent the death of others in this group. NNT = 30

Somewhere out there are similar statistics... Seems to me to be good stuff for assessing the effectiveness of various treatments... I thought these things were "more preventive" than the NNT indicates.

Read about it in the NYT.

http://www.nytimes.com/2015/01/27/upshot/can-this-treatment-help-me-theres-a-statistic-for-that.html?_r=0&abt=0002&abg=0

Azviking

7 Comments

Effectiveness of PM's?

by azviking - 2015-01-28 02:01:31


Now that I think of it - how effective are pacemakers in

preventing or delaying another heart attack or heart failure death?

Anyone know the statistics?

The NNTs?


Azviking

ROBO is absolutely right

by IAN MC - 2015-01-28 03:01:52

Maybe if you had asked how effective PMs are at treating bradycardia and preventing bradycardia-related deaths then you may get some meaningful responses !

But the concept of NNTs is interesting. If we all looked at the NNTs for taking statins or for reducing sodium intake ,both of which are fashionable at the moment then we would see some fairly huge NNTs. I stopped taking statins for that very reason, I would also only reduce sodium intake if I was convinced that I am genetically at risk from high levels of sodium.

One problem with NNTs is that they only look at death-prevention and don't consider improvements in quality of life. I know that my PM has stopped me from feeling faint, but has it stopped me from dying, who knows !

Ian

Brady Deaths

by azviking - 2015-01-28 04:01:33

Thanks for the responses ROBO and IAN. I am missing somethng in.ROBO's comment.

Mayo Clinic and the Heart assoc.. write that Cardio leads to inadequate blood flow/ fainting as well as sudden cardiac arrest and sudden death.

It may be that the probability of death and arrest are very low and, if so, PM's main role is to increase blood flow and quality of life..... I can understand it in that way.

The PM's NNT would then be very high, Insignificant?

I am slowly learning.

Azviking



It seems logical

by Artist - 2015-01-28 04:01:58

I have been informed by several highly competent nurses and doctors that Afib can result in the release of blood clots throughout your body and makes it five times more likely that a person could then have a heart attack or stroke. So, in my case the pacer has enabled me to tolerate the medications that have now greatly reduced the frequency and severity of afib episodes. So my conclusion is a resounding Yes--pacers do help prevent heart attacks and strokes along with improving quality of life!

Yes, I am Confused.

by azviking - 2015-01-28 07:01:14

I like the electrical-mechanical analogy.

Might it be possible for a clot to develop in small pools of blood that accumulate in the atrial or ventricle - due to an electrical malfunction and associated low pulse?

This clot then finds its way to the vessels carrying blood to the heart muscles - leading to failure.

I am a novice in this discussion.



Azviking

Blood flow primer

by donr - 2015-01-29 12:01:58

Blood comes OUT of the LEFT Ventricle & enters the Aorta. From the Aorta, it flows to the entire body, brain included. Blood goes from the RIGHT Ventricle through the Pulmonary Artery to the lungs, which happens BEFORE the blood gets to the LEFT ventricle, so A-Fib will not cause pulmonary embolisms.

A-Fib affecting the LEFT ATRIUM can pool in abnormal surface conditions of that chamber due to the Fibrillation, break off & flow through the LEFT Ventricle up into the Aorta. The Coronary arteries take their blood from immediately after it enters the Aorta and they are relatively small, compared to the Aorta so they will unlikely pickup clots. That's why we don't have heart attacks due to clots from A-Fib.

Here I'm going to slip into my mechanical engineer hat & look at the fluid dynamics of liquid flow in order to make an educated guess about further reasons why the Coronary Arteries don't pick up clots from the A-Fib. Normally, flow through the heart & its valves is pretty turbulent - that's what the tech hears when you have an Echo Cardiogram. When it comes out of the LEFT Ventricle into the Aorta the flow smooths out (Called Laminar flow) & INCREASES in speed because the diameter of the Aorta is less than the diameter of the Left Ventricle. Like all things in the body, it is well designed, so as the blood transitions into the Aorta, the walls guide it smoothly into the more constricted space. The Coronary Arteries are fed from just this transition point, so I suspect that the blood flows past the relatively small diameter branches quite fast & small clots are not picked up. The Brain takes a whopping amount of blood to function, so it has a pair of large diameter carotid arteries picking up blood from the Aorta, therefore a lot of clots zoom right into those two arteries.

Donr

Confused Too

by Artist - 2015-02-14 11:02:16

Donr, You seem to be very well informed and I respect and appreciate your comments. This is a learning experience and I probably was told there is an increased probability for stokes and may have assumed also heart attacks. Thank you for your interesting clarification.


You know you're wired when...

You have a dymo-powered bike.

Member Quotes

I am just now 40 but have had these blackouts all my life. I am thrilled with the pacer and would do it all over again.