How Can Both of These Stories Be True?

About this series:

The Cause That Isn’t Destiny is a series of eight essays exploring cholesterol, causality, and the limits of any single measurement to predict an individual’s future.

The patients in these essays are composites, drawn from many people I’ve cared for over three decades as a cardiologist. No single case is reproduced, and no individual patient can be identified.

The people in these pages are fictional; the questions they raise are not.

Recently I met a woman at my clinic. She is 78 years old. Her LDL cholesterol is 224 mg/dL (5.8 mmol/L). These are high numbers, hard to look past. At least, I think most cardiologists would act on them without much hesitation. Her coronary calcium score is zero. The CT angiogram of her vessels, done alongside it a few weeks ago, shows no soft plaque either. In other words: a 78-year-old woman with what we would call “normal coronary arteries.”

Her younger brother had died of a heart attack at fifty-two — an anterior myocardial infarction, an acute coronary occlusion. A well-known cause of sudden death. She has now lived twenty-six years longer than he did, with a cholesterol level more than double his.

She didn’t come to me because she thought her cholesterol was bad. She came because her grandchild had had her lipids checked at a health day at work, and came home frightened by numbers she didn’t understand, marked in red with a warning symbol. She asked her grandmother whether she had ever had hers measured. She thought she remembered it being done, many years before, and that it hadn’t come out particularly well. That was when she came to see me.

I think she had fully expected bad numbers. The results didn’t seem to surprise her much. And yet she was worried. She lived a good life, with good people around her, and her health was good. She looked at me silently at first, then asked, seriously: “Do I need to worry?”

She had brought a folded printout of her grandchild’s results with her, the numbers from the health day in traffic-light colours. She turned it over on her knee, looking back and forth between me and the page.

It may be a hard thing to admit that I had no good answer, and still don’t. That, really, is what this piece is about.

I explained to her what we actually had in front of us, which was, of course, no answer at all. I told her that her coronary arteries, on the images before me, were as healthy as they could possibly be for a woman her age, and that I didn’t really know why. Her brother’s arteries had not been healthy — that much was clear — and I didn’t know why that was, either. Maybe she had lived a healthy life. She made little of it, said she’d simply lived like anyone else. She asked whether the measurements could be wrong, hers or his. I said I didn’t think either number was wrong. They simply couldn’t tell us what we wanted them to tell us.

All this struck her, naturally, as strange. What’s the point of measuring cholesterol if it tells you nothing? A fair question, and I told her I understood it very well.

Then she asked, naturally, whether she could do anything differently — change her diet, exercise more, take up some new routine at 78. I told her what I thought, which is that I didn’t see the sense in changing her life to influence a number that showed no sign of doing her any real harm.

She hesitated for a moment. “Several of my relatives take medication to lower their cholesterol. Do I need to as well?” I had known all along, of course, that we would have to answer this question. The risk calculator was fairly clear. What I saw on her scans told a different story. I’ll admit I trust what I see more than a formula built on epidemiological studies. Statin, or no statin? I told her what I thought. She seemed satisfied, but her expression showed she wasn’t entirely sure.

I sometimes wonder whether she should have asked me a different question. Whether I would have put her brother on a statin, if he had survived that morning on the golf course. I would have said yes, without much hesitation. I suspect that answer would only have made the whole thing harder for her to understand — not easier.

Over decades as a cardiologist, I have turned this question over more times than I could possibly count. More often than not the decision has been difficult, and I have never been entirely certain I was doing the right thing. There is much in medicine that can be said with real confidence. And other things that cannot. Clinical guidelines certainly help — but the situation is different when it concerns one particular life.

I don’t think my answers were what she expected. She had assumed, I think, as most people do, that cholesterol was simply the problem: a number to be brought into the light, and then dealt with, the way one deals with a blocked pipe.

I understand that position well. I assumed something similar myself once, before I had met enough patients like her to know better.

I’m not saying the position is wrong. It simply isn’t enough to explain what is happening with her, and what happened to her brother. I tried to explain this to her, in the short time we had that morning.

Our message to people, over recent decades, has been that cholesterol causes cardiovascular disease, and that high cholesterol is something that must be addressed — often with statin medication. A doctor is more likely to be criticized for not putting someone on a statin than for doing so.

But what do we actually mean when we say that something causes a disease? In most cases, such a claim is a considerable simplification. That is reflected clearly enough in the story of this one ordinary woman and her brother.

I explained to her what I saw. I had a harder time explaining why it fit so poorly with the numbers in her blood test — or with her brother’s history.

What I know is less than what she wanted to know.

I still don’t have the sentence that explains the contradiction in her story and her brother’s. In fact, I don’t think the explanation is to be found in the blood values themselves.

Part 2 - What Does It Mean to Call Something a Cause?

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