RESUMO
Objective: To evaluate the consistency on the determination of target heart rate by simple calculation method based on resting heart rate and by anaerobic threshold method in cardiopulmonary exercise test (CPET) for patients with coronary artery disease after percutaneous coronary intervention (PCI). Methods: This study was a diagnostic test. Patients with coronary artery disease who underwent the first PCI in the Department of Cardiology of Peking University People's Hospital from October 2011 to April 2021 were enrolled. Patients were further divided into subgroups according to gender, age (<60 years group and ≥60 years group), with or without myocardial infarction history (myocardial infarction group and angina pectoris group) and whether β blockers were applied. The general clinical data of patients, resting heart rate (RHR) and anaerobic threshold heart rate in CPET were collected through the electronic medical record system. The simple target rate (RHR plus 20 or 30 bpm) and the target rate calculated by anaerobic threshold (anaerobic threshold heart rate minus 10 bpm) were both calculated in each patient. Consistency test of target heart rate derived by above the two methods was shown by intra-class correlation (ICC) and Bland-Altman plots. Results: A total of 439 patients were included, age was (56.2±8.8) years, body mass index was (25.77±2.34) kg/m2, there were 382 males (87.0%). The target heart rate determined by anaerobic threshold method was (90.0±11.8)bpm, and the simple target heart rate determined by RHR plus 20 bpm was (91.0±8.4)bpm. There was no significant difference on the target heart rate derived from the two calculation methods (P=0.091). The simple target heart rate determined by RHR plus 30 bpm was (101.0±8.4)bpm, which was significant higher than that determined by anaerobic threshold method (P<0.001). In the following analysis, RHR plus 20 bpm was defined as the simple target heart rate. The ICC value of target heart rate determined by anaerobic threshold and resting rate plus 20 bpm was 0.529(95%CI 0.458-0.593, P<0.001). Bland-Altman plots analysis showed that the ratio of the simple target heart rate and the target heart rate determined by anaerobic threshold method was 1.03±0.11 and the 95% limits of agreement (LOA) were 0.812-1.245. In the subgroup of patients aged<60 years (n=247), the ICC value was 0.492, the ratio by Bland-Altman plots analysis was 1.02±0.11 and LOA was 0.814-1.234; in the subgroup of patients aged ≥60 years (n=192), the ICC value was 0.566, the ratio by Bland-Altman plots analysis was 1.03±0.11 and LOA was 0.810-1.260. In male subgroup(n=382), the ICC value was 0.540, the ratio by Bland-Altman plots analysis was 1.03±0.11 and LOA was 0.813-1.246; in female subgroup(n=57), the ICC value was 0.445, the ratio by Bland-Altman plots analysis was 1.03±0.11 and LOA was 0.810-1.240.In myocardial infarction subgroup (n=186), the ICC value was 0.568, the ratio by Bland-Altman plots analysis was 1.02±0.11 and LOA was 0.810-1.227; in angina pectoris subgroup (n=253), the ICC value was 0.495, the ratio by Bland-Altman plots analysis was 1.04±0.11 and LOA was 0.813-1.260. In the subgroup of patients with β blockers (n=353), the ICC value was 0.520, the ratio by Bland-Altman plots analysis was 1.03±0.11 and LOA was 0.810-1.252; in the subgroup of patients without β blockers (n=86), the ICC value was 0.570, the ratio by Bland-Altman plots analysis was 1.02±0.10 and LOA was 0.821-1.219. Conclusions: The simple target heart rate determined by RHR plus 20 bpm is consistent with the target heart rate determined by anaerobic threshold in patients with coronary artery disease after PCI. But the simple target heart rate determined by RHR plus 20 bpm can't replace the target heart rate determined by anaerobic threshold in this patient cohort.