Johns Hopkins cardiologists state that they have developed a formula designed to estimate an individual’s risk of dying over a decade based upon their ability to exercise on a treadmill at an increasing speed and incline. The formula finds its roots in data analyzed from 58,000 heart stress tests.
A Johns Hopkins news release notes that the new algorithm, known as the FIT Treadmill Score appearing in the journal Mayo Clinic Proceedings, can reportedly gauge long-term death risk in anyone based solely upon treadmill exercise performance. According to the research team, the score could offer key clues about an individual’s health and should be calculated for the millions of patients who undergo cardiac stress testing in the US yearly.
Haitham Ahmed, MD, MPH, a cardiology fellow at the Johns Hopkins University School of Medicine, explains that while the concept that being in good physical shape foreshadows lower death risk is not new, researchers wanted to quantify that risk precisely by age, gender, and fitness level and do so “with an elegantly simple equation that requires no additional fancy testing beyond the standard stress test.”
The release notes that in addition to age and gender, the formula is intended to factor in peak heart rate reached during intense exercise and the ability to tolerate physical exertion as measured by so-called metabolic equivalents, or METs, a gauge of how much energy the body expends during exercise.
Michael Blaha, MD, MPH, director of clinical research at the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, says that researchers “hope the score will become a mainstay in cardiologists and primary clinicians’ offices as a meaningful way to illustrate risk among those who undergo cardiac stress testing and propel people with poor results to become more physically active.”
During the study, the team analyzed information on 58,020 individuals aged 18 to 96 years old, from Detroit who underwent standard exercise stress tests between the years of 1991 and 2009 for evaluation of chest pain, shortness of breath, fainting, or dizziness. The researchers then tracked how many of the participants with each fitness level died from any cause during the next decade.
Study results indicate that among individuals of the same age and gender, fitness level measured by METs and peak heart rate reached during exercise were the greatest indicators of death risk. The release states that fitness level remained the single most powerful predictor of death and survival, even after researchers adjusted for other key variables such as diabetes and family history of premature death.
According to the release, scores ranged from negative 200 to positive 200, with those above 0 having lower mortality risk and those in the negative range facing highest risk of dying. Patients who scored 100 or higher had a 2% risk of dying during the next 10 years, while those with scores between 0 and 100 faced a 3% death risk during the next decade. Specifically, the release explains this indicates two of 100 people of the same age and gender with a score of 100 or higher would die during the next decade, compared to three out of 100 for those with a fitness score between 0 and 100.
Individuals with scores between negative 100 and 0 had an 11% risk of dying in the next 10 years, while those with scores lower than negative 100 had a 38% risk of dying, results say.
The published study also features a chart depicting death risk by age, gender, and fitness level. The chart can be printed on placards for us in physician’s offices to guide clinical advice, the release states.
Blaha adds that researchers “hope that illustrating risk that way could become a catalyst for patients to increase exercise and improve cardiovascular fitness.”
[Source: Johns Hopkins Medicine]