By Mary Carpenter
THE RAPID heartbeat that woke Lake Tahoe medical writer D.P. in the middle of the night, insisted her doctor, must have come from nightmares she didn’t remember. D.P. wrote in an email that it took two more years before she received a diagnosis of potentially life threatening AFib (atrial fibrillation—irregular or very fast heartbeats, over about 100 beats per minute), after which she had two ablation surgeries to create scarring that can block abnormal electrical signals.
For Florida golfer G.D., her doctor dismissed reports of chest pains because all the usual tests showed a healthy heart. For Paris-based clothes designer L.K., her athletic appearance and good test scores made her long-time internist pooh-pooh any concerns. On annual physical exams, both women had good cholesterol “ratios”—the comparison of worrisome LDL (low-density lipoprotein) cholesterol levels with those of healthy HDL (high-density lipoprotein) —long considered to indicate good heart health.
Both also scored low on the heart-risk calculators relied on by many cardiologists, which tally responses to lifestyle questions such as smoking along with data that include the cholesterol ratio. But when the women obtained CT scans of their coronary arteries—known as calcium scans or CAC screening—these showed calcium deposits that can narrow the arteries, leading their doctors to prescribe cholesterol-lowering statin medications.
The lesson in these cases may be the limitations of current tools for assessing heart health, suggested D.P., who trained and worked as a nurse before spending 40 years as a writer and editor of medical articles and books. All heart tests have some shortcomings, she explained, and new assessments, such as the CAC scan, can take many years to be added to guidelines.
Another issue with heart health is that most patients are unaware of their personal risks or of what symptoms might look like if they occur. For AFib, few people know about the condition, and its symptoms can be silent. And even when experienced individuals feel their hearts speed up, they can be unsure whether to push unwilling doctors for more tests—despite AFib officially affecting some 10% of people over age 65, a number that could be much higher because of unreported or silent symptoms.
D.P. herself ignored early flutters until snowshoeing made her dizzy. And even after her surgeries and getting a heart rhythm app on her smartwatch, she heard the app’s alarm go off one night as she was lying in bed, watched her heart rate climb from 130 to 139 to 150— and still wasn’t sure if she needed to call for help, partly due to fears of the high costs of emergency care. At D.P.’s next checkup, the nurse practitioner told her: “Call 911!” explaining that EMTs should check the heart rate and only proceed with additional care if necessary.
Before obtaining her AFib diagnosis, D.P.’s ECG and exercise stress test were both normal, as was a second stress test from a heart rhythm specialist who “cranked up the treadmill incline as high as I could manage.” But as D.P. sat recovering afterwards, she mentioned the feeling of fullness in her chest and pressure in her neck that usually happened about half an hour after she plunged into icy Lake Tahoe or snowshoed up to a high mountain ridge. As a result, the doctor repeated the ECG both 15 minutes and a half-hour after the treadmill test. “Lo and behold,” D.P. wrote, “there it was: the occasional too-close-together peaks on the graph.”
Some people who report occasional heart palpitations receive a wearable heart monitor for a week or two. And AFib can also show up on a routine ECG or on smart watch heart rhythm apps, although the accuracy of the Apple watch varies among individuals, and in one study detected abnormal heartbeats only about one-third of the time. But AFib can be dangerous. Those with AFib have a risk of stroke 4-5 times higher than in people without the condition, and their strokes are generally more severe —though the highest risk occurs among those with other conditions as well, such as diabetes and high blood pressure.
In the cases of the women who had CAC screenings, the presence of coronary artery calcium “provides insight into the patient’s level of cardiovascular disease risk and is helpful for guiding interventions,” according to a National Library of Medicine report. But because CACs still have not made it onto many guidelines, most patients must first request a referral from their doctor and then pay for the test themselves, which usually costs between $40 and $150.
Calcium scans are “very useful if there’s uncertainty about a person’s risk of heart disease or the need for statins,” Brigham and Women’s Hospital cardiologist Ron Blankstein told Harvard Health—but not for anyone who already has coronary artery disease or has a low risk of heart disease, including most people under 40. Good candidates come from the “immediate-risk group…people ages 40 to 75 whose 10-year risk of heart disease or stroke ranges from 7.5% to 20%.”
Ten-year risk determinations using heart disease calculators, however, fail to add important considerations such as family history, diet, exercise and ability to control stress. As a result, according to Sanjay Basu, Stanford University researcher and author of an NIH-funded study, results from these calculators are often “way too high or low for some patients.”
As early as 2013, a study showed “that coronary artery calcium screening…should play a more prominent role in helping determine a person’s risk for heart attack and heart disease-related death,” according to a Johns Hopkins statement. But physicians continue to argue about the usefulness of CAC screening.
Even L.K.’s cardiologist said his decision to prescribe statins was based not on her CAC results but on the need to lower her LDL cholesterol, stating that reliance on cholesterol ratios is unproven and unreliable. According to the Mayo Clinic, “For predicting your risk of heart disease, many doctors now believe that determining your non-HDL cholesterol level may be more useful” than the ratio. (The non-HDL level, which should be below 130 mg/dL, comes from subtracting the HDL number from that of total cholesterol.)
For all three women, their recent treatments have promised better heart health—though all have remaining questions about the future, and these are the hard ones: what happens next, what are their ongoing risks, what more can they do to prevent future problems? Writes D.P, “what I really want to know is how long do I have? And that question, as it turns out, I don’t have the nerve to ask.”
Despite my good cholesterol ratios and healthy risk calculator scores, I will try to get a CAC screening to help with ongoing uncertainty about whether I need statins because my non-HDL cholesterol levels are high. I have tried Lipitor, which created not-uncommon alterations in liver enzymes, followed by pravastatin; and both caused muscle aches, a common but unproven side effect of statins. With any new indication of increased risk to my heart, however, I would certainly be willing to take them again.
—Mary Carpenter regularly reports on need-to-know topics in health and medicine.