Cardiopulmonary exercise test with bicycle stress echocardiography for predicting adverse cardiac events in patients with stage A or B heart failure

Background: Given the high prevalence of stage A or B heart failure (HF), comprehensive screening for new-onset HF is cost-prohibitive. Therefore, further risk stratification is warranted to identify at-risk patients. This study aimed to evaluate the prognostic utility of cardiopulmonary exercise test (CPET) with bicycle stress echocardiography (BSE) in patients with stage A or B HF.

Methods: Among 687 consecutive patients who underwent CPET-BSE, 410 with stage A or B HF were analyzed. The association between the CPET-BSE parameters and adverse cardiac events (hospitalization for HF or cardiac-related death) was analyzed using the Cox proportional hazard model under univariate and multivariate analyses.

Results: After a median 9 years of follow-up, 47 (11.5 %) of the 410 patients had events. In the univariable analysis, age, diuretics, BUN, creatinine, peak oxygen uptake (VO2), ventilatory efficiency (VE/VCO₂), time to VT and peak exercise, left atrial volume index, rest and exercise E/e', and tricuspid regurgitation velocity demonstrated significant parameters. In multivariate analysis, VE/VCO₂ (hazard ratio [HR] 1.205, 95 % CI 1.095-1.327) and VO₂ at peak exercise (HR 1.164, 95 % CI 1.022-1.325), time to VT (HR 0.993, 95 % CI 0.989-0.997), and exercise E/e' (HR 1.582, 95 % CI 1.199-2.087) were only independent predictors for events.

Conclusions: In patients with stage A or B HF, four parameters of CPET-BSE were good predictors of future development of HF or cardiac death. If patients are unable to perform complete exercise, the time to VT may serve as a sufficiently predictive parameter for clinical events.