Chronotropic incompetence could negatively influence post-operative risk assessment in patients before lung cancer surgery

Background: Cardiopulmonary exercise testing (CPET) is a standard part of preoperative evaluation in patients before lung surgical resection. According to current guidelines the risk of such a procedure is estimated according to maximum oxygen consumption (VO(2)max). Chronotropic incompetence (CI) is a prevalent condition which could possibly influence cardiopulmonary fitness. The aim of this study was to assess the prevalence of CI in patients before surgical lung resections and its influence on CPET results. Methods: This study enrolled 154 patients (97 men) of average age 66.4 +/- 8.3 with newly diagnosed lung cancer indicated for surgical lung resections. All patients underwent CPET (cycle ergometry). Age predicted maximal HR was calculated using the traditional equation (220 - age). Three levels of CI were defined as, 85% HR(pred, )80% HRpred and 70% HRpred. The influence of CI on CPET results was evaluated. Results: CI was present in the following ratios: 85% HRpred-48.7%; 80% HRpred-39.6% and 70% HRpred-16.9%. A significant negative correlation was also found between VO(2)max, maximal heart rate (HR) and maximal work load among all CI groups (P<0.0001). The presence of CI significantly correlated with beta-blocker treatment (P<0.0001). Conclusions: CI significantly decreases VO(2)max in patients before lung cancer surgery. It is strongly associated with beta-blocker treatment which could negatively influence risk assessment. It is thus a matter for future discussion, as to whether the evaluation of CI should be part of preoperative care guidelines.