Heart failure Prognosis over time: how the prognostic role of peak VO2 and ventilation efficiency during exercise has changed in the last 20 years : On behalf of the MECKI score research group

Aims Exercise‐derived parameters, specifically peak exercise oxygen uptake (peak VO2) and minute ventilation/carbon dioxide relationship slope (VE/VCO2 slope), have a pivotal prognostic value in heart failure (HF). It is unknown how the prognostic threshold of peak VO2 and VE/VCO2 slope has changed over the last 20 years in parallel with HF prognosis improvement. Methods and results Data from 6083 HF patients (81% male, age 61 ±13 years), enrolled in the MECKI score database between 1993 and 2015, were retrospectively analysed. By enrolment year, four groups were generated: group 1 1993–2000 (n =440), group 2 2001–2005 (n =1288), group 3 2006–2010 (n =2368), and group 4 2011–2015 (n =1987). We compared the 10‐ year survival of groups and analysed how the overall risk (cardiovascular death, urgent heart transplantation, or left ventricular assist device implantation) changed over time according to peak VO2 and VE/VCO2 slope and to major clinical and therapeutic variables. At 10 years, a progressively higher survival from group 1 to group 3 was observed, with no further improvement afterwards. A 20% risk for peak VO2 15 mL/min/kg (95% confidence interval 16–13), 9 (11–8), 4 (4–2) and 5 (7–4) was observed in group 1, 2, 3, and 4, respectively, while the VE/VCO2 slope value for a 20% risk was 32 (37–29), 47 (51–43), 59 (64–55), and 57 (63–52), respectively. Conclusions Heart failure prognosis improved over time up to 2010 in a HF population followed by experienced centres. The peak VO2 and VE/VCO2 slope cut‐offs identifying a definite risk progressively decreased and increased over time, respectively. The prognostic threshold of peak VO2 and VE/VCO2 slope must be updated whenever HF prognosis improves.