Patient education key for identification, treatment of silent MI
For patients and cardiologists, recovery after an MI can be complex and challenging, often requiring new medications, dietary adjustments, and commitment to an exercise and rehabilitation program. In a study recently published in Circulation, researchers reported that nearly half of all patients with MI in the United States do not benefit from any of these measures because the MIs are “silent” and go completely unnoticed. Other research has indicated that patients with silent MI are three times more likely to die of CVD.
Cardiology Today and Healio.com/Cardiology spoke with Robert A. Vogel, MD, clinical professor of medicine at the University of Colorado at Denver and advising cardiologist to the Pritikin Intensive Cardiac Rehab program, about measures that patients and health care providers can take to identify silent MI and facilitate prompt and optimized care.
Q: Recognizing the “symptoms” of a silent MI is challenging, given that, by definition, a silent MI involves ambiguous symptoms or no symptoms. Are there other signs to identify a silent MI?
A: The traditional symptoms of MI are chest pain, pain radiating down the arm, jaw pain, shortness of breath, sweating and nausea.
Silent MIs account for approximately 200,000 MIs per year in the United States. That is a big number. There are two types of silent MI. One is the type where there are truly no symptoms. For a true silent MI, we can see it on an EKG, or the patient maybe comes in with HF due to the MI. We’ll do an echocardiogram or other test, and we can see the MI. Then, there are the kinds of silent MIs where patients have symptoms, but the symptoms are unrecognized. This is very common in women’s heart disease. The symptoms are different than those in men. Women don’t characteristically present with the chest pain that goes down the arm. They may just feel out of sorts, tired or a little short of breath. Women might not think about going to the hospital or seeing a doctor as a result of symptoms like these. However, it could be an MI because MIs in women don’t show up with the same clarity as they do in men.
Q: Most people today, both men and women, occasionally feel tired or out of sorts. How does the patient recognize when such a common complaint may be cause for concern?
A: The best thing we can do is educate patients about their individual risks, and what a particular symptom would mean based on that. A 20-year-old woman who is feeling tired is probably not having an MI. But a 60-year-old women who is a smoker, has diabetes and is overweight has a greater likelihood of having an MI — silent or typical.
Another thing a patient can ask themselves is whether the tiredness is “out of the ordinary.” For example, if a patient has been walking up two flights of stairs with their groceries for 10 years but now, after one flight of stairs, it “doesn’t feel right.” That’s when you go and see your doctor.
It is also important to take family history into consideration. If you have a parent who had an MI (father younger than 55 years; mother younger than 65 years), your risk for developing an MI is three times higher than someone whose parent did not have a heart attack.
Patients should also be aware of their BMI, cholesterol, BP and prediabetes/diabetes status.
Q: What are the consequences of overlooking a silent MI?
A: If you ignore it, you are missing the opportunity to improve it. If you miss a silent MI, that portion of the heart muscle dies. In the days following an MI, sudden cardiac death can occur. If sudden cardiac death occurs outside of a hospital, the likelihood of survival is low. Sudden cardiac death that occurs in the hospital is associated with greater survival due to access to cardiac resuscitation and defibrillation. It is estimated that hundreds of thousands of people in the United States die as a result of sudden cardiac death, and one of the causes is silent MI.
Today, the common treatment for MI is angioplasty stenting. These strategies are very effective if we get to it early — within 12 hours of the MI occurring.
We have a saying in cardiology: “Time is muscle after a heart attack.” You’re losing muscle, and the faster we can open that artery, the better the outcomes will be.
So, the two main concerns with silent MI are that the patient is at increased risk for sudden cardiac death and we may miss the lifesaving opportunity to open up the artery with available treatment options. – by Jennifer Byrne
Reference:
Zhang ZM, et al. Circulation. 2016;doi:10.1161/CIRCULATIONAHA.115.021177.
Disclosure: Vogel reports consulting for Pritikin.