Heart attack and longevity

The thread on Emphysema and longevity got such interesting responses that I thought I would raise the same question for a person who has suffered a heart attack.

What’s the question?

In general, a myocardial infarction is caused by underlying vascular disease, often in association with other diseases or risk factors for other diseases. The extent of both the underlying vascular disease as well as post-event interventions makes it difficult to give an easy answer to such a broad question. Most modern longevity studies look at the effects of post-ischemic event interventions rather than overall longevity.

It’s possible to have an isolated coronary artery lesion (say, for example, in the left anterior descending coronary artery) treated with an arterial graft (say, for example, from the left internal mammary artery). In such a patient, if that is the only vascular lesion they have anywhere, their survival might approach normal. On the other hand, a patient with severe and diffuse arterial pathology, including multiple areas in the coronary arteries, might have a tiny myocardial ischemic event with minimal or no permanent damage from that event and yet have a poor long-term prognosis.

There was a time when myocardial infarction was considered such a dire event that long term survival was actually reportable in the medical literature. cite

This is no longer the case, obviously (and I should add that the diagnosis of MI at that time was a fairly crude approach).

This is a much more complicated question since so many variables come in to play.

For starters, survival is going to be influenced by:

  • age, gender, race, and socio-economic status

But, it’s also dependent on:

  • associated blood vessel conditions such as stroke, periperhal vascular disease
  • associated medical conditions such as diabetes, high blood pressure, depression, kidney failure, . . . and their treatment

Then, you have to take into account:

  • type of heart attack (i.e. “anterior” or not, “ST-segment elevation” or not)
  • therapy around time of heart attack (e.g. “clot buster”, angioplasty, stent (and type thereof), bypass surgery)
  • therapy continued long after heart attack (e.g. beta-blocker drugs, cholesterol lowering drugs, aspirin, Plavix, . . . )
  • more novel therapies (e.g. implantable defibrillators)

With those huge cofounders, I think the following are correct:

  1. In-hospital death rates have dropped from around 30% to 10%
  2. Annual mortality rates after a heart attack have dropped from around 10% to 2% (but, people who are elderly and of lower socio-economic status still have a rate of about 10 percent annually)

Bottom Line: It depends (sorry)

I’ve wondered whether a lot of conditions are created by unknown infections.

Can arterial blockages, for example, result from an infection of the lining which encourages buildup? It seems that there’s no cause-and-effect, the results are very erratic (as with many aspects of how the human body behaves). People with abysmal lifestyles can escape blockages, and people with relatively clean lifestyles can still get blockages - although generally wellness (ability to fight infection?) seems to mean no blockages.

One of my relatives, for example, got a stent but the blockage regrew over it; then he had the balloon angioplasty and has been fine since for 15 years. (Never actually had a heart attack). Why did one obvious treatment work and another not? Is it just an occasioanl infection?

Usually when something happens for no direct reason in the body, it is related to infection of some sort.

Yes, around 1900 the famed pathologist Virchow postulated an infective cause for atherosclerosis. More recently, there was quite a vogue regarding the possibility, especially, of infection with Chlamydia pneumoniae as a causal factor in heart attacks, etc. However, AFAIK, all attempts to influence the course of atherosclerosis by antibiotics (in humans) have come to naught.

Ah well, it seems the question was too broad; there is just too many unknowns. I have survived my heart attack by 45 years and I just wondered how much longer I should plan on.