Climbing a flight of stairs puts a considerable amount of demand on the heart, which is why some cardiologists have been using a "step test" to evaluate their patient's heart health for decades. Sometimes, the patient may be asked to perform the test during a consultation since every hospital or clinic has some stairs. It's simple and free, unlike other diagnosis methods that can be cumbersome and cost money. But is the step test really that effective? New research seems to suggest so.
Researchers at the European Society of Cardiology (ESC) recruited 165 volunteers who have known or suspected coronary artery disease, which causes chest pain or shortness of breath during strenuous exercise. First, the volunteers were asked to walk or run on a treadmill, with the intensity gradually increasing until exhaustion. This initial trial allowed the researchers to calculate each participant's exercise capacity, measured as metabolic equivalents (METs).
Vigorous physical activity like climbing stairs raises the demand for blood and oxygen to your extremities. The body deals with this demand by increasing the output of blood the heart pumps, which can happen in two ways: either by increasing the rate at which the blood is pumping (this explains why your heart rate jumps during exercise) or by increasing the amount of blood that's pumping out of the left ventricle. The MET level is linked to the amount of oxygen the heart uses, which in turn depends on the heart rate and blood pressure. As such, the MET level is a useful indicator when determining the risk of a cardiac event, such as a stroke, in the next 10 years.
After a brief rest after their treadmill trial, the patients had to climb four flights of stairs (60 stairs) hastily without stopping, but not at a running pace. The time it took each patient to finish climbing the stairs was compared to their METs. Those who could climb the stairs in less than 45 seconds had METs between 9 and 10. Previously, studies showed that 10 METs during exercise are linked with a low mortality rate (less than 1% per year or 10% in 10 years). In contrast, those who took 1.5 minutes or longed to climb the stairs had less than 8 METs, which is associated with a mortality rate of 2% to 4% per year, or 30% in 10 years.
The researchers also scanned the patients' hearts while they performed the treadmill test. These images showed if the heart worked normally during the exercise and whether or not there's a likelihood of coronary artery disease. When the researchers compared these images to the step test results, they found that 58% of patients who took more than 1.5 minutes to climb the stairs had abnormal heart function. In contrast, just 32% of those who completed the stairs in less than a minute had abnormal heart function during the treadmill examination.
Previously, a 2018 study performed by the same authors that involved more than 12,000 participants who had to walk up three to four flights of stairs found those who couldn't complete the task quickly enough had nearly three times the mortality rate from heart disease five years later than those who could.
The fact that a day-to-day activity, such as climbing stairs, can be so closely linked to results obtained from testing in a laboratory is pretty great news. It means we can also employ the step test mindfully and then visit a cardiologist if we catch ourselves short of breath or exhausted.
"The stairs test is an easy way to check your heart health," said study author Dr. Jesús Peteiro, a cardiologist at University Hospital A Coruña, Spain. "If it takes you more than one-and-a-half minutes to ascend four flights of stairs, your health is suboptimal, and it would be a good idea to consult a doctor."
"The idea was to find a simple and inexpensive method of assessing heart health," said Dr. Peteiro. "This can help physicians triage patients for more extensive examinations."
Heart disease is the leading cause of death for both men and women in the United States, with coronary heart disease being the most common type of heart disease. When coronary arteries cannot supply the necessary amount of blood to the heart due to the buildup of plaque, there is a high risk of heart failure and stroke.
The ESC recommends at least 150 minutes a week of moderate aerobic physical activity or 75 minutes a week of vigorous aerobic physical activity to strengthen the heart and lower the risk of heart disease.