Background: Chronotropic incompetence (CI) is defined as the inability of the heart to increase its rate commensurate with increased activity or demand. CI is an independent predictor of major adverse cardiovascular events and overall mortality, in patients with heart failure with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF), and has also been recently associated with increased risk of developing atrial fibrillation (AF).
However, few information are available on the role of CI in the general population at CV risk, its relation with left atrial size and its predictors.
Aim: To evaluate if CI is associated with worse exercise performance at cardiopulmonary exercise test (CPET), and if some echocardiographic predictors can be found, in a healthy population with a cardiovascular (CV) high risk profile.
Methods: 172 patients, with at least one CV risk factor (hypertension, diabetes, tabagism, dyslipidemia, BMI > 25) and no beta-blocker therapy, underwent maximal CPET and subsequent echocardiography (within 1 month). CI was defined as the inability to reach 80% of the chronotropic index, which is the ratio of peak HR - rest HR and peak HR - age predicted maximal heart rate (AMPHR: 220 - age).
Results: 128 subjects (73.6%) presented with CI. The differences in the subgroups with and without CI are shown in the table.
Conclusions: CI, even in the healthy population at different CV risk, is related to worse exercise performance at CPET. Interestingly, left atrial dimension emerged as the only cardiac parameter associated with CI. Considering the remarkable clinical value of these abnormalities in overt cardiac dysfunction, their early recognition and treatment in the general healthy population at CV risk seems highly worthy.